Taking into account the entire BCG:
(I search tech and general but could not find a clear answer, apologies if my search-fu sucks)
Thanks,
A
Because there is no “clear” answer.
Extractor spring/Extractor
Ejector spring/ejector
Lugs on the bolt
Extractor
How many rounds from a new virgin gun before you replace these pieces on a duty gun?
As I stated. There is no “solid” number because it doesn’t exist. I have a BCM BCG with over 12,5K rounds through it and I have only replaced the ejector spring. It has the original extractor and spring assy.
Thank you sir.
A
Why do you want to replace the whole bcg? The carrier will last forever.
Just thinking out loud. I understand your point though.
IG can verify that BCGs last a long time, he staked the new carrer key on one of mine about 2 weeks ago. It’s got over 20 years of use and unknown number of rounds fired. Same parts none replaced otherwise. He can comment how beat up it was… 
Gas system length and quality of components will also play a roll in how long bolt parts last.
That thing was incredible and I wish it was in my inventory.
Correct, but nobody has quantified just how much an improvement in parts life would be realized. Same with an LMT enhanced carrier, and supposedly the Vltor A5 system (slowing & delaying extraction as well as cyclic rate).
I always have several quality spare bolts on hand (LMT/BCM/Rainier are all in my parts room).
So will rate of fire. It’s all very subjective. I used to change out springs and things around the 5K mark for guaranteed reliability, but nothing in life is, since I got a couple of fails below that, so I kept moving the goal post to look for it. I never got a conclusive, no shit answer.
Keeping a good supply of quality spare parts is probably the best sound answer.
You’ll get more reliability using Springco springs (Red or Blue, which has a higher life cycle than most will ever use in their gun) with an H buffer (or H2), a 5 coil extractor spring with black insert, and using a FA BCG. How long they’ll last without failure, is anyone’s guess.
What kills me is when folks post, “I’ve had this AR (Name your POS AR here) for 20 years and it’s ran flawlessly and didn’t change a thing”. Then when you try to pin them down on amount of usage or round count, it’s got less than 2000 rounds through it (Most with less than 1000 rounds fired, less than what you’d burn through in a normal carbine course in a weekend) or they won’t own up to their extremely low usage and you never hear from them again. Context matters…
The carrier should be good for a looong time, order yourself a couple of spare bolts and you should be worry free for a long time.
Iam also waiting to get a couple of bolts, I wish BCM would get some in stock. Seems like Windham is the only one taking orders. Iam holding out for BCM to get some in stock.
Check the “Where to Get” thread. G&R has them.
Eric
Hey blade! Good to see you on here. That original Colt carrier really is a testament to the strength of the carrier and was just plain neat to see. The gas key was beat to hell, but a quick replacement and it was as good as new.
IG
You got the old gas key… Now if I can find NOS bolt for it… I’ll try to snap a few photos of it. “now that old bolt or extractor will probable fail”
you should be more worried about he bolt and extractor more than the carriers. I have spare bolts and extractors, not carriers.
Yep. I showed it off during the class in Sandy Springs. :eek:
The only things replaced on the rifle from Jan 1988 on is at least 3 hammers, sears. and few weeks ago IG installed the new carrier key. The strange thing is the extractor spring buffer is white. The round count on all the parts is unknown by me, I assembled it in Jan 1988 and just shot the crap out of it.