I was reading on line and it says that all I have to do is swap out the barrel. Is that true? Can I use the same bolt, mags, buffer and spring? Are there any potential problems that I will encounter by not getting a complete upper? and Is there any where that i can get a 300 black out barrel that is cheap? I dont care if it is used if its under 1000 rds. thanks

All you need to do is change the barrel, depending on your has system (ie you have a carbine gas system now) will stay the same, muzzle device needs to be .308 (different thread pitch). Best place to find a cheap barrel is on the equipment exchange.  You shouldn't run into any issues by just changing the barrel.

Yes just change the barrel. There are plenty of places that sell them. Midway is a start. If you want a good barrel custom built Grim Reaper Tactical is good and wont break you.

If you keep your existing gas system on a 16" carbine, you need to ensure that you get a carbine length gas system instead of a pistol length barrel.  

If you have a midlength or full length gas system on your .223, then you will need a new gas tube.  If your front sight/gas block is pinned on military style, I would sell the whole barrel assembly and then buy a new gas block and tube and delta assembly or free float handguard.  The reason is it is really easy to mess up the holes for the gas block on a new barrel if you don't have the right vises, jigs and bits (it is a taper bit).

Use the equipment exchange to sell your old barrel/assembly to offset your cost of the new 300 BLK barrel.  It is probably the cheapest caliber conversion you can do if done this way.

Check out Sota Arms for ultra cheap barrels or try your luck on the EE (they get bought up pretty quick if priced right).

Factory barrels are hard to find in stock, but check your favorite barrel maker's and their distributors sites often because they all get bought up quickly and patience is required.

I'd probably replace the Bolt with a new one depending on how many rounds you've sent down range.

This is a good idea.  

You could also use it until it fails and acquire a spare that has been tested in the rifle on-hand (you can fit it in the pistol grip) in case it breaks or the springs/gas rings/etc. wear out on it.  Bolt life can go from a few rounds on a bad one or 10's of thousands on a good one.  They typically go 5-15,000 rounds before major issues besides springs/rings.

This is one of the principal advantages of the 300 Blackout.  I already have two spare bolts that have brand new springs on-hand that fit several rifles (.223 and 300 BLK) if I ever need them.  Plus I can use any of my rifles as a donor gun for the others if it ever becomes necessary.

The bolt is the main part that can quickly limit you to less than one shot if it breaks or seriously malfunctions.  The gas system can be out line or come loose/leak and you still have a bolt action if you remove the parts if they get in the way.  With the lugs, bolt or ejector/extractors breaking, your rifle will not eject the spent round or chamber a new one if it does fail on you.

You know. You could just get a new upper & pull 2 pins swap & push the pins back in.

Thanks for the help. I don't want to get a whole new upper. Id rather just get a barrel and start saving for a suppressor. I looked up SOTA and there barrels are pretty inexpensive. Do you know of any 300 blk out barrels that are shorter in length that are around the same price point? I would like to make this ar nice and compact. most of my shooting is going to be under 200 yards with the majority being 50-100yrds. Thanks for Helping.

SBR barrels at 8-11 inches are great and need a pistol gas system.
You need to fill out the SBR paperwork and get it approved and in hand with tax stamp before you have the upper and lower in the same area.........

anything under 16 rifle requires an SBR stamp before you make it...


16 inchers work well with a carbine gas system

My DSA stainless barrel  upper was inexpensive and accurate

You left out the $200 for the tax stamp.

NVM

I looked up the requirements about class three items a while back and i've decided to make it a suppressed pistol for a while before I submit any paperwork for an SBR. as long as The suppressor is on the trust I can use it on multiple firearms. I will probably get a thread adapter for other calibers, if it doesn't require a seperate 200 tax. but this is getting a bit in the future. I just need to worry about converting my 5.56 to a reliable, trouble free 300 blk out. thank you.

A suppressor has it's own SN. As long as you legally own it, you can switch between weapons anyway (trust or sig).

BTW, PM sent.