Any issues with .22LR conversions in SS barrels?

[Skyyr]

Currently, I only have Novekse SS barrels and I'm really starting to consider a .22LR conversion kit. Are there any adverse effects when using .22LR in Polygonal AR barrels? I know the H&K USP has a Polygonal barrel and they advise against using exposed-lead ammo. Do AR barrels follow the same logic?

Thanks!

[ALCOAR]

My biggest concern and reason I personally would not do it is because of the potential build up of lead around the gas port hole....I saw a pic on tos that scared the you know what outta me and while it might be rare, nothing I want to chance w. esp. one of the nicer barrels made in your Noveske SS. Hopefully others will weigh in that know more on this issue than I do as the concept has always sounded great to me but the practice of it has scared me away from it.

[Boss Hogg]

I wouldn't use one in a match barrel. You're introducing a steel case with potentially sharp edges into a match chamber.

Chrome lined? No worries. Just snake the bore and fire a few rounds of 5.56 to blow out the gas port every 300-500 rounds.

[Suwannee Tim]

From my experience with handguns, a clean barrel fouled with jacketed bullets then shot with lead bullets will foul faster much faster than if the clean barrel was fired with lead bullets. Folks who shoot cast bullets in center fire rifles will scrupulously clean before switching from jacketed to cast or vice versa. You may see accelerated fouling. Also, the 22 LR wants a much slower twist than any 1/8 or 1/7. I have a dedicated 22 LR barrel. More costly but I shoot enough to justify it.

[MrMilspecer]

I just put one in my new DDM4. I was hesitant about using it because yesterday when I was trying to install it the fit seemed to tight. But today after having my AR apart a bunch of times i tried it again. Just wiggeled it a bit and seated in just right. Just stepped out and shot 20 rds no problems at all. What a hoot ! Hopefully I dont f-up my new
M4( paranoid). From what ive read they seem pretty harmless as long as you clean it out every couple hundred rounds. I'll do some accuracy testing later to see for myself. I cant find a good thread where anyone has bench tested accuracy. If your interested I'll let you know. I say go for it. You bought the best for a reason. Now go get the SS CMMG conversion and shoot the shit out of it. Check out this site. Great deal.http://palmettostatearmory.com/22-lr-upper.php

[Boss Hogg]

It shouldn't degrade accuracy in a chrome barrel.

I've fired approx. 3000 rds of Federal 550 through a CMMG 1/7 16" barrel with their 22LR conversion kit. The accuracy with 22LR is sufficient for training (sight alignment and trigger control) When I shoot decent 5.56 it'll still print 2 MOA groups.

The important thing is to "blow out" the gas port residue every few hundred rounds.

[Quib]

The important thing is to "blow out" the gas port residue every few hundred rounds.


Fire a mag of 5.56mm after each .22 range session to keep the gas port and gas system clear of lead build-up. The photos below were taken during the rebuilding my sons AR which was used as a dedicated .22 trainer.

The barrel gas port, FSB gas passage, as well as the first 1/4 inch or so of the gas tube, was totally blocked with lead build-up. I was aware of the consequences of our actions, and planned on the upcoming gas system maintenance. The amount of build-up was no surprise during the re-build.


http://farm3.static.flickr.com/2620/4112740373_bcc438b0e2.jpg

http://farm3.static.flickr.com/2546/4113508784_1ce9703588.jpg

[ALCOAR]

Great pics Quib :)

[Quib]

Thank you Sir. :)

[sgtlmj]

No way would I shoot 22LR through my Noveske SS bbl. Noveske uses his own chamber dimensions, and I'd wager that the 22LR insert isn't designed for it. Maybe with o-rings, etc., but why risk it? Just build a dedicated upper. Lots of old 1:12 twist GI bbls out there to play with if you don't want to spend the $$ on a pre-built kit.

[Magsz]

Quib,

How hard was it to clean out the lead residue? What lengths did you have to go to or was the residue able to be disolved with solvents?

[Quib]

Quib,

How hard was it to clean out the lead residue? What lengths did you have to go to or was the residue able to be disolved with solvents?

Not too complicated. Probably a twenty minute job.


A micro torch on the gas tube took care of the lead build-up there.



A dental pick knocked loose the plug in the barrel gas port.



A combination of dental pick and micro torch cleared up the FSB.

[Magsz]

Quib,

Thank you very much for the response.

[Quib]

Quib,

Thank you very much for the response.

You're welcome. :)

Always glad to contribute where I can.

[Xhado]

did you use standard lead .22 or copper plated .22?

[Quib]

did you use standard lead .22 or copper plated .22?

Copper plated....which equates more to "copper washed".

[MrMilspecer]

After trying mine out a little more i would say. Save your money and spend it on a dedicated upper. Get something with the right twist for a few hundred more bucks. Better accuracy and no worries . Good luck.