15-22 firing pin protrusion

[kamikaze1a]

I had posted that my firing pin dents looked light on my month old 15-22. A forum member posted pics of his brass and his dents looked deeper. It was suggested that I check my bolt and wanted to ask you other 15-22 owners to check your firing pin protrusion.

If I hold the fp flush against the back of the bolt, my fp does not protrude past the bolt face. I believe inertia is all that is igniting my primers. Can someone check if their fp protrudes past the bolt face with the tail of their firing pin held blush with the back of the bolt?

I know with out of spec AR's, you can turn down the tail of the bolt if you need to increase fp protrusion... My 15-22 may need similar treatment, but will probably send it back to S&W if mine is out of spec...

 

[Brett248Vista]

I just put the end of my digital calipers against the FP and pushed in till it was flush with the bolt (doesn't get any more square than using calipers) and my FP does not protrude past the bolt face, in fact I'd say it's maybe 0.001 short of being flush with the bolt face.

 

[john16443]

While Brett was checking his, I went out and took some photos. My pin does extend beyond the recess of the face as shown if I push the pin from the back with a pencil eraser as far as it will go. The second pic shows it better.

 

[Brett248Vista]

John,

The bolt "face" would be the section outside of the area where the round is held. My firing pin extends into the cavity where the round is held, it does not extend past the bolt's "face" which would be the part that makes contact with the end of the chamber.

 

[kamikaze1a]

While Brett was checking his, I went out and took some photos. My pin does extend beyond the recess of the face as shown if I push the pin from the back with a pencil eraser as far as it will go. The second pic shows it better.

Thanks for the pics...but does it protrude if you hold the rear of the fp square or flush with the rear of the bolt. Kind what the hammer would do after the trigger was pulled. Use the edge of a ruler against the rear of the firing pin and press inwards until the edge of the ruler is square against the rear of the bolt. Don't push the fp beyond flush with the rear of the bolt.

Thanks!

 

[kamikaze1a]

I just put the end of my digital calipers against the FP and pushed in till it was flush with the bolt (doesn't get any more square than using calipers) and my FP does not protrude past the bolt face, in fact I'd say it's maybe 0.001 short of being flush with the bolt face.

That's pretty much where my fp is...how does your brass look after firing? Are the fp dents deep like you would expect from a rifle? Mine are pretty light though it does fire...

Thanks for checking!

 

[kamikaze1a]

This is what "stu" posted on the other thread. His fp hitting way harder...

 

[Brett248Vista]

Kamikaze,

Mine get hit as hard as Stu's.

 

[chuck s]

The face of the bolt is the area which makes contact with the cartridge base. In the 15-22 it is the "cavity."

Here's two more examples. The bolt face is in the recess of the left bolt and surrounds the rim (as does the 15-22). The bolt face on the right does not surround the rim.

-- Chuck

 

[tacticool22]

One of the first things I checked when I picked up the rifle was how far the firing pin came out. It comes out past the recess (otherwise it would not crush the rim) but does not go past the face of the bolt. There must be a hard stop machined into the bolt to keep the firing pin from coming in contact with the breech face. So you can probably dry fire all you want without damaging anything.
The .22 rifles of yesterday had a round firing pin, like the modern center fires of today. Some had very sharp shoulders where the pin became larger for the hammer to hit. This sharp corner is a weak point on all round (turned) parts. And can start cracking from heat treating and just get worse from there. The metals, design, manufacturing and heat treatment have come a long way just in the last 20 years. We are told to not dry fire a .22 because we have been told that for over 100 years. It's time to let that archaic way of thinking die.

 

[Brett248Vista]

Jody,

Poor metals were an issue in the past for sure, the FP could begin to split if it was too soft, if it was too hard it could chip or crack off. But I think another thing to consider with Rimfire rifles is that it's possible in some rifles for the FP to contact the chamber wall, and that can peen the chamber and cause issues with the cartridge seating into the chamber.

I don't dry fire my 15-22 because if you push the pin all the way in, it does extend past the face. On my centerfire's I'm not as worried.

 

[kamikaze1a]

The 15-22 has a recessed bolt face so the fp should not strike the breach...but the fp bottoming on the fp stop could be equally bad. Can someone with a fp that hits hard check their fp protrusion please?

 

[Brett248Vista]

Kamikaze,

How do you want it checked.. You said check it with the end of the FP flush with the bolt I did that. Do you want me to push the FP as far as it will go? Flush isn't as far as it will go.

 

[kamikaze1a]

Kamikaze,

Mine get hit as hard as Stu's.

Hmmmm....if your fp protrusion is the same as mine, I wonder why my strikes are light? It's all original and only thing I've done is polished the sear. Springs installed correctly and double checked lastnight. Well lubed and clean...

 

[Brett248Vista]

Kami,

Good question, and one I don't have an answer to!

 

[kamikaze1a]

Brett,

I was re-reading your earlier reply. To clarify, I believe the bolt face is the surface that contacts the base of the shell. In the 15-22, it would be the recessed ares immediately surrounding the fp hole.

Your fp protrudes past that surface? Is that correct?

 

[Brett248Vista]

Yes if you are considering the recess where the shell lays as the "bolt face" then my FP most certainly protrudes into that recess. if I depress the FP so that it's flush on the back of the bolt, it protrudes almost as high as the higher area of the bolt face (the part that touches the chamber).

 

[john16443]

Yes if you are considering the recess where the shell lays as the "bolt face" then my FP most certainly protrudes into that recess. if I depress the FP so that it's flush on the back of the bolt, it protrudes almost as high as the higher area of the bolt face (the part that touches the chamber).

Which is exactly what the pics I provided shows, and as Brett says, it doesn't extend beyond the highest area of the bolt face.

 

[kamikaze1a]

Thanks for confirming that... Houston, we have a problem! My fp does not protrude past this

surface marked with the arrow. The fp tip is just below this surface so does not stick out at all... It's not wonder my strikes look light.

 

[kamikaze1a]

Which is exactly what the pics I provided shows, and as Brett says, it doesn't extend beyond the highest area of the bolt face.

10-4 My fp does not stick out like yours. I think I need to contact S&W...I thought when you said you were pressing with a pencil, you were pushing the fp in past even with the back of the bolt.

Thanks guys!

 

[kamikaze1a]

While Brett was checking his, I went out and took some photos. My pin does extend beyond the recess of the face as shown if I push the pin from the back with a pencil eraser as far as it will go. The second pic shows it better.

John, in this pic, is the rear of your fp "in" the bolt or flush with the surface of the bolt?

 

[Brett248Vista]

Just so I am crystal clear here...

I snapped a couple photos for you. Here is what I did. I took a perfectly straight edge and depressed the firing pin till it was precisely flush with the res of the bolt where the hammer strikes the pin. And this is the result:

 

[john16443]

John, in this pic, is the rear of your fp "in" the bolt or flush with the surface of the bolt?

Went back outside and checked. Yes, my original pics were with the FP pushed all the way in until it stopped. That isn't what we need to be comparing to. Below are pics of my pin position with the FP just pushed in to be flush with the back of the bolt. It shows that the FP does not protrude past the face of the recessed portion of the bolt. Your rifle is fine in my opinion, and there is no problem in Houston.

I also included a couple pics of my primer strikes on a casing I found tonight in a box of Blazer with no bullet in it. I just shot the primer and this is the mark the gun made not 30 minutes ago. LET ME CAUTION YOU RIGHT NOW! The strike mark in the photos looks MUCH deeper than in real life. I think the macro aspects of the photos that Stu and I took make it LOOK like the FP marks are much deeper than they really are. If you've got a digital camera with macro mode (they all have it), try this yourself. Remove a bullet from the casing, dump the powder and set off the primer in your garage. It will be amazingly quiet and you won't disturb anyone. Look at your mark and then take a picture of it. The pic will look like the mark is deep as all get out, but your eyes don't see it like that.

 

[john16443]

Brett I just posted what you did, hold the pin flush with the back of the bolt, and got different results. My original photos look like yours , but that was with the pencil eraser pushing the FP all the way in until it stopped. Now I'm confused as well

 

[kamikaze1a]

My fp looks like john's...but my fp strikes don't come close to what the strikes look like. If you view my brass from the side and look at the rim, it is hard to tell where the fp strike was.

I took a few pics with my camera and you are right, they do look better in a pic... Will let you know what S&W says

 

[chuck s]

If the firing pin doesn't project beyond the face of the bolt it will not strike the primer! Simple as that. If you're mis-identifying the face of the bolt (or slide) you'll confuse yourself.

The 15-22 firing pin is non-inertial (non-rebounding), meaning it projects beyond the face of the bolt all the time the hammer is resting against it. Inertial firing pins are shorter and only project beyond the face of the bolt momentarily when struck by the hammer. They retract inside the face of the bolt immediately regardless of hammer position. The M1911 is the best example.

-- Chuck

 

[kamikaze1a]

I emailed S&W and the CSR checked a 15-22 bolt he had. He said that fp protrudes so is sending shipping label for return...no questions asked. Great service!

It's hard to believe that it's that far out of spec. I wonder if the fp is short or the bolt long?

 

[VooDuuChild]

One of the first things I checked when I picked up the rifle was how far the firing pin came out. It comes out past the recess (otherwise it would not crush the rim) but does not go past the face of the bolt. There must be a hard stop machined into the bolt to keep the firing pin from coming in contact with the breech face. So you can probably dry fire all you want without damaging anything.
The .22 rifles of yesterday had a round firing pin, like the modern center fires of today. Some had very sharp shoulders where the pin became larger for the hammer to hit. This sharp corner is a weak point on all round (turned) parts. And can start cracking from heat treating and just get worse from there. The metals, design, manufacturing and heat treatment have come a long way just in the last 20 years. We are told to not dry fire a .22 because we have been told that for over 100 years. It's time to let that archaic way of thinking die.

I'm pretty sure there's a reason for them to say no dry-firing, so I'm gonna just rely on their word for it like I do my Walther P22, except my Walther manual says it's ok, as long as the safety's on. So there's at least one .22 where it's ok *at least with the safety engaged.

 

[john16443]

I'm not going to worry about my FP even if it doesn't protrude with the pin flush against the back of the bolt. I had a wonderful 450 round range session yesterday using Blazer 40gr LRN without a single firing or ejection related hiccup. Now if only the LRHO tab would consistently engage...

 

[corpulent]

My FP does not extend past the face either; same as kamikaze and john. Haven't had any issues, though, so what's the concern? Should it be fixed anyway?

The 15-22 firing pin is non-inertial (non-rebounding), meaning it projects beyond the face of the bolt all the time the hammer is resting against it. Inertial firing pins are shorter and only project beyond the face of the bolt momentarily when struck by the hammer. They retract inside the face of the bolt immediately regardless of hammer position. The M1911 is the best example.

-- Chuck

Really? For me (and prolly the other two gents) it does not extend (with a straightedge against it); unless the hammer itself pushes it slightly deeper than flush. Hammer is kinda rounded, but I can't see what it actually looks like when it's closed. It seems like it is inertial. Hammer hits it hard enough to push it past flush momentarily, and then it springs back. (?)

I must digress though, I don't really know what I'm talking about.