So my Hk branded 416 .22lr has started keyholing through paper. No suppressor attached. I have about 700 rounds through the rifle at this point shooting mainly Remington thunderbolt ammo. Is this a normal indication of needing to clean the barrel? I have lost all accuracy at this point whereas in the beginning I was hitting steel at 200 yards consistently.
Keyholing at 7 yards
- Thread starter aslrookie
- Start date
You’re not gonna make it shoot any worse if you do clean it so I would definitely clean it. Any sort of muzzle device on it? I know you mentioned no suppressor but that doesn’t mean you don’t have a flash hider or something of the sorts on it.
22lr have you checked for carbon ring or whatever
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22 LR Accuracy Killer
I've been reading Bill Calfee's book and several things I knew about really popped out clearly in my mind and I learned a few things too or at least the reason some of these things happen. The one thing is the Carbon Ring that builds up right in front of the case mouth. As rounds are fired...
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Check out this thread on Remington Thunderbolts causing a leading issue in a HK416 https://www.rimfirecentral.com/forums/showthread.php?t=579284
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Thunderbolts are horrible about leading up the barrel. I had a bunch that a family member bought and never used so I ran it though my pistol. After two or three bricks it was shooting all over the place because there was a big deposit of lead and carbon just forward of the chamber and the entire crown area was full of lead and you raised up from the muzzle. Give it a good cleaning and you should be back to normal. Unless you have a ton of that stuff around, I would look for another ammo.
Your barrel is leading.
Remington Thunderbolt is notorious for doing this. If you are shooting fast groups or even slow singles, the soft lead will melt, coat the barrel and the result will be like having a smooth bore. What you describe happened to me with 2 .22 target pistols. I don’t know why but fat barrels don’t seem to have this problem where thinner ones do (.750 vs .920). My Kidd heavy barrel 10/22 and my Lothar-Walther heavy barreled AR22 don’t have this problem. Twist rate could also a potential problem as traditional .22 LR barrels utilize a slower 1:16 twist whereas most AR barrels are between 1:7 and 1:9. There is a ton of information on the web about the Remington Thunderbolt problems. JB Bore paste and elbow grease is your friend. In the final analysis, stop using Thunderbolts in that rifle.
Good luck friend, you have a lot of work ahead of you.
Remington Thunderbolt is notorious for doing this. If you are shooting fast groups or even slow singles, the soft lead will melt, coat the barrel and the result will be like having a smooth bore. What you describe happened to me with 2 .22 target pistols. I don’t know why but fat barrels don’t seem to have this problem where thinner ones do (.750 vs .920). My Kidd heavy barrel 10/22 and my Lothar-Walther heavy barreled AR22 don’t have this problem. Twist rate could also a potential problem as traditional .22 LR barrels utilize a slower 1:16 twist whereas most AR barrels are between 1:7 and 1:9. There is a ton of information on the web about the Remington Thunderbolt problems. JB Bore paste and elbow grease is your friend. In the final analysis, stop using Thunderbolts in that rifle.
Good luck friend, you have a lot of work ahead of you.
You couldn't find worse ammunition than the thunderbolts if you tried!
I think the finish quality of the bore has more to do with the leading process than the diameter of the barrel. The Kidd and Lothar-Walther barrels I have messed with in the past have had really nice lapped bores that have a nice smooth finish. Some factory barrels are no where near that nice so they can pull lead off the bullet to fill in the imperfections and as that builds up it causes the issues.
Originally, I was shooting suppressed with a obsidian 45. I pulled the can off for cleaning and put the factory flashider back on it. The rounds were going astray when the suppressor was on and off. I started shooting with the with suppressor on from the first round to the 700th. Accuracy noticeably fell apart close to the 700th.
I will check those out. My .22cal cleaning stuff is not compatible with the .22lr barrel. So I need to grab a rimfire cleaning kit.
I will check those out. My .22cal cleaning stuff is not compatible with the .22lr barrel. So I need to grab a rimfire cleaning kit.
The first and last time I used Thunderbolts, 6 years ago during that shortage, and they leaded up my barrels so bad I could hardly get my cleaning rod in the barrels. Upon some considerable effort I managed to removed chunks and flakes of lead out and get the cleaning rod in to do a proper cleaning.
This is what some of that looked like from out of a single barrel:
This is what some of that looked like from out of a single barrel:
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Wow, that's bad. I still have half a brick of Thunderbolts from 30+ years ago. Shot a lot of them when I was a kid with my Marlin 60.
That’s what I thought. It seemed like my brush was going to get stuck. Figured maybe I needed a dedicated rimfire kit.
Not unless your barrel is heavily leaded, or you try to pull and push the brush back and forth without letting the bristles clear the barrel.
I switched to using a bore snake a couple years ago, but after wearing out a few of those I'm switching to lead and carbon "blends" with a nylon bore brush, and patches with Rimfire Blend and Carbon Remover.
The barrel ID has a huge influence on leading.
Any lead bullet that doesn't fully obturate, either due to lead hardness being too high for the pressure developed by the propellant or due to the bore being just too large, lets combustion gas leak around the OD the bullet literally melting lead as the bullet travels down the bore.
It's pretty obvious that if you were hitting steel at 200 even with thunder stuff you now have a major lead/carbon ring that is stripping the driving band off the bullet and turned your .22 into a musket. May come out fast like the Pic of the patch in the thread or may have to work it a bit. Patch left in place to dwell, maybe JB's. JB will also polish throat area and maybe help slow the leading process.
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