Do you have threads checked for alignment?

OLM-Medic · Jun 21, 2018

Is it true you should have your threads and mount inspected by a gunsmith for concentricity to the bore before shooting through the suppressor?

My friend never does it and has no issues, but I really don't want to blow up my can if something isnt aligned right.

I'm not sure what the general consensus is on this topic.

erwos · Jun 21, 2018

This is generally considered to only be a problem worth checking on AKs and home-threaded guns. It would probably behoove you to give things a quick eyeball, but all of the major American barrel-makers produce barrels that are going to be fine.

outrider58 · Jun 21, 2018

I always do. You can take your guns and cans to a Smith or shop that has bore concentricity gauges and have them checked. You'd be surprised how many bbls come close to failure.

44man · Jun 21, 2018

Don’t they make tools in different calibers to check to see if your can is out of line?

I am at 6 months waiting on my first stamp

I hate waiting

outrider58 · Jun 21, 2018

44man said:
Don’t they make tools in different calibers to check to see if your can is out of line?

I am at 6 months waiting on my first stamp

I hate waiting

Yes. Basically, it is a steel rod that fits snugly to the rifling of the barrel. You insert it through your suppressor. If the rod touches the mouth of the can, it is considered a failure. You can buy them from Brownells IIRC.

inkd · Jun 21, 2018

If you have a timed muzzle device for a QD suppressor, make sure it wasn't timed using a crush washer.

smdub · Jun 21, 2018

My MP5K-N bbl had a misthreaded navy thread protector (the Navy bbl is both threaded for screw on can, or you can put a smooth thread protector on that and use a 3-lug.) It forced my 3-lug off angle and would have destroyed the suppressor on the first shot had I not caught it. I machined a new protector that was concentric w/ the threads.
I check all new bbls to be concentric before firing them the first time. You can sight from the muzzle end and see any misalignment easily w/ the action open (and unloaded of course!) W/ a light shining into the open breech you should see 3 concentric rings. 1) The muzzle end of the suppressor 2) the muzzle of the bbl and 3) the breech. The human eye can detect very small offsets easily. Its free, works with any caliber, and doesn't ever touch the rifling. Don't shoot your eye out.

rsideout · Jun 21, 2018

The only problem with barrel threading that I have ever had was with an AK. That gun just never gets run with a can. I did have a problem once with an interchangeable threaded end cap for a large subgun can. It was threaded slightly off line. The manufacturer took care of it without issue.

303_enfield · Jun 21, 2018

Eyeball it.
Looking down a barrel and seeing if you see baffles is 10 times better way to check that most of these alignment rods.

From the guy that's done 15+ barrels for me.
https://www.ar15.com/forums/equipme...FAL-PAPM92-Pin-and-Welds/143-1029861/&page=51

Butcher · Jun 25, 2018

I’ve had problems twice with shitty local gunsmiths and concentricity. Never again. If you’re sending your gun off to get threaded, use a reputable smith like Adco Firearms or Buhler Ballistics.

outrider58 · Jun 26, 2018

303_enfield said:
Eyeball it.
Looking down a barrel and seeing if you see baffles is 10 times better way to check that most of these alignment rods.

From the guy that's done 15+ barrels for me.
https://www.ar15.com/forums/equipme...FAL-PAPM92-Pin-and-Welds/143-1029861/&page=51

Ya think?

rayrevolver · Jun 28, 2018

I don't trust my eyes.

I bought 3 McMaster Carr drill rods for 22/223, 9mm, and 30 cal. They don't need to be snug per se. I start at the chamber end and slowly pop it out the suppressor and see how it looks. Only issue I had was with a SLR106UR (AK74 in 5.56). Luckily the muzzle was obviously not 100% square and I used a Lee 223 case cutter to square it bubba style. It worked since the 24mm adapter indexed off the muzzle.

Here is the after photo. Can't find the before shot, but the rod was very offset but not touching the can. I did not want to take a chance.

If you want to spend some money, Geissele sells rods for 5x the cost of high tolerance drill rods from McMaster Carr.

ohen cepel · Jun 28, 2018

I bought machine rods to check mine. Not that much $$ in the long run.

I have a older Rem 700 barrel which does not have a concentric bore for example. The rods helped to make sure I was still good to go.

DutchV · Jun 28, 2018

303_enfield said:
Eyeball it.
Looking down a barrel and seeing if you see baffles is 10 times better way to check that most of these alignment rods.

From the guy that's done 15+ barrels for me.
https://www.ar15.com/forums/equipme...FAL-PAPM92-Pin-and-Welds/143-1029861/&page=51

Morgan is awesome. Zero complaints about the work he's done for me. Four barrels so far. One was fixing a bad job I had made the mistake of getting done locally.

Adco also did a fine job on the barrel I sent them.

rayrevolver · Jun 29, 2018

DutchV said:
Morgan is awesome. Zero complaints about the work he's done for me. Four barrels so far. One was fixing a bad job I had made the mistake of getting done locally.

Adco also did a fine job on the barrel I sent them.

Here Here!

Morgan did my M&P15-22. Its perfect. He was on the hook to help me with my SLR106UR if I couldn't get it straight. Dude is legit.

outrider58 · Jun 30, 2018

I'm having trouble understanding peoples' problem with gauging their suppressors for concentricity. Not everyone has a "Morgan" near by. :shrug:

clandestine · Jun 30, 2018

If one is using a QD Mount, using a gauge is important. Even direct thread suppressors can be off.

A good (concentric) barrel thread job is only half or 1/3 of the equation.

303_enfield · Jul 27, 2018

outrider58 said:
I'm having trouble understanding peoples' problem with gauging their suppressors for concentricity. Not everyone has a "Morgan" near by.

Well, Morgan is only a USPS/UPS/FEDEX truck away. Alignment rods can be great if they don't have play in them. But if your barrels thread is F'd to begin with your wasting time.

It's sooooooooo much fun when after waiting a year for the can to get out of jail. Take it home an thread it on your _____, to find out your $$$$ thread job is F'd. The local "Smith" said he'd fix it but it's a 12 week wait. Morgan had it back perfect in 5 days.

Hawkeye · Jul 27, 2018

If anyone wants to check at home for a reasonable amount of money, you can get tightly toleranced ground to diameter (not extruded) tool steel rods from McMaster Carr for this purpose.

I bought:
8893K193 Tight-Tolerance Multipurpose O1 Tool Steel Rod, 0.2188" Diameter, 3 Feet Long
8893K219 Tight-Tolerance Multipurpose O1 Tool Steel Rod, 0.2969" Diameter, 3 Feet Long
8893K191 Tight-Tolerance Multipurpose O1 Tool Steel Rod, 0.2120" Diameter, 3 Feet Long

The first is good for .223 / 5.56, the second for .308 / .300blk (with a tiny bit of play), and the third for .22. The cost for all three of these shipped next day to my house was $22.98. They may not be as "perfect" as the very expensive gauge rods that are out there, but they're good enough to let you know if you have a problem or not.

outrider58 · Jul 28, 2018

303_enfield said:
Well, Morgan is only a USPS/UPS/FEDEX truck away. Alignment rods can be great if they don't have play in them. But if your barrels thread is F'd to begin with your wasting time.

It's sooooooooo much fun when after waiting a year for the can to get out of jail. Take it home an thread it on your _____, to find out your $$$$ thread job is F'd. The local "Smith" said he'd fix it but it's a 12 week wait. Morgan had it back perfect in 5 days.

ADCO FTW!

Do you have threads checked for alignment?

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