Another Dum Dum Silencer Build Question

[Ben]

So for this Winter cardio rifle build that I keep talking about, I have everything here except the buffer system. I decided I wanted to tune at the buffer rather than at the gas block (I'm using a BCM MK2 upper).

I've gotten a little confused from all the Internet experts, but currently, I'm looking at pulling the trigger on the BCM MK2 recoil mitigation system. My understanding is that it's the same as the VLTOR A5 (very slightly different weights). BCM only sells it as a kit with a T1 buffer (I can order a separate T2 from them for an extra $50). Mr Skinny jeans over at TREX sells them, and also includes a handy little chart that seems to show that for 14.5-16" barrels, using a low back pressure can (I'm putting a FOR RECCE on it), the T2 is the best weight, and he sells the kit with the T2.

With the understanding that the B5/MK2 systems are somewhat proprietary, are they a better option for tuning for a can, vs one of the carbine systems? It will have a Reardon flash hider on it, and likely be run suppressed 90% of the time. I got the MK2 charging handle for it. I was looking at the Raptor SD and Geiselle, but it seems the three of them are about the same for the small amount of help they are for gas, so I just ordered the MK2 when I ordered the upper (also with the BCM BCG).

[dogmush]

Answering the questions out of order:

With the understanding that the B5/MK2 systems are somewhat proprietary, are they a better option for tuning for a can, vs one of the carbine systems?

Yes.  Hands down.  Lower Bolt velocity, slower unlocking, smoother function and less wear.

Mr Skinny jeans over at TREX sells them, and also includes a handy little chart that seems to show that for 14.5-16" barrels, using a low back pressure can (I'm putting a FOR RECCE on it), the T2 is the best weight, and he sells the kit with the T2.

Yes, 5.6oz is probably what you want.

Now for the "however, but:"

I don't love the BCM system. It is the least "smooth" of the various A5 buffer setups.  What I run on my suppressed DI guns is:

Griffin Armament A2 Suppressor Optimized Buffer: $60
Griffin Armament A2 extra power (+15%) Spring: $14 (Sprinco is just as good, I try and limit shipping costs since I'm ordering from Griffin anyways)
Forward Controls Design A5 Length Buffer tube: $57.50 @ Primary Arms
Mil-Spec castle nut and end plate: $7 @ Primary Arms

That's ~$140 whereas the BCM/T2 is $123@Primary Arms or $125 from Lucas (although he's out of stock right now).  For that you get a nicer extension with the maritime drain holes (you may or may not care) and a *much* nicer two stage buffer.  Griffin does pretend to sell the whole "A2  Stock Mounting Kit" (Receiver Extension, Spring, Nut, End plate, Buffer) for $105, but that buffer tube has been out of stock for like a year and a half.

[Ben]

Thanks, I was unfamiliar with the Griffin Armaments one. I will do some interneting. Is it pretty obvious which parts to order with which, as in, is there only one type of each Griffin part, or multiple versions?

[dogmush]

There's a Carbine Version and an A2 version.  You want the A2.  Same with the springs.

On the reciever extension, any one that is marketed as "A5 Length" as the Griffin parts work with the original VLTOR "A5" idea/design.  I *think* the BCM set-up is 100% proprietary to them, but am not 100% sure on that.

[Ben]

Okay - as long as there aren't multiple A2 versions, I should be able to figure it out. 

[dogmush]

I forgot to ask, what gas length is that upper?  Tuning can only do so much.

[Ben]

I forgot to ask, what gas length is that upper?  Tuning can only do so much.

Mid-length, 14.5. I was going to get the 16 but changed my mind at the last second and am doing a pin and weld. Again, only going by the interwebz, the BCM MK2s are supposed to be a little better for cans than the standard BCMs. I don't know if that means the gas block is kinda tuned to "mediocre" to work with canned/uncanned or what.

[dogmush]

I haven't shot a Mk2 so I don't know how they are gassed.  14.5/mid length could be OK.  After shooting it you might want a Bootleg BCG.

[Ben]

I haven't shot a Mk2 so I don't know how they are gassed.  14.5/mid length could be OK.  After shooting it you might want a Bootleg BCG.

Yeah, it'll be an experiment. I'm hearing pretty good thinks about the FOR RECCE regarding gas. I've only shot it on my piston guns, and it performs well there, but the DI gun will be the test. Especially this being my first canned DI gun.

[Ben]

Answering the questions out of order:
Yes.  Hands down.  Lower Bolt velocity, slower unlocking, smoother function and less wear.

Yes, 5.6oz is probably what you want.

Now for the "however, but:"

I don't love the BCM system. It is the least "smooth" of the various A5 buffer setups.  What I run on my suppressed DI guns is:

Griffin Armament A2 Suppressor Optimized Buffer: $60
Griffin Armament A2 extra power (+15%) Spring: $14 (Sprinco is just as good, I try and limit shipping costs since I'm ordering from Griffin anyways)
Forward Controls Design A5 Length Buffer tube: $57.50 @ Primary Arms
Mil-Spec castle nut and end plate: $7 @ Primary Arms

That's ~$140 whereas the BCM/T2 is $123@Primary Arms or $125 from Lucas (although he's out of stock right now).  For that you get a nicer extension with the maritime drain holes (you may or may not care) and a *much* nicer two stage buffer.  Griffin does pretend to sell the whole "A2  Stock Mounting Kit" (Receiver Extension, Spring, Nut, End plate, Buffer) for $105, but that buffer tube has been out of stock for like a year and a half.

I took your advice and copied what you have. Other than Primary Arms has a new Next Level Armament castle nut/end plate on special that uses a locking screw vs staking, so I figured what the heck, try that.

Also, tangent. I still had to order an ambi safety and was going for the Radian Talon, which I already use, and discovered they sell a "modular" one with four levers that lets you put the long lever on the right side, for a true "left-handed ambi safety". While the longer lever on the left was never a deal breaker for me, it does irritate me on occasion. It will be nice to have something ambi made for lefties. Not cheap at $85, but it turned out I had $80 in bonus bucks at Primary Arms, so almost free. 

[dogmush]

That's a nice Safety.

[Ben]

That's a nice Safety.

You running at 90 or 45? I was thinking about going 45 on the last one, but with my main working guns at 90, I didn't want to introduce something new. Interestingly, when I was on the Griffin website, I was looking at their ambi safety that runs at 55, and they had a blurb about how 55 was the lowest you should go for safety. I have no idea on the validity of that or if it's a sales blurb. One would think that if 45 were a problem, companies like Radian would have had to deal with it by now.

[dogmush]

45.  I run all 45(ish)* safeties.

I had a whole post 9n here at one point, but they are faster.

[Ben]

The last of the parts finally came in and I put the lower together this evening. That is one heavy buffer! I will be interested to see how it feels.

Dogmush - how does that buffer+spring combo run without a can on the end? Not that I'll be shooting that way regularly, but when I do the first shots tomorrow to check function, I planned on doing them canless first and then putting the can on and sighting in.

Tangent: Jiminy Christmas! After all this time, I STILL have issues getting the &*$^%! front takedown pin in. I use the clevis pin trick and everything, and I still shot the detent across the room twice. I should have bought a lottery ticket, because I found it both times. I think I'm just retarded or something.

[dogmush]

Dogmush - how does that buffer+spring combo run without a can on the end? Not that I'll be shooting that way regularly, but when I do the first shots tomorrow to check function, I planned on doing them canless first and then putting the can on and sighting in.

No idea.

I pretty much never shoot unsuppressed rifles any more.  My main guns all have dedicated cans that just stay on.  I'm not even sure I can get my RC2 off anymore.

[Ben]

Hey Dogmush - hanks for that parts recommendation! A couple of days late trying it out, bu for a mid-tier build, this is probably he best build I've done. here was ZERO perceived gas back in my face this morning. I think I ge more gas back from my MK111 with the Rex can (admittedly, made for quie vs he FOR, made for low backpressure). Absolute pleasure to shoot and zero malfunctions in speed shooting.

he whole build went smooth this time (except for the $*^& front pivot pin, as usual). Plus for my birhday/Christmas presen to myself this year, I splurged on the ACOG/RMR combo Mr Skinny Jeans sells, that he had on Christmas sale. Not only a really nice optic, but I didn't have to make a single zero adjustment. Threw it on he rifle, shot the firs five at 50 meters, and they all went into the X. I don't think hat's ever happened to me with a new optic before. 

[dogmush]

Glad you like it.  It makes for a really nice shooting gun IMO.

As you can see from my pic upthread, I have come full circle back to the ACOG I had on my second tour.  It's not perfect for everything, but it does a lot of things really well, and is a great general purpose combat optic. Sounds like you have a pretty solid general purpose build going.

Did you get the Dual illumination ACOG like I have, or the LED one.  I kinda want to try the LED on so I can forward mount the RMR.

[MechAg94]

The ACOG I have always ends up on guns I don't shoot much.  I need to go see what it is mounted on. 

Pretty much any rifle I intend to shoot more than 100 yards, I try to add some magnification.  I tend to go for the Primary Arms 3X prism optic as they are cheaper, but the ACOG works well. 

[dogmush]

I shot a gas gun match with my ACOG a couple months ago.  One of the places where ACOGs truely shine is that FOV.  If you're getting on glass and scanning for a target, you can see soooo much.  And the glass is amazing.*  I loves me some PA scopes, and I have a 3x and 5x prism of there's, but I'm the opposite of MechAg.  Those PA's are on guns I don't shoot much, while my ACOGs are on guns I need to use.  We are spoiled though with the glut of choices for really solid optics that came out during the GWOT.  So many more good choices than when I started scope shoping for my Mini-14 in the early 90's.

Fun Fact:  I actually have a personal ACOG on my M4 in the arms room, because I don't like the M68 CCO the unit i'm in now issues to us.  So I just keep one of my personal M150 RCO's and RMR setups on it.


*Of course, for what Trijicon asks for them, it damn well better be.

[Ben]

Did you get the Dual illumination ACOG like I have, or the LED one.  I kinda want to try the LED on so I can forward mount the RMR.

I got he LED one, with a primary reason being that forward mount RMR. Plus in my research I saw everybody seems to tape up that FO illuminator. Honesly, I sho mine all morning without ever urning the illuminaor on.

I will say I'm no sure if I will keep it on tthis rifle. I built he gun as my "cardio rifle", so was kinda going for ligher weigh. But I like the setup so much I'm thinking of duplicaing the build, maybe with a 16" upper, puting the ACOG and other suff on that, as a GPR, as you alluded, and a spare Eotech on his one, as it's for 100 meters and in mostly. We'll see.  I really like the ACOG setup.

[dogmush]

I got he LED one, with a primary reason being that forward mount RMR. Plus in my research I saw everybody seems to tape up that FO illuminator. Honesly, I sho mine all morning without ever urning the illuminaor on.

I will say I'm no sure if I will keep it on tthis rifle. I built he gun as my "cardio rifle", so was kinda going for ligher weigh. But I like the setup so much I'm thinking of duplicaing the build, maybe with a 16" upper, puting the ACOG and other suff on that, as a GPR, as you alluded, and a spare Eotech on his one, as it's for 100 meters and in mostly. We'll see.  I really like the ACOG setup.

If you even think you might want to build a 16" rifle soon, buy this barrel right now:  https://www.roscomanufacturing.com/shop/barrels/k9-barrels/k9-16-barrel-hatchet-5-56-nato-intermediate-length/

It's a proprietary length gas system and shoot's amazingly.  The problem is, they have to run the gas tubes in batches, so when they are out of stock, they are out of stock for a while.  I run mine with that A5 buffer setup, and a Cataba Valley K can, which is just a normal high back pressure baffle can, but it runs like a dream.  This is the gas port and gas length you want on a 16" barrel.  I was part of the R&D shooting where Roy and Eric dialed the gas port in.

Video on the barrel if you want to see groups and stuff: https://www.youtube.com/watch?v=NYZBY3hFeQA&t=205s