$50 bolt carrier groups

[lysanderxiii]

The difference in plating and lining has a very different, very important implication for BCG’s.

The purpose of the chromium plating in a bolt carrier is to:

1) ensure that the chance of corrosion is mimimized,
2) provide a hard, smooth, low friction surface, and
3) ease cleaning.

Which of these functions are not provided by nitriding?

 

[Varminterror]

Plating on the exterior of the bolt, I can take or leave. Any number of finishes or coatings will be fine.

Chrome lining of the boltway (aka the piston) is a very different thing than the finish applied to the exterior of the bolt carrier.

 

[M1key]

That would be my thought.

M

 

[someguy2800]

The only problem I can really see from a non chromed carrier is corrosion. Beyond that I can’t really see why nitriding would not be perfectly suitable. Then again most of my AR steel parts are nitrided simply because I like the semi gloss look of nitrided steel and I’ve never had any corrosion on any of my ARs even when put away wet.

My only other experience with nitriding is crankshafts. You can leave a nitrided crank on the shelf for ages with no oil on them and they never seem to rust. A good nitrided crank is also so wear resistant that when you take apart a motor that has had debris go through the bearings a lot of the time the crank will be perfect whereas a normal steel crank would be grooved. The motor in my race car pounded out a main bearing so bad from harmonics they stuck to the crank when I pulled it out. Even after that the crank was perfect and it’s still in there with just a couple new bearing shells.

 

[ar-newbie]

These same sorts of arguments pop up all the time, and the vast majority will never come close to shooting enough for it to be a real issue. Those who will shoot enough, wouldn't have bought the less expensive stuff so it's a moot point for them.

 

[M1key]

Well I would rather spend $20 more and get a premium BCG as mentioned at the beginning of this thread. Like the engine of a car, it is what makes it run.

M

 

[Varminterror]

Those who will shoot enough, wouldn't have bought the less expensive stuff so it's a moot point for them.

Eh, some of us buy a dozen or two BCG's every year and try to save money on some of them where and when we can.

I know I like the idea of my gas rings riding against and the high temp, high pressure plasma of my gas operation impinging upon chrome lining, not against nitrided steel. Can't sell me a chrome lined barrel and convince me it's premium, but when it comes to BCG's, chrome lining, I like.

 

[HB]

If I buy one of these BCGs, will it grow into a rifle?

I foresee the bolt prompting an upper purchase. Then the upper will likely grow legs?

 

[someguy2800]

If I buy one of these BCGs, will it grow into a rifle?

I foresee the bolt prompting an upper purchase. Then the upper will likely grow legs?

Only if you stick it in the yard like a tomato stake and water it everyday. If you use enough miracle grow it will turn into an AR10.

 

[lysanderxiii]

Plating on the exterior of the bolt, I can take or leave. Any number of finishes or coatings will be fine.

Chrome lining of the boltway (aka the piston) is a very different thing than the finish applied to the exterior of the bolt carrier.

As stated above, the chrome plating inside the bore and carrier key is to prevent corrosion, provide a hard smooth surface, and make cleaning easier.

You don't say how nitriding fails to fulfill these requirements.

 

[lysanderxiii]

Eh, some of us buy a dozen or two BCG's every year and try to save money on some of them where and when we can.

I know I like the idea of my gas rings riding against and the high temp, high pressure plasma of my gas operation impinging upon chrome lining, not against nitrided steel. Can't sell me a chrome lined barrel and convince me it's premium, but when it comes to BCG's, chrome lining, I like.

1) the gas is nowhere near a plasma jet.
2) the temperature of the gas is only 2000 degrees K for a duration of of 1.5 milliseconds, well within the ability of nitriding to handle.

Your personal preference for chrome plating is not a technical reason why nitriding is inadequate for the job.

 

[Varminterror]

Your personal preference for chrome plating is not a technical reason why nitriding is inadequate for the job.

I do know, however, what the inside of my carriers look like after sonic cleaning following 10 and 20k round counts. My chromes look like chrome, my nitrides don't look like nitride any more.

But hey, buy what you will.

 

[lysanderxiii]

I do know, however, what the inside of my carriers look like after sonic cleaning following 10 and 20k round counts. My chromes look like chrome, my nitrides don't look like nitride any more.

But hey, buy what you will.

Well, let's see what they look like, if you have some technical evidence that nitriding is less effective, I would love to learn something new.

 

[armoredman]

My $49 PSA BCG arrived last week, will get assembled into a new toy this coming week. I am happy with it. I know little about ARs, just what I learned from my one and only, and the guy who helps build them for me. The only AR I have cost me $138 total, works like a charm, and I'm good with it. This build will run me about $240 when it's all said and done, and I will be good with that too, because I have little to invest. However, the NEXT one I will try to buy some higher quality parts to build something nice enough to go back country with.

 

[armoredman]

And it seemed to work just fine, for a $50 BCG.



75 yards with irons front rested, first time fired, dang that flyer. It will win no matches, but it will hit Mr Wile E Coyote!

 

[IndianaBoy]

I read an article this morning which stated they were producing 77,000 receivers annually, based on ATF numbers, and selling 4,800 rifles.

ETA: yup, reading the annual report, I think it’s a really far stretch of the imagination to say PSA has sold more AR’s than any other brand. Definitely a heavy hitter in annual sales, but looking at their rifle numbers from 2017, they sold sparsely a thousand or so more rifles than Delton. Looks like Aero ran about half of the volume of PSA, so it’s further a pretty far stretch to say those two made up 75%+ of the market... I think you’ve fallen victim to some creative authorship in some article somewhere.

I think the big volume that PSA is moving is in their kits and uppers, not in complete rifles.

Most of their really good deals are a kit that is everything but the lower. Then guys snag a local $40 lower to complete their kit and avoid FFL transfer fees.

 

[IndianaBoy]

I have stuck with the 'premium' offerings in bolt carrier groups from Palmetto. Which are made by Toolcraft, who is a large OEM for many manufacturers for bolt carrier groups.

So I can't speak to their nitrided carriers. I have some nitrided barrels that I am very happy with. I do have a QPQ/Melonite (similar or same process as nitride, just with a different name), JP Enterprises low mass carrier that has roughly 10k rounds on it and it still looks brand new.