What does "450 short chamber" mean?

[Skans]

I happened to acquire an STI custom 2011 a couple of years ago. It has a schuemann ported barrel on it stamped "450". I looked at the schuemann website and found that they sell several "short chamber" barrels, one specifically being 450.

Now, I've fired cheap .45 ammo out of this gun and it works just fine. But, I was wondering if any of you guys with competition guns know what the designation 450 short chamber really means?

I'd really like to know what this gun was designed for before I decide to sell, trade or perhaps even possibly use it.

I purchased it as in impulse buy at a live auction - and I still don't have much information on it. I've posted pictures of it here before, but here are a couple more:

 

[Scorch]

"Short chamber" generally means that the chamber must be reamed to finished size after the barrel is fitted. As opposed to a chamber that is cut generously to allow for little to no loss of chamber length during fitting, as with a "drop in" barrel.

 

[Skans]

So, it's basically a barrel who's chamber is fitted precisely for the gun it's going to be used in? In other words, if you bought one of these "short chambered" barrels and tried to drop them without reaming the chamber, it wouldn't feed, right. I presume that the precise fitting leads to potentially increased accuracy.

 

[RickB]

The chamber should be cut to depth after fitting the exterior of the barrel to the individual gun. G.I. chambers can be as deep as .920", for a nominal case length of .895". Custom-cut chambers usually run around .905". All "gunsmith fit" barrels should have a short chamber.