Kahr 380 Striker Ultimate Fix

[Whaleman]

I have had one broken striker in my P380. I hope this proves out. Dan

[dirtengineer]

I'm quite interested as long as the price isn't crazy.

[ReManG]

Interesting to say the least... If I remember right, S7 can be heat treated to 60 rockwell and still bent 90 degrees... I believe that it was the toughest steel I have ever dealt with when doing tool and die work.. This may be the ticket for a dead nuts reliable striker...

[ulflyer]

Any plans to make these for other models? Particularly the 45 cal.

[Alfonse]

Any plans to make these for other models? Particularly the 45 cal.

I'll have to see how the .380 goes before looking at others. Thanks!~

[z8894]

I'll be ordering one too. I had one break and your design addresses exactly what I think the problem was.

[Bobshouse]

Alfonse, are you going to email us when your ready for payment or post here?

[Alfonse]

Alfonse, are you going to email us when your ready for payment or post here?

I will post here. Thanks!

[Gun Doctor]

I believe that the Kahr design is sound, but the heat treating of the part is suspect. Over time dry firing can cause metal to become crystallized and brittle.

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?

[muggsy]

Muggsy, the logic to our fix is pretty simple. I take the area that was breaking and make it several times stronger by the geometry of the design and then use the toughest material for the application. While I was at it, I also made another change to the geometry that keeps the striker from hitting the round below in the magazine that has caused light strikes for some. To allow the part to be thicker and wider in the weak area, the spacer has to change. Since the spacer is lightly stressed, and the striker is more highly stressed, it works out pretty well. The result might well be called "over built." but that is what makes it the ultimate solution that ends breakage of the part.

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.

[muggsy]

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?

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.

[Alfonse]

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.

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.

[muggsy]

Muggsy, material was added where it helps. It was also removed in the spacer and in 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.

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.

[Bobshouse]

Between the two of us that constitutes over 100 years of shooting.

Quit being so modest, everyone knows your dad didn't shoot, if he did, that first number would be a 2.

[Alfonse]

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.

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.