Have had this vintage Colt 1911 22 conversion unit for a few years and am finally taking a look at it's failure to fire issues again. Use it on my Gold Cup series 70.
It does indeed only put a very light strike on the rim of ctgs. Thought it might be hard brass cases and so tried various ammo with the same results. It requires plated bullets as soft lead just shaves off between the floating chamber and barrel causing issues.
There is no sign of dry firing on the edge of the chamber. Even though the firing pin did not look broomed or broken off a the tip I got found a replacement and it is exactly the same length as original and has the same failure to fire issue.
Comparing the 45 upper to the 22 upper I find the following difference though:
The tip of the firing pin in the 45 upper is almost flush but a few thousands inside the breach face when the rear is pushed flush with the retainer.
The 22 unit requires the rear of the firing pin to be pushed in so far to have the tip at the same point just a few thousands inside the breach face that the retainer can actually be slid down.
I know these are both inertial design firing pins, but can anyone lend insight into the engineering differences behind the centrefire vs. rimfire of these units?
Thought about a shorter/weaker spring but not sure as the rear of the pin has to stick out all that is available past the retainer to ensure the hammer strikes it solidly.
BTW, with the floating chamber design it is more about duplicating 45 recoil for practice than accuracy. My Marvel 22 conversion makes a true 22 target pistol on the 1911, but then it has no movement between sights and barrel either more like a S&W 41 design.
Also wondering if I should limit the shooting of this 22 unit (since it is steel and the slide does indeed work back and forth along the frame - but it is free with no friction whatsoever though) so as not to create slop between slide/frame fit on my original 45 upper on the Gold Cup as it shoots quite nice groups.
Thanks for any help/insight,
CD
It does indeed only put a very light strike on the rim of ctgs. Thought it might be hard brass cases and so tried various ammo with the same results. It requires plated bullets as soft lead just shaves off between the floating chamber and barrel causing issues.
There is no sign of dry firing on the edge of the chamber. Even though the firing pin did not look broomed or broken off a the tip I got found a replacement and it is exactly the same length as original and has the same failure to fire issue.
Comparing the 45 upper to the 22 upper I find the following difference though:
The tip of the firing pin in the 45 upper is almost flush but a few thousands inside the breach face when the rear is pushed flush with the retainer.
The 22 unit requires the rear of the firing pin to be pushed in so far to have the tip at the same point just a few thousands inside the breach face that the retainer can actually be slid down.
I know these are both inertial design firing pins, but can anyone lend insight into the engineering differences behind the centrefire vs. rimfire of these units?
Thought about a shorter/weaker spring but not sure as the rear of the pin has to stick out all that is available past the retainer to ensure the hammer strikes it solidly.
BTW, with the floating chamber design it is more about duplicating 45 recoil for practice than accuracy. My Marvel 22 conversion makes a true 22 target pistol on the 1911, but then it has no movement between sights and barrel either more like a S&W 41 design.
Also wondering if I should limit the shooting of this 22 unit (since it is steel and the slide does indeed work back and forth along the frame - but it is free with no friction whatsoever though) so as not to create slop between slide/frame fit on my original 45 upper on the Gold Cup as it shoots quite nice groups.
Thanks for any help/insight,
CD
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