First build, 10.5" LMT

[Artiz]

Hi, a few weeks back I was looking in my gun cabinet and that stripped Aero Precision lower was looking at me funny, so I decided to make my first 100% custom AR. It was to be a 10.5 or 11.5, so I spent a few days reading a crapload of information about different SBR setups, barrels and gas ports and the winner was the LMT 10.5". Here in Canada we have pretty much everything LMT available, 10.5 barrel assemblies included. Long thing short I wanted to make the best AR I could.

Now let me say this, the fact that LMT doesn't parkerize under the FSB is now a no brainer to me. It's unnecessary, the FSB was extremely, mark my words, EXTREMELY tight around the barrel, so much that I had to use penetrating oil and heat, and even then I had to use a hammer and some gorilla muscle. It is more clear to me now why LMT doesn't parkerize, they hold extremely tight tolerances. I wouldn't be surprised if they actually slide on the FSB during the Cryo treatment. The gas port measured right around 0.070". I had to lap the inside of the FSB with 2000 wet sandpaper to get it back on, I did a bit at a time, a few hours later (yes, hours) I got it on, but it still required A LOT of muscle and the hammer and brass punch to set it the last ½" of the way. The pins went in and out without too much or too little force. Used only hand tools to cut/shape the FSB.

I'll let the pics tell the rest of the story.

http://imageshack.us/a/img834/9066/hz9m.jpg

http://imageshack.us/a/img823/7704/tx3p.jpg

http://imageshack.us/a/img138/4127/i8uc.jpg

http://imageshack.us/a/img844/3576/wclo.jpg

http://imageshack.us/a/img854/260/ah1p.jpg

http://img9.imageshack.us/img9/1572/9l6h.jpg

Specs:

Aero Precision upper and lower receivers.
Daniel Defense LPK.
Umbrella Corp grip.
Mil-spec spring and 7075 receiver extention
BCM castle nut
H2 LMT buffer
LMT 10.5" barrel assembly
DD gas tube
DD A2 birdcage
BCM BCG
Fortis REV 9 rail
Magpul BUS
Inforce HSP WML
Aimpoint H1
Daniel Defense micro mount
Standard CH but that will change once the Raptors are back in stock.

The stock is my 14.5 LMT's MOE stock, I'm still waiting for the B5 Bravo stock to arrive.

I'm still debating the front sight, I'll run it for a while and see if I'll put a DD fixed front.

Thanks for looking and tell me what you think!

[Redbeardsong]

Good looking gun! What is the process for building/buying an SBR in Canada? Is it the same as a 16" AR?

[Artiz]

Good looking gun! What is the process for building/buying an SBR in Canada? Is it the same as a 16" AR?

Thanks! Our AR's are classified as restricted, like handguns, so any barrel lenght is restricted, 7" or 24", doesn't matter. We can't hunt with them tho, only at the range... and our mags are pinned to 5, but that's another story.

[46and2]

looks great. Nice parts list

[Artiz]

Got it to the range today to test it out, I only shot about 50 rounds but that was enough, my feet and hands were getting frozen solid, I actually called the three fliers at the bottom right of the 25rd target because I couldn't feel my trigger finger anymore and the shots went off before I was ready. Everything was shot at 50m, the groups got tighter as I shot more rounds through the barrel, as expected. It seems to like the 55gr .223 AE black box. Ejection was strong and reliable with the H2 buffer and ran pretty smooth actually. She's a keeper for sure.

http://img46.imageshack.us/img46/7114/xp7p.jpg

[HaydenB]

Looks solid buddy, nice write up too. I would also recommend that dd front sight wholeheartedly.

[Jester617]

Whats the diameter on the front sight post /gas block on your upper ? .625 or .750 I asked LMT and they still haven't responded .

[Artiz]

Whats the diameter on the front sight post /gas block on your upper ? .625 or .750 I asked LMT and they still haven't responded .

It's .750

[BOOSTjunkie]

great build! i love the 10.5

[duece71]

Very nice job, especially the shaved FFS. Sorry to hear about your mag restrictions, sadly it seems, some places down here are headed that way too. Great build. I hope to have an SBR some day, hopefully in 300blk.

[BigBubbaJ]

Did you notice that the pins on the a2 weren't tapered? I just pounded mine off and found it PITA as well. Had to use a ball peen hammer in the vice on the sight post to get it off and it took like 100 hits to get it off. And yes, not finished under either. TIGHT.

[Artiz]

Did you notice that the pins on the a2 weren't tapered? I just pounded mine off and found it PITA as well. Had to use a ball peen hammer in the vice on the sight post to get it off and it took like 100 hits to get it off. And yes, not finished under either. TIGHT.

Yeah, TIGHT is the word. haha. Wait until you try to put it back on. :D

The idea behind tapered pins is to pull the FSB on top of the barrel/gas port, but with that tight of a fit it's just not needed.

I wonder if the other manufacturers that use straight pins also get their FSB as tightly around the barrel, I doubt it. Everything LMT does different has some solid engineering behind it.

[BigBubbaJ]

Yeah, TIGHT is the word. haha. Wait until you try to put it back on. :D

The idea behind tapered pins is to pull the FSB on top of the barrel/gas port, but with that tight of a fit it's just not needed.

I wonder if the other manufacturers that use straight pins also get their FSB as tightly around the barrel, I doubt it. Everything LMT does different has some solid engineering behind it.

Fortunately I'm swapping for a Low Profile Gas Block :)

[Artiz]

Fortunately I'm swapping for a Low Profile Gas Block :)

I had one, but I just preferred the strenght of the FSB with pins.

[BigBubbaJ]

Yeah, I have some concerns as well but my LP block is arriving today. I'm mid upgrades :) I might just shave it down and keep it handy like you did. I went for the Fortis rail as well, but 12" as it's a 16" barrel. The 10.5 is SWEET!

[TurretGunner]

Funny you post this. I am planning on doing the EXACT same thing with the same componets next month. Any lead on where you got LMT 10.5 barrels/uppers?

[Artiz]

Funny you post this. I am planning on doing the EXACT same thing with the same componets next month. Any lead on where you got LMT 10.5 barrels/uppers?
I don't know if you are in Canada, but here we get them from Questar International.

[bigredneck61088]

looks good! any issues with the 10.5??

[jaragon]

That's a very nice looking build. Looks like great work on the fsb.

[Artiz]

looks good! any issues with the 10.5??

Nope. Very reliable. Then again I don't shoot Wolf or any underpowered crap.