Is this build possible?

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07-25-2012, 10:29 AM
MDM

Is this 7 SAUM build possible?

I'd like to build a 7 SAUM on a 4.4" SA. I'm thinking a Stevens 200 CF short action, but I know some changes will be required to the bolt head, I'm just not sure what. I have a really nice Mcree's Precision chassis that is set up for a 4.4" SA and I'd like to have a 7SAUM barreled action I could drop in it. I'm thinking 26" Criterion bull. Got to call Jim and see what the freebore is on Criterion's reamer to see if a SA is even possible. I plan on shooting the 162 amax and using Accurate mags and could modify the feed ramp if need be. Thanks for the help.
07-25-2012, 10:45 AM
MDM

Just got some info from Jim. Criterion only makes the 7 SAUM in large shank, so that would pretty much dictate a LRP repeater action. Just have to figure out what I would need to do to make the bolt assembly correct. The reamer specs are .321" and .090" freebore which should give me plenty of room in the mag box for the 162 amax. I could probably even have my smith open it up a little with his throating reamer to give me more case capacity. If anyone has a similar build with a Criterion, I'd like to OAL measurements with the 162 amax and 180 bergers.
07-25-2012, 11:17 AM
stangfish

You can have a competent smith rethread your action to the LRP threads. Simple process really, It just requires a little patience due to the interupted cut and the hardness of the reciever.
07-25-2012, 01:13 PM
Admin

Quote:

Originally Posted by MDM

Just got some info from Jim. Criterion only makes the 7 SAUM in large shank, so that would pretty much dictate a LRP repeater action.

Not necessarily - pretty much any Savage that left the factory as a WSM should have a large shank action. IIRC the limited run of 14/114W's sold through Jerry's several years ago were all large shank as well.
07-25-2012, 08:19 PM
Opus Dei

Quote:

Originally Posted by MDM

I'd like to build a 7 SAUM on a 4.4" SA. I'm thinking a Stevens 200 CF short action, but I know some changes will be required to the bolt head, I'm just not sure what. I have a really nice Mcree's Precision chassis that is set up for a 4.4" SA and I'd like to have a 7SAUM barreled action I could drop in it. I'm thinking 26" Criterion bull. Got to call Jim and see what the freebore is on Criterion's reamer to see if a SA is even possible. I plan on shooting the 162 amax and using Accurate mags and could modify the feed ramp if need be. Thanks for the help.

Your build is essentially what I'm doing. Only differences are barrel (Brux), magazine (Alpha) and caliber (7 WSM). I am months out on the barrel, but everything else is ready and waiting.

How well do those magazines fit in the chassis? I found the Alphas are quite tight (but in all fainess, even Scott's own magazines were tight). I did a little light filing on the magwell and the McRee .308 magazines now drop freely, and the Alphas are much better fitting. They won't drop free, though. The first Alpha I ordered was the 7-rounder, and after a longish backorder wait, I was sent a 10-rounder at no extra cost. Actually, I'm kinda glad since the fit is still snug after magwell relieving, and the extra length of the 10-rounder helps for removal.
09-13-2012, 05:02 PM
Kelly Jackson

Would it be safe, pressure wise to use a small shank barrel on a 7saum?
I see where Criterion does large shank.

Have been thinking of building for a small skank with a Kregier 8 twist barrel throated to run 180's
Think it would still run 162Amax accurately at mag length.

edit to add The 700 family all have the same thread tenon, 1 1/16 - 16 just wondering why this would have to be large shank for a savage build.

Regards
Kelly
09-14-2012, 05:57 AM
efm77

It can be done on a small shank. Lots of folks have built RSAUM's, WSM's, and RUM's on small shanks without any problems. In fact Savage did it that way to start with and then changed to the large shank probably for a little extra margin of safety. I personally am no comfortable with the small shank on the larger diameter cartridges like these and would opt for the large shank myself. Yes the Remington is the same shank size with even coarser/deeper threads than the Savage which takes even more metal off of the shank and I haven't heard of any problems with them either. I just like having thicker chamber walls for the larger diameter rounds. I had my actions re-threaded to the large shank size.
09-14-2012, 08:18 AM
nsaqam

Quote:

Originally Posted by efm77

It can be done on a small shank. Lots of folks have built RSAUM's, WSM's, and RUM's on small shanks without any problems. In fact Savage did it that way to start with and then changed to the large shank probably for a little extra margin of safety. I personally am no comfortable with the small shank on the larger diameter cartridges like these and would opt for the large shank myself. Yes the Remington is the same shank size with even coarser/deeper threads than the Savage which takes even more metal off of the shank and I haven't heard of any problems with them either. I just like having thicker chamber walls for the larger diameter rounds. I had my actions re-threaded to the large shank size.

True but the 700 barrel ahead of the receiver is larger in diameter than even the large shank Savage due to the 700 being a shouldered barrel.
09-14-2012, 10:18 AM
efm77

Yeah except for the part under the recoil lug. That's the area I would be concerned about. There you have the shank exposed from the receiver with only the recoil lug over it. The recoil lug doesn't fit the barrel shank tight enough nor is it strong enough to add any additional strength to the barrel there. If it's gonna let go, I would be that would be where it would. So I still think the Savage Large Shank gives a greater margin of safety.
09-15-2012, 01:33 AM
psharon97

For years, Savage was building magnum caliber rifles (300 win mag, 7mm rem mag) on standard sized actions. Once the wsm and the rsaum debuted, Savage decided to start building on a larger shank. I'm certain everyone on here will agree that the wsm and the rsaum have relatively the same pressures as the longer cartridges. IE, the 300 wsm should have relatively the same pressure as the 300 win mag. If this is true, why did Savage feel the need to switch to a large shank barrel for the short magnums and not all the magnums?
09-15-2012, 01:55 AM
M.O.A.

I think that's it because the short mags have the same pressure in a shorter case therefore it is dispersed over a smaller area.
09-15-2012, 07:16 AM
efm77

No, it's because the WSM, RSAUM, and RUM cases are larger diameter than belted magnums and therefore, have thinner chamber walls when built on the standard shank action. They can be built on the small shank and Savage made them on the small shank to start with. But, I think it's getting close to not being safe. On the large shank the chamber walls are thicker thus making it a stronger chamber. And yes they do operate at roughly the same pressure although the WSM's are loaded to higher pressures than belted mags in factory fodder. But, with that larger diameter case and slightly larger diameter head you have the same pressure over a larger surface area at the case head which will create more rearward bolt thrust even though it's the same PSI. It's the same PSI over a larger area. If you'll notice the locking lugs are thicker on a WSM Savage action.