strange failure to fire /odd strikes on base of shell

[edwardh1]

I have an old (1937) remington .22 LR sportmaster rifle. I replaced the bolt's firing pin and the main spring and the extractor with new parts. I am still getting failure to fire on about one in 50 shells. CCI minimags-

the shells go all the way into the chamber and will fall out if you point the rifle upward (chamber is not tight. not loose either)

on 3 shell casing I have from the range, one is clearly indented by the firing pin on the base almost as if a chisel had been used to ignite the powder, that is there is a straight line on the shell edge pointing inward. on the other two shells , there is less of an indent and its more on the shell edge and its also round. the firing pin is a chisel shape on the tip.

The shells fit very tightly into the front of the bolt (is that normal?) almost no side play- should there be some? I wonderif some of the shell's bases are too big and not fitting into the bolt recess well, causing the mistrike by the firing pin. Is all ammo the same size, and the same size as in 1937?

[The British Soldier]

Could insufficient firing pin protrusion be the culprit?

[cntryboy1289]

No, there shouldn't be any side to side movement if the extractor is doing what it is supposed to do and yours seems to be doing fine. Like the British soldier asked, make sure you have sufficient firing pin protrusion. Chances are very good that you have a little too much headspace, not to worry though, and this is the culprit combined with the firing pin not protruding far enough.

Since it is only 1 in 50, I might just let it go myself. Change ammo and see if you can find a rim that yours likes best. Many times the ammo will have different thicknesses of the rims and this will have an effect on the FTF's

[edwardh1]

that the new firing pin would protrude further. what do you do grind out the inside of the bolt to get it to protrude more? putting bolt together was no fun

on another subject
For typical wally world .22 purchases of .22 ammo (I am a ways from a gun shop) what are the names of "regular", medium, and high velocity ammo from the brands wally world sells?
typically CCI, remington, winchester and ??

I tried the manufacturers web sites but the names are confusing.

For CCI I think the medium strength is Mini mags and the Hi vel is Stingers.

Or is there a web site that shows this?

[hIPSHOT33]

Don't grind on the bolt . If you think you don't have enough fireing pin protrusion ,work on the pin . there should be a hole in the pin or an indentation where the fireing pin is held to the bolt by another pin . with a small file work on the rear edge of that hole to alow the fireing pin to move further forward .
The problem dose not sound like fireing pin protrusion . one round in 50 dose not sound to bad to me .

[James K]

Hi, edwardh1,

Can you post pics of the firing pin strikes. I can't quite envision the three strikes you describe.

The firing pin should NOT be pointed, or "chisel shaped". It should have a flat tip, rectangular, about .10" long (radially to the shell) and about .05" wide. (Those are very rough estimates.)

And it should protrude to the point where the end of the firing pin is even with the bolt face; in other words it should protrude the whole amount of the recessed area but not enough to pass the non-recessed area of the bolt face.

If protrusion is not enough, you can trim a bit off the lower face of the firing pin, that is the firing pin stop point. But be careful. If you have too much firing pin protrusion, dry firing will batter the barrel.

Jim

[edwardh1]

first pix (the circles) shows as my drawing how the strikes look- only two shapes on the strikes-
one (on bottom) is a chisel shape - a straight line really aimed at the center like a bike spoke
the other is more round, and is right on the edge - probably the firing pin just striking the edge of the shell base less than in the other picture(are these terms right?)

?- what would cause that - maybe the shell is not seating all the way in the bolt recess?
---------------------------------------------
501 picture- the firing pin - at 3 o clock on the bolt- does seem to protrude flush or very very close to flush with the face of the bolt- going well through the recess area.

----------------
is there a web site on what the sizes of .22 ammo sold today is for different manufacturers? ?

[cntryboy1289]

I don't think you will find all of a batch of ammo having the exact same size. I would just get a couple of different brands and see which one your rifle likes best. Then just go from their.

[James K]

The firing pin looks as it should. But the pics seem to show a vertical movement of either the bolt or the cartridge.

There is one suggestion I might make and that is to go to a standard velocity ammo. Those "mag" cartridges run a bit higher pressure and the cases are made a tad thicker. That means the old guns were not made to hit hard enough to ignite the thicker cartridges.

There is also a possibility that the chamber has been enlarged at one time or another, maybe to polish it or eliminate rust. (BTW, basic cartridge dimensions have not changed since 1937.)

Jim

[edwardh1]

I thought CCI mini mags were a "medium" power cartridge? and the CCI stingers were "max" power???????

I will try it...... what are Rem and win standard shells called (basic dumb ? but who else can I ask - the Waldo mart guy?

[cntryboy1289]

I would suggest some Winchester dynapoints, Federal Lightening, and Remington yellow jackets and the brass plated bullets.

[James K]

Try a box of standard velocity Remington Target in the plain green box or Winchester equivalent. Leave off the high speed stuff for the moment.

Jim

[edwardh1]

will let you know

[Harry Bonar]

Dear Shooter:
JIM KEENAN is on the right track - you might have an oversize chamber due to the look of the pin hits.
If you dress that firing pin to get a good hit be sure you don't go too far or you'll have a burred chamber at the top.
Do what JIM says, get some different ammo - in my groundhog hunting days as a kid with my 22 (I killed more hogs with that old Remington than all the high-powered stuff ever did). I liked "Super X" 22 LR. Hollow point!
Have fun with that old rifle.
Harry b.

[edwardh1]

the key seems in the pin hits.
At first I thought the shell was not seating in the bolt recessed area properly but if that happened it seems the bolt would then not close properly?
i did buy some rem green box (sub sonic? whats that

and winc super X

will try it this weekend

[cntryboy1289]

Exactly what it says, the rounds are slower than the speed of sound which will make them shoot without giving off the crack as they exceed the speed of sound. They should do well in a bolt action, some semi's won't cycle them very well without some mods to the back of the bolt. Let us know if what you find out about the strikes. Like I said earlier, if it's just one in 50, that isn't too bad for such an old rifle. You can live with that many if you don't want to spend any mnoney on it.