Chambering for short barreled build

[codyadams]

Oh, and you can shoot 7 saum factory ammo, just like a proper chambered ackley improved as well, if your in a pinch and need to use factory ammo. My fireforming loads (pictured above) on the first batch, before the brass came properly formed, hovered around half MOA.

 

[bamban]

Rifle from gimme parts.

SS 700 Magnum given to me
Badger Ordnance M40a3/5 lug given to me
A very old 28 inch fluted 10T Hart varmint contour barrel set up for 1000 yard prone matches. Given to me.
Borrowed the NXS from my suppresor only 16-1/2 308 bolt gun.
EGW Hunter 20 MOA pic rail
Vortex pro line rings
Oryx stock, bought here
90 T AAC 3/4x24 brake/suppressor adapter Modified A191 Reamer 300WM. Still waiting on stamp

I harvested 21-3/4, the shortest I could get and not infringe on the fluting. Chambered it with my modified A191 reamer. Rifle is waiting on the stamp for the AAC Titan QD

Using FGMM 190 SMKs, surprisingly the velocity is higher than I expected, still @ 2935 compared to 3060 from another 300WM 26 inch tube. Shot #1 not shown on the display was from another rifle a club member wanted to sample velocity with his 6.5 something rifle.

 

[Slick8]

I had the same thoughts about a year ago and was bouncing between WSM, SAUM and Sherman's.

I ended up with a 20 inch 7 SAUM with a .195 throat for heavy VLD's. I'm running 180 hybrids at 2840 over H1K and getting right at an inch at 300. I'm going to run a seating depth test next weekend but don't expect to see much of an improvement just looking for a consistent node.

I ran a different bullet last year which was not quite as good as this one but it's what I could find. I'm about 120 rounds in and the barrel seems to have sped up at 90-100.

 

[BrentM]

View attachment 395440
All the pieces and parts are in…mesa, lone peak mid, Hawkins hunter, bix n andy, carbon six will finish 21". Can is a few month out… was figuring on a 7 SAUM but no joy on brass for months now… so may sort hornady brass and go 7WSM… Manners LRH mid on order… maybe give up and order a 6.5 barrel and do a PRC… but then I'd really want to get my hand on 156 Bergers… decision. decisions

PRC is a solid option still. Brass is becoming easier to locate. 156's, not so much but there are other options that work well depending on your goals. Having a 22 and 18 inch prc I have zero issue with the set up and get fairly decent velocity for that size of cartridge.

 

[7.62 Gunner]

View attachment 395440
All the pieces and parts are in…mesa, lone peak mid, Hawkins hunter, bix n andy, carbon six will finish 21". Can is a few month out… was figuring on a 7 SAUM but no joy on brass for months now… so may sort hornady brass and go 7WSM… Manners LRH mid on order… maybe give up and order a 6.5 barrel and do a PRC… but then I'd really want to get my hand on 156 Bergers… decision. decisions

Right on that'll be a sweet build.
I love the 7 wsm, it'll crush the saum and Sherman max.
I had good luck with Hornady wsm brass, it was very consistent you just can't put ejector marks in it or your pockets will loosen up.
Another easy ish option would be to neck ADG 300 wsm brass down and fire form off a false shoulder.

 

[waveslayer]

For short barreled fun you'd get more out of a 6.5 SAUM. Just neck down your 7 SAUM brass, easy to make just takes initial time. You will get more going that route

 

[JuddL]

Rifle from gimme parts.

SS 700 Magnum given to me
Badger Ordnance M40a3/5 lug given to me
A very old 28 inch fluted 10T Hart varmint contour barrel set up for 1000 yard prone matches. Given to me.
Borrowed the NXS from my suppresor only 16-1/2 308 bolt gun.
EGW Hunter 20 MOA pic rail
Vortex pro line rings
Oryx stock, bought here
90 T AAC 3/4x24 brake/suppressor adapter Modified A191 Reamer 300WM. Still waiting on stamp

I harvested 21-3/4, the shortest I could get and not infringe on the fluting. Chambered it with my modified A191 reamer. Rifle is waiting on the stamp for the AAC Titan QD

Using FGMM 190 SMKs, surprisingly the velocity is higher than I expected, still @ 2935 compared to 3060 from another 300WM 26 inch tube. Shot #1 not shown on the display was from another rifle a club member wanted to sample velocity with his 6.5 something rifle.

View attachment 395457

bamban…neat little handy rifle.

What is the split ring you're using the hold the barrel and how does it work? Interesting setup.

To the OP…6.5saum is a beast in a short barrel. My last one a buddy wanted it more than I did and I ran scenar 123's at 3060 out of a 16.5" proof barrel. My current one is a #3 Brux at 16" and I'm working up a load with vld-h 130's…looks like 3k isn't going to be off the table. I think it's about perfect for 500y and in rifle.

 

[bamban]

bamban…neat little handy rifle.

What is the split ring you're using the hold the barrel and how does it work? Interesting setup.

To the OP…6.5saum is a beast in a short barrel. My last one a buddy wanted it more than I did and I ran scenar 123's at 3060 out of a 16.5" proof barrel. My current one is a #3 Brux at 16" and I'm working up a load with vld-h 130's…looks like 3k isn't going to be off the table. I think it's about perfect for 500y and in rifle.

Thank you for asking.

The split ring is akin to using copper ring. The ID is beveled on both sides to allow the barrel to gimbal as you adjust the outboard spider. The thicker OD allows for more surface area for the jaws to bear on. The chuck in use is a set thru Bison that adjust like a 4J. Set thru chucks provides a more constant grip on the workpiece.

I have multiple split rings for all different OD for muzzle and tenon shank.

I copied the scheme from one of my benchrest gunsmith mentors, Mike Bryant. https://bryantcustom.com/

 

[chutinlead]

I harvested 21-3/4, the shortest I could get and not infringe on the fluting. Chambered it with my modified A191 reamer. Rifle is waiting on the stamp for the AAC Titan QD

I did a similar thing with a throw away "shot out" 6.5x47 barrel in except I chopped it off and threaded my muzzle in the flutes. Still has a .800 shoulder, it's just a little interrupted lol. No big deal.

OP if you're already considering on of the Sherman cases go with the 6.5/7SS or SST unless you need factory ammo then go PRC.