Briley Bushing 1911

Any ever try one, 

How hard are they to fit and install?

The Similar topics listed below this thread have some interesting information.
I looked through them a while back and ordered one.
I am waiting to the get the mandrel to fit it to my slide. 
It seems like I'll need to take about 0.004 off the OD to fit.

The Mandrel screws into the back of the bushing with a half inch shank for turning in a lathe.

Midway lists it, but it's out of stock.
It is a little hard to find on the Briley site. Briley MFG - Briley Bushing mandrel

While reading about the Pachmayr 1911 builds I noticed he had a similar type of 1911 bushing,

Rich, I will share my secret with you. Briley Bushings hate me. You can measure the barrel 5 times. Come up with the same measurement 5 times. Order the Bushing and it won't fit. Not like you want it to. I have quite a few 1911s so I decided to cheat. I bought the 5 most common sizes and when I want to fit a new barrel I use the one that actually fits and then replace the one I used in my kit. It's only expensive once and eliminates the pain/embarrassment of ordering the wrong one again. On my RO that's been converted to 38 super I'm on my 4th barrel. Only 2 were the same size. That picture reminded me that you can buy the rings separately 

Fitting the bushing od to a slide isn't harder than any other. However for them to be happy you need to find a barrel with truely straight od, not relieved a few thousands back from the muzzle for regular bushing clearance, which most barrels are now.

I had one of their barrels installed and it had lots of upper lug engagement , so much that firing pin strikes were too off center for small primer brass, and I needed more than a full turn of elevation over my kart barrel zero