11.5" Carbine Barrels

[GOST]

I've noticed that some companies have quit making 11.5" carbine barrels while others don't make carbine barrels shorter than 11.5". A local Gunsmith advised that my new upper that I'm building be a 11.5" rather than a 10.5" due to reliability. Do 10.5" barreled uppers have that much of issue with reliability? I have been considering using a 11.5" barrel with an 10.75" URX 3.1.

[Hmac]

Dwell time is an important consideration in having a reliable gas system. An 11.5 with carbine length gas system has a 40% longer dwell time than a 10.5 according to Paul Buffoni at BCM. I have a couple of BCM BFH barrels in 11.5. They have .073 gas ports and Bravo Company recommends an H buffer, but they cycle most lots of PMC Bronze just fine with an H2 buffer and full-auto BCG.

[KevinBLC]

Dwell time? Is that how long the gas is in the gas tube? Sorry for the newbie question. Still learning here.

[GOST]

Thanks HMAC this is my first venture with a SBR.

[Hmac]

I have no experience with 10.5s, but can attest that my 11.5 inch barrels run very well. I should specify that I don't run a suppressor on any rifle. That makes a difference as it changes the pressure profile.

[tact]

10.5s are perfectly fine and have been ran in special units for quite a few years.....no problems with my DI 10.5 or. 7.5 piston.....having the right size gas port is essential though.

[Hmac]

10.5s are perfectly fine and have been ran in special units for quite a few years.....no problems with my DI 10.5 or. 7.5 piston.....having the right size gas port is essential though.

Yup. No doubt. I'd have no worries running a 10.5 built by a reputable firearms mfgr or skilled armorer. Noveske makes a 10.5 that is tuned to perfection, I hear. The OP is building his SBR. What size gas port should he be drilling in his 10.5?

[tact]

Yup. No doubt. I'd have no worries running a 10.5 built by a reputable firearms mfgr or skilled armorer. Noveske makes a 10.5 that is tuned to perfection, I hear. The OP is building his SBR. What size gas port should he be drilling in his 10.5?

It all depends on the manufacturer as some are more gassed than others, but there is plenty of data out there now for most flavors.

[GOST]

It's between a 10.5" and a 11.5". If I do a 10.5" the barrel will be a Noveske. I haven't decided on a barrel if I were to do a 11.5".

[MoxyDave]

Keep in mind there is a shit-ton of blast (technical term) from a 10.5" barrel. The manual for my Gemtech 5.56 suppressor says the warranty is borked if used on a barrel less than 12". Just something to consider.

[FortTom]

Keep in mind there is a shit-ton of blast (technical term) from a 10.5" barrel. The manual for my Gemtech 5.56 suppressor says the warranty is borked if used on a barrel less than 12". Just something to consider.

Ha..Ha...ha.. MD, I experienced this about two weeks ago. Me and a bud went to the range and took several rifles with us. I shot his SBR piston pistol, and not only did I have a hell of a time controlling it, rapid fire, but the muzzle blast was something to behold. Something I was fairly familiar with from my days of handgun hunting, and working up loads at the bench, but this one caught me off guard. Now I know the proper unit of measure for this is "Shit-tons".

FT

[tact]

Keep in mind there is a shit-ton of blast (technical term) from a 10.5" barrel. The manual for my Gemtech 5.56 suppressor says the warranty is borked if used on a barrel less than 12". Just something to consider.

There are better suppressors that will handle a 7" barrel just fine.

[KevinBLC]

There are better suppressors that will handle a 7" barrel just fine.

Which ones? And will the warranty cover it?

[tact]

Which ones? And will the warranty cover it?

Yes I have the email with direct response from Silencerco rep on Saker series. They use a material 30% stronger than the regular Inconel.

[GOST]

Is the blast much different between a 10.5" and a 11.5"?