Could the 358 SOCOM (358-458 SOCOM) be of any use? The 458 SOCOM has 61.6 grains capacity so a necked down version would be about the same as the 358 Win.
Yes, there is the 358 WSSM but the 470 rim of the SOCOM makes things interesting. Should push 220's and 250's at decent velocities to be a viable 300 yard 358 for AR 15's and micro actions.
Seems to me that with the hornady 180's it would be close to the 308 in power at lower preasures.
Should be just a barrel swap for a 458 SOCOM right?

Bolt thrust will increase when you neck the case down. The bolt thrust is already maxed out on the 458 SOCOM. You might be able to get a .473 boltface superbolt upper from Olympic and make it work, but the entire upper is proprietary. Bolt, carrier, upper, barrel extension and barrel are all nonstandard.

Will the bolt thrust be less because of the lighter bullets? The preasure for the case is limited to 35K PSI

I'd like a little more info too. I was unaware that necking down would increase bolt thrust. But then, I'm unaware of a lot of stuff.

quote:

Originally posted by Ralfboy:
Bolt thrust will increase when you neck the case down. The bolt thrust is already maxed out on the 458 SOCOM. You might be able to get a .473 boltface superbolt upper from Olympic and make it work, but the entire upper is proprietary. Bolt, carrier, upper, barrel extension and barrel are all nonstandard.

No sir -- bolt thrust is PSI*surface area .. 17 to 600 caliber, the same case, at the same pressure, has the same bolt thrust .. a 22x308 has the same bolt thrust as a 375-06, at the same pressure.

DURATION can change, max doesn't.

9x39 russian is the same thing,, close enouhg,,, been around forever

quote:

I'd like a little more info too. I was unaware that necking down would increase bolt thrust. But then, I'm unaware of a lot of stuff

+1

Thanks for the input
the 9x39 is a pretty cool round and this would be a "Magnum" version with a .1" fatter casehead. Assuming a 35K PSI I was thinking this would push regular weight 358 rifle bullets inside their functional impact velocities and the lighter 35 Rem bullets plenty fast. I read that the 358 SOCOM uses regular 223 mags but will max out at 10 rounds just like the 458 SOCOM but that is a lot of heavy lead out to 300 yards in a small package. The 458 SOCOM seems to be best with the 300 grain bullets at about 2,000 fps and that is about the max weight for 35 bullets. This idea I think would fall between the 358 Win and the 35 Rem and that is plenty cool IMHO. I was thinking the 200 grain bullets @ 2400 to 2500 would be an ideal goal for this concept and that would make a good large thin skinned game round. If you need more than 10 rounds for a moose there are other problems

Ramrod... Do you have quickload?
Or can anyone tell me what a 200 grain bullet with 59 grains capacity will do?
Thanks!

I never did this b4:

quote:

Ramrod... Do you have quickload?
Or can anyone tell me what a 200 grain bullet with 59 grains capacity will do?
Thanks

Don't I wish. I got a free copy of Loadtech when I gave them permission to include my PDK series in their database. It isn't wildcatter friendly by any means. Maybe Mrs. Santa will bring me Quickload if I treat her real nice.

Thanks Ramrod!
So at 30.6K PSI we get 200 @ 2150
what happens at 35K PSI?

35k

Thanks Rich!
Question...
if the 35 Rem is 37K PSI and this case is larger how come this so far is getting marginal 35 rem velocity in theory?
Could it be the powder?
The 358 Gremlin does 200 @ 2300 and that is a much smaler case but 40K psi

Could be the vagaries of the program, too. When you're working up for the AR platform you have to consider the pressure at the port first. That will limit powder choices and ultimately velocity.

Looks to me like you're trading a little sectional density gain for a lot of velocity loss, bullet weight being equal. That would make sense with the smaller piston area and the limited pressure. Plus, frontal area has it's own pluses. So far I don't see a big advantage.

Tigertate...
This makes me wonder if the 6.8 SPC case necked up to 375 is the best way to put a lot of heavy lead down range fast.

It seems to me with the smaller cases, pressure is everything. You usally can't get enough slower powder in the case to get more velocity with less pressure.

Rich

The 45-70 case has the potential for good capacity due to it's internal dimensions. The 45-70 has more capacity than the 450 marlin.
maybe a rimless 1.7" 45-70 necked to 375 with 375 Win bullets is the way to go. 225 to 250 grain bullets @ 2,200 to 2,300 in a case that can go up to 40K PSI

Think of it as a rimless 38-56 improved with a short neck

I think the only .458 SOCOM based wildcat was the .475 Tremor, which was a one off. Marty explained to me some years back that trying to go any smaller than .458 wouldn't work all that well.

I'd kill for a .375 SOCOM

quote:

Originally posted by Collins:
I'd kill for a .375 SOCOM

Collins...

What do you think of the 375 on a 1.7" rimless 45-70 case? Should have the same capacity as the 458 SOCOM

Maybe use the 284 Win case and the 375 improved reamer to the right depth.

shoot 200 to 300 grainers

I think the 225 grain 375 bullet would be best @ 2300 to 2400 FPS

keep the same rim and capacity for similar weight and velocity at the same preasure.

The 260 grain accubonds would be interesting

I believe that there was a 44 version of the Socom. 44 Thermopylae, but nothing happened perhaps beyond discussion.

I think the 375 would be great, as long as you had enough magazine length to handle long bullets. Might have to work on something like this, this Winter.

quote:

Originally posted by Rockrat:
I believe that there was a 44 version of the Socom. 44 Thermopylae, but nothing happened perhaps beyond discussion.

I think the 375 would be great, as long as you had enough magazine length to handle long bullets. Might have to work on something like this, this Winter.

The 375 bullets could be the 375 Win bullets that are in the 200 to 250 grain weights and lower functional impact velocities.

It would be good to have the neck in such a way as to hold on to the longer heavier ones too.

quote:

Originally posted by Rockrat:
I believe that there was a 44 version of the Socom. 44 Thermopylae, but nothing happened perhaps beyond discussion.

I think the 375 would be great, as long as you had enough magazine length to handle long bullets. Might have to work on something like this, this Winter.

Several years ago I helped Marty get this started by pitching in on the first batch of brass from Starline, still have most of it. A few years ago I built a 44 SOCOM I called the 44 Fat Boy by rebarreling a Savage 110, I'm still playing with this project and I'd have to look at my notes to get ballistic info. I had Hornady build some dies a while back for it. I did loan the reamer to a guy that built one on an AR15 and said it ran like a champ and was the pooky for wild hogs.

Interesting to note is that if you neck the 450 Bushmaster to 35 you would have the same capacity as the 35 Rem so you would have a plethera of load work already done and at preasures workable in AR15 guns.
450 Bushmaster 55 grains
35 Rem 51 grains
350 Bushmaster?

quote:

Originally posted by boom stick:
Interesting to note is that if you neck the 450 Bushmaster to 35 you would have the same capacity as the 35 Rem so you would have a plethera of load work already done and at preasures workable in AR15 guns.
450 Bushmaster 55 grains
35 Rem 51 grains
350 Bushmaster?

For that matter, necking the 7.62 x 39 to 35 caliber can equal the 35 Remington with 180 and 200 grain bullets, too. Someone used to do Ruger mini 30 conversions like that. I think Ross Seyfried was the first to write about it.

quote:

Originally posted by tiggertate:

quote:

Originally posted by boom stick:
Interesting to note is that if you neck the 450 Bushmaster to 35 you would have the same capacity as the 35 Rem so you would have a plethera of load work already done and at preasures workable in AR15 guns.
450 Bushmaster 55 grains
35 Rem 51 grains
350 Bushmaster?

For that matter, necking the 7.62 x 39 to 35 caliber can equal the 35 Remington with 180 and 200 grain bullets, too. Someone used to do Ruger mini 30 conversions like that. I think Ross Seyfried was the first to write about it.

The capacity is less so that means higher preasures but yes doable like the 358 Gremlin. I posted an article on the mini 30 conversions on the 35 Gremlin thread.

The capacity of the 7.62x39 necked up would be about 37 grains so the 14 grain capacity increase of a 358 Bushmaster can mean higher performance or lower preasure obviously but I think having the same capacity makes load development a snap!
200 grains @ 2300 and 220 grains @ 2200 at modest preasures in an ar15 would be a sweet spot.

Yes, I think the 358 x 39 would need a bolt gun to reach the same peak. In fact, my dimming memory thinks there were some issues with the Mini 35 craking bolts or receivers. Maybe not.

quote:

Originally posted by tiggertate:
Yes, I think the 358 x 39 would need a bolt gun to reach the same peak. In fact, my dimming memory thinks there were some issues with the Mini 35 craking bolts or receivers. Maybe not.

That would be the beauty of the 358 bushmaster
form from Bushmaster brass or 284 Win brass

I think the 358 Norma reamer could be used to make the short 35