S&W 617 4" primer strike issues?

[sota]

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. I already checked the strain screw and it's as tight as it can go.

Thanks!

note: the picture source is YUGE, so open it in a new tab to get some serious magnification, if you want.

[Boo Vuccla]

I would try another brand of shell and see how it works. If that is a gun that is rather new or not had many rounds through it, check to make sure those Federals are seating all the way in the cylinder. (And make sure your cylinders are clean and free of debris. At the star as well).

[Hawk]

Did you buy it new or used?

There are aftermarket hammer spring kits that lighten the trigger pull by changing out the hammer spring with one that is lighter. If the previous owner performed this mod, he may of used too light of a hammer spring. .22 revolvers typically need a lot of hammer force for proper impact on the .22 rim fire cartridge. Also, I believe on that model that there is a screw adjustment under the grips on the front of the grip frame that adjusts tension on the hammer spring. If it was used, someone could of backed down the tension.

If the pistol is new, then try some CCI mini-mags and see if that makes a difference.

[Bang]

From the photos, it appears there are two differing strike points on the heads near the rims from the 617's FTF. One strike is slightly inboard of the rim, the other on the rim and then some. Perhaps that is just lighting and shadows.

May I suggest, if you agree there are differences...ascertain which type of strike occurs on the first hammer fall resulting in no ignition.

Note that the rim of the shell is slightly warped from the first strike, possibly having two effects. It backs the shell a little bit away from the cylinder and a bit closer to the hammer...suggesting a headspace problem.....and also may cause the shell to lie in the chamber slightly shifted, presenting a better ignition condition.

Slightly too much headspace is often caused by fore-and-aft shake (end shake) of the cylinder on the yoke. If the cylinder is driven forward by the hammer strike, the impact of the firing pin upon the primed rim is lessened, kind of how a boxer pulls his face away from an impending blow, lessening impact.

The firing pin should protrude from its bushing or channel by about .023". The screw at the bottom of the forward grip frame applies retention and pressure on the hammer spring and is intended to be completely seated and tight. It is not designed to vary spring pressure. That is a common misconception.

The suggestion to try different brands of ammo is a good one. Measure rim thicknesses on various brands of .22LR. You'll find the thicknesses vary.

[sota]

I noticed the same thing about the different impact marks. My next range outing I will be more diligent about trying to observe what markings are created and when, and possibly see if it's at all related to the position on the cylinder.