Finishing up an AR rebuild.

[Coal Dragger]

As the thread title suggests I am slowly but surely re-building the CMMG AR that I have had since 2005-6. This project started out of a desire to replace the craptastic barrel that CMMG sourced for this rifle. It had a 16" 1/7 govt' profile chrome lined barrel. The chrome lining was very poor and flaked out near the muzzle at some point, and I will admit that I didn't like the rifle very much so it didn't get shot often and was stored for quite some time. At some point the barrel developed some pitting where the chrome lining evidently came out. Maybe it wasn't chrome lined at all, although CMMG claimed it was when I bought it.

At any rate when I brought this to their attention the first time, about the chrome lining issue prior to pitting, they more or less told me they were too backed up to take care of it. Fine. No customer support, I'll deal with it later. So later means about 5 years later...

The rifle came equipped with a Yankee Hill Machine quad rail forearm, which is too damn large in diameter, and uncomfortable with or without rail covers. It also has the lousy atrocious stock GI style trigger. The current gas block is also a Yankee Hill Machine part with a rail section on top of it, not too fond of this since I would just rather have more forearm. There are no iron sights, but I have an old Aimpoint Comp M2 that has been around the world with me, I also have a Nightforce 3.5-15X50 NXS sitting around with nothing to do and I might slap it on until something more reasonably sized can be acquired.

So far I have changed the barrel out, and put a nice Daniel Defense 18" S2W contour cold hammer forged 4150 CMV 1/7 bbl back on. This barrel is nitrocarburized (salt bath nitride) inside and out, instead of chrome lined. Nitrocarburizing is supposed to be extremely durable and doesn't alter bore dimensions. Some consider it superior to chrome lining. So far it seems to shoot very well, and the smaller gas port in the barrel really smoothed out the rifle over the 16" CMMG bbl that was on originally. I have read that most AR's are way over gassed, and I believe it now.

I am looking to change out the forearm, trigger, and gas block. I am also going to add some back up iron sights. Additionally I want to ditch the A2 style birdcage flash hider and install a good muzzle brake/suppressor adapter.

So for those with any experience with these matters I'll ask some advice on the parts I am considering:

1.) Trigger options: American Trigger Corp AR Gold, or a Geissele Automatics SSA-E or Super Dynamic. Thoughts between the two?

2.) Forearm options: JP rifle length VTac free float forearm, or a similar Daniel Defense unit. Needs to be large enough to clear a low profile gas block. Anyone used both? Thoughts?

3.) Gas block options: Syrac Ordnance low profile adjustable gas block, or PRI low profile adjustable gas block. Both should fit underneath a forearm, any experience with either one?

4.) BUIS options: Dueck Defense offset iron sights, or a more conventional set? Really not sure on this one, by the time a good front and rear sight are paid for cost is pretty similar. I played with a current Matech USGI BUIS rear and liked it OK, but not needing to even take optics off if I want to use the irons is a nice option. Anyone used both? What is your preference?

5.) Muzzle brake/suppressor mount options: Wait for new Surefire brakes to come out that mount their new SOCCOM suppressors, and that have a good reputation as being highly effective muzzle brakes. Go with an Advanced Armament Corp muzzle brake that is more readily available. Go with a Battle Comp 2.0 that tries to be both flash hider and effective muzzle brake. I'm more interested in making the rifle stay on target than I am hiding muzzle flash.

All opinions are welcome, curious to hear everyone's reasoning.

 

[dvdcrr]

Ssa-e I have and recommend highly. Matech is good to go too.

 

[Warp]

You can't go wrong with Geissle.

What optic?

 

[Coal Dragger]

Well the Aimpoint will stick around as needed, for a magnified optic I am leaning towards eventually putting on a Nightforce NXS 2.5-10X32. Useful magnification range, compact size, good glass. I owned one for a little while to put on a Cooper M5s in .280AI but the windage turret stuck out too far and dinged up brass and sometimes knocked it back into the action on ejection. So it got sent back to Midway USA in exchange for a Swarovski Z3, but it was a great scope and I really liked it a lot. I also came across a pretty good deal on a Schmidt and Bender 1.5-6X42 with a plain duplex reticle, I am tempted to pick it up since it is great glass, even though there is no range compensating ability to it. I like strait forward reticles.

Until then the same mount that would work for the Nightforce or S&B will work for the big Nightforce I already have.

 

[Warp]

Well the Aimpoint will stick around as needed, for a magnified optic I am leaning towards eventually putting on a Nightforce NXS 2.5-10X32. Useful magnification range, compact size, good glass. I owned one for a little while to put on a Cooper M5s in .280AI but the windage turret stuck out too far and dinged up brass and sometimes knocked it back into the action on ejection. So it got sent back to Midway USA in exchange for a Swarovski Z3, but it was a great scope and I really liked it a lot. I also came across a pretty good deal on a Schmidt and Bender 1.5-6X42 with a plain duplex reticle, I am tempted to pick it up since it is great glass, even though there is no range compensating ability to it. I like strait forward reticles.

Until then the same mount that would work for the Nightforce or S&B will work for the big Nightforce I already have.

If you go with a 2.5-10 I would do the offset irons. At that point they aren't really a 'back-up' sighting system, they are a 'close range' sighting system.

With an aimpoint, 1-4x scope, etc, I think you would be fine with typical BUIS on the rail since the irons really would be back-up only for that setup

Now, the 1.5-6 I just don't understand. I think companies really need to make those low power variables start with a 'true 1x' on the bottom.

 

[Coal Dragger]

The 1.5-6X42 is really a big game hunting optic. Probably be perfect on a .375H&H. Just liked it for the really excellent glass, and the price is good.

 

[Coal Dragger]

Well placed an order with Brownells for the trigger, gas block, and a muzzle brake.

Went with the Geissele Super Dynamic 3 gun trigger, we'll see how I like it.

For the gas block the adjustable Syrac Ordnance got the nod, went with the clamp on type for a better gas seal.

The Surefire brakes are currently vapor-ware so I elected to go with the biggest brake Brownells offered and got a Dreadnaught F2. When I get a suppressor I'll order an adapter at that time.