Request for Recipe (.223 77gr HPBT), also info to share

[Jicko]

(Most info would be for 77gr HPBT, but other bullet wts are being added -Jicko 1/29/09)

I'm trying to develop a 223 Rem, 77gr load for the use in a 1x7 twist 18" SPR, the goal is to try to achieve Mk 262 -like performance at a reasonable cost. (I will experiment these load with my 1x7 16" M4 and with my 1x9 24" bull upper later too)

My first attempt will be with
Bullet: Nosler Custom Comp 77gr HPBT
Powder: RL15 or Ramshot TAC or VV N540
Primer: CCI #41 or #BR4
Brass: Fed 223 Rem or LC 05/06

If you have a recipe(for 77gr, or similar wt.) that you would like to share, please do. I can use as much references as I can get. Any numbers/info would be great - brand of bullet, HP? BT?, what powder, what loading wt.(gr), what primers, OAL, brass, velocity, barrel lenght, twist rate, accuracy, group size, etc...



I had done my homework, and I had consolidated(w/ links) all the info/data/numbers I had found from various sites. Some definitely provide more info than others. I am biased towards the powders/bullets that I had chosen. I may go plot these as graphs or such to investigate more, but here are what I have now, and I am sharing with you (standard disclaimer, use at your own risk):




--------------------------------------------
LOAD DATA FROM BULLETS & POWDER MANUF
--------------------------------------------

Nosler's website
http://www.nosler.com/index.php?p=15&b=22%20Cal&s=6

Bullet: 77gr Nosler Custom Competition HPBT
Ballistic Coefficient: .340
Sectional Density: .219

Primer: ?
Brass: ?
OAL: ?
Trim-to: ?
Barrel: ?
Twist: 1x7

Powder: RL-15
22.5gr - 2487fps (86% density)
23.5gr - 2633fps (89% density)
24.5gr - 2741fps (93% density) <- most accurate out of this 3

Powder: VV N135
20.5gr - 2451fps (78% density) <- most accurate out of this 3
21.5gr - 2555fps (82% density)
22.5gr - 2664fps (86% density)

Powder: Varget
22.5gr - 2466fps (86% density) <- most accurate out of this 3
23.5gr - 2598fps (89% density)
24.5gr - 2693fps (93% density)



Sierra's website
http://accurateshooter.net/Downloads/sierra223ar.pdf

Bullet: 77gr Sierra MatchKing HPBT
Ballistic Coefficient: .362 @ 1800fps+ / .343 @ 1800fps-
Sectional Density: .219

Primer: Rem 7 1/2
Brass: Fed
OAL: 2.260"
Trim-to: 1.750"
Barrel: 20" Colt HBAR
Twist: 1x7

Powder: Ramshot TAC
21.8gr - 2500fps
22.2gr - 2550fps
22.7gr - 2600fps
23.1gr - 2650fps
23.6gr - 2700fps
24.0gr - 2750fps

Powder: RL-15
22.3gr - 2400fps
23.2gr - 2500fps
23.6gr - 2550fps
24.1gr - 2600fps

Powder: VV N540
22.9gr - 2400fps
23.7gr - 2500fps
24.1gr - 2550fps
24.5gr - 2600fps
24.9gr - 2650fps

Powder: VV N140
22.3gr - 2400fps
23.2gr - 2500fps
23.6gr - 2550fps
24.1gr - 2600fps <- most accurate out of all tests (more in the pdf)
24.5gr - 2650fps



Alliant Powder's website
http://www.alliantpowder.com/reloade...9&bulletid=446

Bullet: 77gr Sierra HPBT
Powder: 24.1gr RL15
Primer: Fed 205M
Brass: Win
OAL: 2.26
Barrel: 24"
Twist:?
Velocity: 2793fps
Pressure: 51200psi



Lapua/Vihtavuori Powder's website
http://www.lapua.com/index.php?id=850
http://www.lapua.com/fileadmin/user_...ngData2006.pdf

Primer: Small Rifle
Brass: Lapua
Trim-to: 1.752"
Barrel: 25"
Twist: 1x7

Bullet: 69gr Sierra HPBT
OAL: 2.244"
Powder: 24.1gr N540 (min)
Velocity: 2703fps
Powder: 26.4gr N540 (max)
Velocity: 2986fps

Bullet: 75gr Hornady HPBT
OAL: 2.260"
Powder: 23.1gr N540 (min)
Velocity: 2536fps
Powder: 25.8gr N540 (max)
Velocity: 2831fps

Bullet: 80gr Sierra HPBT
OAL: 2.551"
Powder: 21.4gr N540 (min)
Velocity: 2395fps
Powder: 23.7gr N540 (max)
Velocity: 2652fps



Ramshot Powder's website
http://www.ramshot.com/powders/
http://www.ramshot.com/powders/loadg...tion%204.2.pdf

Bullet: 77gr Nosler HPBT
Primer: Fed 205
OAL: 2.260"
Barrel: 24"
Twist: 1x7 or 1x9

Powder: 21.2gr TAC (min)
Velocity: 2515fps
Powder: 23.5gr TAC (max)
Velocity: 2794fps
Pressure: 52500psi (max)




LOAD DATA FROM INDIVIDUALS
------------------------------

From ocabj (on calguns):

Bullet: 77gr Nosler CC HPBT
Powder: 24.0gr RL15
Primer: CCI #BR4
Brass: LC

Barrel: 20"
Twist: 1x7
Velocity: 2740fps

Barrel: 18"
Twist: 1x7
Velocity: ~2650fps (unconfirmed, just a wild guess)


Bullet: Sierra Match King 77gr BTHP
Powder: 25.3gr Hodgdon Varget
Primer: Winchester SR Primer
Brass: LC

Barrel: 18" WOA SPR w/ Wylde chamber
Twist: 1x7
Velocity: 2788fps (avg from 5: 2772, 2797, 2793, 2798, 2779)



From thmpr (on calguns):

Bullet: 77 grains Nosler
Powder: 25gr Ramshot TAC
OAL: 2.255" (probably inconsistant OAL, therefore, ES is high)
Barrel: 20" JP CTR-02
Twist: 1x8
Velocity: 2786fps (avg out of 10: 2821, 2786, 2832, 2800, 2799, 2745, 2781, 2776, 2796, 2720)

Powder: 24.8gr Ramshot TAC
Velocity: ?

Bullet: 77 grains Nosler
Powder: 25gr Ramshot TAC
OAL: 2.255"
Barrel: 20" JP CTR-02
Twist: 1x8
Velocity: 2798fps (avg out of 10: 2801, 2793, 2802, 2800, 2799, 2795, 2791, 2804, 2796, 2798)
ES: 13



(on ar15.com):
http://www.ar15.com/content/page.html?id=206
Most likely 1x8 and 1x7 twist.

From billyhill
Bullet: 77 gr Nosler CC HPBT
Powder: 23.7gr Hodgdon Varget
Primer: CCI #BR4
Brass: LC
Brass Trim: ?
OAL: ?
Barrel: 20"
Twist: ?
Velocity: 2786fps
ES: ?
SD: 16fps

From overdriv
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 23.9gr Alliant RL15
Primer: WSR
Brass: LC
Brass Trim: ?
OAL: 2.255
Barrel: 20"
Twist: ?
Velocity: 2583fps
ES: 69fps
SD: 16fps

From overdriv
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 23.6gr Ramshot TAC
Primer: WSR
Brass: Remington
Barrel: 20"
Velocity: 2687fps
ES: 30fps
SD: 9fps

From sig685 (exact duplicate of BH 223 Blue Box)
Bullet: 77 gr Sierra MatchKing (Moly) HPBT
Powder: 24.5gr Hodgdon Varget
Primer: Rem 7.5
Brass: LC
Brass Trim: 1.760
OAL: 2.258
Barrel: 24" SS
Twist: ?
Velocity: 2730fps
ES: 51fps
SD: 12fps

From shootsenmeister
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 24.0gr VV N140
Primer: CCI #BR4
Brass: LC
Brass Trim: 1.750
OAL: 2.260
Barrel: 16" SS
Twist: ?
Velocity: 2618fps
ES: 42fps
SD: 16fps

(Extracted from a thread http://www.ar15.com/forums/topic.html?b=1&f=9&t=500036)

From Lawman734
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 25.3gr Hodgdon Varget
Primer: WSR
Brass: LC
Barrel: 18" SPR
Twist: 1x7
Velocity: 2780fps

From Lawman734
Bullet: 77 gr Nosler CC HPBT
Powder: 24gr RL-15
Primer: WSR
Brass: Winchester
Barrel: 18" SPR
Twist: 1x7
Velocity: 2730fps

From Ex0331
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 23.5gr AA2230C
Primer: CCI #400
Brass: LC
OAL: 2.250
Barrel: 20"
Twist: 1x9 (JR: he must be lucky)
Velocity: 2769fps
ES: 24
SD: 17

From Silly_Look
Bullet: 77 gr Nosler HPBT with Cannuelure
Powder: 24.5gr RL-15
Primer: CCI #450 Magnum Primer (JR: I'd rather use #41 Military primer)
Brass: New Winchester
Barrel: 20"
Twist: 1x8 RRA Varmint A4 Heavy Barrel
Velocity: 2662fps
ES: 40
SD: 11






AMMO SPEC & INFO
-------------------

Specification of Mk 262 Mod 1 (non-official source)
http://www.gunsandammomag.com/ammunition/mk262_080105/ (Guns & Ammo article)

Manufacturer: Black Hills Ammunition
Brass: BHA
Bullet: 77gr Sierra MatchKing OTM w/ cannelure
Primer: ? (non-corrosive boxer, crimped)
OAL: ?
Barrel: 18" (Mk12 SPR)
Twist: 1x7
Powder: ? (custom version of Ramshot TAC??)
Velocity: 2783fps

Ballistics
Range: Muzzle (measured @ 12ft/4yds)
Velocity: 2783fps
Path: -2.75" (0" drift from 10mph wind)

Range: 100yds
Velocity: 2534fps
Path: +3.99" (.9" drift from 10mph wind)

Range: 200yds
Velocity: 2299fps
Path: +5.2" (3.8" drift from 10mph wind)

Range: 300yds
Velocity: 2076fps
Path: 0" (9" drift from 10mph wind)

Range: 400yds
Velocity: 1866fps
Path: -13.3" (16.8" drift from 10mph wind)

Range: 500yds
Velocity: 1670fps
Path: -36.7" (27.7" drift from 10mph wind)

Range: 600yds
Velocity: 1438fps
Path: -72.7" (42.3" drift from 10mph wind)

Range: 700yds
Velocity: 1320fps
Path: -124.5" (61.1" drift from 10mph wind)

Range: 800yds
Velocity: 1186fps
Path: -196.2" (84.4" drift from 10mph wind)


Velocity from Various Weapons
(10 rounds @ 12ft/3yds, Oehler 35P chronograph, 30 deg F, 100ft above sea level)
Barrel: 18" (Mk 12 Mod 0)
Velocity: 2783fps

Barrel: 18" (Mk 12 Mod 1)
Velocity: 2791fps

Barrel: 16" (AR carbine)
Velocity: 2751fps

Barrel: 13" (AR carbine)
Velocity: 2534fps


MK262 Velocity data from Novelske (I think..)

7.5" 2053 FPS ... 10.5" 2363 FPS
DIFF 310 FPS
DIFF/IN 103 FPS

10.5" 2363 FPS ... 14.5" 2576 FPS
DIFF 213 FPS
DIFF/IN 53 FPS

14.5" 2576 FPS ... 16" 2669 FPS
DIFF 93 FPS
DIFF/IN 62 FPS

16" 2669 FPS ... 18" 2769 FPS
DIFF 100 FPS
DIFF/IN 50 FPS

18" 2769 FPS ... 20" 2818 FPS
DIFF 49 FPS
DIFF/IN 25 FPS





OTHERS MISC INFO
-------------------


SAAMI Max PSI - 223 Remington 55000psi

6mmBR.com 223 info, great!!
http://www.6mmbr.com/223Rem.html

Accurate Powder - 223Rem data
http://www.accuratepowder.com/data/P...0and%20377.pdf

5.56 NATO Specification
http://en.wikipedia.org/wiki/5.56_x_45_mm_NATO

Mk262 Mod1 Performance
http://www.btammolabs.com/tests/6.htm
http://www.btammolabs.com/tests/5.htm

Great info on Mk262 and other commerical ammo that are like it.
http://www.ar15.com/forums/topic.html?b=3&f=16&t=406469

[PistolPete75]

this is a good thread. it should be a sticky

[ocabj]

There have been posts on Mk262 recipes before. I've posted the one I developed for my 18" SPR when I still had it.

NOTE: The following data exceeds SAAMI specifications and can be dangerous to use in certain rifles.

Sierra Match King 77gr BTHP
25.3gr Hodgdon Varget
LC Brass
Winchester SR Primer

Developed in a White Oak Armament 18" SPR configuration with a Wylde chamber.



Note: At the time, I was using Winchester SR primers. I would recommend Remington or CCI instead.

Any load that will give you Mk262 performance will exceed SAAMI specifications for .223. Thus, you're not going to find any published commercial data that will meet Mk262 velocities.

You shouldn't use anyone's Mk262 'recipe' straight up.

If you want to make your own Mk262 clone ammo, you NEED to get a chronograph and work up the load appropriately. Don't kid yourself thinking you can just use someone else's recipe or the commercial data and guestimate the proper load to meet a specific velocity. The Mk262 pressures/velocities are pretty hot and you're going to need to carefully find the right load for your specific rifle. And when you do find the correct load for your specific rifle, you need to reconfirm the load everytime you go to a new lot # in bullets, powder, primers, or cases.

Also, that Nosler load quoted as mine was not confirmed to be 2650fps in an 18". That is my load I use in Service Rifle and it clocks 2740fps in a 20" Service Rifle barrel. I would estimate that it shoots 2650fps in an 18", but I have never clocked it in a 18" barrel.

[Jicko]

Originally Posted by ocabj

There have been posts on Mk262 recipes before.

I tried to search for it, but I couldn't find it.... any link?

Originally Posted by ocabj

I've posted the one I developed for my 18" SPR when I still had it.

NOTE: The following data exceeds SAAMI specifications and can be dangerous to use in certain rifles.

Sierra Match King 77gr BTHP
25.3gr Hodgdon Varget
LC Brass
Winchester SR Primer

Developed in a White Oak Armament 18" SPR configuration with a Wylde chamber.

Note: At the time, I was using Winchester SR primers. I would recommend Remington or CCI instead.

Any load that will give you Mk262 performance will exceed SAAMI specifications for .223. Thus, you're not going to find any published commercial data that will meet Mk262 velocities.

Thanks for the above info, great info!

BTW, how do you figure out whether your load exceed SAAMI pressure spec? How do you "economically" measure pressure? Is there a formula you can calculate what will be your "pressure"?

Originally Posted by ocabj

You shouldn't use anyone's Mk262 'recipe' straight up.

Certainly NOT, I am not recommending anyone to do this!!

I'm just looking for some starting points, and data points for me to maybe plot some graphs to start this process.

Also so ideas as to what other powder or components that I may want to acquire and try.... (I think I have got quite some components to try now...)

Originally Posted by ocabj

If you want to make your own Mk262 clone ammo, you NEED to get a chronograph and work up the load appropriately. Don't kid yourself thinking you can just use someone else's recipe or the commercial data and guestimate the proper load to meet a specific velocity. The Mk262 pressures/velocities are pretty hot and you're going to need to carefully find the right load for your specific rifle. And when you do find the correct load for your specific rifle, you need to reconfirm the load everytime you go to a new lot # in bullets, powder, primers, or cases.

This is EXACTLY what I am going to do. For any numbers that I've got, I will probably back down 10-15% as my starting load and then work my way up.

But I need to find some starting point.

Originally Posted by ocabj

Also, that Nosler load quoted as mine was not confirmed to be 2650fps in an 18". That is my load I use in Service Rifle and it clocks 2740fps in a 20" Service Rifle barrel. I would estimate that it shoots 2650fps in an 18", but I have never clocked it in a 18" barrel.

That's the "~" there for... it is a *guess*...

[thmpr]

77 grains Nosler (25 grains TAC)
---> 2.255 OAL
1) 2821 35.4
2) 2786 0.4
3) 2832 46.4
4) 2800 14.4
5) 2799 13.4
6) 2745 -40.6
7) 2781 -4.6
8) 2776 -9.6
9) 2796 10.4
10) 2720 -65.6
High: 2832
Low: 2720
E.S.: 112
Ave.: 2785.6
S.D.: 33.2
95%: ±27.0


Rifle: JP CTR-02 20"

[brando]

Good thread worth a sticky. I've been working up a load in my 18" SPR build using 77gr SMK, Remington Brass, CCI and N140. Like the Sierra manual says, around 24.1g seems to be the sweet spot.

[Bolt2Bounce]

Colt 20" 1-7 HBAR and Bushmaster 24" 1-9
No pressure sighs with these loads in my rifles...
I'd try a different Primer but winchester are the easiest for me to get.. I'd like to use CCI's but I haven't been able to fine them lately...


5.56MM 77 Gr Sierra BTHP MATCH 1-7” TWIST
POWDER: WCC 846 25.0 GRAINS
LC CASES 96 TRIMMED
WIN PRIMER
INFO: FOR 1-7 twist

5.56MM 77 Gr Sierra BTHP MATCH 1-7” TWIST
POWDER: RL #15 25.0 GRAINS
LC CASES 96 TRIMMED
PRIMER: WIN SR
Info: FOR COLT UPPER shot well at 100 yards

223 75 Gr Nosler BTHP MOLLY MATCH
POWDER: IMR4064 24.4 GRAINS
LC CASES 96 TRIMMED
PRIMER: WIN
COMMENT: shot well at 100 yards Out of 24" 1-9 twist Bushmaster upper

223 75 Gr Nosler BTHP MOLLY MATCH
POWDER: W846 24.4 GRAINS
LC CASES 96 TRIMMED
WIN SR PRIMER

B2B

[Jicko]

Originally Posted by thmpr

Rifle: JP CTR-02 20"

Nice! What twist rate did you end up with? 1x9 or 1x8?

[thmpr]

1X8.....Ideal for the 69 to 80 grain bullet. As you can see, the load is a bit unpredicatable with >100 E.S. From my last test, 24.8 grains of TAC was the sweet spot I was looking for. Did not have a chance to chrono the new load but saw no differences with accuracy for a 10 shot group (<.73 MOA)

[Jicko]

Originally Posted by Bolt2Bounce

Colt 20" 1-7 HBAR and Bushmaster 24" 1-9
No pressure sighs with these loads in my rifles...
I'd try a different Primer but winchester are the easiest for me to get.. I'd like to use CCI's but I haven't been able to fine them lately...

5.56MM 77 Gr Sierra BTHP MATCH 1-7” TWIST
POWDER: RL #15 25.0 GRAINS
LC CASES 96 TRIMMED
PRIMER: WIN SR
Info: FOR COLT UPPER shot well at 100 yards

B2B

25gr of RL15 seems pretty HIGH.... I loaded a couple last nite, the case is like... PACKED.... and it is certainly crushing the powder when seating the bullet... according to Nosler, 24.5gr is already 93% density... so 25gr must be like 95% density

I loaded many different wt of RL15 to be tested this weekend from 22gr up to 25gr... I will definitely work it up....

BTW, anything over 24gr is like crushing powder already... and the seating die is making a mark on the bullets.... (I'm using Dillon 550B and Dillon's 223 dies set).... is this normal?

[ocabj]

Originally Posted by JickoRicko

BTW, anything over 24gr is like crushing powder already... and the seating die is making a mark on the bullets.... (I'm using Dillon 550B and Dillon's 223 dies set).... is this normal?

Yes, for the most part you're going to see marks on the bullet from the seating die if compressing powder. But I load as much as 24.5gr of RL15 without any issues because I use one of these:

http://www.midwayusa.com/eproductpag...eitemid=293879

The long drop tube helps to guide the powder in better so it packs a lot better.

This thing helped me get over 25 grains of Varget into an LC case with a 77gr SMK.

[Bolt2Bounce]

yeah it is a compressed powder charge, and a Max load for my NRA Highpower Upper. a long drop tube works well for helping with this problem of over full cases, your loads need to be worked up from the bottom of the data charges, it seems in some guns the hot rod loads shoot better groups and in HP it's dam near mandatory to have a High velocity loads that reduces wind drift at long range targets. Some of the pro's load a charge up until they blow primers and then back down, not recommending that, but hot is good sometimes. remember 5.56mm Nato ammo, mil spec is not SAMMI spec, it's pressure is higher.. I use LC brass and IVI brass, so it is thick and tough. B2B.

[Jicko]

My question is, HOW can I find out what "pressure" these rounds are.... SAAMI spec for 223 is 55000psi... according to Alliant's website, 24.1gr of RL15 should yield 51200psi.

I know that 3 rounds are probably not enough, but I just want to establish some base data for my rifle, and then I can zoom into a few particular load to work on. I will working on loads with Ramshot TAC and Vihtavuori N540 next week.

All of the brass from these loads, even up to 25.0gr of RL-15, didn't show ANY sign of stress. They all look pretty good. So, which "load" should I be going after? I think, from these numbers, if I just want to duplicate Mk262 performance(muzzle velocity of around 2750-2780fps), I should be able to stop at around 24.7gr.

Or maybe I should load like 10 of each of 24.6gr, 24.7gr, 24.8gr and maybe up to 25.0gr and test for accuracy....

I causally shot these 3 rounds groups, and all of them are within 1" @ 50yds....

Any comments?

-------------------

Day 1 of load development

Barrel: Douglas Air-gauged SS Match Barrel tuned by Compass Lake Engineering
Chamber: Wlyde
Length: 18" SPR

Bullet: Nosler Custom Competition 223Rem 77gr HPBT (non-cannuellure, non-crimped)
Brass: Fed 223 Rem
Primer: CCI #41 (5.56 Military)
Chrono distance: 7ft

Powder: Alliant RL-15

Wt: 22.5gr
Round 1 (2.2520 OAL): 2489fps
Round 2 (2.2530 OAL): 2458fps
Round 3 (2.2560 OAL): 2438fps
Avg OAL: 2.254
Avg Velocity: 2462fps
ES: 51
SD: 25.7

Wt: 23.5gr
Round 1 (2.2520 OAL): 2541fps
Round 2 (2.2530 OAL): 2572fps
Round 3 (2.2560 OAL): 2572fps
Avg OAL: 2.255
Avg Velocity: 2562fps
ES: 31
SD: 17.9

Wt: 24.0gr [compressed powder, ie. ring mark on the bullet]
Round 1 (2.2580 OAL): 2631fps
Round 2 (2.2590 OAL): 2604fps
Round 3 (2.2550 OAL): 2636fps
Avg OAL: 2.257
Avg Velocity: 2624fps
ES: 32
SD: 17.2

Wt: 24.1gr [compressed powder]
Round 1 (2.2590 OAL): 2687fps
Round 2 (2.2585 OAL): 2644fps
Round 3 (2.2555 OAL): 2644fps
Avg OAL: 2.258
Avg Velocity: 2658fps
ES: 43
SD: 24.8

Wt: 24.5gr [compressed powder]
Round 1 (2.2535 OAL): 2700fps
Round 2 (2.2570 OAL): 2728fps
Round 3 (2.2580 OAL): 2714fps
Avg OAL: 2.256
Avg Velocity: 2714fps
ES: 28
SD: 14.0

Wt: 24.7gr [compressed powder]
Round 1 (2.2535 OAL): 2789fps
Round 2 (2.2570 OAL): 2784fps
Round 3 (2.2580 OAL): 2756fps
Avg OAL: 2.254
Avg Velocity: 2776fps <========= **
ES: 33
SD: 17.8

Wt: 25.0gr [compressed powder]
Round 1 (2.2580 OAL): 2819fps
Round 2 (2.2590 OAL): 2844fps
Round 3 (2.2600 OAL): 2840fps
Avg OAL: 2.259
Avg Velocity: 2834fps
ES: 25
SD: 13.4

Wt: 25.0gr [load to longer than magazine OAL]
Round 1 (2.387 OAL): 2907fps


Control Tests:

Federal AE223 (55gr FMJBT)
Round 1 (2.2070 OAL): 3005fps
Round 2 (2.1990 OAL): 2967fps
Round 3 (2.2020 OAL): 2980fps
Avg OAL: 2.203
Avg Velocity: 2984fps
ES: 38
SD: 19.3

Federal XM193 (55gr FMJBT)
Round 1 (2.2480 OAL): 3172fps
Round 2 (2.2440 OAL): 3201fps
Round 3 (2.2480 OAL): 3183fps
Avg OAL: 2.247
Avg Velocity: 3185fps
ES: 29
SD: 14.6

-------------------

I will be loading 5 rounds each of 24.7gr, 24.8gr, 24.9gr, 25.0gr & 25.1gr and redo the above test; then, hopefully will nail down a RL-15 recipe. Then I will compare the results with Ramshot TAC's and VV N540's.

[phish]

There is a pressure gauge kit that you can buy for about $270. It has a PC interface and you attach the strain gauges to the rifle's chamber.

It's kind of a hassle attaching them to an upper, much easier to do on a bolt gun.

http://www.shootingsoftware.com

[Jicko]

I doubt that everybody got that..... so, is there another way to figure out where I need to "stop"? Per se, I want to maximize the amount of powder I can put in, while being safe? ie. find out the "maximum", then back down a gr or 2, so any inconsistancy in my powder measure won't push my round over the line...

[Jicko]

Originally Posted by ocabj

Yes, for the most part you're going to see marks on the bullet from the seating die if compressing powder. But I load as much as 24.5gr of RL15 without any issues because I use one of these:

http://www.midwayusa.com/eproductpag...eitemid=293879

The long drop tube helps to guide the powder in better so it packs a lot better.

This thing helped me get over 25 grains of Varget into an LC case with a 77gr SMK.

Hmmm how can I use a LONG DROP TUBE, if I am using a Dillion 550B? The powder measure drop powder into the case.... I don't measure them one by one....

[ocabj]

I honestly don't know. I've been using a single-stage since day 1.

[ETD1010]

I love this thread. Thanks so much for whoever had the idea to start it! I've also been looking for a recipe to start with on 77 gr. SMKs. Aside from using a pressure gauge, can't you also look at the primer strike and jusdge pressure (or too much, that is?) Also, does LC 5.56 brass have a thicker case than a .223 case? Or does it not matter? As soon as I can get a hold of some SMKs (all out here, although i COULD order online), I'm gonna start some loads up

[5968]

Good info. Tagged and saved!

[FreedomIsNotFree]

Here is a link to some tried and true recipe's from AR15.com. They have both rifle and pistol info listed.

http://www.ar15.com/forums/topic.html?b=1&f=9&t=475975

[Jicko]

Originally Posted by FreedomIsNotFree

Here is a link to some tried and true recipe's from AR15.com. They have both rifle and pistol info listed.

http://www.ar15.com/forums/topic.html?b=1&f=9&t=475975

Thanks for the link. I did refer to that when I was developing my "starting points". Unfortunately, none of what is posted on ar15.com is closer to the MK262 performance. Once I've a recipe down, I'll submit that to ar15.com's database.

[Jicko]

Finally got my Shooting Chrony....

Ramshot TAC is obviously perform better in terms of having much less "powder compression", only a few of all these have "ring mark".

-------------------

Day 2 of load development

Barrel: Douglas Premium Air-gauged SS Match Barrel tuned by Compass Lake Engineering
Chamber: Wlyde
Length: 18" SPR

Bullet: Nosler Custom Competition 223Rem 77gr HPBT (non-cannuellure, non-crimped)
Brass: Fed 223 Rem
Primer: CCI #41 (5.56 Military)
Chrono distance: 7ft

Powder: Ramshot TAC

Wt: 21.2gr
Round 1 (2.2555 OAL): 2445fps
Round 2 (2.2555 OAL): 2464fps
Round 3 (2.2560 OAL): 2417fps
Avg OAL: 2.256
Avg Velocity: 2442fps
ES: 47
SD: 23.6

Wt: 22.0gr
Round 1 (2.2555 OAL): 2518fps
Round 2 (2.2550 OAL): 2573fps
Round 3 (2.2565 OAL): 2510fps
Avg OAL: 2.256
Avg Velocity: 2534fps
ES: 63
SD: 34.3

Wt: 23.0gr
Round 1 (2.2530 OAL): 2598fps
Round 2 (2.2545 OAL): 2642fps
Round 3 (2.2550 OAL): 2632fps
Avg OAL: 2.254
Avg Velocity: 2624fps
ES: 44
SD: 23.1

Wt: 23.6gr
Round 1 (2.2580 OAL): 2611fps [compressed powder, ie. ring mark on the bullet]
Round 2 (2.2560 OAL): 2655fps
Round 3 (2.2570 OAL): 2677fps
Avg OAL: 2.257
Avg Velocity: 2648fps
ES: 66
SD: 33.6

Wt: 23.8gr
Round 1 (2.2555 OAL): 2674fps
Round 2 (2.2525 OAL): 2662fps
Round 3 (2.2585 OAL): 2682fps
Avg OAL: 2.256
Avg Velocity: 2673fps
ES: 20
SD: 10.1

Wt: 24.0gr
Round 1 (2.2540 OAL): 2685fps
Round 2 (2.2550 OAL): 2723fps
Round 3 (2.2580 OAL): 2719fps [compressed powder]
Avg OAL: 2.256
Avg Velocity: 2709fps
ES: 38
SD: 20.9

Wt: 24.3gr
Round 1 (2.2570 OAL): 2736fps
Round 2 (2.2540 OAL): 2744fps
Round 3 (2.2580 OAL): 2742fps
Avg OAL: 2.256
Avg Velocity: 2741fps
ES: 8
SD: 4.2

Wt: 24.7gr
Round 1 (2.2570 OAL): 2794fps
Round 2 (2.2575 OAL): 2781fps
Round 3 (2.2540 OAL): 2758fps
Avg OAL: 2.256
Avg Velocity: 2778fps <========= **
ES: 36
SD: 18.2

Wt: 25.0gr
Round 1 (2.2590 OAL): 2817fps [compressed powder]
Round 2 (2.2560 OAL): 2804fps
Round 3 (2.2550 OAL): 2821fps
Avg OAL: 2.257
Avg Velocity: 2814fps
ES: 17
SD: 8.9

-------------------

Seemingly, just like Alliant's RL-15, 24.7gr seems to hit the right velocity as compare to test-results of Mk262 Mod1 rounds. I'll probably load some more Ramshot TACs around 24.7gr and then do further tests.

[6172crew]

Im going to abuse my power and stick this baby for awhile.

WHat kinda groups are you getting with the last loads? Im rigging a SPR soon and have already started buying 77 grain bullets plus I have some 69 grain black hills stuff for goofy off with as well. I can get some Mk262 BH ammo if I need it but its $400 for 500 rounds.

[Jicko]

I have 3-rounds group pics @ 50yards, I causally shoot them tho, since I am more interested in the chrono results than the grouping for now. But my 2nd round of 5 or 10 shots each when I am in the fine tuning phase, I'd definitely be more concerns about the accuracy.

I will definitely post those 5-rounds group pics when I have them. Right now, 3-rounds group are not that good of a representation, yet they are generally within around .5" to 1" (@ 50yds tho), shooting front bipod and not rear support.

PS. I do want some Mk262 Mod1 rounds if anyone of you can spare me some, I need them for control tests, for accuracy and velocity comparison, so I don't need too many (maybe 20-40). Please let me know if you can help. THANKS in advance!!

[dw1784]

good work, Ricko!
thanks for the update

[Jicko]

Update from thmpr

77 grains SMK 25 grains TAC 2.255 OAL
1) 2821 35.4
2) 2786 0.4
3) 2832 46.4
4) 2800 14.4
5) 2799 13.4
6) 2745 -40.6
7) 2781 -4.6
8) 2776 -9.6
9) 2796 10.4
10) 2720 -65.6
High: 2832
Low: 2720
E.S.: 112
Ave.: 2785.6
S.D.: 33.2
95%: ±27.0

The Extreme speed is a bit high which I think is caused by the OAL. Once I got the seating depth consistent, here are the numbers:

77 grains SMK 25 grains TAC 2.255 OAL
1) 2801
2) 2793
3) 2802
4) 2800
5) 2799
6) 2795
7) 2791
8) 2804
9) 2796
10) 2798
High: 2804
Low: 2791

[Jicko]

-------------------

Day 3(part 1) of load development

Barrel: Douglas Premium Air-gauged SS Match Barrel tuned by Compass Lake Engineering
Chamber: Wlyde
Length: 18" SPR

Bullet: Nosler Custom Competition 223Rem 77gr HPBT (non-cannuellure, non-crimped)
Brass: Fed 223 Rem
Primer: CCI #41 (5.56 Military)
Chrono distance: 6ft

Powder: VihtaVuori N540 [compressed powder, all, ie. ring mark on the bullet]

Wt: 23.0gr
Round 1 (2.2585 OAL): 2463fps
Round 2 (2.2585 OAL): 2407fps
Round 3 (2.2580 OAL): 2486fps
Avg OAL: 2.259
Avg Velocity: 2452fps
ES: 79
SD: 40.6

Wt: 24.0gr
Round 1 (2.2550 OAL): 2603fps
Round 2 (2.2520 OAL): 2568fps
Round 3 (2.2545 OAL): 2543fps
Avg OAL: 2.254
Avg Velocity: 2571fps
ES: 60
SD: 30.1

Wt: 24.5gr
Round 1 (2.2560 OAL): 2617fps
Round 2 (2.2485 OAL): 2611fps
Round 3 (2.2590 OAL): 2662fps
Avg OAL: 2.255
Avg Velocity: 2630fps
ES: 51
SD: 27.9

Wt: 24.7gr
Round 1 (2.2560 OAL): 2675fps
Round 2 (2.2590 OAL): 2613fps
Round 3 (2.2580 OAL): 2602fps
Avg OAL: 2.258
Avg Velocity: 2630fps
ES: 73
SD: 39.4

Wt: 24.9gr
Round 1 (2.2540 OAL): 2643fps
Round 2 (2.2590 OAL): 2641fps
Round 3 (2.2590 OAL): 2666fps
Avg OAL: 2.257
Avg Velocity: 2650fps
ES: 25
SD: 13.9

Wt: 25.1gr
Round 1 (2.2555 OAL): 2694fps
Round 2 (2.2585 OAL): 2651fps
Round 3 (2.2600 OAL): 2703fps
Avg OAL: 2.258
Avg Velocity: 2683fps
ES: 52
SD: 27.8

Wt: 25.4gr
Round 1 (2.2590 OAL): 2697fps
Round 2 (2.2580 OAL): 2689fps
Round 3 (2.2600 OAL): 2708fps
Avg OAL: 2.259
Avg Velocity: 2698fps
ES: 19
SD: 9.5

-------------------

Unfortunately, NONE my VV N540 loads reach my target of 2780fps. Since all the brass and spent primers look good on these VV N540 loads, I may make a couple more "hotter" rounds to try them out.

[ETD1010]

Awesome project. I'm very curious to see how Varget does, if you are considering testing it in these loads. Thanks for the great info!

[Jicko]

Unfortunately, Varget wasn't on my original plan.... and now, I actually would like to consider Varget in my project too (but I don't have any Varget powder...) :-(

[Bolt2Bounce]

I just loaded 100 rds of Berger 73Gr match with 24 Gr of RL15 just a side note RL 15 and Varget are so similar to each other they could be interchanged... I moved down to 24 Grs with the Burger 72 even though they weigh less then the 77 SMK for two reasons I've heard that burger has thinner jackets than Sierra's MK and it's a new bullet to me.
I'll see how they preform. All of my OAL length is magazine length, I don't measure I just make sure they fit in the mags. As to the question how hot to load a round, if you use Military cases they will hold less powder but are tougher, if you use civilian brass they will hold more powder but are thinner and softer. So primer flatting and normal pressure signs will have to be the method, at the top end the smallest powder increase will push velocity and pressure a large amount. B2B

[Jicko]

These results are a little strange, I really would like to explain it myself too, but I couldn't PLEASE HELP ME!!

Originally on Par 1 of this load development exercise, it was determined that 24.7gr of RL15 should yield MK262 performance of avg 2775fps; here are my intent to fine-tune RL15.

-------------------

Part 4 of load development

Barrel: Douglas Premium Air-gauged SS Match Barrel tuned by Compass Lake Engineering
Chamber: Wlyde
Length: 18" SPR

Bullet: Nosler Custom Competition 223Rem 77gr HPBT (non-cannuellure, non-crimped)
Brass: Fed 223 Rem
Primer: CCI #41 (5.56 Military)
Chrono distance: 6ft

Powder: Alliant RL15 [compressed powder, all, ie. ring mark on the bullet]

Wt: 24.7gr
Round 1 (2.2555 OAL): 2700fps
Round 2 (2.2570 OAL): 2714fps
Round 3 (2.2480 OAL): 2693fps
Round 4 (2.2580 OAL): 2688fps
Round 5 (2.2580 OAL): 2705fps
Avg OAL: 2.255
Avg Velocity: 2700fps (WHAT!!!??? WHY??)
ES: 26
SD: 10.2

Wt: 24.8gr
Round 1 (2.2555 OAL): 2742fps
Round 2 (2.2570 OAL): 2727fps
Round 3 (2.2480 OAL): 2738fps
Round 4 (2.2580 OAL): 2730fps
Round 5 (2.2580 OAL): 2741fps
Avg OAL: 2.259
Avg Velocity: 2738fps
ES: 12
SD: 4.7

Wt: 24.9gr
Round 1 (2.2600 OAL): 2732fps
Round 2 (2.2580 OAL): 2728fps
Round 3 (2.2540 OAL): 2749fps
Round 4 (2.2550 OAL): 2741fps
Round 5 (2.2545 OAL): 2741fps
Avg OAL: 2.256
Avg Velocity: 2738fps (WHAT!!!??? 24.8 and 24.9 is THE SAME??)
ES: 21
SD: 8.3

Wt: 25.0gr
Round 1 (2.2550 OAL): 2781fps
Round 2 (2.2580 OAL): 2726fps
Round 3 (2.2550 OAL): 2756fps
Round 4 (2.2575 OAL): 2758fps
Round 5 (2.2560 OAL): 2739fps
Avg OAL: 2.256
Avg Velocity: 2752fps
ES: 55
SD: 20.8

Wt: 25.1gr
Round 1 (2.2590 OAL): 2779fps
Round 2 (2.2515 OAL): 2763fps
Round 3 (2.2570 OAL): 2761fps
Round 4 (2.2600 OAL): 2802fps
Round 5 (2.2545 OAL): 2754fps
Avg OAL: 2.256
Avg Velocity: 2772fps (Finally, but I really dun like the ES and SD #)
ES: 48
SD: 19.2

Wt: 25.2gr
Round 1 (2.2600 OAL): 2789fps
Round 2 (2.2550 OAL): 2788fps
Round 3 (2.2555 OAL): 2775fps
Round 4 (2.2600 OAL): 2783fps
Round 5 (2.2575 OAL): 2754fps
Avg OAL: 2.258
Avg Velocity: 2778fps (This may be more dependable)
ES: 35
SD: 14.4


==============

Control Tests:

Federal XM193 (55gr FMJBT)
Round 1 : 3191fps
Round 2 : 3177fps
Round 3 : 3182fps
Round 3 : 3289fps
Round 3 : 3220fps
Avg Velocity: 3212fps (This control have comparable vel as day 1, but also suffer from high ES/SD)
ES: 112
SD: 46.3

-------------------

So, what do you guys think??

[Bolt2Bounce]

I just shot Burger bullets for the first time in a NRA High Power match. They were very accurate. I loaded a 73 Gr burger bullet behind a charge of 24 grains of RL15 I used IVI 85 case and winchester Small rifle primer, no problems with pressure or any other kind. I loaded them to magazine length. As a side note I looked in the Hodgen loading manual and they have a listed load with the 75 gr bullet with H4895 of 27 grains at a listed velocity of 2950fps. Thats kinda hot.... B2B

[Bolt2Bounce]

JickoRicko I'd change my brass from Fed (which have had major problems in 223 brass) to a Military case like LC or IVI, IMI etc. You will probably be able to reach your velocity goal of 2775 with less powder because of the small case volume. B2B

[6172crew]

Im working on getting a couple of boxes of MK262 ammo for the guys who want to test it out. Should know more later in the week.

[Bolt2Bounce]

Sorry guys that load was A 6mm223 load 27gr with a 75 gr bullet at 2950 the load for 223 is 24.5 gr 4895 at 2905 check your loading data in a manual. Still hot... My bad... B2B

[Jicko]

Originally Posted by 6172crew

Im working on getting a couple of boxes of MK262 ammo for the guys who want to test it out. Should know more later in the week.

Please keep me informed, I am very interested.

I've got a couple of rounds that someone gave me told me that they are Mk262s, but they are moly coated, so I think they may be the BHA AMU load rather than the real Mk262 Mod1.

[thmpr]

Originally Posted by JickoRicko

Please keep me informed, I am very interested.

I've got a couple of rounds that someone gave me told me that they are Mk262s, but they are moly coated, so I think they may be the BHA AMU load rather than the real Mk262 Mod1.

JR,
You seem to be on a quest. What are your goals and expectations? Target velocity has been reached that mimics the MK262 and don't know what the accuracy results are from the experimental loads you have made. Thus what is the goal?

[Jicko]

Last FRI, I rushly loaded 70 rounds of 24.7gr Ramshot TAC for Sat's NRA 3x600 match. And.... sadly, it was a failure on one hand.... but, I learnt a lot.



I learnt a few things:

> It wasn't my shooting, but my handloaded rounds are BAD!

It is a match of 60 rounds, out of my first 25 shots, I have 10 M(isses)!!! ie. couldn't even hit a 60" target @ 600yds even with my 9x scope!!! Whereas other shooters are getting Xs(6" center) with *IRON SIGHTS*!! And my hits are like everywhere, up and down, left and right!!

So WHY???

There was a guy in my squad and we were so frustrated that he decided to have me try his loads (24gr AA-2230 / 77gr SMK / Fed205m / LC case / OAL 2.244).

Man, now, we are in business..... the next 35 rounds, I've got 4-Xs, 6-10s, 14-9s etc....

As a conclusion......


> AMMO is VERY important (duh!)

> The "ring" mark on my rounds are ABNORMAL! I can shake my case, and I can *still* hear the powder inside, so the "ring" mark is not likely to be cause by "powder compression".... and there are even copper jacket shavings from the case mouth.... so, either my sizing die, or my dillon powder funnel is setted up wrong.... I'll be contacting Dillon and see how they can help....

[Jicko]

Originally Posted by thmpr

JR,
You seem to be on a quest. What are your goals and expectations? Target velocity has been reached that mimics the MK262 and don't know what the accuracy results are from the experimental loads you have made. Thus what is the goal?

Thmpr,

The "goal" as stated in my original post: "is to try to achieve Mk 262-like performance at a reasonable cost. "

"Performance" will be in terms of velocity as well as accuracy.

My work is by no means completed. I will definitely post "accuracy" result soon. But currently I'm NOT happy with the "accuracy" that I am getting, and I believed it is the result of a "case neck tension" problem. I am still trying to debug that with my reloading setup. This bug is causing uneven OAL and "ogive ring mark" on the bullets, hence, accuracy suffers.

Once I have that fixed and dialed in, I'll zoom into the powder type and wt which will give me the "target velocity", and then evaluate them base on "accuracy". And at that point, I'll post "groups" pic.

At the end, I am hoping to archieve sub 1/2-1 MOA groups. ie. < .5-1" @ 100yds or .25-.5" @ 50yds.

PS. I am hunting for some REAL Mk262 Mod1 rounds for "velocity" & "accuracy" measurements, please let me know if any of you have some that can support my effort here.

[ocabj]

I'm nearly positive that the powder charge weights you'll use to achieve Mk262 muzzle velocities in your handloads will be above the maximum data listed in every published data book out there.

In your most recent post with your recorded MVs, you stated 25.2gr of RL15 got you 2778fps. This is about on par with what was reported in the Guns & Ammo article (accessible via the web) for an 18" barrel.

25.3gr of Varget got me 2787fps out of an 18" 1-7" twist SPR barrel.

As far as accuracy, if your 25.2gr RL15 load gives you 1MOA, I'd be content with it.

If it doesn't, I'd try switching powders to see if you get better results with a different burning powder. Varget is another option in the same price range as RL15. N140 is more expensive and harder to come by.

You can try a ball powder like W748, but I have no experience with it. It has been used successfully for .223 in the past, but you'll need to work up carefully for heavy weight bullets like the 77gr.

MK262 wasn't meant to give benchrest sized groups.

Frankly, the more I played with my own MK262 experiments, I came to the realization that it wasn't a very optimal round as far as accuracy is concerned. If you think about it, Mk262 was designed to give enough power to the bullet out of barrels as short as 14.5". I don't have a 14.5" barrel, but if you apply the theoretical 50fps per 1" rule, a 14.5" barrel will give a MV of around 2625fps. 2650-2750 is about the sweet spot for the 77gr.

I'd be willing to bet that commercial/SAAMI 77gr BTHP muzzle velocities will result in better accuracy in an 18" SPR barrel than MK262 muzzle velocities. And even more so out of a 20" barrel.

Action type and barrel length aside, I'm sure that you can get a 77gr BTHP moving above 2800fps MV and find a 'pulse' in the pressure curve of the powder and bullet combination that yields excellent accuracy. Whether or not you can even get that much powder into the case and push the bullet that fast out of the 18" barrel is another question.