Good deal for you!
There is nothing wrong with the 7 BR, but if you want some more oomph, you can try either 7mm-08, which would be my choice or you could go with a rimmed case ala 7mm Bellm or 7x444. If you really wanted to go the whole hog, you could go with 7x57 mauser or 280 rem or one of the 7 maggies, but I don't think you gain too much over a 7-08 in a 15 inch barrel.
There are a few wildcat rounds that are between the 7br and 7-08.One is the 7IHMSA ,the 300 savage necked to 7mm. I don't know what your plans are for the barrel ,but for deer and sillywets the 7BR is hard to beat! I've taken deer at 200+ yards with mine,and with the 7IHMSA also.Recoil can be a problem with heavier bullets at higher velocities in larger cases though. I'd think long and hard on any changes prior to doing anything.
I have several 7tc/u barrels(various lengths) and 7BR & IHMSA bolt pistols.Also the 7-08 ,280 Rem &7mmmag rifles.The 140 grain bullet will take every thing in North America BUT the really big stuff.I use 120,even for deer. 168's will take Elk in the larger cases,not to say a &7 br won't. You just got to get closer.
You need to be careful what you rechamber a 7 BR to. The 7BR has a very large diameter at the body shoulder junction. Some reamers will not clean up the old chamber and will leave a ring in the finished chamber. The 7 IHMSA was one of those, they required a special reamer to keep from leaving a ring.
Mugs is right.
I was considering turning my 7BR Encore into possibly a 7-08. I took the chamber drawings of both of them in Autocad and did an overlay of the two chambers. According to the theoritical numbers, a 7BR chamber will not clean up with the 7-08 reamer. It would leave a ring where the shoulder and neck come together on the 7BR leaving a very bad ring part way down the body of the 7-08. It might cause the cases to stick very badly in the chamber. If I remember correctly the 7 IHMSA would not clean up either. The only way it would really work well would be to set the barrel back and re-weld on the lug. Not a very good option.
I think your best option would be to trade the barrels for what you want, which will also save you the cost of the re-chamber.
A forum community dedicated to the great outdoors and hunting enthusiasts. Come join the discussion about hunting, fishing, survival, archery gunsmithing, optics, reviews, accessories, classifieds, and more!