User Panel
Posted: 6/13/2024 5:32:50 PM EDT
Looking to throw an upper together, and most 12.5s I see are carbine length.
Anyone decent making 12.5 mids? Who are my options. CHF/CL preferred, but I'm open to suggestions. Thanks in advance. |
|
|
[#1]
Criterion
|
|
|
[Last Edit: AccuracyArsenal]
[#2]
|
|
|
[#3]
Faxon makes a 12.5" Mid, it's 4150 QPQ though, not CL.
https://faxonfirearms.com/faxon-duty-series-12-5-gunner-5-56-nato-mid-length-4150-qpq-nitride-ar-15-barrel/ My Faxon barrel shoots pretty decent |
|
|
[#4]
Originally Posted By AccuracyArsenal: Faxon makes a 12.5" Mid, it's 4150 QPQ though, not CL. https://faxonfirearms.com/faxon-duty-series-12-5-gunner-5-56-nato-mid-length-4150-qpq-nitride-ar-15-barrel/ My Faxon barrel shoots pretty decent View Quote I built one of these. No complaints |
|
|
[Last Edit: vanquishings]
[#5]
Originally Posted By Switchback_Arms: Criterion View Quote Sadly, no mids. Originally Posted By PewPewPew1212: I built one of these. No complaints View Quote I'll give it a look, Aero Precision makes a 12.5 mid that's CHF, but just wanted to make sure there wasn't another offering out there that wasn't going under my radar. |
|
|
[#6]
Blackstone Arms has 12.5" ARP barrels with mid gas. It's the only 12.5" I've used and I had no complaints.
|
|
|
[#7]
|
|
“Necessary? Is it necessary for me to drink my own urine? No, but I do it anyway because it’s sterile and I like the taste.” -Patches O’Houlihan
"I don't eff with poorsies." -Mona-Lisa Saperstein |
[#8]
Originally Posted By vanquishings: Looking to throw an upper together, and most 12.5s I see are carbine length. Anyone decent making 12.5 mids? Who are my options. CHF/CL preferred, but I'm open to suggestions. Thanks in advance. View Quote 100% suppressed? Otherwise, what's the point? |
|
|
[#9]
KAK Industry has 12.5" mid-length options.
|
|
Left-handed and right-minded!
|
[#10]
Rosco has a 12.5 proprietary “patrol” length between mid and carbine. Mine shoots pretty nice.
|
|
|
[#11]
Originally Posted By Luny421: https://www.ar15.com/forums/AR-15/12-5-Midlength-barrels/12-783801/ View Quote Ooh, perfect. I've never mastered the search function here, so I'll give this a read. Originally Posted By s4s4u: 100% suppressed? Otherwise, what's the point? View Quote Correct you are. I'd say 95% suppressed, just in case I have the can on something else for a moment. Originally Posted By WrenchGuy: KAK Industry has 12.5" mid-length options. View Quote What's KAK barrel life like? I always kind of associated them with just shitty mil spec LPKs and the weird dust covers. Have they upped their game? Originally Posted By bluedog82: Rosco has a 12.5 proprietary “patrol” length between mid and carbine. Mine shoots pretty nice. View Quote Had a not so great experience with a rosco 6ARC barrel, so probably steering clear of them, for now. |
|
|
[#12]
I like this BRT barrel, has an intermediate gas system. Very soft shooting but may be overgassed for a dedicated suppressor host
https://blackrivertactical.com/WP/BRT-12-5-OPTIMUM-Hammer-Forged-Chrome-Lined-Barrel-p258933205 |
|
|
[Last Edit: WrenchGuy]
[#13]
Originally Posted By vanquishings: What's KAK barrel life like? I always kind of associated them with just shitty mil spec LPKs and the weird dust covers. Have they upped their game? View Quote I can't speak to all of their barrels, but they have used Green Mountain for many if not most of their blanks. Green Mountain make some very good barrels. |
|
Left-handed and right-minded!
|
[Last Edit: SubSonic1836]
[#14]
This probably doesn’t help, but I had my DD 14.5 mid cut down and the gas port opened up to .080, runs great. Over gassed suppressed though. My can is pretty high back pressure though
|
|
|
[#15]
Originally Posted By SubSonic1836: This probably doesn’t help, but I had my DD 14.5 mid cut down and the gas port opened up to .080, runs great. Over gassed suppressed though. My can is pretty high back pressure though View Quote Probably looking like the smartest option, given the choices. Also helpful on the port size. I'll start looking for that info to see what the most common port size is for this set up. |
|
|
[#16]
Triarc if you can find them in stock anywhere.
|
|
Fuck Cancer. Love you Pop.
|
[Last Edit: Joedirt199]
[#17]
Had John Thomas cut down a BCM 14.5" mid and run it suppressed all the time. Added a .060 transfer port restriction inside the front site and it runs awesome with stock carbine spring and H1 buffer. So smooth.
|
|
|
[Last Edit: STJ]
[#18]
|
|
|
[#19]
I shoot my criterion carbine almost 100% suppressed and it's easy to tame/gassed correct enough to still be enjoyable. A buffer/spring upgrade would most likely be all you need if you can get away from the mid-length requirements.
|
|
|
[#20]
I’ve had very good results with my rainier arms mountain barrel. It’s a bit heavy, as expected. I’ve worked up a 50gr vmax load with lt30 powder that can shoot just under moa at 100 yards if I do my part. It tends to like lighter bullets in general. I can hit at 400 yards consistently with it and have made what I consider an acceptable amount of hits at 500 with it. I run 100% suppressed with a superlative bleed off gas block and h2 buffer. It’s as soft shooting as I think is possible
|
|
|
[#21]
Sonics makes a CL 12.5" mid but not CHF. They have standard and reduced gas port sizes.
|
|
|
[Last Edit: spyderboy03]
[#22]
I'm happy with my 12.5" Geissele barrel. There aren't many options for mid-length with CL or CHF. Easy to get both in carbine length. I had a Criterion Core and it was great too. Factory gassing was a bit softer for unsuppressed than the Geissele, but a Turbo K lives on the rifle so I have a Black River .0635 gas tube (.0615 gas port) and it shoots super smooth. It does still function unsuppressed if needed as well. Unless my fundamentals or reloading techniques have improved since swapping from Criterion to Geissele, the Geissele shoots a bit tighter than the Criterion with my main 69gr hpbt load.
|
|
|
[#23]
Originally Posted By Plumber576: Sonics makes a CL 12.5" mid but not CHF. They have standard and reduced gas port sizes. View Quote Last time I corresponded with them, Sionics uses Green Mountain barrels or blanks...very good quality. |
|
Left-handed and right-minded!
|
[#24]
Just because you can doesn't mean you should.
"No 12.5" barrels with midlength gas" In some cultures, this is referred to as a "clue". If you want the look, go get a Kino barrel, otherwise a midlength doesn't belong on everything. |
|
|
[Last Edit: Zerlak]
[#25]
Originally Posted By BSWilson: Just because you can doesn't mean you should. "No 12.5" barrels with midlength gas" In some cultures, this is referred to as a "clue". If you want the look, go get a Kino barrel, otherwise a midlength doesn't belong on everything. View Quote Except it does work great on a 12.5" barrel. The LMT 12.5 midlength setup even has some limited military adoption with the Specwar. Most AR manufacturers are afraid to deviate from the norm. |
|
|
[Last Edit: 1168RGR]
[#26]
Would anybody be willing to show me evidence that on a 12.5” barrel, a midlength gas system is better than a carbine length one, and in what way? Like, an actual comparison that minimizes variables, not “mine shoots great” or, “I heard so and so uses them”.
|
|
|
[#27]
Originally Posted By 1168RGR: Would anybody be willing to show me evidence that on a 12.5” barrel, a midlength gas system is better than a carbine length one, and in what way? Like, an actual comparison that minimizes variables, not “mine shoots great” or, “I heard so and so uses them”. View Quote Why limit it to just 12.5s? Let's do the same with 13.9", 14.5", 16", etc. Can we also do mid-length vs rifle length for 16" & 18"? Why does more than one gas system length exist for a given barrel length? |
|
“Necessary? Is it necessary for me to drink my own urine? No, but I do it anyway because it’s sterile and I like the taste.” -Patches O’Houlihan
"I don't eff with poorsies." -Mona-Lisa Saperstein |
[Last Edit: 1168RGR]
[#28]
Originally Posted By Luny421: Why limit it to just 12.5s? Let's do the same with 13.9", 14.5", 16", etc. Can we also do mid-length vs rifle length for 16" & 18"? Why does more than one gas system length exist for a given barrel length? View Quote I’ve actually been meaning to grab a 12.5” mid barrel myself, specifically for a cyclic rate experiment. Because 14.5” has already been done, and the only other length I shoot a lot is 12.5”. You strike me as a smart dude, so would you mind elaborating on what you’re getting at? |
|
|
[Last Edit: 1168RGR]
[#29]
For those that don’t frequent the silencer forum, here’s copypasta from what I posted in a thread there:
“Generally speaking, when barrel makers are like “look, we put a longer gas system than the previous norm for barrel length on this one to make it more suppressor friendly”, they put a larger gas port with that, too. I’ve chased that unicorn in the past, and found that the longer gas systems actually gave me more drama than the normal ones. Others disagree, so it’s probably just different samples. But Crane found this, too.That’s a 9% change in cyclic rate going from unsuppressed to suppressed with a regular 14.5” M4, carbine gas, and a 19% change in cyclic rate with a 14.5” midlength going from unsuppressed to suppressed. Now, in that test, the middy started with an advantage…the state of tune or whatever factors, caused it to start with a lower cyclic rate. So, a given percentage of a lower cyclic rate is a smaller absolute change, right? Meh, even in terms of raw, unmolested numbers, the delta is 80 vs 144, in favor of carbine gas when switching between unsuppressed and suppressed. The middy also ended in an advantage in cyclic rate. But, given that this was a test to see if it could do better than carbine gas, I suspect that this has to do with the gas port size or buffer weight. Because both starting and ending were lower, but with a drastically wider spread between the two points of suppressed and unsuppressed. Point being, it definitely lost when comparing the delta between unsuppressed and suppressed without modifying the gun between the iterations.” Original Thread |
|
|
[#30]
Originally Posted By Zerlak: Except it does work great on a 12.5" barrel. The LMT 12.5 midlength setup even has some limited military adoption with the Specwar. Most AR manufacturers are afraid to deviate from the norm. View Quote This, the 12.5" is my son's favorite and only went to a full 16" due to the stupid ATF pistol brace rule that just recently got tossed...so he"s going back to the 12.5, and I'll likely build an upper too. It works fine, really well actually, if it doesn't then the barrel has the wrong gas port size, pretty simple. |
|
Left-handed and right-minded!
|
[Last Edit: Luny421]
[#31]
Originally Posted By 1168RGR: Single (two, really, because gas ports should not be the same) variable, and because the thread is about 12.5”s. But for 14.5”, I’ll refer you to the thread in the silencer forum asking about the Roscoe 12.5”. I’ve actually been meaning to grab a 12.5” mid barrel myself, specifically for a cyclic rate experiment. Because 14.5” has already been done, and the only other length I shoot a lot is 12.5”. You strike me as a smart dude, so would you mind elaborating on what you’re getting at? View Quote View All Quotes View All Quotes Originally Posted By 1168RGR: Originally Posted By Luny421: Why limit it to just 12.5s? Let's do the same with 13.9", 14.5", 16", etc. Can we also do mid-length vs rifle length for 16" & 18"? Why does more than one gas system length exist for a given barrel length? I’ve actually been meaning to grab a 12.5” mid barrel myself, specifically for a cyclic rate experiment. Because 14.5” has already been done, and the only other length I shoot a lot is 12.5”. You strike me as a smart dude, so would you mind elaborating on what you’re getting at? I think the only thing I was getting at is that you can extrapolate data from other barrel lengths, to a degree. And also, “better” is subjective. Considering that 12.5” mid-length is relatively new and niche, I doubt you’re going to find any testing as exhaustive as what you posted for the 14.5”. Perhaps Crane has compared the two, but who knows. If they have, is it publicly available? Will 12.5M have a lower cyclic rate than 12.5C? Yep, I’d take that bet. By how much? I have no clue. Will 12.5M have less perceived recoil than 12.5C (and as a side effect put less strain on operating parts)? All else (including port size) being equal, again, I’ll take that bet. But whether any of that is better or worse is subjective and user dependent. I don’t know if there’s enough data to prove “better”, but it can prove “different”. I could be 100% wrong about everything posted above, and remember, my opinions are worth what you paid for them. |
|
“Necessary? Is it necessary for me to drink my own urine? No, but I do it anyway because it’s sterile and I like the taste.” -Patches O’Houlihan
"I don't eff with poorsies." -Mona-Lisa Saperstein |
[Last Edit: 1168RGR]
[#32]
Originally Posted By Luny421: I think the only thing I was getting at is that you can extrapolate data from other barrel lengths, to a degree. And also, “better” is subjective. Considering that 12.5” mid-length is relatively new and niche, I doubt you’re going to find any testing as exhaustive as what you posted for the 14.5”. Perhaps Crane has compared the two, but who knows. If they have, is it publicly available? Will 12.5M have a lower cyclic rate than 12.5C? Yep, I’d take that bet. By how much? I have no clue. Will 12.5M have less perceived recoil than 12.5C (and as a side effect put less strain on operating parts)? All else (including port size) being equal, again, I’ll take that bet. But whether any of that is better or worse is subjective and user dependent. I don’t know if there’s enough data to prove “better”, but it can prove “different”. I could be 100% wrong about everything posted above, and remember, my opinions are worth what you paid for them. View Quote Now, if we switch to drill bits more appropriate for the different systems, lets say we go to .070” for the carbine gas barrel. Wanna say BCM does that. Maybe a bit much with a silencer, but not too crazy without one. Wouldn’t be my choice but it would work. A .078” mid (Triarc) would almost certainly have a lower cyclic rate, and I think your bet would be a safe one. But, a .085” (Noveske)? Maybe. How about a .09-something (IWI)? I think in that case the mid would have the higher cyclic rate. Gas system length does not solely dictate cyclic rate, or the user’s perception of overgassed, or reliable, or whatever. At least with reasonable gas system lengths. Think of it like multiplication…2*X is not always smaller than 4*Y. You have to consider what X and Y are. But the Crane study implies that the shorter system may be more forgiving. If you’d like, I can PM you my plan for testing that hypothesis with 12.5” guns, but I don’t want to clutter up this thread much more than I already have. |
|
|
[#33]
Not sure exactly where all this discussion has led but I've been thoroughly happy with my Porter's Basement/Sionics 12.5" midlength 50/50 upper. It was developed for shooting both suppressed and unsuppressed; I've done both. It is a .078 gas port which is quite a bit smaller than the Faxon, which is somewhere near .087 I believe? I've heard they are quite punchy, but haven't experienced it myself. For reference, I also had a Hodge .064 12.5 carbine barrel and much prefer the Sionics middy I have now. I will say they don't advertise it on their main site; it is through another party since it is a special project barrel.
|
|
|
[#34]
I only have anecdotal information, but I just shot my KAK 12.5” mid barreled upper this past weekend and I was pleased with how it shot from an impulse perspective (I didn’t accuracy test it due to time and weather issues). It was reliable both suppressed and unsuppressed and felt very soft shooting.
|
|
-"The truth does not require your belief in it to function."
-Genuine science is about gathering evidence and testing the veracity of theories, not cheerleading for a particular ideology. |
[#35]
I bought my Triarc years ago and it's been really accurate. Not sure if they are still around or how their quality is now.
|
|
Does Somebody Need A Hug?
|
[#36]
12.5 is too short for a reliable mid gas position. Just get a carbine gas.
|
|
|
[Last Edit: PistoleroJesse]
[#37]
|
|
|
[#38]
Socom did go to mid gas with the urgi. I think the lower cyclic rate is more ideal/ more quiet, and more reliable. The stack of more cyclic % increase is an interesting statistic. The 12.5 mid gas barrel seems to have a lower percentage of cyclic increase than a longer mid gas barrel. I guess seeing that same data I read mid gas still works better, but adjustable gas would be nice / superior to have. |
|
Austin, Managing Partner - www.GriffinArmament.com
|
[#39]
I have a TriArc 12.5” midlength barrel for a dedicated suppressed setup. Others here have stated the gas port on that barrel is .078”. I had quite a time taming the gas on that rifle but I am using a gassy Saker 556 ASR. I put a Superlative Arms AGB on it and was still over gassed with no further adjustments available in “bleed off mode”. H Buffer and Tubbs flatware spring in use with standard M16 BCG. I placed a BRT EZ tune tube on it with .070”, this allowed me to use the AGB in bleed off mode to dial in the pressures using PPU/Winchester/Frontier M193.
10 shot group stats at 100yds: 1.25 MOA - AAC 77gr OTM 2.40 MOA - Frontier M193 2.75 MOA - Winchester M193 Frontier was far more consistent with 2 shots that opened up that MOA measurement. |
|
|
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.