First SBR and a question

[pacecars]

I just bought a Sig PM400 Elite 300 Blackout pistol with the intention of doing an SBR with it. I also bought a nice lower the other day and got to thinking if I should do the SBR on it instead? Or does it really matter?

[dtom29]

Doesn't matter. Send in a form one on both lowers. You'll be getting another anyway...

[Joker31D]

Thats a real open ended question, I'd say it depends on your use, I recently started sending one in each month for the next few months because I have a use for them, I have wounded vets using them that I hunt with who have a hard time holding up a long barrel, especially with a can on it. If your like most people, you just use them for targets and plinking, then I'd say you need to see if your budget allows for it, I usually try to talk my friends out of SBR's because there is very little on the practical upside of having one, you lose some velocity, sometimes you lose reliability (Less nowadays), some more expense, noise, theres added danger of your hand slipping in front of the muzzle and if you shoot with a can, the life of your Suppressor may be shortened. long story short...too late, You have to weigh the Pro's and Cons yourself. I'd say one AR pattern is most likely enough for most people.

[hardcase]

I would say it depends on the caliber. Most folks with 300 AAC Blackout are very happy with their SBR. My suppressor has a barrel limit of 9 inches. Anything shorter and damage to the suppressor is possible.

As a general rule of thumb with the 300 BO you lose about 25 fps for each inch shorter than 16 inches. If you reload you can still easily get in excess of 2,000 fps with a 125 gr bullet making it a suitable deer rifle with modern expanding bullets at 100 yards or less. Even if you don't reload you can get suitable ammo. DoubleTap sells loaded ammo with the Barnes 110 gr TTSX lead free bullet advertised at 2,250 fps with a 16 inch barrel.

I don't own a 5.56 SBR but from what I've read this caliber does not work well in SBR mode.

[Bendersquint]

I don't own a 5.56 SBR but from what I've read this caliber does not work well in SBR mode.

All of mine run like raped apes. Never had an issue with a 5.56 SBR

[cyclone72]

I don't own a 5.56 SBR but from what I've read this caliber does not work well in SBR mode.

All of mine run like raped apes. Never had an issue with a 5.56 SBR

THIS ^^^

In a bit, I will have an SBR'd 5.56 as well as 300BO and .22 and I think that if you have the right lengthened barrel they will work fine.

For a 5.56 I went with a 10'' barrel
For the 300 BO I went with 9.5 and for the .22 I went with 4.5 inches. I think I will be ok. Any shorter than I imagine I might run into issues.

[Bendersquint]

I don't own a 5.56 SBR but from what I've read this caliber does not work well in SBR mode.

All of mine run like raped apes. Never had an issue with a 5.56 SBR

THIS ^^^

In a bit, I will have an SBR'd 5.56 as well as 300BO and .22 and I think that if you have the right lengthened barrel they will work fine.

For a 5.56 I went with a 10'' barrel
For the 300 BO I went with 9.5 and for the .22 I went with 4.5 inches. I think I will be ok. Any shorter than I imagine I might run into issues.

My 7" AR15 was perfect till I decided to convert it to a 22lr barrel. Probably shot close to 4K through the 7" with only one operator induced jam.

[cyclone72]

My 7" AR15 was perfect till I decided to convert it to a 22lr barrel. Probably shot close to 4K through the 7" with only one operator induced jam.

Damn! 7 inches is ideal for me but I'm gonna stay with 10 for now. What kind of gas system did you have with it. I went with 10 cause I think it was ideally a safe length but if 7 works than I may have to think about that. That's also why I sbr'd 3 different lowers in 3 different calibers. So I can tweak them to work with the caliber they are. I thought it might be cheaper to have one lower and three different caliber/length uppers but I thought I might run into cycling issues or other issues.

[Bendersquint]

My 7" AR15 was perfect till I decided to convert it to a 22lr barrel. Probably shot close to 4K through the 7" with only one operator induced jam.

Damn! 7 inches is ideal for me but I'm gonna stay with 10 for now. What kind of gas system did you have with it. I went with 10 cause I think it was ideally a safe length but if 7 works than I may have to think about that. That's also why I sbr'd 3 different lowers in 3 different calibers. So I can tweak them to work with the caliber they are. I thought it might be cheaper to have one lower and three different caliber/length uppers but I thought I might run into cycling issues or other issues.

Pistol length gas system, straight gas block no special adjustables or anything.

[cyclone72]

My 7" AR15 was perfect till I decided to convert it to a 22lr barrel. Probably shot close to 4K through the 7" with only one operator induced jam.

Damn! 7 inches is ideal for me but I'm gonna stay with 10 for now. What kind of gas system did you have with it. I went with 10 cause I think it was ideally a safe length but if 7 works than I may have to think about that. That's also why I sbr'd 3 different lowers in 3 different calibers. So I can tweak them to work with the caliber they are. I thought it might be cheaper to have one lower and three different caliber/length uppers but I thought I might run into cycling issues or other issues.

Pistol length gas system, straight gas block no special adjustables or anything.

Cool, thanks!