Tuning impact barrel tuner on a mk2

[dannya1a]

ok. so shot a lot today, and now see a definite need to weight sort my ammo. I'm seeing two sometime 3 different poi/poa groupings down range. tune seems to be holding, but starting to see alot of regulator creep in the the setup currently. seeing a 3 bar over set point with a lot sitting time and 3 bar under when shooting. this coupled with the slug weight is most likely the cause of the wandering groups.

may have to see about what to do without voiding warranty and getting the reg so it holds stable. I run Sekhmet gauges this is how I have an accurate regulator swing that I see.

 

[corny]

Take the liner tension nut out of the equation by installing a cf tube which it would bottom out on if the tube is cut to the right length it should keep the liner more straight otherwise the torque on that nut is going to change ever thing because it will bow the liner I would start out by torquing to like 60 inlbs and go from there once you find a good number by testing stick to it

I don’t think it’s a good idea to have the cf liner contact the tensioning nut. Ur taking the risk of having no tension on the actual liner 

 

[Vetmx]

Looking at your groups tells me you’re still a long way from attempting to use the barrel tuner to squeeze the last bit of accuracy out of a good tune. The fact that you are not shooting locked into a nice comfortable set of bags and not taking all the tedious steps to find the best accuracy at or close to your desired speed leads me to believe that you’re looking for a one or two clicks miracle. Start from scratch, develop a good solid base tune at the speed you want, then play with the barrel tuner. Do not torque your liner nut to 60in pounds. I torque mine to 20. Like someone else said, the barrel tuner is not going to fix those crappy groups. It’s intended purpose, if it even works, is to squeak that last 1/4” out of your groups. But you need good groups to start with, which you don’t.

 

[dannya1a]

i agree vetmx...

what was a great tune has gone away on me, currently working to get it back to where it was, trying to determine why i can seem to get the FPS i once had and what has changed to drop so much of what i had off. i thought a reset of my c1 and a bump in regulator and hammer spring would get it back, but its still a bit low from where i know it once was. so i may have to go deeper back in and start the whole process from a low reg pressure and work it back up...

 

[Vetmx]

i agree vetmx...

what was a great tune has gone away on me, currently working to get it back to where it was, trying to determine why i can seem to get the FPS i once had and what has changed to drop so much of what i had off. i thought a reset of my c1 and a bump in regulator and hammer spring would get it back, but its still a bit low from where i know it once was. so i may have to go deeper back in and start the whole process from a low reg pressure and work it back up...

Yep, this is the story of the Impact. Finding a good tune and accuracy is only half of life with the gun. The other half is trying to keep or get back to a good tune you once had. FX guns are probably responsible for the pellet shortage and enable slug makers to buy houses on remote islands. I have wasted far more slugs chasing or because of a problem than I have just enjoying the gun. Mine is finally lined out once again and I’m happy. But for how long is the question. The best advice I can give is always take your time and document everything. Don’t make more than one change at a time.