Okay, here is another newbie question.  Having just ventured into the AR arena with my first retro (M16 A1) under way I want to do what everyone else wants to do, build another reto, like a carbine.

Problem = cash

Seems to me, and I don't really know, that uppers should interchange pretty easy with lowers.  So being short of cash, couldn't you have a dedicated lower and switch out different uppers and butt stocks with that single lower to configure between a rifle and a carbine?

Does this work like I think it should?

Everything else I own, the barrel is attached to the receiver so if you have a rifle, you have a rifle and you are not going to quickly change out the barrel and make a carbine out of it.

Thanks,
Bugs762

You are correct. As long as you are not putting a less than 16" barrel carbine upper on a non-registered SBR lower.

ADDED: I guess that is one of the great things about an AR. The ability to swap uppers without having to do any modifications.

Very nice

That's the beauty of the AR15 platform.  It's like a Lego set for grownups!

You could build an XM177E2 clone with a 12.5"bbl. With the moderator & grenade ring permanently attached, it would be over 16".

Quoted: You could build an XM177E2 clone with a 12.5"bbl. With the moderator & grenade ring permanently attached, it would be over 16".

Where and what do you look for in a carbine upper?

It seems like all the M16 complete uppers that show up on the market are for A1 rifles.

You usually have to make one yourself with a modern barrel installed on an A1 reciever.

Original Colt carbine uppers are very expensive. Someone offered me a 653 upper today for $700

You can buy a rifle upper and take the barrel off and resell it. It will almost cover the cost of a new carbine barrel.

Check out the carbine models HERE and see what you like best....

Looks like I'll be doing a 654 clone.  I snagged a SP-1 carbine barreled upper (16" barral and no FA) that looks like it will transition on to my 603 lower without to many problems.

Short of finding a Type 2 retractable stock, what is the next best bet for a stock?

Will there be difference in size of the front and rear pin holes between the SP-1 upper and NDS lower?

Thanks,
Bugs762

You could build a 652 then you wouldn't have to change the stock out.

If you want a collapsible stock, I like the Essential Arms with the shiny finish.

click here

You will need an offset  pin for the SP1 upper.


Kinda funny, I replied to your post here and then saw the "I'll take it" in justinwb's thread.
You are working fast on this project!!!
Are you near PDX?

Yes, I'm down in Springfield.  

I did get a bt of rabid and jump on that post.  Ever have that happen when you get something in your mind and all of a sudden in materializes in front of you and you think "My god that was easy, there must be hundreds of then around" and you pass on it and then you never see then again.

It really looked like what I was looking for and at a reasonable price, who could resist?  Only problem is that I see I'm going to have to get another NDS lower.

I'll have to meet you guys up north sometime.  I could have stood outside I5 last night and been blown there by morniing from the storm.

Best,
Bugs762

654 is what I am working on too. AF GAU5 could be in many configurations. A Generation III stock could be on a later one. I have seen them. Some with pencil barrel, some with M4 barrel. Some slickside upper, some A2. I just bought a  mil-spec gen III stock and compared it to my clone. No difference other than the N. Gen III is much cheaper than the 2 pos original ($300) or clone $85-$100.
Good luck.

Quoted: Will there be difference in size of the front and rear pin holes between the SP-1 upper and NDS lower? Thanks, Bugs762

Yes there will. You will have to sleeve the uper to 1/4 inch size to get a fit, and it takes a bit of doing.

First, you'll need one of the sleeves that DPMS sells. They're only a couple of bucks. so get two, in case you lose one.

You'll notice that the hole thru the sleeve is off center, and that's intentional.  Put the sleeve, with the thinner side up into the upper, and mount the upper. Check to see if the front and rear of the seam between the two is even.  You may have to move the sleeve slightly forward or back to get a good even fit..

Once you've established the proper position for the sleeve, take it out and use an appropriate sealant to secure it when you replace it.  If the sleeve is a fairly snug fit, you can use a high strength Loctite. In my own case, the fit in my upper was just loose enough that Loctite wouldn't set; and I had to use a high grade epoxy to secure the sleeve.

Good luck and welcome to retro.

Quoted: 654 is what I am working on too. AF GAU5 could be in many configurations. A Generation III stock could be on a later one. I have seen them. Some with pencil barrel, some with M4 barrel. Some slickside upper, some A2. I just bought a  mil-spec gen III stock and compared it to my clone. No difference other than the N. Gen III is much cheaper than the 2 pos original ($300) or clone $85-$100. Good luck.

Sorry, what's the difference between the GenIII, 2pos orgional (from essen arms?), and the clone(also from essen. arms?)?

Quoted: 654 is what I am working on too. AF GAU5 could be in many configurations. A Generation III stock could be on a later one. I have seen them. Some with pencil barrel, some with M4 barrel. Some slickside upper, some A2. I just bought a  mil-spec gen III stock and compared it to my clone. No difference other than the N. Gen III is much cheaper than the 2 pos original ($300) or clone $85-$100. Good luck.

Thanks for the info.  It's always nice to have options when putting a retro together.

Best,
Bugs762

Quoted: Quoted: 654 is what I am working on too. AF GAU5 could be in many configurations. A Generation III stock could be on a later one. I have seen them. Some with pencil barrel, some with M4 barrel. Some slickside upper, some A2. I just bought a  mil-spec gen III stock and compared it to my clone. No difference other than the N. Gen III is much cheaper than the 2 pos original ($300) or clone $85-$100. Good luck. Sorry, what's the difference between the GenIII, 2pos orgional (from essen arms?), and the clone(also from essen. arms?)?

I just got off the phone with Essential Arms.  They have a mil spec gen II, two position stock that they claim is identical to the original.  They also have a four position (masybe a two position) stock built to commercial specs that looks the same.  I think the only differences amount to a few thousand'ths difference in the tube diameter.  

They also said that this would probably be their last run of aluminum stocks, too hard to compete with cheap plastic.

Quoted: They also said that this would probably be their last run of aluminum stocks, too hard to compete with cheap plastic.

After posting that in THIS forum, I have a feeling there will be a run on these before they're gone.

I just use th 4 pos. Much cheaper and its still aluminum....