First let me qualify myself.I have been in the firearms industry for 12 years.I'm a N.R.A. instructor & manged a gun shop for 11 years.I'm also a certified Colt Law Enforcement Armorer for the M16,M-4,AR15 weapons systems.
Thanks for stopping by; however, a lot of what you say flat out contradicts my own experience with the AR15 system or is simply wrong and the way you said it made it difficult to read and understand.
The staking have to be cut,then u need a Colt specific spanner wrench.To replace use locktite & a spanner wrench.
Staking the castle nut is done because vibration will work the castle nut loose (along with the telestock) eventually. Loctite is a good soluton as well though.
The 1/7 bbls for the M-4 was designed specificlly for the Military issue SS109 62gr .233 ammunition.
Actually, it was chosen to allow the rifle to fire the longer M856 tracer. That round needs the faster twist to stabilize it.
Someone posted that 1/7 twist is better for 72gr or higher bullets that is completely wrong.The 1/9 bbl is better for high gr bullets & also lower gr bullets like the most common one used the 55 gr.
The 1/7 twist is commonly regarded as a better choice because it will fire both the heavier 73gr+ rounds and the lighter rounds (down to 45gr) accurately. Many 1/9s will fire 73gr+ rounds accurately; but not all of them will. The 1/9 twist is borderline enough that some will work and some won't. You'll even have 1/9 barrels right on the edge that will only work when it is hot outside. Nobody wants to fire match ammo and get a 4-5" group at 100yds and that is what you can see with some 1/9 barrels.
Its not that the1/7 won't shot them,it will,but not as well or as accurately becuase the 1/7 wasn,t designed for those bullets weights.It was designed for the 62gr SS109 or the M193 both current U.S. Military issue.
You realize that the M193 is a 55gr bullet? Just above you say the 1/7 will not shoot that weight as accurately and now you are saying that it won't do that because it was designed for a 55gr bullet?
In my experience, the 1/7 will shoot bullets as light as 45gr as accurately as any 1/9 barrel I've owned in the past. If there is a difference, it is smaller than any shooter I've seen can measure.
The carrier keys screws aren't staked there pinched which is efficent unless because of rotten luck or whatever u bend or damage the carrier key & need to replace it.Well then get a dremmel,a good thin file,or go see a competent gunsmith to take those screws off.Oh if u go the gunsmith way which I reccomend unless u know what ur doing it gonna be expensive.
The "pinching" you describe is the proper way to stake a carrier key. I've owned, built and worked on ARs since 1990 and never had to replace a damaged carrier key. I've tightened up a few improperly staked and/or loose ones though. Also, I don't know what you consider expensive; but an entirely new AR15 bolt carrier with key (staked) costs about $92.50 and can be replaced by even a monkey.
The M16 versus the AR15 bolt carrier it doesn't matter unless u own a regidtered machine gun(M16 pre 86 transeferable).
Actually, it can make a difference since the notched AR15 hammer likes to grab the collar of the firing pin and smash it against the firing pin retaining pin. This happens on a Colt AR15 bolt carrier because the firing pin isn't shrouded like a Colt M16 bolt carrier. As long as the firing pin is shrouded, then I agree that the weight difference between an AR15 and M16 carrier isn't a significant one and won't make a difference in functioning unless the rifle was already marginal to begin with.
FN supplied M16 & M4 for a while,but problems arose & they were replaced by Colts.
There was no problem with FN other than the Army lost a lawsuit to Colt over improperly supplying the TDP for the M4 to FN. FN still manufactures the M16A2 and M16A4 for the Marines and Army. Colt has the sole legal rights to produce or license the M4 for some time to come, so M4s must be produced by Colt as part of the terms of the legal settlement.
Returning to the carrier key screw I've yet to see any come loose in A Bushmaster,DPMS, or anyothe rifle.
Actually Bushmaster improperly staked hundreds of carrier keys on their rifles and had a major issue with this in 2003-2004.
MP or magenitical particle testing done on Colt bbls or parts is nice,but doesn't make that much of a difference.
Well, I'd be inclined to agree with you based on my own experience; but I don't understand how you can argue that Wolf may cause sudden extractor failure that could cost you your life and should be avoided at all costs a few sentences later. Using Wolf saves money (and a fair amount of money as well) just as using non-MP parts saves money. In both cases, you accept a higher risk of failure as the price of saving money. Why is it OK in one case and not OK in the other? Because in my experience, I've seen more cracked bolt lugs and cam pins than I have seen sudden extractor failures.