keyhole problems

My MkIIBTV has developed a problem with tumbling bullets. My gunsmith says it must be the crown but I've been careful not to put any deformed bullets in the gun. Still the way the gun feeds it's possible to mutilate soft lead I suppose. I've used a microscope to check the outside of the crown and I can't see any problems. I still have some time left on my warranty.

I was just wondering if I'd be better off just to go ahead and have the barrel re-crowned or whether I should ship it back to Savage. I believe it's possible that it could be some other problem besides the crown but I'm no gunsmith. Mainly I just hate to be without my MkII for a week or two or however long it takes.

Any helpful comments or suggestions would be appreciated. Should I send it back to Savage?

What distance are you shooting?

I recently read a thread on another board where a person was having keyhole issues as well. His was a centerfire and every type of round keyholed. After a lot of frustration and ammo consumption he decided to fire at a closer target. It turns out the guy had his scope adjusted so that the bullets where hitting the ground about midway to the target then ricocheting up into the target.

I am not saying this is the case with you but if you are shooting at a long distance it might be possible the bullets are hitting something in between.

Here is the thread if anyone is interested in reading it:
http://www.ar15.com/forums/topic.htm...=318086&light=
The guy was honest enough to come back in and say what was wrong. We all got a pretty good checkle out of it.

Dolomite

The first factor to check for keyholing in centerfire rifles is usually the crown - it's the last part of the firearm to touch the bullet, so it's the most llikely suspect to upset the bullet. And sometimes the crown can be fine, but the bore's just so worn that the only solution is replacement. You're not there! - Your gun is still too new and a rimfire takes a lot of shooting to wear a barrel out.

You didn't mention if you had changed ammo before the keyholing was noted. Try different ammo at the same distance to see if the keyholing still exists. Since you can't change cartridge components with a rimfire, changing ammo's the only way to find out what shoots best in your rifle.

good luck!

is the gun clean or leaded up?
same ammo, or did you change?

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It turns out the guy had his scope adjusted so that the bullets where hitting the ground about midway to the target then ricocheting up into the target.

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LOL I'm not quite that new to this stuff. I'm shooting at 50 yards. I haven't changed anything on my rifle or anything so I'm not bouncing anything to the target. :D I can actually still shoot decent groups much of the time because it doesn't tumble every shot. But the times it does tumble makes for a much lower score on my target than I was getting. I shoot ARA targets and I had gotten my scores up above 1600 and one 1700. Now I'm down to 1400 or so. My group size was about .5" but now it's more like .75". I've tried several different kinds of ammo and I gave each brand a chance to settle in before I gave up on it. I've shot everything from Federal bulk ammo to Eley Tenex and I get the same problems every time. But I had been shooting Wolf MT for a long time when this started. I had tried other ammo before of course but that had been quite a while before the problems. I switched to other ammo when I started having problems to see if ammo was the problem too. It wasn't the problem. I still had the same issues with every type of ammo I used.

I've also tried cleaning the bore with several different cleaners. I hadn't used anything but a bore snake to clean that rifle for months before it started acting up like that and it started all at once. Yes I know that could lead to a buildup but I've tried several name brand products on the market since then and I still have the problem. If it's a lead problem it is a stubborn one. I've cleaned the bore so many times now that I worry about damaging the bore by over cleaning. I'm only talking about cleaning it about 5 times but it was all with different products and with the same technique I've been using for a long time without any bad effects.

You probably see why my gunsmith says it's the crown. I know the barrel isn't shot out but a crown can be damaged by a deformed bullet can't it? I think the way this rifle feeds could have caused a problem with a bullet. It just doesn't feed smoothly all the time. In fact it feeds pretty rough at times. It doesn't really have a feed ramp like most guns have. Obviously it is setup to feed but it could be made to feed much smoother.

The place where I bought my rifle has shipped other guns back to the factory for me. I plan on taking it them today to see what they say.

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Originally Posted by King Ghidora

I know the barrel isn't shot out but a crown can be damaged by a deformed bullet can't it?

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Not really - more likely to have problems from pulling a bore snake out at an angle (sawing it against the edge of the crown as you pull it through), damaging it with a cleaning rod, or bumping it against something. Doesn't take much to damage the crown on a 22.

Take a micrometer to 50 or so bullets from this lot.

What do they spec out at?

Josh

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Not really - more likely to have problems from pulling a bore snake out at an angle (sawing it against the edge of the crown as you pull it through), damaging it with a cleaning rod, or bumping it against something. Doesn't take much to damage the crown on a 22.

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It's a step target crown so I don't think I could have bumped anything. I hadn't used a cleaning rod for a long time before the problem started happening. I didn't even use the bore snake very often to be honest. I'm a believer in not cleaning a .22 any more than needed. Unless I start having a problem I usually won't touch a .22 with anything. But I did use a bore snake with a cloth pull string sometimes. I probably only cleaned the bore about once every 500 rounds on average. I don't remember cleaning the bore just before the problem came up but maybe I did.

At any rate are you saying it's probably the crown? The rimfire sites all had people saying to only use a bore snake. I know a cleaning rod can do damage but I'm surprised at the idea a bore snake could do it. I've read a lot of posts from some very smart people that said a bore snake would not hurt a bore unless you dropped in in sand or tried pulling it backwards when you had it half way through the bore or something equally silly. In fact I've been using the equivalent of a bore snake to clean bores all my life. We made out own when we were kids. Dad showed us how to do it. That would have been in the late 1950's / early 1960's.

Whatever did it there is a problem though. My main concern now to figure out how to fix it. Then I'll worry about how to prevent it from happening again. I've been looking at getting a bore guide but I didn't think I really needed one with a bore snake.

[quote=King Ghidora ]

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It just doesn't feed smoothly all the time. In fact it feeds pretty rough at times. It doesn't really have a feed ramp like most guns have. Obviously it is setup to feed but it could be made to feed much smoother.

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This would be my guess, bullets getting deformed as they feed.

Maybe you can try single loading a bunch and shooting them, see if that fixes the problem.


Michael Grace

It doesn't have feed issues often enough to account for all the keyholes I'm getting. I've only seen it fail to feed ammo smoothly maybe a dozen times or so. I had thought that a single deformed bullet could cause damage to the crown. Maybe that isn't possible though. I do know that certain brands of ammo have a lot more problems feeding than others. Eley Tenex just won't feed at all in this rifle. The cartridges stick up too far in the front and the second shell down actually pushes against the area under the chamber. It's weird to see what it does. I had the same problems with CCI Minimags a couple of days ago. Strangely enough if I only half load a mag all ammo will feed just fine. Also the Minimags had less of a problem with keyholes than anything I've shot for a while. But I did get a few. Accuracy was way off too. This rifle is very particular about what it shoots IMO. Mine does very well with Wolf ammo but even the accuracy of it has dropped off lately. I went from hitting the 50 circle or better on an ARA target at 50 yards to hitting the 25 circle or even the 10 circle almost all the time. My scores dropped from around 1600-1700 to about 1400. I suppose the rifle still shoots accurate but it was very accurate before this. Hopefully Savage can fix it for me because tomorrow it goes back to the factory.

have you tried looking at the torque on the action bolts? i recrown all my savage rifles right off the bat before i even take them to the range. i have found them to be way off on thier angles. always one side that the cutter hits first. when i get aftermarket barrels for my savage centerfires i have never seen a crown off on them like they are on the factory barrels.

Yeah I've checked the torque often and I've set it to different levels trying to get the problems I have fixed. I had to buy a torque screwdriver that would go as low as the torque settings on this gun requires. I even did some pillar bedding so I could put more torque on the front action screw.

I just posted another thread about this gun. Maybe you could read it and see what you think.