22.LR chamber "iron"

[Milsurp Junkie]

My dad found a pretty nice condition Remington model 12 22LR pump. Everything is good, although one out of 5 rounds do not extract from the chamber. The extractor looks in good shape, and I think it is peening the chamber from dry firing that is causing the issue. Brownells used to have a 22lr chamber iron, but I haven't seen them lately. I figured it would not make it worse if I was careful. Anyone have one I can borrow or buy cheaply?

Jonathan

[M-Tecs]

https://www.tandemkross.com/ChamberMadeChamberIroningSwage

The Menck 22 Chamber Ironing Swage Rimfire Gunsmith Tool isn't made anymore but one on ebay.

[303Guy]

Just a sharp cutting blade will cut it away. Done that once or twice. Not ideal if the hammering has deformed the chamber but the instances I had were just burrs on the edge of the chamber. Of course the firing pin should not be able to reach the breach face but sometimes they do.

[uscra112]

I would think that it'd be easy enough to make the tool. Buy a gage pin of the right size and grind a flat on it.

A #4 taper pin could work even better. Nominally .219" small end.

If your local hardware doesn't have one for a $buck:

https://www.mcmaster.com/taper-pins/head-type~plain/small-end-diameter~0-219inches/

[Petrol & Powder]

I agree. You could probably make a simple tool to swage a burr out of a .22 RF chamber.

[Der Gebirgsjager]

The correct way to go on this problem is pretty much a case by case thing. The firing pin striking the edge of the chamber's mouth when dry firing displaces the metal at that point into a burr that extrudes a bit into the chamber, causing a fired cartridge to seize up on the burr and resist extraction. Sometimes it can be cured by carefully running a .22 chambering reamer into the chamber and cutting off the burr. This is often the best solution if the burr isn't very large. Sometimes, though, if the burr is quite large, after the reamer removes the burr a hole/depression is left in the chamber rim and the firearm will no longer fire reliably as there is insufficient resistance to the strike of the firing pin, as the rim is no longer properly supported. So the gunsmith has to assess the extent of the damage, and in other cases swaging the metal back into place into it's original location is the correct answer. To do this, as suggested by uscra112, a taper pin might be a good tool to move the metal out and away from the inner surface of the chamber, and a pin punch and small hammer used to flatten it back down to it's original position while using the taper punch as an anvil. Again, many, depending on the severity of the burr, have been restored to operation by just removing the burr, and if extraction is the only problem and the gun continues to fire reliably that may be the simple answer.

DG

[oldsalt444]

I'm no gunsmith, but I have seen difficult extraction in some older guns. I've been told that the dimensions of 22LR ammo changed slightly which in effect made the chambers tighter using today's ammo. The difference isn't much, but it's enough. I used a chamber reamer in my S&W K22 revolver and then extraction was much easier. Before that, I had to hit the extractor rod with something to get spent cases out of the cylinder.

[Petrol & Powder]

I don't think the dimensions of .22LR have changed. I think there's always the possibility that an individual cartridge has dimensions that are outside of the specifications but I don't believe it is a systemic change in the standard.

Difficult extraction on a particular K-22, or any other older gun, is more likely due to rusty chambers, pitting or some other anomaly in that particular gun. The fact that a reamer corrected the condition isn't proof that the dimensions of .22 LR chambers have been altered over the years.

[oconeedan]

Home fix...I have fixed this same problem using a tapered pin punch. I repaired a semi auto Marlin, so the back of the action was closed. I put the barrel muzzle down on a pad. Dropped the right size tapered punch in the chamber. And since I couldn't get a hammer on the back of the punch, I used an aluminum scrap as a drift on the back of the punch and tapped with a hammer. It doesn't take much , you are only moving the burr back to it's original position.
NOW...investigate if there are worn firing pin parts. In my case, the firing pin was worn and allowed it to travel further forward, making contact with the rear of the barrel / chamber edge.
Dan

[uscra112]

NOMINAL .22 ammo dimensions haven't changed, but in measuring cheap bulk ammo I've found significant variation in size. One brick of Carter-era Thunderduds had many bullets that miked .2260. Stuff would go into loose "sporting" chambers with difficulty, and would not enter competition chambers at all.

Speaking of chambers - some "commodity" rifles have chamber mouths as big as .2290". Especially semi-autos like the 10/22. Even the celebrated Bentz chamber mouth is nominally .2278", while real match rifles have chamber mouths much smaller. My Lilja reamer cuts to .2252" if I am careful, and the old Freeland reamer of days gone by cut a nominal .2242". Those rifles would obviously be much more sensitive to chamber peening.

[Milsurp Junkie]

Thank you all for your responses. A member here is going to lend me his. Otherwise, the tapered pin idea would have been next choice.