Guess what happened here.

[WardenWolf]

The bent firing pin made this essentially a fixed firing pin firearm. I've always been curious how fixed pin open bolt firearms avoid firing out of battery. It seems like it would be common.

Hard military primers, and feed ramps that ensure the bullet doesn't straighten out and place the primer in front of the firing pin until right at the end.

One way of doing it is to have the lower part of the bolt that strips the round from the magazine extend forward beyond the normal bolt face. When the round reaches the end of the feed ramp and straightens out, it slips off this guide, the firing pin slams it, and it fires.

 

[Thompsoncustom]

Can you expand on this? How sore was your hand? How black was it? Were you wearing gloves the second time?

Ya the top part of my index finger back to the lower knuckle on my thumb was black just from unburnt powder I would imagine and no I didn't put gloves on just held it differently.

Ya I replaced the spring and firing pin that day but it was just the firing pin causing the problem as I have a shorter firing pin and with those same springs there was no problems.

 

[MaterDei]

Cool, thanks.

Sorry for hijacking your thread.

 

[DanTheFarmer]

The only open bolt, fixed firing pin guns that I know about are Advanced Primer Ignition Blowback designs. The bolt is still moving forward when the fixed firing pin sets off the primer so the backward pressure first has to overcome the forward momentum of the bolt and then accelerate the bolt backward to cycle the firearm. In a sense these guns are never "in battery". Since they're blowback the bolt is never locked and since they are API all this stuff is happening on the fly. I'm no expert so please correct me if I'm wrong or provide other examples of an open bolt design functioning differently.

 

[Jim K]

The lighter spring had nothing to do with it. The Hi Point is a blowback pistol and is kept closed until pressure drops by the mass of the breechblock. The only function of the recoil spring is to return the slide to battery.

There is NO doubt that the gun fired out of battery and the cause was the stuck firing pin that fired the partially chambered round as the slide closed. The normal result will be a bulged and bent magazine and broken grips, not to mention a stinging or bloody hand if the pistol is being held normally.

Jim

 

[chris in va]

After the first explosion I looked down to see if my hand was still there and it was a little black but unharmed. So I disabled the gun and beat the lead round out of the barrel and took the hunk of brass out and looks over the gun and decided it was fine and did some more shooting untill it happened again than I pulled the springs and changed to a firing pin that wasn't bent and it works like a champ again. The Hi point it's self is fine and shows no signs that it ever even happened.

No offense, but please reconsider taking this course of experimentation before you do permanent damage to you or someone else. What you're doing is NOT safe.