Originally Posted By: scottmilk9Thank you JoeBob, I sat on my hands for several days wanting to type something similar, but glad you educated folks. Keep up the good work.
My opinion, is that its not a matter of wearing out, its a matter of holding up to the pressure. It might work great, but I'm not willing to take the chance on my customers.
Yep. At the point of a bolt failure then there is going to be possible collateral damage. If bolt lugs break off then they have to go somewhere and there is going to be a major malfunction inside the action. Ideally you want to swap the bolt PRIOR to it failing.
8620 bolts only popped up because of the banic. Otherwise, the market would have never accepted them, and they still are, hence the ridiculously low price. Palmetto is making pennies on the dollar to try to move overstocked low volume items. Once they are gone, I highly doubt they reorder any. I couldn't see the cost difference being more than a couple dollars but the market price is much lower.
If any big "name-brand" like DD, BCM, Spike's, Colt, etc then they would lose all credibility...and rightfully so. They're not mil-spec and aren't really the point where you should skimp on a build, IMO. ANY bcg an have a premature failure, regardless of material. It could be a hot round that causes an issue, or bore obstruction, poor heat treatment, or even a stress crack. However, the better materials should hold up better over the long-haul.
Materials on barrels matter less than BCG, IMO. 4140CM versus 4150CM for example. 4150 is a better barrel choice, but very few people will outshoot a barrel and 4150 can cost a good bit more. The same could be said for 416 and 416R. IF the accuracy degrades, it will do it in a very slow manner. Nothing should ever break or fail as a barrel goes out. You may go from 1.5" groups to 2.5" groups, but the reliability of the rifle won't be compromised and you'll still have combat accuracy and be minute of coyote at normal ranges. Very few people shoot a coyote rifle 15K rounds though. Prairie dog guns, yes. Competitive shooters, yes.
IIRC:
When they bumped up the 5.56 max pressure a few decades ago that's when they decided it would be beneficial to bump up to C158/9310 from the original 8620 design. The original 5.56 rounds fired in the original AR15's were much weaker and shooting a lighter bullet out of a faster twist barrel. They made the switch on the bolt materials and barrel twist to match the newer faster, heavier loads.
Due to this, its not recommended to shoot modern-day 5.56 through the older bolts and barrels of original M16's. I know that was a major issue when I went through Basic Training in '05. We had some really old M16s we used solely for blank fire that had the original bolts and barrels.
