7 Saum mag fed pressure test rl26

[Alex Wheeler]

I just finished my Saum. Its a no-turn for Norma cases with a short throat to seat 180s at 2.950 for a wyatts bdl box. I went out with 180 hybrids .020" in the lands and ran it up to pressure. I never hit stiff bolt but the top two were showing light ejector marks. I would run it there so long as it is ok in the summer. I will pressure up H4831sc next which is the powder I prefer to use.

 

[BIGMAC]

Please share your finding/ results with H4831sc. Thanks

 

[Alex Wheeler]

Sure will

 

[Zero333]

Nice !
Thanks for sharing.

Is that a 28" blowgun ?

 

[Alex Wheeler]

26"

 

[6fatrat]

I finally finished my ultimate mountain rifle this past summer. A 7 SAUM with a 24" third time chambered Krieger 1/9 #5 contoured SS barrel.
With Remington brass and 150gr. Nosler BT I get 3010 fps with 63.5 gr.
H4831SC and a Fed. 215 primer.
I used the standard PTG finish reamer, limited testing out to 600 yards is yielding apx. 1/2 MOA.
Steve Bair

 

[22DASHER]

What are the details of that build Alex? I need to get a LR elk rifle done

 

[Alex Wheeler]

I ran 4831sc up to pressure last night. I did not hit heavy bolt lift. My top charge was 62.5 2995 fps and I got a very faint ejector mark. I would think you would feel bolt lift around 63-63.5. If there is a node around 3000 with this powder I will run it. The whole 10 shot group from 58-62.5 was about an inch at 100.

 

[Alex Wheeler]

What are the details of that build Alex? I need to get a LR elk rifle done

I built this on a Defiance ultralight, timed it to a jewell trigger, Broughton rem mag sporter contour 26", Mcmillan hunter, vx6hd 3-18.

 

[22DASHER]

What’s the final weight?

 

[Alex Wheeler]

9lb 5oz.
The ultralight is a bit of a misnomer. It weighs about the same as a 700 but you get integral lug and rail. The stock is also NOT edge fill. That alone would save 1/2 pound. I personally would not want a true ultra light unless I was going for sheep, then it would be a 6.5mm.

 

[Elwood]

I ran 4831sc up to pressure last night. I did not hit heavy bolt lift. My top charge was 62.5 2995 fps and I got a very faint ejector mark. I would think you would feel bolt like at 63-63.5. If there is a node around 3000 with this powder I will run it. The whole 10 shot group from 58-62.5 was about an inch at 100.

I think that's pretty good from a 26" barrel.
I recently tested two different lots of H4381sc with the 180's but with a 30" barrel. With 62 grains from one batch I got an average of 3010 fps over 15 shots and with the second batch of H4381 sc I got a average of 2975 fps with 62.2 grains. No pressure signs with either load.

 

[rudysts]

Seeing this thread is making me anxious for what Alex is building me. hoping to keep it at around 9lbs or less

 

[long40shot]

Did you build this with any particular trip in mind?

 

[Alex Wheeler]

Did you build this with any particular trip in mind?

I just hunt locally. I have a heavier 30 Nosler for long shots, but I dont like carrying it far, its also no good for a fast shot off hand. It serves its purpose well, but I needed something to carry. I only hunt elk. If I could only have one it would be a 10lb scoped 30 nosler.

 

[missed]

Nice Alex!

A 7SAUM is next on my list in my SA Mausingfield. Loading 180g Berger's to AICS mag length is a requirement. I'm going to start gathering up parts for it soon.

 

[Sheldon N]

Thanks for sharing Alex, that's great info. I'm about to try RL-26 in a 7SAUM mag fed with the Berger 195's. They'll be stuffed down in the case but the results you're getting with the 180's are very encouraging.

Was this virgin brass/virgin barrel or had you already broken things in?

 

[Alex Wheeler]

Virgin brass and barrel.

 

[JBT47]

It appears your Broughton barrel is making good velocity.

 

[Alex Wheeler]

They seem to do that