Need some help to ID two BCG

[cosme9242]

Just bought these from my neighbor who's husband passed a few months ago and these were in a box so I paid her a fair price. One is supposed to be an LMT and the other a Rock river but I can't find a definite answer online because of all the different gen carriers LMT has. One is a semi as you can see and also has some unique cuts along the carrier that start in front of the forward assist grooves. Neither of the bolts have any marking on them like (MP) The gas key bolts on the semi carrier has the letters YFS on them. Any idea which one is which and if they are even an LMT and a Rock River??

[Toecheese]

They both look GTG.....I think the YFS bolts are made in Asia and outsourced but I could be wrong. Lube them up and run them!

[cosme9242]

Yeah I heard that about the YFS bolts. The only companies that I know for sure that use them was with the PSA non premium carrier and I heard Bushmaster used them also

[Iraqgunz]

Neither of them is LMT. LMT marks their bolts and they do not use YFS fasteners. The one with the unique profile is similar if not identical to the ones that were made by Burke Industries a couple of years back during the panic.

Hopefully you didn't pay much for them. An absence of markings is a tell tale sign of Tier 0 stuff.

[cosme9242]

Thanks for the replies all, considering I paid $150 for both I think I made out good

[LRRPF52]

Yup. YFS fasteners are made in Taiwan. They can be made to work, but why cut corners when you can buy US-Made Grade 8 fasteners with certs that actually hold certain min/max dimensions that have been proven to provide more purchasing area in the threads?

A crate full of fasteners bought from Asian parts suppliers is no way to run an AR15 assembly line, but is great for people who cut corners given every opportunity. And people wonder why there is a difference between a real AR15 and a really bad copy.

Not to knock the parts in the OP, but case in point.

[Shao]

Yeah I heard that about the YFS bolts. The only companies that I know for sure that use them was with the PSA non premium carrier and I heard Bushmaster used them also

I thought Wilson Combat also uses YFS gas key carrier screws. I could be mistaken but I thought Young Mfg. does too. There's too much hate for the YFS screws - they carry the proper ISO certifications and honestly I'd rather trust YFS screws than some no-name USA made screws simply because they were manufactured in the US. Taiwan is not red China folks. It took the Spyderco folks years to accept the fact that the best Spyderco knives do indeed come from Taiwan. I remember when Sal Glesser made the announcement that he would be shifting a lot of production of his higher-end knives to Taiwan and everyone started crying foul until they got their hands on them and realized that they were better than both the Golden and Seki knives. Most machine shops that I've visited in Taiwan look like a laboratory clean room compared to their dank and dirty US counterparts. Run them until/if they break, then report back.

[cosme9242]

Most people can't look at things objectively in the AR world. Once something gets a bad rap then its next to impossible for said product to claw their way back. As to the thing or incident that gave the YFS screws a bad rap in the 1st place I've yet to hear about.

[Shao]

Most people can't look at things objectively in the AR world. Once something gets a bad rap then its next to impossible for said product to claw their way back. As to the thing or incident that gave the YFS screws a bad rap in the 1st place I've yet to hear about.

I've scoured the internet and have only found second-hand stories and questionable accounts with absolutely no pictures of damaged YFS screws. My DD rails purchased from DD on assembled DD uppers all seem to use YFS screws. I don't think Daniel Defense would use inferior quality screws on high-end parts.

Edited to add: I would be way more concerned using a MIM or cast gas key. Google "broken gas key screw" and hit the images button. Tell me how many broken YFS screws you see. I can't find any. I see plenty of pictures of unmarked "no-name" gas key screws broken... and for the record - YFS gas key screws ARE grade 8. I think they've gotten a bad rap because some BCG assemblers who use them also use MIMed or cast gas keys or don't properly stake or torque their screws. The only way to end this argument once and for all is if someone were to buy a large number of various quality "Made in the US" and some YFS screws and run them through a series of torture tests. I can almost guarantee that many of the US-made fasteners will fail first.