Retaining pin is retaining to well...

[sandz]

New M4 build completed (pics to follow once all the kinks are ironed out). During first breakdown of BCG I noticed that the retaining pin was a little tight (not firing pin) and had to get some needle nose pliers to remove the pin. Once out i noticed that the pin was "slightly" spread apart at the end. Didn't think much of it at the time. Lubed the bolt and carrier and reassembled. A little tough to get the retaining pin back in, but at the time I thought it was maybe a bit dry, or due to the fact that it's a brand new rifle. Took it out and put about 60 - 70 rounds of Winchster .223 through it with no issues.

Broke the rifle down this evening to clean it, and the retaining pin is stuck solid. :confused: I've been able to get it about half way out using needle nose pliers but am hesitant to apply to much pressure. Anybody run into something similar to this? I'm a former jarhead so I've disassembled multiple BCGs hundreds of times, and this is the first time I've run into something like this.

I put a few drops of CLP and let it sit, but to no avail. Sprayed it with some WD40, and nothing. Not sure what to do from here. I guess when I noticed that the pin was spread apart slightly during the initial cleaning I should've stopped and picked up a new one.

[nimdabew]

Before I knew better, I bought 5 extra oly arms firing pin retaining pins for spares. When I actually needed to use one, I couldn't get it. I bought a bunch of BCM spares instead and those worked much better.

I would use prying pressure instead of pulling pressure. I typically use whatever pointy object is around to get the pin out and lever against the BCG. It won't hurt the pin or the BCG AFAIK. If it does, replace the pin with a BCM retaining pin.

[markm]

Rip that ****er out. Then start with a replacement to see if that gets rid of your problem.

It's a good idea to have a few extra pins around anyway. Brownells will have Colt pins. I keep a handfull of those various little Colt parts on hand. I get them at Brownells.

[DWood]

It also helps to spin the pin a little as you try to get it started. Not sure exactly why, maybe magic. :smile:

[johns961]

Maybe you should contact the vendor.
I had a problem with a brand new BCM bolt carrier group.
I had to hammer the the cotter key back in. And I had to do the same thing with the extractor pin. I tried my spare pins with the same results.
I emailed bravo company. They requested I send it to them. In five days I had a new one from them. It worked perfectly.
Good luck.

John!

[sandz]

I would use prying pressure instead of pulling pressure. I typically use whatever pointy object is around to get the pin out and lever against the BCG. It won't hurt the pin or the BCG AFAIK. If it does, replace the pin with a BCM retaining pin.

Will try this later on tonight. Was thinking that only one side is binded or caught so maybe cutting it would allow me to remove one side and then the other....


start with a replacement to see if that gets rid of your problem.

It's a good idea to have a few extra pins around anyway. Brownells will have Colt pins. I keep a handfull of those various little Colt parts on hand. I get them at Brownells.

Plan on picking up a couple. Didn't realize Brownells had them. :D


It also helps to spin the pin a little as you try to get it started. Not sure exactly why, maybe magic. :smile:

So I spun it a little and now it's turned 90 degrees and not turning back :lol: so will try something else.


Maybe you should contact the vendor.
I had a problem with a brand new BCM bolt carrier group.
I had to hammer the the cotter key back in. And I had to do the same thing with the extractor pin. I tried my spare pins with the same results.
I emailed bravo company. They requested I send it to them. In five days I had a new one from them. It worked perfectly.
Good luck.

John!

I'll start with the replacement, and if I run into any issues or if I notice that there's an issue with the BCG I will forward it to the BCM.

Thanks again everyone. Your responses are appreciated! :)

[Bob Reed]

New M4 build completed (pics to follow once all the kinks are ironed out). During first breakdown of BCG I noticed that the retaining pin was a little tight (not firing pin) and had to get some needle nose pliers to remove the pin. Once out i noticed that the pin was "slightly" spread apart at the end. Didn't think much of it at the time. Lubed the bolt and carrier and reassembled. A little tough to get the retaining pin back in, but at the time I thought it was maybe a bit dry, or due to the fact that it's a brand new rifle. Took it out and put about 60 - 70 rounds of Winchster .223 through it with no issues.

Broke the rifle down this evening to clean it, and the retaining pin is stuck solid. :confused: I've been able to get it about half way out using needle nose pliers but am hesitant to apply to much pressure. Anybody run into something similar to this? I'm a former jarhead so I've disassembled multiple BCGs hundreds of times, and this is the first time I've run into something like this.

I put a few drops of CLP and let it sit, but to no avail. Sprayed it with some WD40, and nothing. Not sure what to do from here. I guess when I noticed that the pin was spread apart slightly during the initial cleaning I should've stopped and picked up a new one.
Hello,

The firing pin retaining pin is suppose to be slightly sprung open. That's what keeps it from falling out.
http://www.bing.com/images/search?q=Photo+of+AR-15+Firing+Pin+Retaining+Pin&go=&qs=n&sk=&form=QBIR#x0y120

Here's the best source for Genuine COLT Parts. http://www.specializedarmament.com/catalog/Colt_AR_15_Parts-4-0.html

What brand BCG did you use in this build?

[Brennan]

What brand BCG? This might explain your issue when he explains the design qualities.

http://www.youtube.com/watch?v=vjq4uDLTsbY

[Doc Safari]

I try to rotate the pin a little while inserting it to get it to go in.

Almost every military manual I've ever read says "do not open or close the split end of the pin." Is it okay to pinch the ends together with your fingers slightly to get the pin started?

Also, even though I'm not a fan of monkeying with original parts, has anyone ever tried this:

http://www.dillonprecision.com/content/p/9/pid/25422/catid/17/KNS_Perma_Pin_Firing_Pin_Retainer_for_M_16___AR_15

It looks like the firing pin retaining pin as originally designed for the AR15 back in the 1960's before the military just decided to replace it with a cotter pin.