Baffled by BCGs in Washington State

full auto bcgs are not illegal. whomever you talked to doesnt know much about ar15

Or trying to sell you a semi auto bcg.

I have a RRA chrome bcg, its been exemplary over the years and a couple thousand rounds.

It is much easier to clean and does look nice.

You done good for $160.

Being a Washington resident, I understand your confusion...while full auto firearms ARE illegal in WA State, the full auto bolt carrier group is NOT what determines if an AR is Full or Semi Auto.

That mechanical distinction is found in the trigger group, not the bolt carrier group. Dropping a full auto bolt carrier into a semi only AR will not make it a full auto rifle.

Hope that clears it up.

Tack

Tack,
This is prhaps a dumb question, but wouldn't a full auto trigger group make any AR 'full' auto?

What's the point of a full auto BCG, Is it just tougher/higher quality?

triggerjob said:

Tack,
This is prhaps a dumb question, but wouldn't a full auto trigger group make any AR 'full' auto?

What's the point of a full auto BCG, Is it just tougher/higher quality?

Click to expand...

Yes...an auto trigger group would make it full auto and very illegal without the right paperwork.

Honestly, I don't know the exact difference between semi and full auto BCG's?

There is a visible difference in the carrier area where the hammer swings up and contacts the firing pin but that's the extent of my knowledge.

Perhaps on of out "builders" will be along shortly to clarify.


Tack

The main difference is FA carriers are heavier. By increasing the mass, it slows down the time it takes to cycle thus helping FA become more manageable and reliable.

There is a little shroud too that protects the firing pin as it cycles. The bolt itself is exactly the same, only the carrier is different.

Other than that, not much difference in a semi auto AR. You can used either a FA or SA in a semi, but should only use a FA carrier in a FA/select fire weapon.

Thanks, guys. I mentioned to the gun shop guys what Tack explained (I.e. a full auto BCG in a semi rifle still only leaves you with a semi rifle), and I brought up the ATF letter which specifically permits this configuration), but he said the more restrictive WA law ("RCW" something or other) trumps the more lenient federal provision. I'm still puzzled by it. Now I need a stripped lower, which is a whole new nightmare to deal with. I saw a bunch of lowers at Rainier Arms last Friday when all hell broke loose. Now everybody's out of those too. I guess I should have bought a complete rifle a couple months ago when I first started planning my AR build. Oh well. Rainier is in pretty tight with Mega Arms out of Tumwater, WA, so hopefully they get more in before too long. Thanks again.

AgentTikki said:

The main difference is FA carriers are heavier. By increasing the mass, it slows down the time it takes to cycle thus helping FA become more manageable and reliable.

There is a little shroud too that protects the firing pin as it cycles. The bolt itself is exactly the same, only the carrier is different.

Other than that, not much difference in a semi auto AR. You can used either a FA or SA in a semi, but should only use a FA carrier in a FA/select fire weapon.

Click to expand...

I thought there was a timing issue too, something about the difference on the bottom of the carrier that changed the timing of when the auto sear was engaged? or is that added metal simply there for mass?

I believe that is the shroud I am refering to. IIRC it prevents the hammer from hitting the firing pin as the bcg cycles out of battery. I'm not sure what it does on a FA fire control group tho, as I do not fully understand how they work.

Knowing too much could be too tempting to some. Maybe legally it's better not to fully understand how they work!

For me, and most of us, it's not that tempting. A full auto firearm is the last thing I need but I do want the higher quality bolt and carrier since it's such an important component of the AR. Looking at diagrams of the full auto and burst trigger group it's pretty confusing to me. And it was 1968 since I last held an M16!

70cuda383 said:

I thought there was a timing issue too, something about the difference on the bottom of the carrier that changed the timing of when the auto sear was engaged? or is that added metal simply there for mass?

Click to expand...

The timing issue has to do with the weight. The heavier it is the slower it cylces.

Heavier doesn't necessarily mean better.

The race gun guys like to run lightweight BCGs and Buffers so they can cut down on split times.

Quentin said:

Knowing too much could be too tempting to some. Maybe legally it's better not to fully understand how they work!

Click to expand...

Amen to that.

Most SA BCGs today are enchanced. The top one is really only found on older 30+ year old ARs