556 upper question

Posted: 2/1/2011 11:26:33 AM EDT

Bear with me, I know very little about the 556.

I really want to buy a 556 Patrol and register it as an SBR. Am I correct that the upper on a 556 is the part that is engraved and registered? (Instead of the lower, like an AR15)

I don't like the early style lower receiver (otherwise I would buy a pistol and go from there) Is it possible (feasible) to change a barrel on a 556 upper? If I could buy a 556 pistol barrel, could I replace the 16" barrel on the Patrol?

I also read that when people have registered 556 pistols that SIG will switch out their early style lower with the newer (folding) style. Is this true?

Thanks

Posted: 2/1/2011 1:48:04 PM EDT

[#1]

the upper is in fact the serialized part on the 556. not sure on a barrel swap or cutting down the patrol barrel.

if you are looking to go SBR at some point, there is a guy that is selling a new style(classic) lower pistol build on sturmgewehr. rather than the ar stock style.

I personally ended up buying a pistol, and a classic rifle then swapped lowers to get my SBR, then sold off the ar lower complete rifle. it cost me about $100 when all was said and done. much cheaper than getting a pistol and spending the $600 on a bare classic lower.

here is the ad on sturm.

Posted: 2/2/2011 5:50:07 AM EDT

[#2]

Quoted:
Bear with me, I know very little about the 556.

I really want to buy a 556 Patrol and register it as an SBR. Am I correct that the upper on a 556 is the part that is engraved and registered? (Instead of the lower, like an AR15)

the serialized part is the "firearm", and the firearm is what gets registered as an SBR. the engraving may be placed anywhere on the "frame, barrel, or receiver".

I don't like the early style lower receiver (otherwise I would buy a pistol and go from there) Is it possible (feasible) to change a barrel on a 556 upper? If I could buy a 556 pistol barrel, could I replace the 16" barrel on the Patrol?

it's possible to change the barrel on the 556. i removed the barrel from my classic, had it cut to 12.5", and reinstalled. it's a real pain in the ass though. the tools will remove some finish from the front of the receiver, you MUST make some permanent indexing marks between the barrel and receiver so it can be re-torqued to the correct location, and i wouldn't consider pulling the barrel unless you have access to a LARGE, FIXED, vise. the little vise attached to your workbench isn't going to cut it.

I also read that when people have registered 556 pistols that SIG will switch out their early style lower with the newer (folding) style. Is this true?

i highly doubt this. sig won't touch a form 1 gun. best bet is to poach a "classic" style lower off gunbroker, or grab one from colorado gun. be prepared to pay for it though.

Thanks

Posted: 2/2/2011 7:49:29 AM EDT

[#3]

Well, that answers all my questions. Thanks guys. Now I now what needs to be accomplished, just not sure which way I will go about it.

Thanks again.

Posted: 2/2/2011 8:25:29 AM EDT

[#4]

Quoted:
Well, that answers all my questions. Thanks guys. Now I now what needs to be accomplished, just not sure which way I will go about it.

Thanks again.

i'm not saying you need a machine shop to remove and install the barrel, but you need some good, rugged, equipment, and you are going to need to either buy or build the receiver tool. it's an expensive tool if you are only going to do 1.

if you want my suggestion, fill out your form 1's and send them in. while they are out, have someone engrave the receiver for you. when the forms come back approved, take a hacksaw to the barrel and cut it back leaving about 1/4". then, send the short-barreled upper off to ADCO. steve has the tools there to remove and install sig barrels. he'll be able to pull the barrel for you, finish the cut, threads, and recrown, and send it back to you.

Posted: 2/2/2011 8:49:49 AM EDT

[#5]

That really does sound like the cheapest way. I have been looking around for new style lowers (not sure on the correct term for new and old style) and they seem pretty scarce.

Posted: 2/2/2011 9:22:47 AM EDT

[#6]

Quoted:
That really does sound like the cheapest way. I have been looking around for new style lowers (not sure on the correct term for new and old style) and they seem pretty scarce.

they come up on GB and in the EE from time-to-time. some guys have even traded their old lowers with some cash to folks with "classic" lowers who actually liked the older style better. i suppose you could put up a WTT add in the EE and see what comes up.

your other option would be to just buy one right from CGS:

classic lower

$700 though, and you still need to buy the stock which is going to set you back another $300.

Posted: 2/2/2011 10:00:36 AM EDT

[#7]

Yeah, i looked through that site. There is a lot of sweet stuff, but the prices are outrageous.

When it comes time, maybe I will be able to find someone willing to swap.

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