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

[Jicko]

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/eproductpage.exe/showproduct?saleitemid=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]

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]

Day 2, Ramshot TAC

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

[Jicko]

Day 3(part 1) - VihtaVuori N540

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

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