Dedicated 22lr bbl recommendations for CMMG conversion kit?

[SkepticalTiger]

I'm building a dedicated 22lr upper that'll closely resemble in feel and length to my other uppers between 13.9 P&W to 18". I expect to shoot 5k - 10k rounds a year.

So far I've found
CMMG: 16.1" M4 profile, 17" medium profile
Right to Bear: 16.1 M4 Profile, 16.1 pencil profile, 20" gov't profile (latter 2 OOS)
X-Caliber: 16, 18, and 20 in different profiles from ultralight to heavy / fluted
Keystone Accuracy: various length and profiles.

Any one of these people recommend or that I may be missing? Ideally I'd like a lighter 18" - 20" since I have an AR15 handguard that'd work for that length, but understand 16" is pretty optimal for 22lr. RTB just seems like CMMG for a cheaper price, but I am curious if anyone has tried X-Caliber.

I have a Redi-Mag conversion that'll let me use M&P15-22 magazines w/ a functioning bolt catch. Use case will be for training, plinking, teaching new shooters, testing out how accessories and components. and some ELR. I do shoot ELR with 22 for fun too so a barrel with good accuracy potential would be nice, but most use will be 50 yards or less, maybe 100 yards 25% of the time.

 

[erik72]

I see you mentioned lightweight. Beyer Barrels in Oregon will make a custom length for you. His are the lightweight aluminum barrels with a sst 22LR liner. Many reports of excellent accuracy from his barrels.

 

[SkepticalTiger]

I see you mentioned lightweight. Beyer Barrels in Oregon will make a custom length for you. His are the lightweight aluminum barrels with a sst 22LR liner. Many reports of excellent accuracy from his barrels.

Will this hold up to high round counts? I may see up to 1000 - 1500 rounds in a day. Average should be 300 - 500

 

[erik72]

I would think just as well as any other...maybe even better as the aluminum will dissipate heat quicker. He uses a SST 22LR liner shrouded in aluminum tubing with a 0.920" diam. So you get a bull barrel profile with significantly less weight. Very similar to many 10/22 barrel makers out there like volquartsen, tactical solutions, whistlepig, et. Al. I understand he's very easy to talk to and very helpful. I suggest giving him a call and discussing it with him.

Google search beyer barrels and I bet you'll find tons of positive reviews.

Beyer Barrels - AR15 Barrels

 

[SkepticalTiger]

I would think just as well as any other...maybe even better as the aluminum will dissipate heat quicker. He uses a SST 22LR liner shrouded in aluminum tubing with a 0.920" diam. So you get a bull barrel profile with significantly less weight. Very similar to many 10/22 barrel makers out there like volquartsen, tactical solutions, whistlepig, et. Al. I understand he's very easy to talk to and very helpful. I suggest giving him a call and discussing it with him.

Google search beyer barrels and I bet you'll find tons of positive reviews.

Beyer Barrels - AR15 Barrels

Sounds good to me! I'm used to centerfire bbl's so getting used to how rimfire differs. Definitely making me reconsider an RTB or CMMG since i do want to take this out to ELR ranges as well as mag dumps for drills.

I sent him an email, would phone be better?

 

[Wild_Bill148]

I would call. I sent him an email and never got a response.

 

[erik72]

I'm not sure if he responds to emails. He may but I think most folks have been able to talk to him. I have not. I have never ordered one from him mainly because I have so many AR22 uppers already. Occasionally I see a used Beyer barrel pop up on the classifieds and I have to restrain myself from buying it.
At the risk of getting into a ballistics discussion about barrel lengths, the consensus is that by about 16" all the powder is burnt up and you're at max muzzle velocity. You're not gaining anymore velocity by going longer. I think guys shooting long range precision rimfire like the longer barrels because they see smaller standard deviations from the 22" - 24" barrels. But a 24" bull barrel hanging off the end of an AR is a little unsightly.

Anyway, I'd recommend anything from 16" to 20" to do what you want. The only Alum barreled AR22 I have is a 2A Armament upper. They don't make them anymore but it's a 16.1" barrel and it is fun as hell to shoot.....and mag dump. One other thing that I'll mention is that for accuracy, you may want the Bentz chamber. That's kind or the match chamber for semi-auto. I know Beyer uses this chamber. If you're expecting to mag dump a "bucket 'o freedom", you may want a little looser sporter chamber. The Bentz chamber will shoot most ammo fine but some of the bulk stuff may choke it up. That's been my experience with several Bentz-chambered barrels.

Good luck with your build!

 

[SkepticalTiger]

I'm not sure if he responds to emails. He may but I think most folks have been able to talk to him. I have not. I have never ordered one from him mainly because I have so many AR22 uppers already. Occasionally I see a used Beyer barrel pop up on the classifieds and I have to restrain myself from buying it.
At the risk of getting into a ballistics discussion about barrel lengths, the consensus is that by about 16" all the powder is burnt up and you're at max muzzle velocity. You're not gaining anymore velocity by going longer. I think guys shooting long range precision rimfire like the longer barrels because they see smaller standard deviations from the 22" - 24" barrels. But a 24" bull barrel hanging off the end of an AR is a little unsightly.

Anyway, I'd recommend anything from 16" to 20" to do what you want. The only Alum barreled AR22 I have is a 2A Armament upper. They don't make them anymore but it's a 16.1" barrel and it is fun as hell to shoot.....and mag dump. One other thing that I'll mention is that for accuracy, you may want the Bentz chamber. That's kind or the match chamber for semi-auto. I know Beyer uses this chamber. If you're expecting to mag dump a "bucket 'o freedom", you may want a little looser sporter chamber. The Bentz chamber will shoot most ammo fine but some of the bulk stuff may choke it up. That's been my experience with several Bentz-chambered barrels.

Good luck with your build!

Nice build! So far the cheaper ammo I've standardized on is Federal Champion HP 36gr, CCI SV, Blazer. I don't really shoot Thunderbolt or bucket-o-bullets nor armscor. More expensive ammo outside of match is going to be CCI mini-mag, CCI AR, Velocitor, Stinger, and Federal Punch.

What bulk ammo have you noticed choking in the chamber?

 

[Wild_Bill148]

I'm by no means an expert in this realm but federal auto match has worked well for me in my AR22 and 10/22.

 

[erik72]

Any one of these people recommend or that I may be missing? Ideally I'd like a lighter 18" - 20" since I have an AR15 handguard that'd work for that length, but understand 16" is pretty optimal for 22lr. RTB just seems like CMMG for a cheaper price, but I am curious if anyone has tried X-Caliber.

I have a Redi-Mag conversion that'll let me use M&P15-22 magazines w/ a functioning bolt catch. Use case will be for training, plinking, teaching new shooters, testing out how accessories and components. and some ELR. I do shoot ELR with 22 for fun too so a barrel with good accuracy potential would be nice, but most use will be 50 yards or less, maybe 100 yards 25% of the time.

I looked at the X-Caliber website and they make dedicated barrels but you have to use the chamber adapter. I'm not a fan of that. The chamber adapter is the .223 cartridge shaped adapter in lieu of a round collar that fits over the chamber spud of a dedicated barrel. With the chamber adapter, the projectile is really kind of unsupported for an 1 1/2" until it engages the rifling.

You're on the right track with the better mag adapter and S&W magazines. I have (3) of them and they work great.

 

[erik72]

I'm by no means an expert in this realm but federal auto match has worked well for me in my AR22 and 10/22.

I like Federal Auto Match. For the most part it works well. I've noticed that even if it's a Bentz chamber, each barrel is different and what runs fine in one, may not cycle in another. I've never bought any of the bulk winchester or remington stuff. The bulk pack Federal Target has given me fits in several barrels....all bentz-chambered AR22s. I generally stick to CCI SV, CCI AR Tactical, CCI Mini-mags, Norma Tac22 (the new stuff...I bought a bunch of it when it was like $4/box), Aguila SV. I've never tried any of the SK Std Plus or Rifle Match or any of the "good stuff".

 

[SkepticalTiger]

You're on the right track with the better mag adapter and S&W magazines. I have (3) of them and they work great.

I found some on sale recently and ordered 10 S&W mags. That should be a decent amount for what I do and I got a mcfaden speed loader as well. Normally for classes I bring about 20 mags.

I have a 22lr pistol I train with often so the Federal Champion will suit that just fine. If it doesn't load into the Bentz chamber, I can source another ammo, but definitely giving me something good to think about considering my use case. Also there may be times where I don't know what type of ammo I'll have available so a sporter chamber may be what I opt for or just build TWO 22lr uppers and swap bolts between them haha.

 

[SkepticalTiger]

Called Clint and he told me the only ammo he's seen issues with is really waxy Aguila super extra. I don't stock those since they are pretty unreliable in my semi autos (though they are real nice for ELR on the cheap) so Clint will get my business. Opting for Bore Buddy upgrades because this upper is going to see some pretty high round counts and anything reasonably priced to add to reliability is welcomed.

Just debating on the 16.5" Bull or 18" SPR. The former is a bit less weight and would keep the Muzzle device real close to the end of the handguard, while the latter will just have a thread protector and be a nice in-between since my 16" guns measure 17 - 17.5" and my 18" measures close to 20" with the muzzle devices I've chosen. @erik72 any thoughts?

Parts to be purchased:
Aero M4E1 Enhanced Upper
Aero Enhanced G2 Handguard Mlok
Beyer Barrels (debating between 16.5" bull and SPR 18" 0.920" bull)
Better Mag Adapter
CMMG 22lr Bolt
Bore Buddy Quiet Collar
Bore Buddy AR Premium Reliability Stimulus Bundle
MBUS3 BUIS
Slate Black Industries Vertical Grip

Parts on hand:
Primary Arms 1x Micro Prism
Arken Optics SH4 4-16x50 on 20MOA mount
AR Lowers

 

[erik72]

IMO it looks a little goofy when the barrel is about the same length as the handguard. I'd opt for the longer barrel. How much smaller is the SPR profile than 0.920" Why not just go 18" x 0.920" the whole way...maybe fluted if you wanted to save an ounce or two. I love those Aero Enhanced Uppers/Hanguards. Not sure you need the quiet collar unless you plan to shoot suppressed and silence is critical. It might be fun to play with in the future but I'd just get the std collar and. You can get the quiet collar later. Borebuddy reliability kit is good to go. I've spoken to Will over there. He's really into the AR22 thing and has the CMMG bolt pretty well figured out. Looks like you got a nice build on your hands. Keep us updated.

 

[SkepticalTiger]

IMO it looks a little goofy when the barrel is about the same length as the handguard. I'd opt for the longer barrel. How much smaller is the SPR profile than 0.920" Why not just go 18" x 0.920" the whole way...maybe fluted if you wanted to save an ounce or two. I love those Aero Enhanced Uppers/Hanguards. Not sure you need the quiet collar unless you plan to shoot suppressed and silence is critical. It might be fun to play with in the future but I'd just get the std collar and. You can get the quiet collar later. Borebuddy reliability kit is good to go. I've spoken to Will over there. He's really into the AR22 thing and has the CMMG bolt pretty well figured out. Looks like you got a nice build on your hands. Keep us updated.

Right right, I mocked up some weight and length figures and an 18" with a thread protector will be between my my 16" and 18" built rifles. I don't need weight savings at this point, in fact I'm about 1oz under the weight target I set since my shorter CORE barreled upper is 52oz and my longer Faxon Gunner upper is 57oz.

Bigger focus is actually balance since the two bbl profiles I listed prior keep most of the weight towards the upper, but all things considered nothing an optic can't fix and the Aero upper and handguard should do a good job too. I think I should be fine with an 18" full 0.920" cut at 19.8oz otherwise I'm 2 - 3 oz short of my target.

Talked to Will at Borebuddy and for my needs the stimulus reliability kit is the only thing I need unless I was chasing fractions of dB or full auto. Their bbl's are super tempting and I may get one for another 22lr project down the road. Will saying with my round count I may notice live round extraction issues around the 1000 round mark, but Clint said outside of waxy Aguila Super Extra he hasn't noticed any real issues.

 

[renaissanceman]

Right right, I mocked up some weight and length figures and an 18" with a thread protector will be between my my 16" and 18" built rifles. I don't need weight savings at this point, in fact I'm about 1oz under the weight target I set since my shorter CORE barreled upper is 52oz and my longer Faxon Gunner upper is 57oz.

Bigger focus is actually balance since the two bbl profiles I listed prior keep most of the weight towards the upper, but all things considered nothing an optic can't fix and the Aero upper and handguard should do a good job too. I think I should be fine with an 18" full 0.920" cut at 19.8oz otherwise I'm 2 - 3 oz short of my target.

Talked to Will at Borebuddy and for my needs the stimulus reliability kit is the only thing I need unless I was chasing fractions of dB or full auto. Their bbl's are super tempting and I may get one for another 22lr project down the road. Will saying with my round count I may notice live round extraction issues around the 1000 round mark, but Clint said outside of waxy Aguila Super Extra he hasn't noticed any real issues.

During some barrel testing, I was able to get 2700 rounds through a 16" Borebuddy barrel without cleaning before starting to have minor malfunctions, mostly failures to extract and issues with live round extraction. About 1500 of that total was waxy Aguila ammo (about 800 superextra 40gr, 200 SV 40gr, and 400 60gr SS), with the balance being a mix of match ammo, CCI SV, and a wide variety of junk ammo -- Armscor, Federal, Norma, etc.

I really like the Aguila ammo for blasting -- it's very waxy, but the superextra 40gr gives me the most consistently good performance of any HV ammo. My biggest gripe with the wax is that it clogs up the McFadden Lightning Loader.

 

[SkepticalTiger]

During some barrel testing, I was able to get 2700 rounds through a 16" Borebuddy barrel without cleaning before starting to have minor malfunctions, mostly failures to extract and issues with live round extraction. About 1500 of that total was waxy Aguila ammo (about 800 superextra 40gr, 200 SV 40gr, and 400 60gr SS), with the balance being a mix of match ammo, CCI SV, and a wide variety of junk ammo -- Armscor, Federal, Norma, etc.

I really like the Aguila ammo for blasting -- it's very waxy, but the superextra 40gr gives me the most consistently good performance of any HV ammo. My biggest gripe with the wax is that it clogs up the McFadden Lightning Loader.

What kind of groups were you seeing? Just put in an order for a Beyer bbl, but considering getting the 16" bore buddy to hold me over for the time being.

 

[renaissanceman]

What kind of groups were you seeing? Just put in an order for a Beyer bbl, but considering getting the 16" bore buddy to hold me over for the time being.

Around 1 MOA with CCV SV, around 2 MOA with other cheap ammo.

 

[SkepticalTiger]

Around 1 MOA with CCV SV, around 2 MOA with other cheap ammo.

FYI I'm the guy who made the first post on your discount post in r/gundeals and over torqued his screws Liked your guy's stuff and CS so much I bought some more for a spare PSA 22lr bolt I ordered as a backup... which will actually be going in a 2nd aero enhanced upper w/ their dedicated 15" mlok handguard once my Beyer bbl arrives. I promise I'll post pics soon! Just tweaking the system still.

That aside I've shot about... 3500 rounds shot through the assembled upper using BoreBuddy's 1:12 bbl I built on Sat, and shot Sunday and Tuesday. Haven't shot for groups yet, just been mag dumping a cadence of 250rds within a couple minutes with different ammo types.

Sadly, Federal Champion 36GR HP pressures vary too wildly. Another guy on YT found a SD of over 100fps with some shots being as low as 890ish before hitting 940ish and then 1030ish. CCI Blazer is doing great so far at about... 500 rounds without an issue. I have a 22lr revolver I can still use Champion for, but def a bummer... Luckily 22lr ammo isn't terribly expensive at about 0.063 after tax and shipping for CCI blazer.

I also got 975rds of Federal Automatch to try once I burn through another 500 - 1000 rounds of blazer to hit my 1000 - 1500 total round count between cleanings acceptance criteria. Noticed around the 300 - 500 round mark is when most shooters begin to fatigue. System is running reliably enough with Blazer where I'll start asking people shooting next to me if they want to help me burn through ammo.

 

[SkepticalTiger]

Update:

Fired another 1000 rounds of blazer with no issues so I can confirm that's one of the plinking loads I can get on the cheap.

I decided to set Federal Automatch for failure and emotional damage by not cleaning the bolt, bbl or anything really. Went out to one of my outdoor ranges this time with a friend. Got through about... 750 rounds of automatch before starting to see some failures... with the magazines! Bolt was fine, just needed a little lube and with some clean 10 round mags I hadn't shot much out of, things went swimingly.

My magazines experienced failures where the follower seemed like it had some type of waxy gunk slowing things down especially at 15 rounds or so. Some would not be able to load more than 15 in without the magazine bulging just enough where it couldn't be inserted into the magwell (downloading fixed that). I assume it was a combo of texas heat, texas moon dust getting into some of the mags, and the combination of wax and lead rounds without any cleaning since I opened them up.

Ordered another 1950 rounds of Automatch for a total of a little over 2000 rounds, magazines are currently soaking in some soapy water and will be scrubbed down and checked for any other failures and emotional damage, and I'll inspect the bolt and chamber for any foreign material or damage. I'm wondering if Automatch is dirtier than Blazer or is experiencing some weird issues due to exposed lead vs a waxier coating.

 

[erik72]

Sounds like you're really burning up some ammo. Are you shooting all this up with a Borebuddy Barrel? How are you liking the 1:12 twist rate?

 

[SkepticalTiger]

Sounds like you're really burning up some ammo. Are you shooting all this up with a Borebuddy Barrel? How are you liking the 1:12 twist rate?

100% the borebuddy bbl. Clint is still making my bbl and I am going to call him later this week to verify he has my address I sent via email just in case I miss spoke over the phone. I have another bolt from PSA with a second reliability kit. Quality of PSA isn't bad, but I had to bend it in place a bit compared to the one I got from RTB. That won't be shot until the next bbl comes in since I've already loctite my RTB bolt to function well with my mag dump drill.

I haven't done any groupings yet besides a 25 yard zero with irons and a 1x optic, but it's effectively a ragged hole with Blazer and CCI standard. Once I burn through the next 2k ammo shipment of Automatch I'll take it out to 50 yards and do a more thorough test of which ammo this bbl likes. Typically for ELR I use SV and Velocitor since the accuracy with those is good enough for my needs. With Clint's bbl I won't be mag dumping through that as much if at all and focus more on groups.

I've fired so many rounds so quickly that the bbl collar from Borebuddy has changed color from stainless steel to more of a caramel color in almost a stripe pattern. I'll take pics soon, but no issues reliability wise. Since I'm not using super waxy ammo I haven't had any live extraction issues.

 

[SkepticalTiger]

Tactical Sports USA ships super fast if you're in Austin, literally the next day. My Beyer bbl finally got shipped so looking forward to putting it into a 2nd aero upper I got from Primary Arms on a recent sale.

Shot about... 4 boxes of 325 on top of the other 750~ I fired 2 weekends ago so about 2050 total of Automatch, AM, so far. Taking out the bolt there's so much gunk in the upper it's crusty, the bolt wipes off fine (only a little, so most is still on it). I think the bbl and bolt still hadn't been cleaned from 1500 rounds of blazer so total since last cleaning is about 3500. The RSO and range owner is pretty impressed and know BoreBuddy by name since I don't shut up about it ha ha.

I cleaned out my magazines and found 3 were wearing down plus a 4th after last weekend's range session. 1 will cause stovepipes due to feed lips, 2 are close to doing that but not yet, and a 4th had an issue where the follower was dragging and a round wasn't chambered in time. I plan on taking a heat gun to a couple to remedy this. I may need to order another 10 magazines from Joe Bob Outfitters since they're the cheapest I've found for magazines at 16~ for a 25rd tan magazine. An RSO recommended adding a bit of lube to the springs to help since I have to pull the follower down a bit so rounds don't get jammed and caught in the magazine like what happened 2 weeks ago. My less worn 10 round and 1 25 rounder don't need this.

Ordered about 22 boxes of AM from Brownells today since they're running a deal on 11 boxes per order with CART30 coupon code so they came out to 5.5 cpr shipped after tax. Tempted to buy another 11 - 22 boxes since that's one of the better deals I've seen in a while and the ammo has been working pretty well so far. I still have 2k rounds of Aguila Super Extra HV 40gr Copper-Plated Bullet I want to shoot through as well in case those are on sale or group better than CCI SV.

Once I get the Beyer bbl I'll see how CCI SV, CCI Velocitor, AM, and Aguila group with it and the BoreBuddy bbl. Up for feedback on the below testing methodology I plan to use. Will try Eley, SK, Wolf, Lapua, etc if I intend to take this into competition. MarkandSam AfterWork have pretty good results with CCI SV and CCI Velocitor out to pretty far distances with their precision 22lr builds and from my limited experience taking shots out to as long as 600, see similar results.

Intent of what I'm trying to do is see how the bbl accuracy adjusts from a clean bore, to gradual seasoning before looking to see how multiple 10 shot groups look, what the largest groups will look like at higher round counts and if I were to chamber each round manually to take out any damage from being loaded into the magazine and chambered. Ridiculous yes, but I'm pretty curious and my local indoor range has let me stay there from opening time at 11am to when they close around 6:45 before when I've done other 22lr burn down tests before. Opting for 10 shot groups and taking a mental note of where the first 5 landed to get a better idea of how everything is functioning.

Ammo Testing Methodology:
50 yards indoors
Sitting at bench with rifle in Caldwell Precision Turret
1x 10 round magazine
4x 25 round magazines
350 rounds loaded by hand into magazines to avoid speed loader variable
Time estimate 1 hour 30 minutes to 1 hour 45 minutes
Arken SH-4 Gen 2 4-16x54 optic on 20 MOA single piece mount
1 Large B27E
19 4" Blue Splatter Paper Stickers
Edit: Forgot the lower and trigger I'll be using
KE Arms KP15 lower
LaRue MBT-2S Trigger Straight Bow w/ lighter spring

*Clean bore group
Clean bore
Shoot 10 (I intend this first group to be on a large target so and adjust the optic once I have my group

*Gradual seasoning groups
Repeat 4x times
Shoot group of 25 rounds
Let cool for 10 - 15 minutes
Shoot group of 10
Let cool for 10 - 15 minutes after final 10 shot group

*Seasoned groups
Shoot 5x 10 shot groups consecutively
Let cool for 10 - 15 minutes

*Seasoned max group
Shoot 4 25 shot groups consecutively
Let cool for 10 - 15 minutes

*Seasoned hand load groups
Shoot 5x 10 shot groups consecutively, loading each round into the chamber by hand

 

[obx22]

I’d love to see a pic of your build, the magazine, and what the chamber area looks like with bolt locked back. I’m assuming from the sheer number of rounds fired, you are seeing no peening of the breechface? Can’t wait to hear/see the accuracy results.
I’ve kinda had a long term project AR conversion, and was just given a barrel which may give the accuracy I crave. Discussing this with my AR guru, he explained as long as I’m shooting the military trigger and loose collapsing buttstock, I’ll never see what the gun is really capable of.
While pondering the next steps, I discovered something that, if it works, will give me an excellent test bed for the barrel at least. It turns out the Tac-Sol upper/barrel has nearly identical tenon dimensions to a Sako P94S Finnfire, as in I’ll slap the Tac-Sol barrel into a bolt action with 2oz trigger and benchrest stock and really see what it’s capable of

 

[SkepticalTiger]

Uploading pics and some video's for you right now. I forgot to mention I'll be using a KP15 lower and LaRue MBT-2S Trigger Straight Bow trigger with the lighter spring.

Edit: After nearly... 5k rounds with the MBT-2S I've really grown to appreciate 2 stage triggers for speed and precision. I do shoot pretty quick and there's less warm up with my single stage milspec and especially with my KE Arms RTS-1 trigger, but am quite happy how well the La Rue trigger does at getting my groups tight with even a 1x primary arms cyclops reticle on a 4in target at 50 yards and keeping my shots within about 2.5" just using the magazine as a monopod. My buddy who has shot less than 100 rounds total in his life was able to get a 3" 5 shot group at the same distance, same gun and optic after figuring out where he needed to aim within 10 shots.

 

[SkepticalTiger]

I’d love to see a pic of your build, the magazine, and what the chamber area looks like with bolt locked back. I’m assuming from the sheer number of rounds fired, you are seeing no peening of the breechface? Can’t wait to hear/see the accuracy results.
I’ve kinda had a long term project AR conversion, and was just given a barrel which may give the accuracy I crave. Discussing this with my AR guru, he explained as long as I’m shooting the military trigger and loose collapsing buttstock, I’ll never see what the gun is really capable of.
While pondering the next steps, I discovered something that, if it works, will give me an excellent test bed for the barrel at least. It turns out the Tac-Sol upper/barrel has nearly identical tenon dimensions to a Sako P94S Finnfire, as in I’ll slap the Tac-Sol barrel into a bolt action with 2oz trigger and benchrest stock and really see what it’s capable of

Top rifle is what I've been using to test everything with so far. The magwell is a bit small so the adapter is a nice snug fit. The lower on the bottom is what I will the next upper on. Idea with the first is it's more of a plinking / trainer since it's in the middle length and weight wise compared to my other ARs while the 2nd is going to be dedicated more towards ELR, and distanced stuff.

Edit: Magazines with a black dot mean they gave me some type of issue relating to feeding into the rifle. Red marks are magazines showing signs of feed lip issues. 3 lines mean it'll always cause an issue, a single line across each half is actually me being lazy with two lines meaning it's close, and a single line (not sure if it was shown) means it's beginning to exhibit signs of wear. I base this off of how much the round points upward or can be wiggled vertically when loaded into the magazine. If it wiggles a little then it's a single or double line, if it completely points upward then it's a three line and needs repair.

Someone commented on a youtube video of M&P15-22 magazines wearing out said they took a heat gun to theirs and squished the feed lips together.

 

[SkepticalTiger]

 

[SkepticalTiger]

Waiting for @renaissanceman to see these and be like

 

[obx22]

Excellent! Yours appears to be a much different system, looking forward to seeing your accuracy results with the new build.
Here’s pics of mine currently. Goal is for it to be a match accurate barricade rimfire rifle from 25-400+yds
I’ve fired one match just to establish a baseline, but as I’ve said, accuracy is
Best group fired thus far at 100yds was 1.6” with CCI SV.
Out of over 1000 rounds of various types fired, zero malfunctions.

 

[SkepticalTiger]

Excellent! Yours appears to be a much different system, looking forward to seeing your accuracy results with the new build.
Here’s pics of mine currently. Goal is for it to be a match accurate barricade rimfire rifle from 25-400+yds
I’ve fired one match just to establish a baseline, but as I’ve said, accuracy is
Best group fired thus far at 100yds was 1.6” with CCI SV.
Out of over 1000 rounds of various types fired, zero malfunctions.
View attachment 8166303View attachment 8166305View attachment 8166306View attachment 8166307View attachment 8166308View attachment 8166309

Great looking rifle and excellent photos!

You are correct, I opted for Dedicated 22lr bbl's that play nicely with CMMG's 22lr setup. I might have gone with something else if BoreBuddy didn't have their upgrades to make the system really work nicely.

There's another indoor range I don't have a membership at with a 100 yard bay I'll verify groups at sometime with whichever ammo groups the nicest out of each gun. Where your groups 3, 5, 10 or a different shot group?

 

[SkepticalTiger]

Good news! My Beyer Barrel came in today. Since I'm in Austin the MBT-2S I ordered today should be coming in before the weekend. If not I'll take it out of my current lower. Even got a playlist ready for Sat and Sunday's sessions I'll post pics this weekend.

This will be for 50 yard groups, possibly will do 100 yards next weekend.

 

[obx22]

Great looking rifle and excellent photos!

You are correct, I opted for Dedicated 22lr bbl's that play nicely with CMMG's 22lr setup. I might have gone with something else if BoreBuddy didn't have their upgrades to make the system really work nicely.

There's another indoor range I don't have a membership at with a 100 yard bay I'll verify groups at sometime with whichever ammo groups the nicest out of each gun. Where your groups 3, 5, 10 or a different shot group?

This was the set-up for testing at 100yds, I was able to replace the $30. airgun scope a short time later. I still need to source 10-15 round magazines or cut down a 25 rounder to make it more barricade friendly.

 

[SkepticalTiger]

Upper is built! I attached it to a stripped KP15 lower to see how fitment felt. KE Arms makes their stuff a bit on the tighter side so the enhanced upper mates up well. Redi-Mag adapter needed a few layers of painters tape for a tighter fit so will use that or opt for thicker duct tape to keep it shimmed.

However, I can't help but notice a tiny degree of cant in the bbl towards the right side. I know how to lappe an upper, but lack the tool to do so. My other M4E1 doesn't seem to have this. I'll keep watch of anything abnormal as I put rounds through it. Biggest concern would be the ammo, bolt and/or barrel experiencing issues since it's not lining up perfectly. I know there was someone else besides X-Caliber who made one, but that was a few years ago. I'm a SOTAR alumni so I may see if anyone is willing to lend me theirs. That or putting the Beyer Barrel onto the other upper

With my centerfire ARs I use Loctite Green 620 on precision or rugged builds and Aero Shell 33ms on stuff I want to take apart on a more frequent basis or am still tweaking, this got the latter. Torqued the bbl nut to 30 ft lbs 2 times and then to 55 ft lbs. Handguard screws got blue Loctite and were torqued to 25 in lbs. Scope was torqued to oem specs, 16 in lbs on the rings to the mount. The mount is just snug fit to the upper since I haven't figured out the right spot for it yet. Where I have it now seems good but not settled yet. I'll torque that to 30 in lbs. From my eye the scope seems level.

I have a parts kit to fill the lower less the new MBT-2S trigger I'm still waiting on. If nothing by Friday night I'll install the broken in one. I reckon I'll keep the controls pretty standard. I ended up buying another KP15 lower I'll put ambi controls on. Debating if I want to rebuild the dedicated 22lr parts on another upper to be a bit more light weight since female shooters and skinny armed guy friends say it's kinda heavy even though it weighs in at 6.6lbs w/ optic, back up irons, vfg and balances right at the magwell.

The RSOs and range owner okayed me taking multiple days if needed to do my tests so long as I don't spill CLP everywhere and not pick up after myself.

 

[SkepticalTiger]

View attachment 8166811This was the set-up for testing at 100yds, I was able to replace the $30. airgun scope a short time later. I still need to source 10-15 round magazines or cut down a 25 rounder to make it more barricade friendly.View attachment 8166812

Good group! I'm excited to see how well my bbl does at 50 and 100 yards over the next few weeks. One reason I opted for M&P15-22 magazines as well was I could get 10 rounders a lot easier. I'm tempted to cut down the first really broken one to 10 or 15 down the road too. Would look pretty nifty!

 

[Ernest 5.56]

Good group! I'm excited to see how well my bbl does at 50 and 100 yards over the next few weeks. One reason I opted for M&P15-22 magazines as well was I could get 10 rounders a lot easier. I'm tempted to cut down the first really broken one to 10 or 15 down the road too. Would look pretty nifty!

How does the collar attach to the barrel ?

Do you have any cci velicitator to test ?

 

[SkepticalTiger]

How does the collar attach to the barrel ?

Do you have any cci velicitator to test ?

The attachment point for the handguard is attached to the upper and there is a barrel nut that threads into the middle of that. So instead of being this large barrel nut we're used to it's smaller, but still allows bbls as big as 0.920 (bull profile) to work.

I think I have about... almost 500 rounds of CCI Velocitor so enough for this test at 50, a follow-up at 100 and then 100 or so for outdoors. I managed to get a hit with a stock 10/22 Tactical using a PA 22lr 6x scope out to 600 yards on a hot day. I want to see how much easier that is with this new setup.

 

[SkepticalTiger]

How does the collar attach to the barrel ?

Do you have any cci velicitator to test ?

I completely misunderstood your initial question.

The collar on the 22lr bolts have a small detent that fits into a grove on the bbl. Since the 22lr bbl has to extend into the upper by an inch or so the collar fills this gap and provides a nice feed ramp. BoreBuddy told me it shouldn't be snug, just fit over nicely. I've tensioned mine to be removed with medium finger pressure but not fall out when held upside down. Before I would tighten it down till it stopped, but not snug and then unscrew it a bit when I would take it out.

 

[Ernest 5.56]

I completely misunderstood your initial question.

The collar on the 22lr bolts have a small detent that fits into a grove on the bbl. Since the 22lr bbl has to extend into the upper by an inch or so the collar fills this gap and provides a nice feed ramp. BoreBuddy told me it shouldn't be snug, just fit over nicely. I've tensioned mine to be removed with medium finger pressure but not fall out when held upside down. Before I would tighten it down till it stopped, but not snug and then unscrew it a bit when I would take it out.

Hmmm should not be snug...that's interesting wonder why

 

[SkepticalTiger]

Hmmm should not be snug...that's interesting wonder why

You can adjust it if you have borebuddy's collar. The stock one just slips on and index fine, but I prefer mine to be a bit more.

 

[renaissanceman]

Hmmm should not be snug...that's interesting wonder why

Because it is a ball detent and it is easily destroyed tightening into the barrel groove. On the borebuddy collar, you can remove the ball detent and replace it with an M4 set screw if you want to lock the bolt to the barrel.

 

[Ernest 5.56]

You can adjust it if you have borebuddy's collar. The stock one just slips on and index fine, but I prefer mine to be a bit more.

This collar?

https://borebuddy.com/product/22lr-barrel-collar/

 

[SkepticalTiger]

Because it is a ball detent and it is easily destroyed tightening into the barrel groove. On the borebuddy collar, you can remove the ball detent and replace it with an M4 set screw if you want to lock the bolt to the barrel.

Dumb question, but what's the purpose of a ball detent vs set screw then?

 

[renaissanceman]

Dumb question, but what's the purpose of a ball detent vs set screw then?

It allows the bolt to pull out without tools. it's nice in the field to be able to rip the bolt out to wipe it down or re-lubricate.

 

[SkepticalTiger]

It allows the bolt to pull out without tools. it's nice in the field to be able to rip the bolt out to wipe it down or re-lubricate.

Thanks for the info I was under the impression you tighten the bearing to where it's somewhere between snug and requires a bit of pressure to pull out so you get this middle ground between tensioning to the bbl and field repair.

I'll likely use an M4 screw on the new build once I get it nice and tuned. Any differences in reliability, performance, etc?

 

[renaissanceman]

Thanks for the info I was under the impression you tighten the bearing to where it's somewhere between snug and requires a bit of pressure to pull out so you get this middle ground between tensioning to the bbl and field repair.

I'll likely use an M4 screw on the new build once I get it nice and tuned. Any differences in reliability, performance, etc?

Shouldn't be much, but when you're chasing groups, everything helps. We don't lock them for testing since it's not an officially supported method, but may have to do it in the next batch of testing.

 

[erik72]

However, I can't help but notice a tiny degree of cant in the bbl towards the right side. I know how to lappe an upper, but lack the tool to do so. My other M4E1 doesn't seem to have this. I'll keep watch of anything abnormal as I put rounds through it. Biggest concern would be the ammo, bolt and/or barrel experiencing issues since it's not lining up perfectly. I know there was someone else besides X-Caliber who made one, but that was a few years ago. I'm a SOTAR alumni so I may see if anyone is willing to lend me theirs. That or putting the Beyer Barrel onto the other upper

That's a little concerning. Especially if you can see it. Just spit-balling here....might be something to check to make sure the whole barrel is straight and aligns with the barrel extension. I can't see the upper receiver being off to the extent you can see a crooked barrel? I figured the lapping would just make a flat surface so as to eliminate any rocking with the barrel inserted. But to correct a misalignment issue like that might actually take some machining. The lapping tool extends far into the upper receiver with the idea it is creating a flat surface perpendicular to the receiver. Maybe it could remove enough material to square it up; not sure as I haven't had to do that. Fortunately, the bullet is going where the barrel is pointed so a misalignment between the barrel and upper receiver can be accounted for during the sight in process. The bolt rides on rails so it's not depending on the upper receiver to align with the barrel breech. I guess what I'm saying is that is probably something I'd want to fix but in the end, it may not affect funtion or accuracy of your dedicated upper.

 

[SkepticalTiger]

That's a little concerning. Especially if you can see it. Just spit-balling here....might be something to check to make sure the whole barrel is straight and aligns with the barrel extension. I can't see the upper receiver being off to the extent you can see a crooked barrel? I figured the lapping would just make a flat surface so as to eliminate any rocking with the barrel inserted. But to correct a misalignment issue like that might actually take some machining. The lapping tool extends far into the upper receiver with the idea it is creating a flat surface perpendicular to the receiver. Maybe it could remove enough material to square it up; not sure as I haven't had to do that. Fortunately, the bullet is going where the barrel is pointed so a misalignment between the barrel and upper receiver can be accounted for during the sight in process. The bolt rides on rails so it's not depending on the upper receiver to align with the barrel breech. I guess what I'm saying is that is probably something I'd want to fix but in the end, it may not affect funtion or accuracy of your dedicated upper.

I'll take a look today. Generally speaking Aero uppers can be a bit off to one side. When I was taking an AR15 Gunsmith class from School of the American Rifle, I brought a slick side Aero upper and from memory the face was off by about.... 0.03" so we ended up lapping it to get it nice and straight. Not enough to effect headspace, but we had some shims if push came to shove. As far as lapping goes Chad's 2 cents were you can do it on uppers that don't require a thermal fit because you don't risk dimensions being so tight you take off material inside the upper.

Lapping in general from my own training is to make sure the barrel is aligned with the upper based on the two mating surfaces. Barrel rocking is more of an issue with the empty space the barrel extension fits into. Since most OEMs don't let their uppers sit for the 2 - 4 ish weeks for the aluminum grain to settle after being forged, what happens is that the front of the upper almost has a slight cone shape. So you'd use some type of compound not only to avoid galvanic corrosion, but also to fill empty space. Naturally Loctite Green is ideal, but Aeroshell can be used. There just needs to be something to fill that space really. One reason I'd fix this is mostly just me being a bit ocd / perfectionist about these things. I'd polish up the feed ramp if it wasn't cnc'd and polished. I'm just waiting on a bipod to come in and i'll post an update photo.

Ended up taking out my current MBT-2S since it's broken in. One thing I do need to fix and only found out today while playing around with my lower is that the Redi-Mag converter works best if you fit it into an undersized magwell. When I mean undersized I mean where it only plays nicely with STANNAG and the adapter requires 2 hands and a good amount to a lot of force to get it in. What's happening is that the adapter is snug, but it's easy to move it slightly out of place causing my bolt release to not function and dropping / inserting mags to be sticky until it's pushed back up by a mag insertion. I reckon some thicker tape or something to bond it slightly to the lower would do the trick or just maybe some JB weld to create a ledge that'd stick and I could remove later. Easy fix. Otherwise it sounds and feels great!

 

[SkepticalTiger]

Pardon the notification spam people. I took a second look at my other upper and didn't notice the SLIGHT angle it is towards the right. Didn't notice before since the bbl is so thin but under proper light I'd guestimate it'd be a bit less than the one I just built. Contacted some alumni to see if anyone has one they could lend be, but if nothing by... Sunday I'll buy an X-Caliber and true up the uppers because it's definitely peeving me now ha ha. Love Aero for their affordability, but this is definitely annoying as nearly all Aero uppers I've purchased had slight or fairly significant offset. Easy fix thankfully enough.

 

[Rockfish Dave]

Waiting for my keystone accuracy barrel.

AR-22 Barrels – Keystone Accuracy

keystoneaccuracy.com

 

[SkepticalTiger]

Waiting for my keystone accuracy barrel.

AR-22 Barrels – Keystone Accuracy

keystoneaccuracy.com

These were in my list of options. I didn't go this route due to cost and weight. I might pick one up when I am getting more serious about precision. Why this bbl for your needs?