300 WSM or 7 SAUM

[raschiller]

I’m looking at having my first custom rifle built. I plan on buying a high end SA receiver and having a 24” Bartlein or Proof barrel chambered in a magnum (with a DBM - 2.95” OAL limitation).

I reload and have done research. Good brass can be had in 300 WSM and 7 SAUM.

I intend to build a lighter rifle to use for hunting and some long range target work. The hunting would be elk and smaller.

I intend to use ABLR (and Hammer Hunters where laws prohibit bullets with lead) for hunting and probably ELD/ELD-X or Bergers for target.

I’m trying to combine the most velocity with the highest BC bullets in each caliber.

Which caliber and bullet weight would you choose and why?

 

[gnochi]

If you haven’t already, I’d take a good hard look at the Sherman Short line of cartridges. Proprerly headstamped ADG brass is available. 7 SS is basically an optimized 7 SAUM for reasonable COAL and sufficient neck length.

People seem to like pretty much all of the HH options in 7mm. Since you’re saying elk and below 3in COAL I’d be inclined to go with the 155.

 

[Steel head]

I just built a 7SAUM.
ADG brass seems excellent.
My super mild break in loads ran 2800-2850 and hammered a plate at 1125 yar with 180 eldm’s.
I’m hoping to find a nice mild load at high 2800’s with 180’s.
Recoil is impressively mild.

300wsm would have a hard time matching the 7 saum ballistics but I think it’s a wonderful hunting cartridge.

if you want a 7 saum feeding from SA mags and be close to the lands your gonna want a reamer with a shorter freebore than SAMMI.

That said the 180’s I shot with lots of jump seemed to like it.
I’ll know more this week when I shoot for groups and speeds.

 

[Franko]

I am building a 7SAUM right now. I also considered a 6.5 PRC and 300 WSM. I didn't go with the 6.5 because I wanted slightly heavier bullets and didn't go with the WSM due to the extra recoil. I am trying to build a do it all gun and thought that the SAUM was in the sweet spot. Only time will tell if I got it right.

 

[CStroud]

I have a 7SS being built at TS Customs as we speak. 7 SAUM-7SS, I don't think either will disappoint you for what you're wanting to do.

 

[raschiller]

I just built a 7SAUM.
ADG brass seems excellent.
My super mild break in loads ran 2800-2850 and hammered a plate at 1125 yar with 180 eldm’s.
I’m hoping to find a nice mild load at high 2800’s with 180’s.
Recoil is impressively mild.

300wsm would have a hard time matching the 7 saum ballistics but I think it’s a wonderful hunting cartridge.

if you want a 7 saum feeding from SA mags and be close to the lands your gonna want a reamer with a shorter freebore than SAMMI.

That said the 180’s I shot with lots of jump seemed to like it.
I’ll know more this week when I shoot for groups and speeds.

That’s really good velocity, what barrel length are you shooting?

 

[Steel head]

That’s really good velocity, what barrel length are you shooting?

28”

 

[generalzip]

I have a 300WSM with a TL3 and proof barrel. I got it because I wanted a factory ammo option in addition to being able to handload. I think the 7mm bullets are the best hunting bullets out there for North American game. Best balance of recoil, ballistic, accuracy, etc. That said you likely won't see any practical difference between these 2 calibers at realistic hunting ranges other than maybe a little recoil. My 300WSM is very light and with a can the recoil isn't bad at all unless you're a kid or an old man or otherwise not an experienced shooter.

I'd do a 180 Berger for the 7mm. If you go 30 cal and want to handload the 200-215 berger Hybrid is a great option or if you want to reduce recoil look at the 180 elite hunter. They will all kill, but bergers I've found will give you the most consistent accuracy ad the least amount of tuning.

 

[Hollywood 6mm]

between the two, I would say 7 SAUM - but I'd say 6.5 SAUM over either. I ended up building a 6.5 SAUM and I've been really happy with it.

 

[Steel head]

between the two, I would say 7 SAUM - but I'd say 6.5 SAUM over either. I ended up building a 6.5 SAUM and I've been really happy with it.

The reason I went 7mm over 6.5 is bullet splash.
I can already see the difference between 140-150ish bullets and 180’s.

 

[Hollywood 6mm]

The reason I went 7mm over 6.5 is bullet splash.
I can already see the difference between 140-150ish bullets and 180’s.

That's valid, but you also pay for it a bit in recoil. I had no issues seeing splash at a mile with my SAUM launching 147s at 3125, but the recoil on that load was a noticeable increase over my standard 147@3000 load, too.

 

[generalzip]

OP states his intended use is hunting AND LR target work. And talks about using either a carbon proof or a bart barrel. I think it's crucial to understand how much shooting will be done a year for LR target work and whether you want a Carbon barrel or not. If you plan to shoot 95% targets and 5% hunting (which many do as it only takes 1 shot to kill an animal), and you plan to shoot 700-1000 rounds a year for targets that is important. Carbon barrels expensive. Chambered you are looking at near 1000 bucks. I have a proof carbon prefit in 300wsm for the TL3 which is an option. 7SAUM is not in a prefit.

I would not recommend a 7mm mag and proof barrel for anyone planning to shoot more than 400-500 rounds with it a year as you're going to be burning through those expensive barrels unless money is not an issue for you. If you do steel you can buy 2 barts for the price of one proof blank. The 30 cal is going to have much better barrel life. I'd expect 2000-2500 with it. The 7mm mags I wouldn't expect more than maybe 1000-1200 rounds of match level barrel life. Obviously depends how hot you load it.

 

[Steel head]

That's valid, but you also pay for it a bit in recoil. I had no issues seeing splash at a mile with my SAUM launching 147s at 3125, but the recoil on that load was a noticeable increase over my standard 147@3000 load, too.

I sometimes lose sight of shots with my 260 and 147’s at a mile.
My buddy’s 6.5CM ar10 even more so.
Some days you can’t even tell if you hit it.

If you have a nice groomed area it certainly helps but I’m not gonna rake out a hillside up in the mountains where I mostly shoot that distance.

My rifle gained about 9 ounces with my new 7 Saum barrel. With that and the Sidewinder brake recoil is actually less than my 260

 

[raschiller]

Anybody have any idea what velocity I can expect out of a 24” barrel in the 7 SAUM loaded with 175gr ABLRs and temp stable powder (H1000, H4350, H4831)?

 

[CStroud]

Anybody have any idea what velocity I can expect out of a 24” barrel in the 7 SAUM loaded with 175gr ABLRs and temp stable powder (H1000, H4350, H4831)?

https://www.snipershide.com/shooting/threads/7-saum.6252684/

 

[.50 Cal Cow]

My 7saum is a 24” that is throated long to make use of the defiance intermediate length. Using the 168ablr’s/Norma brass/H4831SC/215M primers my highest optimal node is right around 2882fps with 60.9-61.2gr’s.

I started to see some heavy pressure signs when in the mid-2900’s fps.

For relative reference. Was previously shooting the 180 hybrids with same powder/case combination and getting 2830ish fps at the same powder charge. I never really worked that one up to find a max since it was very accurate and decent velocity. So would maybe expect the 175’s to be somewhere around there?

 

[Steel head]

Anybody have any idea what velocity I can expect out of a 24” barrel in the 7 SAUM loaded with 175gr ABLRs and temp stable powder (H1000, H4350, H4831)?

that length should be about 100 FPS slower than my 28” barrel and with 180’s using H1000 and IMR7977 getting to 2950 was easy and I’m confident could get to 3000.

 

[raschiller]

Thanks for all of the input. I’ve recently begun considering 6.5 PRC as well.
I think 142 ABLRs may meet the mark for the game I would use it on.
The benefit is that recoil would be less.
Thoughts?