Ammo: Federal FED750 lot 1HJ631

Picture shows:
(left) Beretta M9-22 primer strike
(middle) S&W 617 primer strikes
(right) Ruger SR-22 primer strike

The Beretta and Ruger have had no noticeable recurring primer strike issues.  The S&W 617 has been exhibiting regular FTF problems.  As you can see every round ignited after a second strike. I'm wondering if anyone else has one of these, and can compare what their primer strikes look like in relation to mine?  I'm thinking about sending it back to S&W and gave them give it a going over, but I want to check around first.

Thanks!

The 617 uses a standard round nose firing pin,and most semi 22s will use a square nose, so that's why they look different.

First thing first, take the grips off and make sure that the strain screw hasn't loosened up, it's very common that they do. You should blue lock Tite it. ( Screw controls main spring pressure )

 

2nd, if tightening the main spring screw doesn't work, you'll need to check your end shake. This can be done with a simple pair of feeler gauges you can get at any automotive store, or Amazon. Ideally, the less end skake the better - but up to about .002 end shake is fine in these guns. A quick Google search will explain how to do it- but in a nut shell - gap between face of cylinder and forcing cone with cylinder pulled back toward rear minus the gap between forcing cone and face of cylinder with cylinder pushing forward equals end shake.

 

You are essentially measuring the slop in the cylinder movement forward and back. If so much slop you'll be robbing energy from the force of the main spring that would otherwise be used to ignite primers by having to move the cylinder forward a hair first 

 

Good luck.

Alec

strain screw is as tight as it's going to go.

I can dig up my feeler gauge from the garage and see what the play is for the cylinder, but given I cleaned it last night I don't remember noticing or feeling any movement at all.

 

I don't have any newer Smith rimfires, but if your 617 has a floating firing pin (frame mounted), then remove the side plate and pull out the firing pin and spring. Inspect the pin for breakage and the spring to make sure it isn't broken. Clean the firing pin channel and retainer. Do not lube on reassembly.

Beyond all the above suggestions, a trip back to the mothership is called for.

Adios,

Pizza Bob

Is your gun brand new or used,  Did anyone change springs or strain screw.

I use the Miculek main spring with an 11 pound rebound spring, Power Custom extended firing pin and the apex mass driver hammer in my 617 and internals all polished to a mirror finish, currently the DA pull is "about" 7 3/4 lbs using a Timney pull gauge and still ignites everything so far.   each time I go to the range and everything works I file off a .001 -.002 on the strain screw when I get home.  Filing the screw ensures that you tighten it all the way down to keep it from backing out during your shoot.

Next trip to the range I do the same thing, eventually It will fail to ignite and than I measure the total length of the strain screw, add .001 to a replacement screw and than I'm done, I have a dozen or so replacement screws on hand for this. 

I tore it down, gave everything a good cleaning, including the firing pin channel, and discovered a level of hatred for the hand tension spring I didn't know existed.  I used an AR gas tube pipe cleaner to clear the firing pin channel; it came out pretty crummy.  Nothing is broken, so let's see how it works at the next outing.

I just looked at a few pcs of brass out of mine and for what its worth mine doesnt seem to stress the edge of the rim as much as some of yours appear to. Also hard to tell in the pics but mine may also have a more definitive pin print. Anyway good luck.