bt 65 power tune in .25

[Hobbyman2007]

Looking for info on the bt65. What is the most power from this platform? What is required to get it there ? I have an at44 in .25 tuned to 75fpe . wondering if anyone has gotten their bt up to the 100 fpe zone . As it is now the magazine length is holding the Hatsan's back on achievable fpe  (imo). Rat sniper slugs in 45 gr will fit the mag ,so slinging them in 1000fps =99.9 fpe . Sounds like fun.

[blackfocal]

what all did you do to your AT44 to get it to 75FPE?

[Hobbyman2007]

Did all the same mods that Bob did . Only I'm using rat sniper slugs at 37 grain. I'm getting a total of five shots , starting at 930 fps peak at 955fps and back down to 900fps. Just like Bob said in his post could probably get 80+ fpe for one shot and possibly one follow up shot.

[Bwalton]

The Hatsan .30cal is built from the same gun so you should be able to do that without much problem....

[Mod90]

Shouldn't be too difficult. You are going to have to lean on the hammer spring a lot, maybe open up the valve outlet port to match the transfer port. Moving that heavy slug slug that fast your shot count will definitely drop, you should be able to end up with 13-16 very powerful shots.

[Hobbyman2007]

I don't have a BT65 yet, just looking for info. The canadian dealer i got my at44 from is all out of the BT65 in .25. Looks to be a similar set up as the at44 . I think the biggest issue will be port matching the valve seat to transfer port the same size or 80% of bore. I know on the at 44 the valve is restricted quite a bit from factory.If the valve is indeed bigger on the 65 there should be enough meat to get some good air flow out of it .

[trekkerx]

I have .22 cal. I get a high of 955 fps  starting at 930 fpswith JSB Monsters.  Total of 25 shots.

[SpiralGroove]

Hey Hobbyman2007,
Just wondering, what do you shoot (at) with the AT44 at 75 FPE ??
Kirk

[Hobbyman2007]

I'm mostly shooting small game such as rabbits and ground hogs with the odd partridge. I haven't been out for coyote yet , I'm waiting for 100fpe rifle for that. The yotes we have up here are pretty big ( 60 lbs or so) .