quick question keyhole problem

[gumpokc]

I've got a little .22 special pump action rifle.
action is nice and tight, bore looks decent, but under rapid firing, it looks like as it warms up it keyholes from time to time.

any ideas what could cause keyholes when the action and headspace are within specs?

[Lycanthrope]

Leading? I'd start with a good cleaning. I think it would take a lot of rounds to get a rimfire that hot to keyhole.

[Cossack]

Keyholeing usually means that the bullet isn't stabilized. That the rifling twist does not match the length of the bullet used.
Gereally speaking the shorter the bullet the slower the twist. The longer the bullet
the faster the twist has to be. I suppose leading could cause it but that doesn't happen often to that extent in a 22. Are you using a light bullet, like one of the 30 gr high velocity loads? Seems like the smaller bearing surface on one of those coupled with a faster than normal twist rate in your gun could cause keyholeing. Try a standard velocity 40 gr bullet ... after a good barrel cleaning.

[skeet]

is that a Remington 22 Special you are shooting? Same as the 22 Winchester Rimfire?? If it is a Special check the rounds you are shooting. Are they regular 22 LR or the 22 wrf or Remington Special rounds. 2 different critters. If shooting 22 LR in a Special chamber your cases are probably splitting...bullets are different sizes too if I remember correctly!

Would also be a big jump from the case to the rifling if shooting 22 LR in a Special chamber!! Could have an awful lot to do with keyholeing..I'm sure!

[gumpokc]

skeet,
it is .22 special, rather old pump action rifle of my grandad's.
the ammo being used is called .22WRF
they only make a production run of it once every 3 years, as part of their "obsolete" ammo production.

it doesn't od it every shot, on slow fire she's a sweet little number, but speed it up abit, and she seems to start keyholing.

checked the bore, it looks decent, patches weren't too bad, but i may try to let her soak and see if it is leading. Just seems iif it was leading, it would be all the time, not intermittant.

[Rocky Raab]

Good catch, skeet! That ammo aspect got by even me!

I'm at a loss to explain this, also. At the risk of being overly clever, may I suggest that you slow down the rate of fire? Especially with ammo that is only made every few years?

That's a rifle that I'd shoot only on special occasions - like on Grampa's birthday. I'd shoot it as a special remembrance, not as a daily tool. But that's just me.

[gumpokc]

Oh yeah rocky i totally agree, it isn't goign to be a "everyday" gun , though i know thats what grandad would prefer "if you can't use it, why have it?" was one of his favorite sayings.

I had considered the ROF, just didnt think that such a short, smooth pumping action could cause it to keyhole.

It isn't a big deal, since it is not goign to be in regular useage, just got me curious and figured i'd ask here and see if i could get it figured out.

[skeet]

I happen to have a Remington M-12C 22 pump. I have found that it will occassionally print up a flyer. I really think it's because as you pump the rifle sometimes the bulletnose catches on the edge of the chamber and gouges up the bullet on one side. especially happens when pumping the rifle quickly. The way a Rem M-12 feeds is kind of funny. As you bring the pump handle forward after ejecting the fired round the cartridge feeds up onto the bolt face and is held in place by the extractors. If firing fast sometimes the cartridge doesn't attain the right place on the face of the bolt and one side hits the mouth of the chamber gouging the bullet nose pretty badly..not good for accuracy at all. Check yours out. You'll probably see what I mean about feeding.

[skeet]

Forgot to add that the special is a lot longer round than the 22LR and any feeding probs would be enhanced by the extra length. Clean under the extractors and the bolt face and it will probably feed better. I think the 22 wrf has quite a bit of wax on the bullets(lead bullets aren't they?) and it may have built up a bit on the bolt as the wax gets stripped off at the chamber and deposited on the bolt face when the rifle closes fully. Just my take on this as I started thinking:confused:

[gumpokc]

Skeet I think you probably hit the nail on the head on the feeding.

Under slow fire, it works great, just did the keyholes under rapidfire. then slowing down on the next target, it did fine again.

Mine is a Model 12CS as far as i can tell, i posted more info on it awhile back in a rimfire thread with a name soemthing along the klines of "what is the difference in .22long, and .22longrifle"

another good page for info pn the model 12' is here http://www.wisnersinc.com/additionalinfo/remington_m12.htm

[skeet]

That was a nice link. Get some info off of it for certain. I like the ol 12 C I have. The bbl is octagon and it does have a crescent butt and it will occassionally throw one way out if ya pump it too fast. Sometimes you can tell when the next round hits the chamber mouth because it has a gritty feel to the pump action. The Special is a nice round...and I was pretty certain it has a larger bore..which was substantiated on the link page you posted. Thanks

Part of what I like though...NO aluminum or plastic..and it has a real heft to it. You know you have a REAL firearm in your hands...mine shoots pretty good too especially when ya take your time:D :cool:

[gumpokc]

I agree completely skeet, if i could find a new production like the model 12, i'd jump on it fast.

i've seen and tried a few of the rossi pump .22's and they are about the closest thing i've seen to the model 12, good little rifles for plinkers.

this one is a sweetie, and a breakdown as well, at ten yards slowfire, offhand, she'll put 10 shots you can cover with a quarter,
and she hasent been shot in probably 30 years.

i may tear her down soon and take the steamer to the metal, and action, but from what is aw theother day, and what you said i think the feeding is most probably the cause.

the older original production .22 special was waxed lead round nose, the newer production is jacketed.