10/22 Takedown becomes inaccurate after a hundred rounds?

[wally]

I was using Remington Thunderbolts .22lr. Maybe that's the problem.

Before I saw the rest of the thread I was going to say a good cleaning and change of ammo would be the first thing to try.

The remainder of the thread seems to have confirmed it.

Thunderbolt has been crap since about 2006 when they changed from the traditional "waxy" lube to a new shinny polymer coating, was an improvement when loading mags but a disaster when shooting

 

[longshooter99]

My guns get treated like royalty, soft cases, gentle handling, cleaning after every use. Except my 10/22. It's like the AK of the .22 world. I rarely clean it other than when it's been dropped in mud or something, plus i've put probably 1000 rounds of thunderbolt ammo through it. Last week I put a new red dot on it and was getting 1.8 groups at 100 yds with it. I think that's good for a beat up rabbit/varmint gun.

 

[Picher]

I'm wondering whether this is a three-strikes and you're out kinda problem with this particular situation. First strike: a new Ruger 10-22 barrel. Some I've experienced in the past few years have been very rough inside, at least for the first thousand rounds. My B-I-L bought a stainless Wal-Mart 10-22 and I could not get that rifle to shoot, no matter what "magic" I could do for it...until we got a Green Mountain barrel. Then groups shrank from 1 1/2" to 5/8" at 50 yards!!!

Strike Two: Rem Thunderbolts. They're about the worst quality rimfire ammo I've found in over 50 years of shooting. Numerous misfires, noticeable variations in pressure/velocity, dirty shooting. Most knowledgeable shooters shunned them years ago.

Strike Three: Being a semi-auto and a new rifle bore, firing lots of rounds in a hurry, barrel overheating and it's attendent effect on wax-coated bullets was the worst thing to do. If that happened...you're OUT!!!

That was the worst leading I've ever seen in a .22LR, even from old, pitted bores.

 

[Gtscotty]

Before going hog wild, mix a 50-50 solution of hydrogen peroxide and white vinegar. Plug the chamber and being VERY careful not to get any on the bluing (I use a plastic tube or a soda straw) fill the barrel and let it stew a few minutes. Then pour the resulting gray sludge directly down the drain. Repeat as necessary.

Then dry the bore with patches, clean as normal and lubricate.

Be very careful with this, you are basically making "The dip" that people use to clean rimfire suppressors. When you're done you will have a bunch of lead acetate which is apparently very easily absorbed through the skin.

 

[Fremmer]

If you pour that stuff down the drain, it'll end up in a river somewhere (at least it will if you're in the Midwest, lol), so maybe find a better disposal option.

Thunderbolt ammo is quite cheap and very dirty.

 

[d2wing]

If it were me I would fix the rifle by lapping the barrel or replacing it. No matter the ammo, the barrel is the problem. All factory barrels need some break in. Unless the barrel is lapped from the factory, it will be improved by lapping it. A Rimfire should be cleaned every 100 or 200 rounds. That is if you like accuracy. I haven't seen a barrel foul like that, I would call Ruger and get it fixed. Or trade off the ammo like OP said.