7mm SAUM Questions

[VKC]

Re: 7mm SAUM Questions

So I know this is a loaded question, no pun intended, but how much does the difference in length of an Alpha WSM mag vs. a Seekins really matter in case capacity and velocity?

 

[BobinNC]

Re: 7mm SAUM Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vkc</div><div class="ubbcode-body">So I know this is a loaded question, no pun intended, but how much does the difference in length of an Alpha WSM mag vs. a Seekins really matter in case capacity and velocity? </div></div>

Not sure any one can give you an actual measurement. But I can give you a good guess:

7mm SAUM Factory spec COAL 2.8252"
Alpha Mags 2.985" Difference from factory 0.1598"
Seekins Mags 3.14" Difference from Alpha 0.155"

The volume of a 0.284" cylinder with a height of 0.155" when using Seekins Mags vs Alpha Mags, based on the density of water is 0.019687 Fluid oz. or 8.6130625 grains of water (not powder). If I did the math correctly.....

 

[RedGoat]

Re: 7mm SAUM Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Skyking</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Goatphius</div><div class="ubbcode-body">Skyking I know you have already been shooting the 7wsm (I saw your 1400yd video) and now your building a 7 SAUM. Was hoping I could get your opinion/pros&cons on the two. I was going to PM you the question, but figured everyone could benefit from your answer. Thanks for the intel in advance.

-Goat</div></div>

I really cant tell you about the 7saum yet. Just got my gun done on Monday. Plus I am doing a 7suam AI. Blowing the neck out to 35' the same as the WSM. Going to call it the 7STM. I have shoot a few rounds down it to fire form the brass. The one bad thing is Rem brass over the Win brass. I can already tell the Rem brass is softer. We will see if the longer neck give better accuracy, and longer barrel life. I am going to salt bath nitride my barrel so that is not a good comparison anyways. LOSOK Custom Arms will do it for $100 a barrel. Talked with a few of his customers. They are loving it. One guy has done 6 different guns. His 6.5-284 has 5000 rounds down it now.

I absolutely love my WSM. Really wanted to build another gun and could not do to the exactly the same. I really don't think you can beat those Berger 180's.
If I had to do it over again. This is what I would use.

Mcmillan A3-5 Again.
Bighorn action!!! NO question about it. Never build another gun on anything other then that action.
Seeking's BDM
Reamer for the 180's in that bottom metal.

Here is some pictures of my half-way done gun. Need to brake in the barrel. Send to get treated. cerakote it, and turn down the muzzle brake. Don't mind the clay on the stock. I am working on making some new Carbon-Fiber shells with that palm swell for the AICS. So this is a test stock.

From Left to Right,
7wsm 180,7saum AI 180, 7saum 180. OAL. 2.955

</div></div>

I look forward to hearing what you think of the SAUM in the Remington brass, in comparison to the WSM in Winchester brass. I have been disappointed in the reviews I have read of the SAUM Nosler brass, seems to be soft and not making it through many reloads. Has anyone here had good experience with necking-down the 300 SAUM Norma brass, or have anything to say about the Norma brass in general?

Also does anyone know the dimensions of the Bighorn WSM action. Is it the same as the SA with a magnum bolt face, or did they open up the port/feed ramp opening extra to accommodate the longer WSM rounds?

 

[captain zeke]

Re: 7mm SAUM Questions

So does a 2.955 7saum round feed ok in an Alpha mag

 

[RedGoat]

Re: 7mm SAUM Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: captain zeke</div><div class="ubbcode-body">So does a 2.955 7saum round feed ok in an Alpha mag </div></div>

The OAL for the Alpha mag is 2.985", I don't see any reason why a 2.955" round shouldn't feed well out of it.

 

[Wild_Bill]

Re: 7mm SAUM Questions

Hi i shoot a 7mm SAUM extensivly in F Class and have won 7 state titles straight and the Nationals here in Australia with one in long rage F Class from 1000 to 1200 yards and also in short range F Class from 300 to 1000 yards i have also shot it past 1500 yards with 175gr Matchkings with H4831SC, H1000 and also Retumbo.

I have used Rem brass and also Norma both shoot well under 1/2moa the Norma is great but you have to use around a grain less in them.

when i use H4831sc the barrel gets worn a lot faster but H1000 but if you can use Retumbo the barrel wear is a lot less.

The SAUM is an awsome round and gets more velocity with less powder in 28 to 30" barrels the 175gr MatchKings easily get from 3000 to 3100fps.

 

[Skyking]

Re: 7mm SAUM Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: captain zeke</div><div class="ubbcode-body">So does a 2.955 7saum round feed ok in an Alpha mag </div></div>

Feeds great. No problems at all.

 

[mcfred]

Re: 7mm SAUM Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Goatphius</div><div class="ubbcode-body">McFred Thanks for the intel, those numbers look nice, how is the accuracy on your rig? As for barrel length I have been leaning toward a 25" 1:8.5" twist barrel (#14 if Krieger or what ever the equivalent is for Rock Creek). </div></div>

I installed a $60 Remington take off barrel (9.25 twist) just to finish the build but I get about .7 moa, which should be fine for my local precision rifle matches. Whenever I get some time I'll cut, thread, chamber and crown a 27" SS Brux I have. Hopefully the Brux will shoot bugholes.

I think you'll do fine with a 25". Even if you don't get 2900fs you'll be right up there and it's hard to beat the BCs of the heavy 7mms, particularly if you're pointing them.