MCARBO Ruger PCC Bolt Head Pin Failure

MCARBO Pins with about 3-400 rds.(Purchased 11-2019)…look ok so far…:eyes:
MCARBO Extra Power Recoil Spring…~5-600 rds.

Bolt/Receiver with about 1,900 rds…lots of wear on the ALUMINIUM but that’s normal for this kind of design…lMHO…:face_with_monocle::sunglasses:

Check where your bolt stop hits the bolt…loads of where and a gouge there.

Any farm store or auto parts store, though NAPA will put the wood to you 5.00 is Full price anymore is too much


They tend to do that, though I will say they’ve almost always had the parts I needed when I got in a jamb. We’ve got two auto parts stores on the island, will have to check next time I’m in. :+1:



My local Home Depot stocks it: $4.98 for 14 oz. grease gun tube and $9.98 for 11 oz. spray can. Looks like popular Auto Parts stores stock the 14 oz. grease gun tubes for a dollar or so more.


I have had the same failure of the bolt head pins on my PC9…twice. I bought the extractor after having the problems with the factory set-up others have discussed. I bought the pins at the same time and installed them together with the extractor. The extractor is great…no bobbles with it at all after about 1000+ rounds. When I first broke it down for a thorough cleaning I found a broken head on one of the bolt head pins. I removed it, photographed it and sent a message to MCARBO. I immediately got a reply and new pins on the way. I installed those pins recently. This past Saturday, I had a USPSA match of 130 rounds. I pulled the carbine apart for cleaning and to check the pins. One had broken again in the same manner. I called MCARBO and spoke with Jake. I told him I would send the broken pin back for analysis and suggested to him that it was possible a heat treatment problem as the failure looked to be a brittle failure on the thin section of the pin head. The material selection of A2 steel is likely just fine.

I agree with many of the other posters that the PC9 is just simply very fun to shoot…no stress, just enjoyable!


First off @jrquigley, welcome to the Brotherhood.

Second, thank you for this. Interesting to hear this is still an issue with the part. I’m still kind of wondering if the fact that they are harder than the factory pins might not have something to do with this failure. As noted before, maybe the factory pins are softer for a reason…


Thanks for the welcome, chilipepper! Hardness is essentially the resistance to penetration or wear. For example, a file is quite hard so it can cut softer materials including many steels. However, if you put a file in a vise and hit it with a hammer, it will break rather than bend. It is not tough. Many parts used in all kinds of machinery have the need to be hard on the surface and tough on the inside because they have to resist both wear and shocks. The hardness resists wear and the toughness resists shocks. Because of the shape of this pin, I think it’s possible that the head of the pin, being much thinner than the pin itself, is perhaps cooling too fast and was not able to develop the crystalline structure inside the head that it would need to have greater toughness. The factory pins are probably tougher in the head area but would be less resistant to wear. Just a couple of thoughts here from an old retired guy…


Hope they kept records as to when they shipped out the “bad batch”?


I spoke with MCARBO customer service this morning about the pins. Sent them an email with photos as requested but I also mentioned this thread as well as @jrquigley’s 2nd failure with his replacement pins. I’m not sure how tight their records might be on when the bad batch arrived or if they know specifically which pin sets might be bad in their stock. I will be keeping my eye on the new ones once I get and install them, will probably be doing a full tear-down and clean after every range visit from here on out to be safe.


I think so, because they told me it was around the time I bought mine. I gave them the order number and date.

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Someone from MCARBO customer service called me yesterday morning and looked up my order in May. They said that bad batch was identified before then and destroyed therefore I did not get those… [quote=“chilipepper, post:30, topic:10870”]
MCARBO customer service

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Bad batch was from May 2020. According to Tod @MCARBO this morning.

Mine were purchased 11-2019. No problems expected…:grin:

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She didn’t give me any dates on the phone, my order was placed on 11/28/2019. I didn’t install them until sometime in February 2020, and only did so because I had the whole gun torn down for a good de-scuzzing. The gun is currently running the original pins and still working like a champ.


Reckon the pins are safe to order now?
I have a carbine on the way and am putting a M*Carbo order together.


Same here. Also what about a bundle?


I suspect as safe as ever. I never posted an update here but MCARBO sent me replacements, which I have yet to install, the damaged pins were sent back for testing. I’m still running the original factory pins I threw back in at the moment.


@chilipepper…I think I’m gonna pass on them [for now].
Falling back on the old adage: if it ain’t broke…

Will wait and see what goes on with y’alls.


Unfortunately, theres also two others i think of when my life, (or dinner) is on the line…

“if something can go wrong, it probably will”
“Your only as strong as your weakest link”

Let me put it to you this way, I’m still running the original pins I threw back in when the replacements failed (they failed in less than 400 rounds). I purchased them more as “just in case” replacement parts, same with the extractor. I did not have any issues with the factory parts, though the factory pins did (and still do), look a little rough. They have never caused any problems. At this moment, with exception to the trigger itself (wanted metal), extractor and recoil spring retainer (again, metal), the innards of my PCC are bone stock with just shy of 2400 rounds down the pipe. I am not convinced the majority of internal upgrades available are needed or necessary. The PCC has been very reliable and the only issues I’ve suffered were fasteners loosening, something I’ve addressed by applying VC3 to just about every threaded fastener not removed to take the gun down for cleaning.


I’ve run just over 7000 rounds through my Ruger PCC now and after doing a full cleanup last week, noticed that one of the factory bolt head pins had broken. I really can’t say when it happened as I don’t normally take the gun down that far during routine cleaning.

However, I did have on the shelf, a set of the MCarbo replacement pins and have installed them. Looking at my mailing package, it appears I purchased them in January of this year so hopefully the new pins are from a “good” batch and not part of the “bad” batch that was removed from stock.

This particular Ruger is now down to 100 rounds or so a week as I’ve switched to a different gun for some of the weekly matches around here. I’ll keep a closer eye on the pins for the future.

I’m currently only running the pins and the MCarbo extractor in it now as I didn’t feel an immediate need to replace the spring. The extractor is looking great after several thousand rounds.