Dreaming of a 17TCM

[catchbull@4]

I'm having a ton of fun with the 22TCM and while the recoil is very light, it is enough to prevent seeing bullet strikes through high magnification scopes. As much as I like shooting the 17MachIV, I'm thinking the "17Mach3.75" would be even sweeter. With 20gr bullets out of my 17MachIV the visual on prairie dogs hits is awesome. I don't know if it would be worthwhile or not, but I'm thinking that when the 17TCM is shot out, it could be rechambered to MachIV, moving the shoulder .375". The other option is to rechamber to 17 rem, which would remove another 3/8". Am I crazy, or would moving the shoulder/throat forward make a worthwhile improvement in accuracy?

[BK7saum]

I am not sure but the barrel in front of the throat may be fire cracked as well as having an eroded throat. I have a 6x47 that is starting show signs of throat wear and also is rough for about 4-5 inches in front of the chamber. I don't have a bore scope, but am thinking fire cracking due to heat/pressure.

[catchbull@4]

BK7,
I don't actually have a 17TCM, because at this time it is just a dream cartridge. I've never heard of fire cracking, but if the bore is getting rough 4-5 inches from the chamber, the idea of rechambering wouldn't be practical. I like to see the 17TCM developed, but may have to look at the 17Hornet as an alternative. The prime reason I'm dreaming of the 17TCM is the strength of the parent case and endless supply of range brass available.:-D

[BK7saum]

Yeah, I didn't word that correctly, but I don't know if someone shooting a 17 TCM would get usable barrel life through 3 chambers/ rechambers. I don't think the bore would hold up. I could be wrong, but guys/smiths will sometimes set a barrel back to freshen the throat, but noone that I know of uses the barrel past the 1st setback/rechamber.

[catchbull@4]

Thanks BK7. I guess a more useful question to folks who have rechambered or setback a barrel would be how much they typically remove to bring back accuracy. I wonder if the reason only one setback is done has to do with threading into the taper of the barrel and if a full bull barrel would accommodate multiple setbacks.