Which SBR caliber and barrel length in a straight wall state?

[Eship]

So I live in a state that has mixed regs regarding cartridges. Some counties have no restrictions while others allow straight wall. I already have a 16” 350 legend, but will likely get another straight wall gun so that when my wife and I both hunt, we can both be using a suppressed straight wall instead of one of us using a shotgun. With that in mind, I really like AR platforms (I am aware that straight wall cartridges can be finicky in ARs) and will likely just build another AR upper since I have two lowers already, including one that is already SBRd.

I’ll likely stick with 350 legend just for the ease of having less calibers, although I do have an omega 36m and hybrid 46m, so I could suppress up to 450 bushmaster.

I like the idea of a short rifle for hunting from a saddle, so I’ll probably build a 12.5” 350 since barrels are readily available and just put a red dot on it for a sub 100m gun. Is anyone using a similar set up, and if so, what type of ammo are you shooting and how has it performed on animals that you’ve shot?

 

[Bluefish]

I have a 450bm as we used to be straight wall only for deer. Not a favorite of mine as it’s a thumper on both ends. Built it before the 350l came out. Now we are 35 cal or larger, not limited to straight wall and honestly that doesn’t add much for AR based cartridges. There are 4 that I can think of that are main stream ish, 350L, 450bm, 400L and 41gl. Of those, I would run the 350L. The 400L for me was who wants this?, also a poor rollout with ammo on clearance before rifles were even out. The 450 is just more recoil for what? The 41gl looks to be optimized for bolt action with the ability to run more pressure and longer oal, but I am skeptical that the AR loads are really within the pressure limits of the .473 bolt face. Also limited bullet choices.

If not AR based, then you can look at 375 win, 360 bh, 45-70, 445 sm, 444 Marlin, and more. Not sure any offer much better trajectory than the 350l. Big bore, straight wall simply suffer from slow speeds and low bc by design. Not to say they don’t work, but hard to get long ranges with them.

 

[StupidLightweight]

Years ago, I built an AR pistol in .350 Legend with a 12.5-inch barrel. It was awesome. While I never hunted with the pistol, due to the round's efficiency, there will not be a significant reduction in killing power compared to a 16-inch barrel. You could likely

I lived in a blue state at the time and couldn't own suppressor, so i never shot it suppressed, but I was impressed by the lack of a sharp crack from muzzle blast. With a 9mm suppressor, it would be a darling of a short-range hunting gun.

As far as ammo goes, I would handload lightweight Lehigh Controlled Fracturing bullets. They should work better than the factory loads.

 

[omicron1792]

350 Legend - 150gr T-REX - 20 Rounds - HOP Munitions

350 Legend 150gr T-REX: Superior impact with larger wound cavities for quick knockdowns. Ideal for hunters seeking efficient, powerful performance.

hopmunitions.com

 

[Eship]

I have a 450bm as we used to be straight wall only for deer. Not a favorite of mine as it’s a thumper on both ends. Built it before the 350l came out. Now we are 35 cal or larger, not limited to straight wall and honestly that doesn’t add much for AR based cartridges. There are 4 that I can think of that are main stream ish, 350L, 450bm, 400L and 41gl. Of those, I would run the 350L. The 400L for me was who wants this?, also a poor rollout with ammo on clearance before rifles were even out. The 450 is just more recoil for what? The 41gl looks to be optimized for bolt action with the ability to run more pressure and longer oal, but I am skeptical that the AR loads are really within the pressure limits of the .473 bolt face. Also limited bullet choices.

If not AR based, then you can look at 375 win, 360 bh, 45-70, 445 sm, 444 Marlin, and more. Not sure any offer much better trajectory than the 350l. Big bore, straight wall simply suffer from slow speeds and low bc by design. Not to say they don’t work, but hard to get long ranges with them.

Yeah, that all makes me think 350l is definitely the right cartridge for the job. I don’t need anything crazy. I believe it would still be above 2000fps muzzle velocity for 140-160gr rounds out of the 12.5”, which should be good for 100m and in. With the 16”, I’ve had success out to 150

 

[Eship]

350 Legend - 150gr T-REX - 20 Rounds - HOP Munitions

350 Legend 150gr T-REX: Superior impact with larger wound cavities for quick knockdowns. Ideal for hunters seeking efficient, powerful performance.

hopmunitions.com

That looks really appealing, especially as some of the areas I hunt are NWRs which will likely be moving to copper only in the coming years.

Have you shot it or heard of it being shot out of an AR and know anything regarding how it cycles in them?

It seems like the cycling issues with 350l are a result of a multitude of factors rather than one single thing

 

[omicron1792]

That looks really appealing, especially as some of the areas I hunt are NWRs which will likely be moving to copper only in the coming years.

Have you shot it or heard of it being shot out of an AR and know anything regarding how it cycles in them?

It seems like the cycling issues with 350l are a result of a multitude of factors rather than one single thing

I don’t know that. Buddy hunts in Illinois which requires straight wall and uses Rex. But I’ll ask him.

I’ve used makers in other low velocity rounds and they have always done great.

 

[Bluefish]

Yeah, that all makes me think 350l is definitely the right cartridge for the job. I don’t need anything crazy. I believe it would still be above 2000fps muzzle velocity for 140-160gr rounds out of the 12.5”, which should be good for 100m and in. With the 16”, I’ve had success out to 150

If you are 100 and in, I would run the maker subs. Used the 205’s this year in a 360 bh pistol. Yes, they are .355 in a .358 barrel, but they worked great. Big blood trail and only went 30 feet. Really impressed with how well they work. I have also used the 500g subs in a 45-70, they worked equally well.

 

[Eship]

If you are 100 and in, I would run the maker subs. Used the 205’s this year in a 360 bh pistol. Yes, they are .355 in a .358 barrel, but they worked great. Big blood trail and only went 30 feet. Really impressed with how well they work. I have also used the 500g subs in a 45-70, they worked equally well.

What twist did you have in it? I have a 1/14 in my 16”, and I’ve heard that definitely won’t stabilize the subs. Optimally, I’d like something that is able to accommodate both subs and supers

 

[Bluefish]

What twist did you have in it? I have a 1/14 in my 16”, and I’ve heard that definitely won’t stabilize the subs. Optimally, I’d like something that is able to accommodate both subs and supers

It’s a 1:14. It will do the 205g, but not the heavier ones. Maker says a 1:10 for the 250 and 280’s. Although I think the 250’s will stabilize in a 1:12, but it has not been tested. I plan on testing the 250’s this summer as the 205’s are marginal for my legally. Need to be 500 ftlbs at the muzzle and the 205’s may not make it depending on temp. I have not been able to get 1:10 twist barrels in .358, just 1:12, but based on how the 205’s worked, I have no issues using the 250’s vs a 280.

 

[Eship]

It’s a 1:14. It will do the 205g, but not the heavier ones. Maker says a 1:10 for the 250 and 280’s. Although I think the 250’s will stabilize in a 1:12, but it has not been tested. I plan on testing the 250’s this summer as the 205’s are marginal for my legally. Need to be 500 ftlbs at the muzzle and the 205’s may not make it depending on temp. I have not been able to get 1:10 twist barrels in .358, just 1:12, but based on how the 205’s worked, I have no issues using the 250’s vs a 280.

I didn’t think about the muzzle energy requirements. Maryland requires 1200ftlbs for a rifle/shotgun and 700ftlbs for a handgun. Even in a handgun, most 350 legend subsonic loads wouldn’t meet the minimum restrictions. I guess I’ll be sticking with supers for now.