Thread: 7mm Saum - 18" or 20" barrel

Righto I have decided to rebarrel my t3 7mm Mag to 7 Saum

I will use a DPT suppressor on the sharp end of things and I have 150 plus AMax which went very well in the 7RM when seated out - not so good when seated mag length. I have been using N560 getting pretty good velocity out of the 7RM, also have appx 500gn of 2217.

I keen to hear peoples thoughts on barrel length and twist rate for the 7 Saum for suppressed light rifle.

Cheers

AMax

20-24 inch

The one i’m putting together will be 20”.

mines 22 from action face. 162 amax 2217 65.7 gr at coal of 2.184" getting 2953fps

No shorter than 20" I would say

I’d go with 22in, but not shorter than 20in. What’s the twist rate of your 7mm RM barrel ? 1:8 or 8.5 would be best if you want to run bigger high bc pills

22"

20" just short of 3000fps with 168 Berger

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I'd atleast run a 9 twist but ideally I'd run and 8 twist as it's more versatile. I hate long rifles so I'd be running the 18 if I had a suppressor but then again I'd probably just run an unsupressed 20-22inch barrel for weight and performance bonuses

19 inch barrel 2900 168 berger

Just chop your remmag to 20" and your away

Originally Posted by robhughes-games

mines 22 from action face. 162 amax 2217 65.7 gr at coal of 2.184" getting 2953fps

EDIT .......2.814"Coal

My suppressed Mod 7 has a 18" barrel, so a bit more handy in the bush. 160's @ 2725 mag fit, so fair loss from the 2950 mag fit when it was 22". As 199p said above, why not just cut your rem mag back to 20"?
Cheers

Thanks All

A T3 RM has a 1:9.5 twist.

I think I will go with 1:8 or 8.5

Re chopping the RM barrel back to 20" - for me the issue is that the rifle shoots very well when the projectiles are seated out, but does not go anywhere as well when projectiles are seated to fir the mag. I realise that it is possible to play around with the plastic mag to gain a little extra space, however I imported a billet magazine so keen then have rounds all fit into this magazine.

And then of course there is the fun doing something I have never done before i.e. a rebarrel

Cheers

AMac

You will need to play around with different pills if you want to find one that shoots well from Mag length seating COL. And you need to advise your gunsmith what pills you intend running so he can chamber to suit. You’re probably better off running two different pills and loads, one mag length for the Bush and one seated long to maximise case capacity and bullet choice and performance and single feed