Popularity of the 12.5" carbine-gas SBR?

[jerrysimons]

It seems the 12.5" carbine gas SBR is getting more popularity lately. I am curious if anyone else thinks so and can tell me what is driving it? I have come across statements here and there that intimate "hush, hush" groups have chosen that configuration but you know how that tune goes in this industry

I am currently deciding on the old 12.5" vs 11.5" barrel debate (Hodge Defense 11.5" or 10.75" rail in either case) for a bomb-proof SBR build that I imagine as a handy, general purpose set-up that favors maneuverability majority suppressed with either KAC QDC/QDC-CQB or DeadAir Sandman S silencers. This will also be my go-to night vision rig for hog hunting and training as I acquire those assets (NVD helmet rig and rail IR laser/illuminator set-up). Optic will be Aimpoint T2 with Aimpoint's new long-eye relief flip-to-side, twist-off magnifier. Based on the perceived trend stated above I am kinda leaning 12.5" and because it has more dwell time and muzzle velocity. But at the expense of weight and length I question why not go with 11.5"? Do I need the extra rail space a 12.5" offers for IR laser/illuminator set-up? Will 50fps-ish muzzle velocity be missed? I know I will appreciate shorter and lighter.

Why, seemingly, have you and/or friends chosen the 12.5" carbine-gas SBR?

Thanks

[drtywk]

I have both 11.5" and 12.5" SBR's and both are exceptional. The 12.5" is my go-to GP carbine for everything: training, home defense, varmint hunting, etc. Velocity loss is minimal compared to a 14.5" carbine, it suppresses really well with a K type can, and can be run from stinky breath range out to 400+ yards if need be. It handles extremely well and is not finicky when it comes to ammo.

Mine is configured as follows:

Hodge Defense Upper
Hodge Defense 11.5" rail
Hodge Defense LowPro Gas Block
Centurion Arms 12.5" barrel
Sionics NP3 BCG
Geissele Ambi Charging Handle
SiCo/BE Meyers 249 ASR Flash Hider
PEQ15
Surefire M300
Trijicon MRO
Hodge Defense MRO Mount
SiCo Saker K w/ASR Mount

BCM Lower with BCM A5RE and A5H3 buffer
SierraTac Sling


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[Jwknutson17]

I have both 11.5" and 12.5" SBR's and both are exceptional. The 12.5" is my go-to GP carbine for everything: training, home defense, varmint hunting, etc. Velocity loss is minimal compared to a 14.5" carbine, it suppresses really well with a K type can, and can be run from stinky breath range out to 400+ yards if need be. It handles extremely well and is not finicky when it comes to ammo.

I'm going to second these thoughts.

They are just a excellent mix of everything. They are handy yet still effective at further distances. Especially with a LPV optic. It really is the best host for a mini suppressor IMO.

I think most folks don't go for 12.5 because... they already own a 14.5 pinned rifle, or 16" rifle, and wanted to get into a SBR. So they get a MK18 with a suppressor or an 11.5. They aren't looking for a one rifle "do all" build. That's my best guess..

If you could only have one, the 12.5 is it.

[markm]

I find no significant gains in the various SBR lengths. To me it's ENTIRELY about correctly porting the barrel. The reduces port Sionics barrel is simply perfect... and the best, by far, barrel you can buy and run "out of the box".

12.5 feels so long to me after running 10.5 and 11.5.... especially if you add the length of a can. I guess it's just preference.... 12.5 isn't a bad G.P. length at all. I just have a bunch of 14.5 and 10/11.5 already.

[Jwknutson17]

To explain a little further on my post... if you do not have a 11.5 I would go that route for a SBR first. Especially if you already have a 14.5. The 11.5 is my favorite SBR length. If you trying to have ONE rifle that fills that 11.5 to 16 role. IMO the 12.5 with a Mini is the ticket. If you have 14.5/16 rifles already, I think you will be more pleased with the 11.5 this go around.

Like Mark says, the port size is really a deal breaker on some of these SBR barrels. The RGP Sionics is a good barrel and I have 2 currently. Un-suppressed it's really a great shooter. For suppressed I still prefer a smaller port. As Gunz stated this barrel was specific for a LE agency to what they requested.

A chopped 12.5 Centurion C4 barrel down to 11.5 with the .065 gas port, that would be my first choice in an 11.5 build right now. Chopped my Mr Marvin Pitts of course.

[BoringGuy45]

I went with a 12.5 for my first SBR. I filed the Form 1 last July, so I'm hoping to have my approval by end of March. drtywk, where did you find a Hodge 10.75" rail? I can't find it anywhere, and it's on neither the Hodge or the Mega Arms sites. Are they still being made?

[jstalford]

Chopped my Mr Marvin Pitts of course.

Well if he's gonna chop it, might as well dimple too.

[RobertTheTexan]

I would second JW's comment on running the 12.5 with an LPV optic. I have a 12.0 LaRue barreled SBR wth a 1-4 Viper. I can shoot well at 1x with it and 400 yds shots are easily doable if you do your part. It has an AAC 51T Brakeout on it for an AAC 762 SDN-6 can and a LaRue 11" quad rail. (What can I say I'm old school?) I have a 10.3 that is a dedicated unsuppressed CQ AR, also a nice shooting weapon. However, recently I built a very outstanding 11.5 and I LOVE shooting that AR. More so than my 12" which I never thought I would say. Right now it has an EOTech EXPS3-0, but it's very likely to find a Comp4S on it soon or at least a AP PRO. I have not taken the 11.5 out to 400, but as far as grabbing a gun and being able to deal out some accurate lead, my 11.5 is my new go-to. It's lighter than my 10.3 namely because it has a KAC URX 4 rail and not a LaRue quad, and it doesn't have a Redi-Mag like my 10.3 and 12 both have. I don't think I will put one on it either.(the 11.5) so if this your first venture into short barrels, I'd say go 11.5 first, equip it for CQ and use it to train up your skills. Then later on if you feed the need step up in barrel length an inch (or .5") via a new barrel or a cut down as a couple have suggested. Slap an LPV on there and then you still have a CQ worthy weapon, but also one that can serve out similar to a Recce although the barrel most would say is too short for that, but it's a really good gap filler betwix the non-NFA and your 11.5 shorty.
Since you mentioned specifically 12.5, I do have an ol beater 12.5 in my vehicle, but it's nothing but that just in case scenario.


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[Vegas]

I just picked up a Noveske 12.5 midlength barrel. I have a 10.5 upper with an Aimpoint and wanted to try the 12.5 with a 1-6 for a bit more distance. I'm curious about midlength with this barrel length and running it with my A5H3 kitted lower.

[Jwknutson17]

I just picked up a Noveske 12.5 midlength barrel. I have a 10.5 upper with an Aimpoint and wanted to try the 12.5 with a 1-6 for a bit more distance. I'm curious about midlength with this barrel length and running it with my A5H3 kitted lower.

Depends on the port size of the barrel. If it's noveske, your going to be fine with that H3. I have chopped down 12.9/13.0 DD middy barrels with .076 ports. They still run an a5h4 if I put one in there. My Noveske 13.7 is also very gassy.

I'm going to say you will have no issue with a A5H3 and colt spring in that rifle. All pending the quality of ammo you use of course.