Hammer pin rotation...

[racer11]

I have a sp-1 and the hammer push pin rotates with each cycle,,so i bought from cmmg a dual pin set up that has a little connector between the hammer pin and the trigger pin. Ya all most likely know what Iam talking about. Well it worked for a while then I notice the hammer pin rotating and found that the spline on the pin had stripped in the connector. I got a new one from cmmg and now the same problem. Do I need to be concerned with this issue, I am concerned that the pin holes will waller out and my lower will become unuseable. or is there another way to cure this problem or a fix with the pin connector I got........Thanks

[AR15Armory Neil]

That is not good if the splines are wearing out in the anti-rotation pins, yes if the wear is that much it will eventually wear on your pin holes in the lower.

[MisterPX]

Check to make sure your hammer hasn't seized onto the pin. Also, some lube on the pin, in the hammer, doesn't hurt.

[racer11]

Since I posted about this problem that thought came to me to make sure the hammer pin is lubed. It was dry and I put some gun butter on it and let it set last night. I ck it this am and the pin did not move when I cycled the gun. I think the lub on the pin is the key to this.

I have found that the pin now rotates freely in the pin connector so it is not doing its job, it lookes like the spline on the pin is not raised enuf( or just stripped) to make for a tight fit in the connector that connects the hammer and trigger pins. I had this happen before and I bet the problem was the hammer pin laking in lub.

Now that I think I know the cause of the problem and know what the cure may be, How do I get the fit with the hammer pin to be tight again without buying a new anti roll pin. I thought about taking a punch and staking it right in the end but I bet that pin is pretty hard metal but if I put a punch right in the center of the pin it may spread the metal just a bit to make a tight fit again. But Iam working with a pretty small pin here. My other option would maybe to take just a small dab of JB weld and cememt the pin and connector together. It would only take a very small dab and it wouldnt take much to keep the pin from turning, and a small dab would not be really noticeable.....

What's ya think about these two ideas.....

[MisterPX]

I would stake before weld. However, as I haven't seen the mounting sytem, I can't fully say what'll work best. Another idea may to bend the joining strip where it meets the pin, to add friction. Also, you may want to stake the pin right where it meets the retainer pin, crimping it in place, rather than peen the whole pin.

[racer11]

I did stake the pin right in the edge on both sides of the retaining pin. I got a small punch and supported the hammer pin(in a vice)and slipped the retaining connector in place and put two punches on each side and that fixed it and now the hammer pin is no way going to rotate. It is good and tight, in fact it worked so good when i build my AR pistol i will stake it just to make sure it does not get to rotating. I just got thru running a few rounds thru it and it has not moved a bit..........yipee horay !!!!!!!!!

Thanks