Looking at picking up a 10-12oz 556 thread-on can to dedicate to a build. SIG, Gemtech, Griffin, whoever, doesn’t matter.
Currently have a DD 12.5 Gov, very happy with accuracy but I know it’s overgassed. Planning on SLR gas block on the new build so I guess I don’t really care about that. But if I’m semi-perm attaching a can, I’d like to end up right at 16" overall, kicking around 11.5" barrels. I probably would not consider shorter than 11.5 as a 10" rail is about as short as I want to go. I’ve taken my 12.5" to 600y and would like to have my new barrel be able to do the same.
BCM 11.5 standard
BCM 11.5 BHF
BCM ELW tapered (.625 port iirc)
Other 11.5?
Does anyone have a 11.5" tapered profile with a .750 diameter at the port?
The thing about this question is that usually people will say “oh but the LW barrels will never work for suppressed!!!” It’s these people that I think have never seen a gov profile barrel where it’s stupidly thin where you don’t want it to be and thick where you also kind of don’t need it to be. Please keep in mind I’m using the lightest cans available. I would think the whip/stringing/distortion of my DD 12.5 + Socom 556-RC would be more or at least equal to a BCM ELW + 11oz can but I don’t really know. So, thoughts?
Is the BCM LW/ELW tapered barrel as thick or thicker at towards the muzzle compared to the Gov?
I think you’re good with the ELW. POI shift w/ my 11.5 ELW-F and a full size 762 RC is minimal and performs great for me with an A5H3+Sprinco green. Have you thought about an ALG or DD MFR tube rail and the first 1/2 inch of the can tucked under the rail? I’ve heard very good things about the Gemtech Trek. I think Silencerco has a direct thread on can as well. Harvester?
the ELW and LW profiles are the exact same circumference before the MD. My eyes must be deceiving me, looks like the ELW has a much more pronounced taper after the GB, but the string does not lie! I measured exactly 2" circumference on both barrels. If you need pics or anything else, let me know. I’ve got a set of calipers somewhere…
Good to know on the 762-RC and minimal shift. I don’t want the can under the rail for a variety of reasons, not least of all is I don’t like large 1.5+ ID tubes, just don’t like the feel.
Gemtech is still in the running, but honestly I’m hoping the SIG turns out to be the winner, great price, and should be a great performer for a dedicated can (expect it to be like AAC where suppression is good at the expense of blowback, thus the dedicated gas system). The havester is an aluminum tube, and long. I’m no door kicker, but I also don’t want to ever have to think about durability. Esp with the can being semi-perm… My 556-RC looks like crap because it lives on the gun, I don’t want to ever even have it cross my mind.
I’m thinking if for no other reason than Goverment profile is kinda dumb, that the BCM ELW should be fine… Of course BCM can’t be bothered to make the product can take my money (of course), so I guess I’ll wait.
you want the elw bfh too huh? just get the bfh LW and be done with it lol. I have not assembled any BCM barrel with a low profile GB or had a reason to remove the GB.
on both the LW and ELW’s i have on hand, they both have 2 set screws on the bottom. both of them have 1 set screw (closer to the chamber) that is set much deeper than the other. my guess is that there is only 1 dimple. the elw has 0 step up/stop behind the GB (chamber side).
i keep seeing pictures of direct thread socoms, might be a good option for you. i bet they are the “gen2” design as well. i like where youre going with this project. every time i pick up the incredibly light weight 11.5 kmr elw-f, i cry a little inside knowing the surefire brake weights 3x the hand guard.
with a direct thread on can you should be able to get a slightly shorter barrel to rail ratio with maybe the last 1 or 2 threads protruding past the hand guard if it’s like the sig or socom’s with a wrench flats.
i think the govt profile would make barrel whip worse, looking at pictures comparatively, i just cant see how the govt would give you any advantage. a 10.3 with 762RC is shorter than a 16" w/ surefire muzzle brake. like almost an inch. i dont think it should be too hard to build an upper that is right at 16", but if it was my money i think id buy something like this barrel and have it chopped at adco get that small gas port. were you planing on an SLR or something similar? there’s also the micro moa from black river tactical.
you said semi permanent, are you trying to do a 1 stamp gun??
A 13.7 Noveske and a surefire brake is still short of the 16 OAL length. With the muzzle threads taking up .625 of the OAL from the muzzle device, you are short of the 16 OAL to make it in non NFA configuration. Surefire Brake is 2.7 inches. Take away .625 from 2.7 and you get 2.075. Add 2.075 to 13.7 and you get 15.775 inches OAL. Still need to SBR. You need a barrel that is 13.95 with a SFMB. Just FYI.
I like the 13.7 idea still only because I just built one of them… https://www.m4carbine.net/showthread.php?165799-My-different-take-on-a-SPR-rifle-BCM-Noveske-Geissele Thing is a great shooter. I would also consider getting a carbine 16 or 14.5 barrel and having it shortened. I just did this with 3 barrels. Most recently a DD CHF, BCM BFH, and an Aero. The DD was a 14.5 car and I had cut to 12.8 that has a .064 Gas port. The BCM was a mid length and gas port of .0735 and was cut to right under 14 ish. The aero was cut to 10.7 and has a gas port of .064. That 10.7 barrel build will work with 10 inch rails with suppressor mounts and is going to be run suppressed 100 percent of the time. The .064 port for that length barrel is optimal in my opinion for a suppressed rifle. No need to mess with the gas block going that route.
I have run a 11.5 BCM LW barrel with surefire mini with SLR for almost 2k rounds now. My only complaint is that the barrel gets pretty dang hot pretty fast. I personally like the .063-4 gas port size on cut down car barrels instead. Colt, BCM, DD, etc all run there 14.5 and 16 in barrel carbine ports at that area IIRC.
I would check out the KAC QDC CQB if you have not considered one. I have one in my hand and it weights 13.42 oz according to my scale. And the thing is impressive. Just a thought…
I’m not sure who has a 2" suppressor, or if anyone does, one I would want to buy. Also, I’ve had a 13.7 and hated it. I’m not trying to go full circle here
Not specifically trying to do a 1-stamp gun. But keeping that option open.
After everything I have learned testing gas systems, I will have an adjustable block, no question. In this case, yea, the SLR looks like a nice part. I currently have a micro moa, I don’t need or want switching when I dedicate a can to it though.
I’ve been around the block with A5, gas blocks, highspeed testing of bolt velocity, gas blocks again, discovered that DD barrels are overgassed, x vs y suppressor, QD… And I’ve come back to thread-on dedicated ftw.l
Genesis, that is the SF thread on series last I saw. Handled them, seemed good but I have no info. I doubt they are as light as the new SIG cans, but I’ll keep an eye out. One of the reasons I like the socoms is the lower back pressure, but on a dedicated can it doesn’t really matter as much.
As far as the rail to can distance. I’ve never really got the idea of stuffing the can inside the rail or trying to get the can dead nuts up to it. I don’t mind a little exposed barrel, it’s a tool after all. The BCM KMR 10 is about 10.5" if I read right, and the NSR 11 I have now is 11.1 or so, so I’m loosing .6" rail and 1" of barrel, should be fine as I don’t mind the look now.
I just don’t want to mess up by going with the BCM ELW and finding out my gun doesn’t shoot nearly as well as it does with the DD 12.5" I have now. That would bum me out, but it would be an easy fix at least. Barrels are wear items.
This has been covered before by BCM’s Phreakish in the billion page BCM Barrel thread
The ELW barrels are lighter and stiffer than the regular LW offerings. The regular LW offerings have a beefier chamber portion of the barrel, but a skinnier section in the middle which will shift more with comps and suppressors. The ELW has a shorter chamber area (with a more consistent cross sectional area) and a beefier main body area with further weight reduction past the gas block and of course from the removal of the handguard cap shoulder.
The government profile leaves much to be desired. It’s heavier, and will be stiffer, but there’s also a lot of weight that won’t contribute to strength. As such, the added stiffness is not a 1:1 trade for the added weight.
FWIW, I run a BCM 11.5" LW suppressed almost 100% of the time and POI shift is minimal at 200 yards. Doing it over, I’d probably just grab the ELW non-fluted just because.
I agree the 11.5 LW with a suppressor is very minimal POI shift. 11.5 barrels are short and rigid. Not much hanging that far off the end compared to… say… a 16 inch LW barrel. I have a 14.5 ELW barrel that wears a suppressor. It also has less POI shift then I would have expected with a full size can on it. I like the ELW profiles and have no issues with the “no collar” for the gas block sporting only one dimple hole.
Ok, you all pretty much sold me on it. Anyone with an 11.5" BCM (LW, ELW, or not) getting 1MOA out of them? I’ll be bummed if I replace my barrel and then it’s a crap shoot at distance.
The only BCM 11.5 I ever tossed a scope on to shoot groups with was just a tad over 1moa. Like 1.3 something iirc. This was using hornady 75gr hp match ammo.
I wasn’t exactly set up that day to shoot in the same hole, but I’ll take it out of a 11.5.
was only able to get about 2moa at the best today. 60rds of wolf gold and 60 (the last of) my independence m193. shooting seated/supported/suppressed 3x acog horse shoe reticle. i was shooting this noticeably better than the DD mk18 w/ a magnified 3x eotech and a steady diet of WPA muwaha. probably just the becasue the eotechs a starburst and the acogs a perfect dot. (something to think about for users w/ astigmatism, acog has been great!)
last fall 100yds prone with the elwf, same acog, and pmc bronze i had one 4-5 group of a larger spread that could be covered with a quarter, i think it’s a shooter!
