I'll be ordering one too. I had one break and your design addresses exactly what I think the problem was.
I'll be ordering one too. I had one break and your design addresses exactly what I think the problem was.
Alfonse, are you going to email us when your ready for payment or post here?
23 years in a Federal Penitentiary, 6x8 double bunked rooms with toilets
Uh, excuse me, but how can dry firing be more abusive than launching bullets??? If I hit the end of a punch of chisel with a hammer, and the other end of the punch or chisel is NOT in contact with another surface, then the tool just moves through air. If I place the tool tip on a hard surface, and then hit it, I now have compression forces working on the tool. At that time, something HAS to give. Either the surface you are working on (In the case of the striker, this would be the firing pin, and then the primer) has to give, or the tool gives. Often both, resulting in mushrooming of a tool head. So, how is this less damaging?
Please don't think that I'm being at all critical of what you are doing. I don't have any problem with someone building a better mouse trap. All that I'm saying is that I believe Kahr's design to be sound, but that the heat treating process at times is suspect. I don't believe that adding a little material where it can improve reliability is a bad thing even if it slows lock time by a few micro seconds or requires a stronger striker spring. I wouldn't hesitate to use your aftermarket parts should the stock parts fail.
Never trust anyone who doesn't trust you to own a gun.
Life Member - NRA
Colt Gold Cup 70 series
Colt Woodsman
Ruger Mark III .22-45
Kahr CM9
Kahr P380
Doc, when you fire a round the blow to the striker is cushioned by striking the relatively soft primer. When you dry fire a gun the striker is slamming into the hardened face of the slide. If you continually do that over time the striker becomes work hardened. That causes the part to become brittle. I don't dry fire my Kahr pistols without a snap cap in the chamber, except when I'm disassembling my guns for cleaning. You are free to treat your guns in any manner that you choose. I never tell anyone what to do, but I also don't make suggestions without a good reason.
Never trust anyone who doesn't trust you to own a gun.
Life Member - NRA
Colt Gold Cup 70 series
Colt Woodsman
Ruger Mark III .22-45
Kahr CM9
Kahr P380
Muggsy, material was added where it helps. It was also removed in the spacer and in the striker so mass is the same. BTW, the energy put in the primer all comes from the spring. 1/2 ×K (spring constant)×distance squared. The distance is the spring deflection. Mass is not part of that equation.
Regardless, lock times and primer deformation are not effected, other than eliminating light strikes from the striker hitting the top round in the mag.
Steel is always a crystalline structure. That is an outdated explanation for fatigue failure.
Last edited by Alfonse; 01-01-2016 at 11:26 AM.
Aftermarket accessories for Kahr Pistols at https://lakelinellc.com/
There are always more in the pipeline...
I guess that I'm just one of those out dated guys. Most of my information came from a guy who was even more outdated than I am, my old man, but I will say this, I've never had a strike or firing pin break by using snap caps and neither did he. Between the two of us that constitutes over 100 years of shooting.
Never trust anyone who doesn't trust you to own a gun.
Life Member - NRA
Colt Gold Cup 70 series
Colt Woodsman
Ruger Mark III .22-45
Kahr CM9
Kahr P380
You are right on about using snap caps. They cushion the shock and greatly reduce the stress on the part.
My father and I are both engineers. He was taught that metal fatigue was caused by "crystallization" of the metal. Steel, depending on its state and alloy, is usually either body-centered cubic crystalline structure or face-centered cubic. Turns out, it doesn't really change with repeated loading. Things like shot-peening can improve the fatigue resistance of a part, but the crystallization theory can't really explain shot peening's effect.
Just because the taught theory is not in vogue doesn't mean the practical side of things isn't correct. In either theory, if the part is breaking prematurely, the fix is to strengthen the part.
By the time I was in engineering school, growth of "micro-cracks" were used to explain fatigue failure. Since I am probably well past my "best if used by date," I'm not sure how they theorize it works now. But, the theory to achieve fatigue safe, or theoretical infinite life, design strength was that the part had to be stressed lightly enough that the surface cracks in the structure didn't grow.
It is a discussion my father and I have had a couple of times. Neither of us claims to be up to date on the latest material science theories. But, I still get by pretty well. I guess my geek side just came out about the crystallization thing.
Aftermarket accessories for Kahr Pistols at https://lakelinellc.com/
There are always more in the pipeline...