Thread: 7mm RM Shhhhh

http://www.nzhuntingandshooting.co.n...998/#post10559I've just done a 7mmRemMag with a Hardy suppressor. see this post

Yep been through thus shit, I had a 7mm rem mag, with hardy suppressor, was to long for me, speed with amax was 2975fps out if 24in tube, sold it.

Just built a 7mm saum, 23in barrel, with a tuiman2 suppressor, 3 inches forward, stainless construction, under 400grams, couldn't be more happy, 162 amax at over 3000fps, extended mag box to can seat to lands with something like 2mm to spear, short action, love it so far

Originally Posted by Smiddy

Yep been through thus shit, I had a 7mm rem mag, with hardy suppressor, was to long for me, speed with amax was 2975fps out if 24in tube, sold it.

Just built a 7mm saum, 23in barrel, with a tuiman2 suppressor, 3 inches forward, stainless construction, under 400grams, couldn't be more happy, 162 amax at over 3000fps, extended mag box to can seat to lands with something like 2mm to spear, short action, love it so far

Sounds like a nice setup, A great chambering for 2217 powder.

Mike,
Do not put a small thread on a button rifled barrel, especially a TrueFlite. They are the worst for opening up. You will get away with it on most Tikkas, there is usually little change in their bore diameter with even quite a bit of metal removal. But the worst muzzle bore growing we have seen has been with button rifled TrueFlites. We have seen the bore of a 300 RUM that had opened up 2 thou when turned down for a 1/2"x20 thread. Needless to say, it shot like shite! Cutting back to a section that hadn't opened up cured it immediately. Use a sensible/minimal shouldered thread size and you won't have a problem.
As to taking your can on and off, the biggy is making sure the rear bush has sufficient clearance on the outside of the barrel. This must not touch, or if you have some runout here (which you will even if your can is fitted true with the bore, almost no barrels are dead straight), then as you do the can up, it will contact the barrel differently and a tiny bit of change can seriously affect harmonics. We take properly fitted cans on and off all the time without POI shift problems. I would not shorten that barrel for your purposes. Just carry the can in your pack as you suggest, then screw it on when you get there. If the can is going to stay on permanently, then shorten the barrel by all means, but be prepared for a compromise in performance if its a magnum type cartridge requiring slow burning powder.
Short barrels and permanent cans work best with efficient cartridges like the '08's!
Greg

Thanks for that Greg, seems sensible to me.