Before it fails, I’m going to replace the bolt in my Colt BCG that has over 14K rounds on it. I have a spare Rainier Arms bolt marked MPI. Would this be a good replacement for the Colt bolt or should I purchase and run a BCM bolt and keep the Rainier Arms for a spare?
Why not get a Colt bolt? If you aren’t going to then I would say get a BCM bolt or a SIONICS bolt (Carpenter 158 HP/MPI tested).
Thanks Gunz, I was hoping you would reply.
Haven’t had any issues with my rainier nib bcg, or my bcm.
Same here.
I bought a rainier BCG on sale for $100, and it has been fine after 500 rounds.
The Rainer Bolt is 9310 instead of Carpenter 158. I only have a little over 2k on it but it has done well.
My Rainier bolt is the NiB version and is Carpenter 158.
I bought one of their $100 ones. They told me via email that it was C158 because at the time the listing was not marked. I received it and it said 9310 right on it. I would have kept it accept I was told it was supposed to be C158 steel. I asked if I could send it back in and get a discount on any C158 bolt they had and they said they did not have any in stock. So I returned it and ordered up a BCM from them (even though they told me they did not have C158 steel bolts in stock) and no surprise it showed up on my door in a few days, so it must have been in stock. I think they just did not want to give me a discount. I do not really care and I will still do business with them. I might have just been dealing with a new guy or something.
So after all of that, really can say nothing about their bolts other then that it looked like a nice bolt
Here’s mine after about 2-3k estimated rounds. It is NiB, but it looks black from suppressed shooting.
Lol, I’ll stick with the 14K round Colt bolt till I get a proper replacement and peddle the RA bolt to someone who thinks all bolts are created equal.:happy:
Looks like Grant has Colt bolts for $99…I just completed my order. http://www.gandrtactical.com/cgi-bin/commerce.cgi?preadd=action&key=SP64027&reference=/cgi-bin/commerce.cgi%3Fsearch%3Daction%26keywords%3DColt%20bolt%26searchstart%3D54%26template%3DPDGCommTemplates/FullNav/SearchResult.html
I mailed that sucker off to a member here who has some access to metal hardness and material analysis equipment.
Looking forward to the results! Are you thinking the can was responsible for the premature failure?
No, probably improper heat treat. You’d be able to tell doing a hardness test. You can probably do some metallography to find the point of propogation too. I can’t tell from the photos too well but it looks like brittle failure.
I’m willing to bet it wasn’t tempered correctly.
Yeah… The can didn’t do it. I’ve got that gun gassed down to where it shoots smoother than a Mid length.
Wow, I always thought Ranier bolts were good to go. How does everyone know they’re 9310 and not 158? I don’t see it listed on their website?
On a side note (not to hijack the thread), does anyone have any experience with Centurian bolts? I have two after having issues with a BCM bolt and just assumed they were GTG.
Centurion bolts are of high quality and are on par with BCM and Colt in regards to proper material and testing being done.
The rainier ones in question are 9310, MPI and not HP, listed in the sale section for a while now. Centurions are C158, MPI and not HP. I’d say the centurion is higher quality just from the specs but the jury is still out on the benefits or lack there of associated with skipping HP testing. Hard to jump on board the 9310 bandwagon with results like mark’s above. Id have no issues trusting Centurion’s offering though. Only time will tell.
I hope the testing of the bolt will reveal some sort of data that we can draw conclusions from. But I wouldn’t buy another one of these at this point.
I have one new still in the wrapper I can give you a good deal on.