I measured last night. I might just make a muzzle break to take up the difference and a shade more. Looks like since I am in for a penny, I might as well be in for the whole pound. I had this Disco up for sale, but after some ridiclulous offers, decided to keep it. I think I will open up the TP to .095" (is at .085 now) and make a SS breech for it at the same time. Also, I bought one of Steves FFHD's and so I'll make a new endcap for it and give it a try.
The above is a little statterbrained, but once I'm totally finished, I will post the results. As she sits, I am getting 60 good shots with 7.33's from 2.4K down to 1.2K psi, average of 817 fps. Last night, I chronied the 10.34's and decided on opening up the TP a little and using the FFHD instead of adjusting the PA that is installed. When I cranked in to get the 10.34's up in the 820 fps range, it was pretty hard to cock and the shot count dropped to 30 good shots within a flat curve. If I can acheive a little more power via the TP vs spring tension, I think I will have a more consistant and easier shooting rifle. Anyway, that is the plan, but still lots of work to do!