Question for those of you who put the tension system on your 700mm barrel.

[Healthservices]

How did it affect your groups? Did you have to re-tune afterwards?

I did notice that the barrel droop was less with the POI being higher than it was before.

My 700 did pretty great with the barrel tuner, 700mm superior heavy, carbon fiber stiffener, twin port, shogun moderator, and NSA 30 gr 217 slugs, but things opened a bit with the tensioned barrel and that barrel tuner was part of the shroud, so it is not on there now. The groups opened up a fair amount with this setup too.

Allen

 

[Macros]

Hi Allen

For me it was initially a case of similar findings to you. Higher POI and less droop with mod on the end.
Initially groups were worse and the gun required retuning from scratch.

What I did notice was that the difference between a suboptimal tune and a good one (with known good ammo) was smaller than before, I'm guessing due to smaller amplitude of barrel vibrations? So a bad tune might net me one inch groups at 60y with a good one being a ragged hole, whereas before a poor tune could easily open things up to 2 or more inches at the same distance.

A perfect tune results in similar downrange results with or without the tensioner. It's just that now the gun is pretty much impervious to losing that tune or it's zero, either randomly or due to some minor knock.

I wonder if you could modify the back of the tuner shroud to fit over the tension sleeve? I would hesitate to try the direct 1/2inch unf version as that is effectively adding a ~7cm long narrow (1cm) metal tube directly to the end of the barrel and I worry that will wreak havoc with air turbulence behind an exiting slug. At least the shroud version strips away some of that.

 

[Healthservices]

I put on a spin on tuner to see if I could tighten up the groups and it did help. But will have to spend time to retune. Macros that is a good idea as I could probably remove the the rear support cone (spins off as it is threaded) completely to retain the old tuner sleeve but would have to find a way to seal the opening to prevent any noise and lead dust from shooting out. Maybe have Elis5713 make a modified 3d print of the rear cone.

Allen

 

[Macros]

If it works out I might try something similar with my 800mm barreled impact, come to think of it. Getting some good groups so far, but never quite to the level of my 700mm. Can't hurt anything but the wallet to try a tuner up front to tame the harmonics

 

[Motorhead]

While my .30 cal FX 700mm is NOT on an FX product, it is set up with a true "BARREL STRETCHING" tensioned set up that is Very very rigid.
Any other miens of trying to use such a thin and flexy liner was in vain !!!

 

[qball]

No need for tuner most off the time, I tried and it’s still sitting in my parts bin. In fact it’s too much work to get a tuner to work correctly for me.


All you need to do is a little fine tuning now that the barrel harmonic has changed.