Anyone following KO2M?

[hubel458]

Here is picture of 375 HE left, 416 HE next, 416 HSM right..




Here, tentative specs, 416 HSM case we are doing from bmg brass,





A 375 HE, with Lawton action, bunch being done with those .....

[hubel458]

Anyone with Barnard P-Cheytac action, I need some info,

I understand it has action dia of 1.53" and 3 lug bolt,

and need the bolt diameter

And I need a picture of the bolt face...Ed

[ELR Researcher]

Ed:

Bolt dia is .980 - http://www.barnard.co.nz/model-p-chey-action.htm

DEREK RODGERS' 2017 winning Ko2M rifle is based on the P-Chey

[Matthew488]

Hi Ed,
How much are you selling your 375HE brass for? I managed to sell my Weatherby so that will get things going on a build. Planning on the Bat-L action and Bartlein barrel with Lester Bruno doing the build.

[hubel458]

Brass 100 rounds $450 shipping and insurance included. Ed

[hubel458]

A 585 HE ...shot with moderate heavy load......

https://scontent.cdninstagram.com/t5...09533184_n.mp4


Here is a 375 HE target gun set up, by Asteroid Precision...

Here is video of it being tested... And with a 350gr bullet about 3450-3475,

bolt opened easily with one finger...And he's just getting started

and is checking on better powder, Ed..


https://www.facebook.com/AsteroidPre...location=group

[URSA Facilitator]

For those of you that might have missed it, Applied Ballistics (AB) recently announced a new DVD, ELR Shooting with Applied Ballistics: Applied Ballistics' campaign for the 2017 King of 2 Miles competition." [Available at https://store.appliedballisticsllc.c...oductCode=0009 Pre-order pricing still shown.]

I pre-ordered one and received it last week. In watching it today I noted:

1. None of the AB shooters in the video were using anything "special" in the scope and mount department, specifically no TACOMHQ gear. The three team members in the Top 10 were using NT ATACR 7-35x56 scopes. A shot earlier in the DVD showed an Ivey mount on one of the rifles but I was unable to identify it in the actual competition section of the video.
2. At one point the front end of Derek Rogers scope was visible and I noted that he was using a "modifier disk" - I tried my March modifier disk on my 56mm ATACR and it would not fit. For those unfamiliar with such a device, see http://marchoptics.com/accessories . I found no such product on the NF website (at least in the Accessories section).
3. Anyone seriously considering shooting Ko2M - this DVD is well worth the tab.

[kcstott]

Modifier disk is extremely convenient. I’ve been using electrical tape for many years. As much as I hate them you could use a butler creak flip cap and a small hole saw. Buy a few put different diameters in there.

[hubel458]

Another view of 375HE AP target gun. Ed

[hubel458]

Here is recap simple setup to get faster loads with 12ga sabots

& slugs, Example using break actions...., reaming chamber

in a 12ga break action to 3.5" with a 3.5" 12ga reamer, that isn't

something needing special order, and use 3.5" plastic cases , or

get 3.5" brass cases made. With mag shotgun primers and

our slower powder loads you can get a quarter more speed,

which gives 50% more energy...


585 Hubel Express video, 190ft/lbs recoil, heavy load, gun little light.....

https://www.youtube.com/watch?v=tyS9zZ8ElJA


Another view of Asteroid Precision's.... 375 HE target gun,




Here is our 416 HSM we are developing next to 416 Barrett, Ed

[hubel458]

Here in picture of the cases, are shown the steps in making

our 416 HSM case, from BMG brass,, Ed

[Matthew488]

Can a Bat L be used for 416 HSM or does it need a 50 cal action?

[hubel458]

In BAT actions got to use 50 cal action.Ed

[URSA Facilitator]

Originally Posted by hubel458

In BAT actions got to use 50 cal action.Ed

Ed: I thought the 416 HSM is to have a rebated rim - down to CT size. That would allow use of the BAT L action (which is available with CT bolt face).

The L is available 2.0" OD, same as the .50 BMG-focused EX, but the L's loading port is only 3.8" long vs the EX at 5.5". If a shooter wanted to load shell-holder-action style (remove the bolt to R&R cartridges), the L that would work just fine.

Any other issue?

[LynnJr]

URSAFacilitator
You can use the factory scope caps and just have someone with a lathe make an opening for you. Jim Ketchum has made me several for the 56mm Nightforce scopes I use.
If I dig them up I will send you one.

[LynnJr]

Ed Hubel
Who has the 375 HE dies? And how long to get them?

[URSA Facilitator]

For those that missed what Lynn is talking about, my earlier post in this thread mentioned Derek Rogers using a "modifier disk" at the Ko2K. I noted, that while I had a modifier disk for my March scope I could not find one listed on the NF site for their scopes. With that preamble...

Lynn - then I'd have to deal with junk blowing around getting inside (why I close my factory pop-up NF caps when not shooting). I'm looking for a screw-in solution like the March solution that the pop-up lens caps will fit. Did Ketchum machine the older metal NF lens caps or are you talking about their rubber lens caps? If metal, yes, please be so kind as to find and send me one. I'll live with the junk blowing around.

I found a company that supposedly makes what I want BUT their product listing seems to be a one-size-fits-all because they provide only one offering with no way to indicate which scope you have and list several NF scopes as "made to fit" but that have different part numbers for corresponding sunshades for those scopes on the NF site. I've e-mailed their e-mail address because their contact form does not "submit".

All the above noted, in reading about the mirage-reduction capabilities of "modifier disks", I found that different mirage conditions require different size holes/openings in the modifier disks. Some smart person, opportunity knocks - design and market an adjustable-aperture modifier disk. And post on CalGuns to tell us about it. Thanks.

Originally Posted by LynnJr

URSAFacilitator
You can use the factory scope caps and just have someone with a lathe make an opening for you. Jim Ketchum has made me several for the 56mm Nightforce scopes I use.
If I dig them up I will send you one.

[LynnJr]

URSAFacilitator
I will post two pictures showing the modifier discs I use. They are the factory caps that come from Nightforce with the center lathe turned to a given size.
These are threaded with a shoulder and don't vibrate lose so far.
I would think someone with a 3D printer could make them out of plastic and if the shoulder diameter was the right size they would self thread themselves?

[sigstroker]

A little crazy glue on the end of a sunshade, and you're all set. $43.50 on ebay.

[URSA Facilitator]

Lynn - I sold my 3D printer long ago.

Sigstroker - please provide link or at least the word(s) I need to search on. Thanks.

I found a guy that sells mirage caps/modifier disks for NF - http://www.kreativ-solutions.com/mirage-caps.html - his ordering system is not that great, so I strongly suggest you contact him to make sure you get the right version (they are NOT all the same).

[joefrank64k]

Originally Posted by URSA Facilitator

Lynn - I sold my 3D printer long ago.

Sigstroker - please provide link or at least the word(s) I need to search on. Thanks.

I found a guy that sells mirage caps/modifier disks for NF - http://www.kreativ-solutions.com/mirage-caps.html - his ordering system is not that great, so I strongly suggest you contact him to make sure you get the right version (they are NOT all the same).

Facilitator: I searched eBay with “adjustable aperture” found some for $12 to $20: https://www.ebay.com/itm/Adjustable-...r/351953180516

[joefrank64k]

Originally Posted by Kingair001

Hey buddy !



Long time no see !



All ok ?

All is well, thanks for asking!!

I’m recovering from shoulder surgery. I’m on the mend.

Billy Goat Machine just shipped out my big bore switch-barrel stuff (.510 DTC/.375 CT on a BAT EX) so I’m looking forward to getting that sorted out.

Although after reading through this thread, I feel like my rig is already outdated, haha!!

How are things by you??

**Sorry for the hijack, everyone!!**

[hubel458]

The Bat L does not have a large enough diameter bolt for

the 416 HSM, Its 2" action would do if it had bigger bolt, maybe we can

get them to build one with bigger bolt, but not as big as bmg.

The Barnard P-Cheytac will do and few others, as well as bmg ones .

We are getting set up for making 375 HE sizing dies. Ready soon. Ed

......................

[hubel458]

If we could get Bat L with bigger bolt we could open the port to

clear empty 416 HSM ok. I Have handled a Barnard P Cheytac

bolt and it is 3 lugs and would have strength needed.

I 'm setting heavy barrel test gun with a MRC PH

I have here with a .800" dia bolt. To check speed vs pressure.

We may have a source to make an intermediate target action

with a .800-850'' bolt with proper thrust rating on the bolt lugs.. Ed


..................

[hubel458]

Getting closer--

We might have a company that is doing a bolt gun with an action

between BMG size and longer rifle actions used for 375 HE,

375 Lethal, and Cheytacs.. To use for our 416 HSM without

having to do extreme rebating of the rim...Ed

[hubel458]

Here is picture of 620 416 hsm cases half done. Done on cnc ,

that slimmed them down, cut new rim and extractor groove.

There are over 500 more at cnc getting done now, plus we have

1000s more bmg cases we make them from, when needed..

This case is public domain and if anyone wants to make

them we can give the steps involved...Ed.

[ELR Researcher]

Originally Posted by hubel458

The Bat L does not have a large enough diameter bolt for

the 416 HSM, Its 2" action would do if it had bigger bolt, maybe we can

get them to build one with bigger bolt, but not as big as bmg.

The Barnard P-Cheytac will do and few others, as well as bmg ones .

We are getting set up for making 375 HE sizing dies. Ready soon. Ed

......................

Ed, I'm confused. I think you are saying that the receiver's "raceway" is too small in diameter to accept the BMG-ish case diameter. Correct?

BTW, your 9/3/17 post drawing shows .740 above the extractor groove. The corresponding dim of a .50 BMG is close to .804 (CIP dim P1). Are you trimming .032 off the case wall or "swaging" it inside or a combo or? Thanks.

[hubel458]

Yes the raceway, or ID is not big enough.

All Lake City bmg cases we have here, , we have measured elsewhere,

are .996-997" base just ahead of extractor groove...

We first take that down to about .657" with a straight cut,

and same time do new rim and groove size, then we anneal, then

shape on my case lathe and form in 3 dies we have here, the area above about

an inch above base to JUST UNDER .740" on a taper to the bmg shoulder,

then take the rest of the bottom of the case, the one inch area up

from the groove, down to final shape and .740". Make .740 base. We then have taper

from that to original shoulder, then we neck, then fire form out, getting a new shoulder.

The original bmg case has way more thickness than needed near the

bottom for our use, as case was designed originally for MG use.

With an extreme taper and thickness

Here is picture of our HSM and original bmg sectioned and we can see

plenty of thickness for our use.I did similar with my belted 700

and worked ok. That side thickness on the HSM on the left

over 50% thicker than sides our 585/375/416 cases.

The whole process just a minimum. reshaping, where when

we fire form shoulder ahead we in essence lose no

volume, we gain quite a bit....but we don't fire form original shoulder to

a bigger diameter, as we want just the right taper for extraction....Ed



.....

[hubel458]

For big long cases our testing is showing that the 416 is

easier to get powders to work with, with less problems ..

So if you got to buy new barrel, build a target gun, just go

with 416, we got cases, 416 HE and 416 HSM...

CEB and others will have bullets...

CEB will be making .408 and .416 Lazers

.408 ---- 425gr, 450gr and 475gr

.416 ------ 450gr, 475gr, 500gr, 525gr and 550gr

They will be testing around mid-February..

My bigger diameter, 34" long 416 test barrel, was 250 bucks,

1-10 twist, 1- 5/8 inch diameter, work for bullets, 425-450gr or so..;Ed..

[hubel458]

For big long cases our testing is showing that the 416 easier to get powders to work with, less problems ..
Maybe building a target gun,don't have 375 barrel all ready, maybe go 416....

Got sent 5 thick sided sample cases, same OD base as 585/375.416 cases, same belt, just .180" longer,
did a 416 HE, chambered extra barrel , cases stick over 50k. They have about .042" total taper, .021" per
side, when I necked couple to 416. That is a lot of taper , twice the taper of my 416HE...hanging up at 50k..

I could maybe go to 65k with these if we made taper with ..012" - .016" more taper to each side, but that is
no way to build target cases. I'd have to crunch down case shoulder diameter. And would look like 30-30.

And crazy part is, the case has enough brass material to thin up sides and stretch them way out to 4 or
more inches,, They weigh 150 gr more than our 585/375/416,, but with real thick sides they actually
hold less than our 416 HE with thin sides, that is .180" shorter...Our case does 65k ok without sticking..

And we can make super long 4" cases work if we had means to get them built, as we have
15 powders slower than HBMG.Here is pic of thin and thick sided cases, sectioned for comparison.Ed..

[hubel458]

Here is a drawing depicting the layoutof thick and thin sided cases,

like my 585/375/416 HE thin sides ones and the thick one.

And my 585 case is not perfect, as where it transitions from the

heavier corner to the side it isn't gradual, so case separates there

shortening case life. There are others made that way including brand X.

The dotted line is what it should be. ..Ed

[hubel458]

Others have sent cases to section and look at, that are built thick sided and they stick also for the folks, If a longer case with about 5 sq in of side surface sticks and don't spring back, the coefficient of friction is about .01 then the pull needed to move it is 2500-3500 lbs..That is for big cases with normal amount of slant to the sides. Ed.

[hubel458]

Here is picture of six nyati and gibbs size cases sectioned..5th one is present 585 HE]
and 6th is thick sided version. 1st is 600 OK which essentially nyati basic case left straight, belt added.



In the picture the nyati gma is one we built most of our first 585s on. Before we had factory run.
Reworking made it in size that is now my 585 HE, but that brass had the sides of perfect thickness,
not too thick, but thin without sharp transition my new factory 585s had, they last forever as 585s......

Fourth one is an older nyati case I used to make about 10 of my 585s from ...they had thin sides
and sharp transition, and then I tested these 20 years ago, and they would separate after -4-6 hot loads
as 585s, my factory 585 with right powders as a 585 will get 10 hot loads, and necked down to
416/375 4- 6 hot loads, right powders used, Moderate 577 equivalent, factory 585 at least 20 loads..Ed.

[hubel458]

Guy sent thick sided 375 case, next size base diameter up from Nyati.He said,
'Yes I ran them in a ___________ rifle built by ____, the best I
could get was 44000 psi, any more and they were stuck''

Big bore guys. other forums over the years related that trex/african case in 585
size, thick sided cases, stuck when they loaded them over 45k psi.

Another just sent us, thick sided 375, long case, same base OD as our 585 HE,
416 HE, 375 HE, and Mitch's 375 Lethal, and the thick ones stuck over 45k psi.

Now you can fill those cases up, with ultra slow enough powder so they won't
stick, but powder is too slow for max speed. Might get a little more
speed, with thick sides case, but case got to be 4- 4.5 inches long..

. Anyone needing a sectioned case of the ones I made the first of my 585s from,
contact me, if they want to get a general idea of what case side thickness should
be, in Gibbs size cases on up to about trex and 375 VM size case diameter.

Here is pic of our 585 based case next to brand X and thick ones, both have
same sharp, thinner, corner, where transition from heavy angled corner, to the
side, the carbide draw rod could easily be reshaped with diamond wheel,
just by grinding off sharp transition corner. Then sides would be perfect.., .




Here is picture of 416 HE in a Choate target/varmint stock guy is doing,
using long action BSA U9 action.Setting in stock ready to do bedding..Ed

[ELR Researcher]

Ed - at one point not too long ago I'd asked you how you (and now these other folks) are measuring the pressure levels you are noting. I can't find that post but am reasonably sure it was not responded to. I'm thinking you are "just" entering barrel, bullet, case, and powder info into QuickLOAD and accepting the pressure value that it generates. Please advise. Thanks.

[hubel458]

No Quick. I use the paper vel/pressure formula that is basis for online

programs, and older slide rule setups, (57 years ago we helped figure

that formula out, when in college) and it ended up on first slide rule one.

We redid the old calculus ones military used, Leduc's formula..

We put in a pressure fudge factor, and if velocity on chrono matches

we are sure the pressure is within 5-7%. And years ago we had some

lab tested by transducer that verified we were always close.

Some of the other guys probably used Quickload. Which seems to match ours.

Which whole peocess, gets us an idea what case can do for extraction,expansion,

and keeps us under 70k on good cases, when getting near the top.Ed

[hubel458]

Here is picture of thick 375 case sent to me, with thick sided trex case, and our HE case,
The thick 375 case is .050" bigger OD base, but inside is no bigger than HE cases..
These thick sided 375s stuck when loaded over 44,000 psi....



Got guys asking and I'm doing it, to do my 416 HSM case for BMG actions, so leaving rim same,
as the original bmg rim, so will neck them, fire form to the longer shoulder, like the others.
Base a little bigger, Shoulder same diameter, same 30 degree slant, neck will be same..

The inside of case still has close to same shape and volumn within 3 % as the ones we slimmed down.
Some want to use bmg actions and can't wait for intermediate actions, or already have bmg action.
And they are really getting interested in the complete line of 416 CEB bullets now being done..Ed

[hubel458]

There will be 3 versions OF 416 HSM, one for actions one .750" bolt, one for .800-.850" bolt,
And one for bigger bmg bolts. The ones for BMG called 416 HSM2 ..

Here is 416 HSM guy working in a Montana PH, in a heavy thumbhole target stock.
It has a .805" diameter bolt... Ed

[hubel458]

Here is sectioned 585 HE case in the middle, we first made from

another case, years ago before we had factory run of brass and

it had perfect thickness on the sides and inside corrner.

We could fire them many times without sides thinning..

First case is factory run of our 585 HE, 3rd is case that is too thick

of sides and sticks at high pressures..



Here is pic of our factory run cases necked down to 375 and fired 4 times

at high pressure on the right, with unfired case on the left. Our case is not

perfect but does work...Ed

[ELR Researcher]

ED - is the bevel in the flash hole from case prep or?