I can’t seem to find any detailed info on Yankee Hill bolts and BCGs, such as whether they are MPI’d, materials used, etc. Any info on this would be much appreciated.
Basically, are they mil-spec?
Thanks.
Most BCGs come from the same 3 or 4 places the large manufactures of these parts use 158 for the bolt and 8620 for the carrier. 158 has to be purchased as a mill run which is more material than most companies would need this is why the large guys are still using 158.
After the election the demand for bolts was so high and there are many subcontractors that can do this part with ease, BUT they didn’t want to buy a whole mill run of 158. They looked to 9310 because it can be purchased in smaller lots and had already been used for AR bolts though very limited. 9310 does cost more BUT is sold in a size close to the bolts OD so the waste is lower.
As for MPI and Proof tests, these are just QC steps because thats all that sperates these 158/8620 combos from military grade. If you have a 158/8260 combo there a huge chance it came from the same place/s that supply TDP holders and spare part suppliers for the military.
I don’t buy MPI or Proof test bolts or carriers, mainly because I know the suppliers and what material they use, if its 158/8620 I buy. If I don’t know or if its some new metal I pass.
A good 158 bolt will last a long while, its the salting of 8620 bolts on the market by part kit suppliers that have hurt the ARs reputation when it comes to bolts.
As for the carrier this part hardy ever breaks, 8620 is cheap and easy to find, so almost all people cutting these already use it. That shot peen finish is crap IMO. What seperates a good and bad one is the internal grind and honing of the part. A good gas key attached is more important it should be at least 4140 and the carrier top should be precision ground for good key seal. Oh and of course a good staking. I double stake from the top per the USMC spec and from the sides.
I don’t believe this for a minute. Just for top tier manufacturers, there’s a whole slew of companies who make their own bolts: Colt, LMT, DD, FN, KAC…
BCM contracts from an unknown company that makes quality bolts.
Then there’s AO Precision and CMT, which contract for many manufacturers.
LWRC, Rock Rivers Arms, Olympic, Young Manufacturing, and Bushmaster supposedly manufacture their own, as well.
And I’m clueless about who makes bolts for DPMS, Hesse, Vulcan, M1S, etc.
That’s 13 companies not including the last few. Of that, I would only buy bolts from a few.
Your logic is based upon misinformation.
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From what I understand, Shot Peening is a surface treatment. Basically, the surface is “hammered” with BB’s. Kind of like sandblasting with special BB’s. This treatment makes the surface more wear resistant.
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I didnt mean test on the carrier , I meant surface that was a typo, thanks
And I will stand buy the 3 or 4 statement I said most and it is most. Not that all companies buy from 3 or 4 or that all types of speciality, piston, enhanced or “match” grade bolts come from them, though some do. I said most because it truly is a fact most come from 3 or 4 companies.
As for your list of names I know FOR A FACT many of them sub bolts and most buy parts from those big 3-4 companies. When companies run out or can’t get/make enough they just buy from someone else. When someone lowers there price on a part they switch to the other guy. The AR market is different than almost all other firemarms markets in the US, because of the guns modularity the AR industry is as much of a family as the weapon itself. Like any family they fight and pick there sides but almost all of them know each well enough and deal with each other in some form or get supper from the same tables.
Buy a 158/8620 combo and you’ll be GTG
I’m not going to drop names since I worked in the industry and still do, but on here you guys are on the right track compared to the other forum, but still too trusting in what you are told or hear from manufactures and their PR junkies (also know as friends/customers)
My logic based on that I worked with a lot of these companies on a daliy/weekly basis.
If you’re going to throw around these allegations; “I KNOW FOR A FACT…” then you bets back it up with the actual facts, and not some, “oh I can’t drop names, but take my word I work in the industry…” BS. You say that on this forum we take the word of the manufacturers and we shouldn’t, but we should take your word blindly? I believe there is a word for that…hypocrite.
So please, by all means provide these “facts” so we can all be better educated on the matter.
No for contract reasons I will not. Also understand one thing the most important thing, those top tier companies everyone loves here have NEVER that I know of sourced or subcontracted out for shit parts. Their reputations are what they are because of this very thing. Buy with confidance from those guys. Those companies do know whats best for you for your money. The top tier is my favorite section of the industry for this reason. But when it comes to some of these parts there just too cut and dry in how the industry deals with those parts.
I don’t need anyone to believe me or care I’m tring to help a guy out that looking for a BCG. It is a free country I can say the4 word fact because to me it is, I don’t have to disclose it to you for it to become a fact. Everyone on the net states their crap opinions as fact or maybe they don’t use the word and its accepted or not like the guy that replied to me, so… its a fact to me you don’t have to accept it or listen to it. If it makes you feel better I will not use the word fact again and what I post will get mixed in with all the crap out there.
Also I added and edited to that post read it again I don’t spend much time on the forums or posting and where the hell is the spellcheck on this forum the other forum has a spell check icon.
Okay, top tier companies don’t use bad parts and I can buy with confidence from top tier companies; that is as obvious of a statement that could be made.
If you don’t want to provide the facts, thats fine; just don’t go around making statements you care not to back up with said facts.
Making a statement like “You are on the right track here on this forum but still take the word of the manufacturers…” and saying “I know for a FACT, you should take my word…” is bunch of bunk.
Either provide the facts to back your own statements up or don’t qualify the statement in the first place.
Your definition of a “fact” differs very much from mine.
Not backing up statements is why there is so much “Crap” you speak of on the net. Back it up, make it a fact, otherwise it’s just some guy opining on the web.
The net is bunk in general and same with these forum this one is the best IMO on this matter. No company really wants people to know that they subcontract, it their goal to hide that. I have been to a lot of gun companies and its the industry standard to subcontract and a large section subcontract it all. I didn’t accept this because then you don’t have control of production as much. I changed this with my old company and its true business partners not subcontractors. We still had to subcontract and outsource, but to a much much smaller degree than 90% of the AR market.
so is some of yours
yhm makes the following
b/m
dpms
some r.r
olympic
the following make almost nothing
colt
cmt (makes for colt)\
hesse vulcan m-1 sales are all crap . no 1 cares
lmt bolts look just like yhm in tooling marks. at the shot show carl lewis would not confirm or deny who made his bolts. great gear, so no 1 cares.
we sell a lot of yhm and have been in the factory in mass. watching the boxes go out to many well known vendors. have you???
several of the companies u named i am not even familiar with 3rd tier at best. when u go to a bcg company and want to buy bcg, they ask what u want to pay and price parts accordingly.
u need to lighten up a little. many people on this board know a lot. u don’t seem to be 1 of them
i use yhm bcg in all my guns. i will bet my life on them. have ar’s running 9-10k in rds just to see, when thy will fail. no jams yet.
probably sell 100 bolts a year. just shipped 55 to a state police agency who trialed 3 bolts for 60 days. guess who the vendor was. and u have seen how many again please???
YHM has been a OEM supplier for a long time and a large sleeper on this sector of the AR market. BUT always understand all these companies buy from many sources not just one, maybe one if its a pin or screw but after the election where a sight dent stopped rifles from shipping and by the time companies had all the parts the market tanked, any company that went through that now buys from many sources. This is also the reason companies are going out of business and more to follow. It was just a race to ship first and most and the system for procurement made that race very tough.
TRUST ME IT’S A MESS
Great, we have all sorts of informationa nd opinions about who manufactures bolts for who; nohne of it backed up with any facts; and the OP’s question is not answered.
So plsease someone simply answer the question without all the white noise:
Does YHM MPI HPT there bolts? What material do they use?
u are 101% correct.
that is why i only sell quality products
d.d
lmt
yhm
the huge amount of crap out there is staggering. went to my 1st gun show in about a year this weekend. 1 cheap parts company was telling (false hoods ???" tpo almost every customer coming by.
had 18sh girl tell them everything was all colt. oh sure.
good post
tks
It’ll be very entertaining once one of the SMEs looks at this thread. Lots of silliness…
Yankee Hill Macine does not manufacture bolts, let alone conduct HPT or MPI testing on there their bolts. They buy them from Stag. FYI.
Indeed, I’ve been eagerly anticipating a SME showing up…
Last I knew, BCM has three bolt contractors. I know one is CMT and I’m 99% sure another is AO Precision.
Holy shit, you couldn’t be more incorrect. I guess barrels, bolts, receivers, and bolt carriers is almost nothing huh? All those are made in house in Hartford.
Stag doesn’t make Colt parts. :suicide:
As I understand it, you can make a thousands bolts/carriers from the same batch of metal, using the same process, all by the same people, and some will be 100% and some won’t pass muster. That’s why you rely on QC tests.
Saying that just because something was made with a particular material doesn’t mean it’s 100%. You can hand some 158/8620 to a shop student and ask him to cut you something that looks like a bolt, but that doesn’t mean shit about how reliable the end product is. Hence the testing.
Surely you’re not suggesting that QC is irrelevant as long as the right material is used and it’s made by the right company. Because that would be asinine and demonstrably false.