648-6 Extended Firing Pin

[glenncal1]

Long story relatively short. Bought a 648 on sale at Bud's and S&W was doing rebates so the price was very reasonable. Great gun, very accurate, good trigger except for a FTF problem. Sent back to S&W, improved but not fixed. Tried all the usual tricks, shim in the mainspring, remove the transfer bar etc. Still FTF issues especially DA. So I decided to try an extended firing pin. TK Custom makes one for rimfire use (only RF pin out there AFAIK). Ordered, received, installed and shot today. 100% ignition with Federals had a couple DA FTFs with some Fiocci, but I have had issues with that ammo in other guns. Very happy. BTW extremely fast shipping from TK, and a very prompt response to my email question about using the pin in a 648.

 

[Tom S.]

From TK's website: TK Custom Extended Firing Pin Kit – Smith & Wesson Centerfire Revolvers
Not Compatible: Rimfire models or pre-lock Smith & Wesson frames

 

[glenncal1]

Smith & Wesson Revolver Competition 617, 63, 43c .22LR Extended Firing

Choose our S&W 617 extended firing pin for competition use. We have designed this Smith and Wesson 617 replacement part to offer you improved performance.

tkcustom.com

they have a separate one for rimfires.

 

[Thaddeus Beauregard]

I have tried both the TK Custom and Power Custom extended firing pins and have been pleased with their performance so far. All except for 1 have been the CF version. The CF ones I've used from both suppliers have allowed me to reduce the DA pull down to a level I would have previously expected to start getting misfires, and so far they have given me 100% ignition. I wouldn't consider them to be a cure-all and I haven't explored the limits of how light I can go on pull weight with them. Once I hit about 7 lbs minimum DA, I really have no desire to go any lighter anyway. I consider the extended firing pins added insurance. I don't see how adding 0.015" or so of additional firing pin protrusion could hurt anything, as they still retract fully inside the breech after firing and don't hang up on cylinder rotation. I have no idea which is better between the TK Custom and Power Custom, as they look to be the same, and are the same dimemsionally. The great benefit of the S&W frame mounted firing pins is they are super easy and relatively inexpensive to change out if you have problems.

I just installed a RF one in my M63 a few days ago but haven't tried it yet. I don't expect any problems.