I'm a 100% Fucking New Guy for builds. Looking for a little guidance on doing a pistol build.

I have a DPMS Classic 16 that is currently not serving a purpose because my 6720 fills the 16-inch role better.

Rather than try to unload the DPMS (in a poor market) to fund the pistol, I'm thinking I can save a bunch by buying a stripped PSA blem lower, completing it with parts stripped from the DPMS lower, and finishing it off by putting a 10.5" barrel on the DPMS upper.

If my thinking is correct, I'll need to buy the stripped pistol lower, 10.5" barrel, and gas tube. I should be able to strip everything else off of the DPMS, including the lower parts, BCG, and A2 flash hider. Then all I'll have left over is a rifle lower, 16" barrel, and A2 stock.

I should be able to do this for nothing more than the cost of the new lower and barrel, and offset that by unloading the DPMS lower, barrel, and stock.

Since I haven't done any builds at all, my question is, am I on the right track or am I missing something?

All right on. Most all 10.5" 5.56 barrels are carbine length gas, though, so you won't even need a different buffer tube. You can certainly legally use your carbine adjustable receiver extenstion on the pistol, but if you want to go with a SIG brace (or some other options) you'll need to switch to a round "pistol" type buffer tube. They take standard carbine buffer/spring, so your current ones wouldn't be wasted.

However, one minor fly in your ointment -- you won't likely be able to use the A2 pinned gas block that the DPMS carbine has, without sending if off somewhere, unless you've quite handy with drill press and maybe not even then. So you'll probably either need to get barrel with A2 block already on it if that's what you want, or go with some type or other of bolt on gas block.

- OS

Thanks.

Does the "fly in the ointment" apply to removing any A2 FSB, or is there something different about the DPMS that requires drilling? I thought it was just a matter of driving out the sling swivel rivet and the 2 taper pins with a punch. Then again, what I thought doesn't mean much since I haven't done it before.

I would NOT have a pistol using a carbine multi-positional buffer tube. Especially if you have a stock that could be added. Your getting into constructive intent that could be seen as an ATF no no. 10 years in club fed if found guilty.

Use your existing spring/buffer and get a pistol tube. I just picked up a kit complete for 29.99. It doesnt say KAK or Phase 5 on it but will work.

Good luck with your build.

I am posting pics of my new build tonight.

JBL

Pinned FSBs are generally not moveable from one barrel to another.  They're drilled as a unit when first installed, and you'll never get it right trying to drill a virgin barrel with the existing holes in the FSB.

You're going to want to look into a set-screw type FSB.

Yep, that's the gist of what I meant, but didn't explain.

- OS

Meh. As long as you have a legal use for any stock in your possession, you're fine. Multiple parts are fine, if one has a legal use, they all do.

But yeah, if all you own is an AR pistol, or no 16"  barrel in the mix,  I wouldn't have a stock period, regardless of what tube is on the pistol. Simply possessing the stock is iffy, as "attachable" is not defined. And of course if you kept the carbine tube and stock, same as having the carbine tube on the pistol anyway.

- OS

Thanks for all the input.  Even though I have  other lawful  uses for the take-off stock, I'm still going to go with a pistol tube. It won't add that much cost and is prefer a foam cover anyway.

As for the A2 sight...on closer examination I see what you guys are talking about. The taper pins aren't flush to the FSB but completely mushroomed over on both sides. Same on my 6720. Not an easy removal for my skill set. That means my biggest hurdle is finding a 10.5" barrel with the A2 sight, handguard retainer, and barrel nut already installed. I'm not seeing very many out there (at least not in stock). I was really hoping to stick with the A2 sight to keep costs down because I already have a carry handle and a chopped carry handle rear sight that I could use.

About the only thing I see out there is this one from RRA. Any thoughts on it?

Rock River Arms barrels

Model 1 Sales, Jt distributing. Also you can buy a barrel from Classic Firearms classicfirearms.com for like $70 and get an Armalite clamp on FSB for $45.

Personally, I wouldn't strip your lower, some parts are tougher to get out with out breaking the lower, ie; trigger guard, takedown pin, bolt stop. New DPMS LPK is only $50.

Again, it's not just removing the pins. It's more with what's involved with drilling the channels for the A2 in the new barrel, which is even more fraught with probs using an already drilled A2 base.

If you want an A2 base on your pistol barrel, much recommended to just get barrel with one already installed.

- OS

Or you could buy a virgin A2 FSB and send it and your barrel off to some place like ADCO for assembly.  They'd be happy to drill/pin the FSB as well as make sure the barrel nut is in place.  You could then install the gas tube and put it in your upper.