156 EOL at 3100 FPS

[GoosePilot]

I was screwing around last night, I seated a 156 in a necked down 7mag(264wm) and also took a 7lrm case, necked(&turned) it down and seated a 156. The bullet bearing is well above the neck/shoulder junction in the LRM case, and just at the neck/shoulder in the 264wm case. I'd really like to build a 6.5 LRM!

Yes, Or a 6.5 Blaser Improved or Sherman Max

 

[codyadams]

Berger just updated their calculator for this in the past few months.
At slow velocities, they said that that it would be marginally stable, but over 3000 fps of muzzle velocity, I don't think you will notice "marginal" conditions. This lead them to update the suggested twist for most of their 6.5mm line.

I am shooting a 1:8" twist with the 156 EOL and it's 1/4moa at 100 yards and I generally shoot between 1/4 and 1/2 moa at long ranges out to 1400. I live at 1000 fas.

I checked the stability on their calculator today.

 

[highdrum]

Yes, Or a 6.5 Blaser Improved or Sherman Max

Sherman max has 78gr capacity, the blaser imp and lrm will be 86-88gr. It would probably have the better of the barrel life tho.

 

[codyadams]

Gunwerks is to have adg manufactured 7lrm brass in April. There's a good chance I'll have a 6.5 ans 7mm running by summer.

That may change things.....ha ha

 

[highdrum]

That may change things.....ha ha

Covid19 may change the eta, hard to say. KY has orders in affect for closure of non essential businesses.

 

[Mike D Texas]

5 more grains of powder and a far superior Neck is a difference some might consider appealing. Of course my planned build uses an "Ackley" shoulder & .320 Neck, I know he said No Cats. The OP dealing with a Governmental agency that requires a special permit for each and every gun. Something we don't have to tolerate here in the 28th.

Curiosity got the best of me last night. So I grabbed a fully resized 264 Win Mag case and I stepped up the neck in a 257 Wby case to .264 and checked water capacity of each case.

.264 Win Mag case measured 85.4 grains of water. Necked up 257 Wby case measure 86.8 grains. Where were you seeing 5 grains of difference in capacity?

 

[highdrum]

Curiosity got the best of me last night. So I grabbed a fully resized 264 Win Mag case and I stepped up the neck in a 257 Wby case to .264 and checked water capacity of each case.

.264 Win Mag case measured 85.4 grains of water. Necked up 257 Wby case measure 86.8 grains. Where were you seeing 5 grains of difference in capacity?

The usable capacity is probably bout exact same since the wby holds a lot more in the neck. This is with a bullet seated with bearing surface starting right at neck/shoulder junction.

 

[codyadams]

Curiosity got the best of me last night. So I grabbed a fully resized 264 Win Mag case and I stepped up the neck in a 257 Wby case to .264 and checked water capacity of each case.

.264 Win Mag case measured 85.4 grains of water. Necked up 257 Wby case measure 86.8 grains. Where were you seeing 5 grains of difference in capacity?

Yup. Ain't no 5 grain difference there. Both seated properly, the .264 wm may even have more capacity.

 

[DonkeyBoy3333]

Well, I have made up final decision. My next rig will be chambered in 264 win.

 

[Rhett Crider]

I think you made the right decision for what you wanted.

 

[David Malcom]

Yes, Or a 6.5 Blaser Improved or Sherman Max

I started load testing with the 156 berger in my sherman max
yesterday. Saw 3170 before any signs of pressure with n570.

 

[Mike D Texas]

Yup. Ain't no 5 grain difference there. Both seated properly, the .264 wm may even have more capacity.

Maybe. But I bet you can push the Weatherby harder due to the case design and huge amount of freebore. This is based off my experience with my custom 257 Weatherby.

 

[highdrum]

Maybe. But I bet you can push the Weatherby harder due to the case design and huge amount of freebore. This is based off my experience with my custom 257 Weatherby.

If a guy cuts the 264wm w/ 225 freebore and used necked down ADG 7mag brass, I bet it's rum pretty dang fast. I'm watching this thread as my friend and I are planning a pair of fast 6.5 rifles to push 156eol and the 144gr Cayuga hunting solids, they'll be 7 twist and I'd like to build it on a necked down 7lrm case.

 

[Mike D Texas]

If a guy cuts the 264wm w/ 225 freebore and used necked down ADG 7mag brass, I bet it's rum pretty dang fast. I'm watching this thread as my friend and I are planning a pair of fast 6.5 rifles to push 156eol and the 144gr Cayuga hunting solids, they'll be 7 twist and I'd like to build it on a necked down 7lrm case.

What is the 7LRM parent case? I like the steeper shoulder and longer neck. Would be interested to know what the water capacity of the case is.