Semi-auto or Lightweight BCG negatives

[JediGuy]

Are there? I’d planned to pick up some Colt BCG’s for some lightweight builds, as they’re not pricy, and they are a known quantity. But what I’m building will be for kids... What are/Are there negatives to using a quality “semi-auto” or “lightweight?” Are the couple ounces saved offset in some way by problems or increased felt recoil?

[DoubleW]

There is no advantage. The weight savings is negligible at best. The SA carrier will more than likely work fine, but I’d be beyond surprised if anyone notices any weight savings. Prices being what they are, I’d pick up some 6720’s, add rails, or leave as is & leave it at that. You’re going to save a lot more weight based on the barrel & hardware you choose.

[ABNAK]

There is no advantage. The weight savings is negligible at best. The SA carrier will more than likely work fine, but I’d be beyond surprised if anyone notices any weight savings. Prices being what they are, I’d pick up some 6720’s, add rails, or leave as is & leave it at that. You’re going to save a lot more weight based on the barrel & hardware you choose.

Agreed 100%. However, I recall a thread I started some time ago and guesstimated that the difference between a semi and full auto carrier was roughly the difference between one buffer weight and the next one up. In other words if you use a full auto carrier and an H buffer, the same gun with a semi carrier *should* be able to use an H2 without any issues.

[JediGuy]

Thanks guys. I think that’s all I need to know.

[bruin]

I have weighed LMT FA and SA BCGs. The difference is about .3 oz.

Sent from my SM-T810 using Tapatalk

[joeg26er]

If you are building a rifle for recoil sensitive folks like smaller people a LW BCG + adjustable gas block can do more than just reduce static weight
If you are willing to do some tuning, you can get a really soft shooting rifle

[vicious_cb]

If you are building a rifle for recoil sensitive folks like smaller people a LW BCG + adjustable gas block can do more than just reduce static weight
If you are willing to do some tuning, you can get a really soft shooting rifle

Not advisable unless you are trying to make a gamer rifle.

[joeg26er]

Not advisable unless you are trying to make a gamer rifle.

I’ve successfully done this with a 12” triarc mid length barrel
Slr titanium adjustable gas block
Cycled wolf gold and super weak steel case ammunition
As well as full house 556 IMI and sellior and bellot

[Gödel]

Not advisable unless you are trying to make a gamer rifle.

Why isn't it advisable for a range rifle for kids? Is the issue reliability or maintenance?

[markm]

The problem with SOME semi carriers isn't the weight. It's the carriers that are ramped beneath the firing pin. These are designed to work with the type II hammer. They can cause retainer pin damage, etc. Just a needless pain in the butt.

Now if I were wanting a light, low recoil youngster gun, I'd be going BCM middy all day long. There's no AR I've shot that comes close to the smooth shooting characteristics that the BCM middy does. And one of mine is the KMR. So it's also the lightest gun I run. I can blast like it's a rimfire.

[Dr. Bullseye]

Given they have a choice, why would anyone downgrade to a semi-auto BCG if they could get the more beefy version? There is a whole genre of BCG manufacturers who market tougher BCGs and they evidently sell well.

https://www.youtube.com/watch?v=HZkK70Miz60

Maybe a FA BCG is overkill but again if you could have one, why not? What is the upside?

[Todd.K]

Used to be that full auto carriers were only made by quality manufacturers. So it was a easy measure of quality, as well as avoiding some weird ramped ones.

Now you can get great or junk in either. I would just focus on getting a decent quality carrier.

[wanderson]

Unless you have an adjustable gas block, you should choose your BCG & buffer weight based on how over or undergassed your setup is.

My preference runs towards the heavy side of reliable operation. Slows things down and gives the mag a bit more time to bring up the next round. That’s a bigger issue in other calibers like 7.62x39. I like the ‘slower’ recoil feel as well.

Now for range/race guns, lightweight BCGs are great for fast follow ups. If you can dial down the gas. But I’ve read that lightly gassed setups with light BCGs are also more prone to stoppages as they get dirty.

I like to start with a FA carrier and std. buffer and change out steel weights with tungsten til I get it running the way I like.

[Pappabear]

if you buy quality it should not be a problem, but not an area you need to concern yourself with.

PB

[MegademiC]

Gas drive has more to do with recoil than weight IMO - that said I've only adjusted buffer weights, but should be the same as the total reciprocating is changing (carrier vs buffer wont matter unless I'm missing something).

I had a 16" carbine, and 14.5" mid. The mid recoiled less. Tried carbine and H2 buffers.
I ended up cutting the 16" down to 11.5 without changing the gas port (it was way oversized) and is now the lightest recoiling AR I've shot.

All that said, 223 recoil is very light. I'd keep the kids on 22 till they are comfortable, then move them up to 223, maybe put a rubber butt pad on it. Its not going to hurt them.