Take-off
Agree.... With the guys above...
Two thoughts on take off Benchrest barrels...
If.. You get these take off barrels fairly often AND they are truly low round competition I.E. < 1000 rounds, preferably <800. Then I agree with Mike about just building a varmint rifle on a new or used Bat SV action. Worth it then because you can depend on yearly available fully chambered barrels that SHOOT and will wack vermin/punch little holes.
If.... You only have this one barrel and or really have no accessability to a yearly supply of take off barrels and OR this barrel or future take off barrels are way shot out >1500 pretty fire checked. Prob only capable of .250's... >2000+ just DONE! Long heavy fire checking and coppering, only capable of .300 on a good day but most likely .499 or worse..... Guess still ok for vermin.
If the latter is more what your looking at then just scrap using the existing tenon... Find a competent Rifle smith as close to you as possiable and for around 150.00 - 200.00 you have this barrel on your varmint rig. That is if no additional work is required... Only fitting the barrel.
Yes you loose the length of the tenon which shortens the barrel overall but NOW your pretty good, you have fresher cleaner throat and many take off barrels rechambered will SHOOT damn good for at least 800rds and fer vermin, you should see >1000rds easily.
Good luck, think hard about your expenses, it's gonna cost ya $$$ no matter what. Save those coins and just buy a new tube and have a good smith put it on you fav varmint gun.... Make it a tad long and once you got 1500 rds, have it set back the length of the tenon and your good for another 1000 -1500 rds.....
cale