For grins and giggles, let's say a pre-threaded, short chambered barrel is a Shilen. Threaded for a Rem 700 and chambered 223 Rem. What are the chances that said barrel could be reamed to .223 AI and without any further modifications - i.e. tenon shortened, bolt nose recess lengthened, etc?

Can be reamed to AI with out any problems. Must use an AI go gauge as it is .004 shorter then the standard 223 go gauge.

You would probably have more success reaming to a AI, than a standard chamber. I've never used one, but I believe they are not very "short", meaning it doesn't take much to reach headspace. What are the chances the reamer used to finish it out matches the reamer used to chamber in the first place?

A long chambered barrel makes more sense to me.

I can't speak for the 223 & Shilen, but short chambered A&B/Grn Mtn barrels in 257 Bob and 7x57 both went to AI with no set back needed.
They are suppose to be .040" short, generally you only need .012" to make it an AI. Most people will go 1 full turn if trying to index sights or lettering on the barrel. Depending on your thread pitch that could be .062" or so.

Well, if I can round up a reamer and gages, I'm gonna give it a shot.

Try here to rent them.


http://www.4-dproducts.com/display.php?group=Rifle

Maybe you should also think about getting a lathe to do it.

I've always though that a long chambered barrel would be a better idea.

Just face the shoulder to get headspace. No reamer required.

I have a lathe and have done my own threading, chambering, etc. Just so happens I have a short chambered barrel, and figured I give it a shot w/o the lathe. I've seen and heard multiple references to short chambered barrels being a 'breeze' to finish. But to me they were one of those "too good to be true" stories. Hence, I asked here.

If all else fails, in the lathe it'll go.

I would like to hear how the finish reaming on that Short chambered barrel goes. I am getting ready to do two by hand. One .280 AI and one .300 win mag. Shilen short chambered barrels from Midway. Midway says no sweat. Shilen says no sweat, PGT says no sweat. So why am I nervous. They are very close, dropping go and no go gauges in they are very close.

It takes more reaming then you think, because the neck and throat are short and undersized. You will notice the reamer is protruding more then the .010 they say the chamber is short. You will notice that after the first few turns all the chips will be in the throat neck and shoulder area. Still a piece of cake to headspace and finish.

I've done a .223 to 22-204 and a 6x47 Rem to 6mm-204 both with the barrel on the action with a bushing at the rear of the reamer handle to keep it centerred. Both turned out very good and have killed their share of coyotes.

My advice for what it's worth go lightly with the reamer, clean and check headspace often it is very easy to go too far. Use a lot of cutting/reamer oil.