Newbie AR-15 building question...

[titsonritz]

Are you saying the M-LOK bolt touches your gas block? If so it can affect accuracy and should be ground down or moved.

It should not only not touch but have plenty of clearance to account for barrel whip. I won't install anything adjacent to the gas block with my Centurion CMR rail even with a LW .625" gas block journal.

 

[Tony617]

Are you saying the M-LOK bolt touches your gas block? If so it can affect accuracy and should be ground down or moved.

Sorry when I saw it was hitting the gas block I ground the screw down with my Dremel tool. But the damage was done already.

 

[CLee0507]

I would install anything adjacent to the gas with my Centurion CMR rail even with a LW .625" gas block journal.

Yeah, some of those are TIGHT.... I remember when that rail came out and only a few gas blocks fit under it....

 

[arakboss]

I can think of a few reasons:
1. It would require quit a bit of material to be displaced to create an effective staking.
2. Gas blocks can be re-used, if they are being staked it will decrease it's life span. Carrier keys typical are not re-used after stalking them, RE end plate can be re-used but require they are torqued to a different location from the original stakes.
3. Staking without dimpling the barrel would do little good.

I agree barrel needs to be dimpled. Gas blocks are cheap and shouldn't need to be removed or replaced often. I think if it was combined with the other methods it would add an extra layer of protection against screws coming loose. Pinning would be best but not an easy task for the DYI guy.

 

[arakboss]

When I bought the fully assembled uppers from Troy Industries the the gas block bolt were dimpled as well. I put the Magpul AFG on my AR so it M-LOK nicked the gas block a bit. Does not affect the ability to fire my AR.

View attachment 696273

Looks good. It should give you a visual if screws start to work loose. I did a stake job on mine but after looking at yours I think I should've been a little more aggressive with mine.

 

[titsonritz]

I agree barrel needs to be dimpled. Gas blocks are cheap and shouldn't need to be removed or replaced often. I think if it was combined with the other methods it would add an extra layer of protection against screws coming loose. Pinning would be best but not an easy task for the DYI guy.

True, but a lot of people do change out handguards which will most likely require a barrel nut change, thus removal of the gas block. Good gas blocks aren't that cheap, BCM is $45+shp, Geissele is $60+shp. Sure the el-cheap-o aluminum jobs are cheap but I wouldn't use them. A lot of cheap steel one are bulking and limit the handguards that can be used. For the price of a good gas block, I'd just as soon be able to re-use it and since the gas system is the weak link of the AR system I'd want a good one. Agreed, pinning is best, but I know BCM, SOLGW and SIONICS all use a single dimple and red loc-tite on their LPGB and all have had plenty of LE contracts with zero issues.

 

[Jcon268]

The problem with NiB is if not done perfectly the finish can flake off, gumming up the work. It can also create hydrogen embrittlement causing the bolt face lugs to shear more easily under stress.

LPGB = Low Profile Gas Block. The reason for test firing is to make sure the gas block is aligned and located properly and not cause short-stroking. The reason to not fire a bunch is the BCG slightly strikes the gas tube, which in turn can push a LPGB that is not properly secured off the gas port.

The correct way to dimple the barrel is use a dimpling jig to ensure proper alignment. Here is an example (there are others) .750 Dimpling Jig and a video on the subject put out by SOLGW.

The tools to get your gas block on correctly are so cheap I don't know why anyone would skip the steps

 

[Jcon268]

True, but a lot of people do change out handguards which will most likely require a barrel nut change, thus removal of the gas block. Good gas blocks aren't that cheap, BCM is $45+shp, Geissele is $60+shp. Sure the el-cheap-o aluminum jobs are cheap but I wouldn't use them. A lot of cheap steel one are bulking and limit the handguards that can be used. For the price of a good gas block, I'd just as soon be able to re-use it and since the gas system is the weak link of the AR system I'd want a good one. Agreed, pinning is best, but I know BCM, SOLGW and SIONICS all use a single dimple and red loc-tite on their LPGB and all have had plenty of LE contracts with zero issues.

I'm doing the same thing except instead of Red Loc-tite I'm using Vibra-tite Hot Lock. Rated up to 2000 degrees F but low break torque so relatively easy to remove if necessary.

 

[titsonritz]

The tools to get your gas block on correctly are so cheap I don't know why anyone would skip the steps

Yep 30 bucks for a jig is a lot less than the price of even an el-cheap-o barrel.

 

[2thdrglock]

I would have skipped the nickle boron BCG and gone with standard phosphate but at least it is C158 steel so as long as it is done right you should be fine. I've never been a fan of cassette style triggers as they can be more difficult to remove if they get wedged up with foreign object such as a blown primer or torn case rim, but they can be a benefit if the lower trigger/hammer pin holes are slightly out of spec. I can guarantee the barrel is not HPT and MPI inspected or they would be bragging about it and charging accordingly. I would do like @Tony617 and address the gas block issue. The correct path would be to remove the handguard, muzzle device and gas block, then dimple the barrel and red loctite it. Blue loctite the handguard. If you puss out on removing the gas block at least loctite it. I would fire it first to confirm good operation but not so much that the BCG push the LPGB off the gas port. Make sure one screw is good and tight, then remove the other and red loctite it into place. After done and setup do the other one.

Received this reply from PSA when asked...

"Hello Stephen,

All of our barrels and BCG's are batch tested for HP and MPI.

Best Regards,

Joshua
Palmetto State Armory Customer Service
(803) 724-6950
[email protected]

So, no they are not each individually tested, but it seems there is some QC inspection going on...

 

[Jcon268]

Received this reply from PSA when asked...

"Hello Stephen,

All of our barrels and BCG's are batch tested for HP and MPI.

Best Regards,

Joshua
Palmetto State Armory Customer Service
(803) 724-6950
[email protected]

So, no they are not each individually tested, but it seems there is some QC inspection going on...

Testing each one is what takes time and drives the cost up. Batch testing assumes the lot is as good as the one that represents the whole. With C158 I'd be more likely to trust a batch test but, even then, individual is always superior. 9310 is more sensitive to heat treatment and takes more effort to get right I'd look closer at the QC from the source.

 

[2thdrglock]

Well, I got tired of waiting for my Aero M4E1 lower parts kit sans FCG and ordered parts from Primary Arms and AR15Discount now that they are in stock. Put in mail next day. Optics Planet order cancelled. Eager to start putting all this stuff together and see what I come up with. After I get more proficient shooting a rifle, I suspect I will want to put together a new upper with a better barrel, gas system, and handguard.
One fly in the ointment for my CMMG Mk10 Banshee. I bought a Law Tactical folding adapter to install on it so I could carry this pistol in my backpack because I saw that someone had done it on a 9mm Banshee. My bad...apparently the 10mm version is different and the folder is not compatible per CMMG. Maybe I'll put it on the AR-15 build...

 

[2thdrglock]

Finally received my lower parts kit and pistol grip and put the lower together last night. I cheated some by using the Real Avid pivot pin tool (slick!) and my Aero M4E1 lower has the threaded bolt catch roll pin. I added some aeroshell grease to the castle nut threads, and I lightly greased the takedown pins and safety selector (pin portion) since they didn' t seem to operate smoothly without it. Bad idea? I really like the Magpul MOE+ grip I got with the grippy overmoulded rubber. I have small hands and it's got a great feel to it. Boring stuff for you veterans, but maybe another newbie might be interested...

AR15 Pivot Pin Tool – REAL AVID®

www.realavid.com

MOE+® Grip – AR15/M4

The MOE+ Grip

magpul.com

 

[Tony617]

Finally received my lower parts kit and pistol grip and put the lower together last night. I cheated some by using the Real Avid pivot pin tool (slick!) and my Aero M4E1 lower has the threaded bolt catch roll pin. I added some aeroshell grease to the castle nut threads, and I lightly greased the takedown pins and safety selector (pin portion) since they didn' t seem to operate smoothly without it. Bad idea? I really like the Magpul MOE+ grip I got with the grippy overmoulded rubber. I have small hands and it's got a great feel to it. Boring stuff for you veterans, but maybe another newbie might be interested...

AR15 Pivot Pin Tool – REAL AVID®

www.realavid.com

MOE+® Grip – AR15/M4

The MOE+ Grip

magpul.com

I really like the AR15 pivot pin tool and it saved be a lot of grief since I would try use a box cutter and still lost a few springs. I had to order some more springs off of Ebay so I ordered this pivot pin tool as well. I really like the Magpul pistol grips as well. I did manage to find a few springs in my carpet but I still have a few more to find.

 

[Hueco]

Finally received my lower parts kit and pistol grip and put the lower together last night. I cheated some by using the Real Avid pivot pin tool (slick!) and my Aero M4E1 lower has the threaded bolt catch roll pin. I added some aeroshell grease to the castle nut threads, and I lightly greased the takedown pins and safety selector (pin portion) since they didn' t seem to operate smoothly without it. Bad idea? I really like the Magpul MOE+ grip I got with the grippy overmoulded rubber. I have small hands and it's got a great feel to it. Boring stuff for you veterans, but maybe another newbie might be interested...

AR15 Pivot Pin Tool – REAL AVID®

www.realavid.com

MOE+® Grip – AR15/M4

The MOE+ Grip

magpul.com

I just got done with my first build as well. If you ever lose the pivot pin tool, you can get by with a 1/4" dowel with a small hole put through it to save some aggravation and launching of the pivot pin into the ceiling:


I've got sweaty hands and ended up going with the Ergo aggressive texture grip. Feels great!

I've got an Ergo Tactical Deluxe that I bought, tried, decided was too beefy, and then threw in the parts bin. If you're interested in it, let me know. Wasn't planning on selling it, but, one AR noob to another seems right .

 

[Dogman]

Hello All,
I am new to guns in general although I am 58 yrs old. We have a few pistols purchased within the last year or so (3 Glocks, 1 Walther, 1 Sig), have done our basic training and have put several hundred rounds through our small collection. Of course I recently got the bug for the AR style pistols and rifles and ended up recently purchasing a complete AR pistol in 10mm for my first one. Can't speak to it yet, it hasn't even been shipped. So I started thinking about building my own (actually just putting together with parts) an AR-15 chambered in 5.56. Started searching around last night and have come to the conclusion that right now this is an impossible endeavor...There are no parts available. Is this just a temporary thing, or is it common to have almost all the parts out of stock and you just have to sign up on waiting lists? Again, I am a total newb and just trying to educate myself of what to expect. Thanks!

Mid state firearms has stuff in stock! And you can speak directly to the two owners. About a week out to deliver.

 

[2thdrglock]

Thanks for your reply. A while back I completed my first AR15 in 5.56. I ended up buying a PSA barreled upper to eliminate newbie mistakes on head space, etc., with an Aero Precision M4E1 lower and parts kit, a James Madison Tactical (JMT) Saber Single Stage Drop In Trigger, and Magpul stock and grip, buffer/tube/spring, BUIS. I added some things, like a Strike hand stop, QD sling mount, simple 2 point sling, an Odin extended mag release, a Vortex 1-6x scope, and I have a Rome5 red dot to try on it. It seems to shoot well, although I haven't had a chance to shoot it from a bench at the range yet.
Always good to have another parts supplier in my bookmark list...thanks!