I was test cycling a new build.
I pulled the firing pin to cycle in some ammo to make sure it would strip rounds from the mag.

I tried it a few times like that without ammo and it suddenly locked up.

I realized later it must be the cam bolt turned and wouldn't let me pull the bolt out any further.

I luckly got it out again by smacking it into battery and pulling a few times.
It took me a couple of times for me to realize what the problem was.


So how do you keep it from turning so you can chamber ammo without the firing pin?

Never never never use live rounds.

Have someone that reloads make you some inert rounds.

Never never never use live rounds.

Go.. NO go gauges FTW


WTF were you doing ?

If you MUST use live ammo, get a spare firing pin and grind off the last eighth inch of the tip.  You were lucky you didn't end up with a worse jam than you got.

I guess that is why I pulled the firing pin. didn't want any accidents.
didn't think or realize it could jam up like that. But something bugged me about it, which is why I tried it first without ammo and the firing pin.

Guess I will see about some dummy rounds.

Like someone else said, shorten a FP and then notch the hammer end so you can easily identify it visually and by feel.

I will look into that when I start my spare parts order.

I believe you will get more use out of 30 dummy rounds than you will a ruined firing pin. BTW, you found out what could happen if you assemble the BCG without the firing pin being captured by the FP retaining pin, except if you were firing live rounds the gun may have blown up. When messing with the firing pin, be sure its captured.
Anyway, any reloader will be glad to take your fired cases and stick bullets in them - they are always good to have for checking out new mags, new rifles, etc. The only thing you have to worry about when using them indoors is breaking a window when you yank the charging handle to extract - they will fly out pretty hard. And that's what you want to do - yank the handle to extract and let it fly home to load, to simulate what happens when firing. Nothing is learned when doing it 'easy' except it usually will cause a jam.

Inert, or dummy rounds. Priceless tools for the tool box . . .

IM me your mailing address.  I’ll send you some Magpul dummy rounds.  You need them

I did the same thing once.  Everyone probably does it once.  

If you must do this, buy a firing pin and cut it off.  

If you are a reloader, you can make some dummy rounds on the cheap.  

I test all my new builds at the range.  The only time I did cycle tests at home was with shitty CProducts 7.62x39 mags.  

You're supposed to check it with a GO gauge (with the extractor removed, unless it's notched for one). Then reassemble and test feeding using action proving dummies. I recommend Magpul for 5.56 dummies. Those aluminum ones get worn and start chipping aluminum flakes into your action.