So, fiddling with parts last night, pulled the BCG (chrome slickside Brownells) out of the receiver, went to put it on the table, and the firing pin hits the floor.



Pick it up, reinstall, check the retaining pin... well,the hole where I'd installed the nice chrome machined pin (thanks, AR15Sport!). Check the receiver. Check the table. Check my lap. Check the carpet... *there* it is!

Edited to add picture:

Reinsert, tip the BCG, ZOOOP to the carpet again.

Carefully spread the tines with a small screwdriver, now it won't enter the far-side hole. Unspread, insert, very carefully attempt to spread in situ, nope. Repeat assorted fiddling, still won't stay in.

Am I missing something here, or do I just need to wedge it even wider after insertion? There's a similar pin from KNS that says to just have the slot sideways on insertion, but that results in no change - wider spread, no go; less spread, won't stay.

Please note: I'm not interested in the history or machined vs cotter pins, reports of how well they work or fail, et cetera. I just want this lil' sumbitch to stay in so I can have a pretty princess BCG discover reliability for myself, and not have to swear search whatever inappropriate location I've stripped it in for the bugger.

Thanks!

on the very front of the split tines is it chamfered to aid in installation ( notice how I didn't say insertion ). If it is chamfered maybe you just have to push a little harder. Personally, I never had any problems with the cotter pin.

Put grease on it and it will stay in place until you install the bcg into your rifle.

This

this is why you want to pick up a spare parts kit, they are cheap enough to have a couple on hand.

$10 at Midway.

This looks much better than the cotter pin, though.



I'll try to chamfer it a bit tonight, though.

KNS has a nice one as well.

Retro FPRP?

what the hell is FPRP ??  Foundation for the Promotion of Responsible Parenthood

firing pin retaining pin

Lil' bit of chamfer, lil' bit extra wedging, now likes it's new home.

My Young Manufacturing slickside? Didn't even need the chamfering, just opening the tines a tad.

If I was at all smart, I'd be getting the final color adjustments done to the LPK components that need it and assembling the lower this weekend...

Damn abbreviations. Firing pin retaining pin.


Honestly had no idea that the early guns (601/602?) used machined retaining pins.

Learnt sumthing today.  

Early SP1's used parkerized machined FPRP's too and they are worth a pretty penny.

KNS Permapin.