Installed my new 700mm slug liner on my Impact and started tuning...

But things just did not werq out for the second time! I started by power tuning then went on to the harmonic tune. I finally got three through the same hole and so shot at 100 yards but ended up with a two inch group so started again on another power setting. Got three through the same hole again and shot at 100 yards got a half inch group two pellets through the same hole and another a quarter inch away. I was elated until I shot the next group that resembled a shotgun pattern. So started again only to quickly discover I had come off of the regulator. Grrr. Next time out a few days later I started over took pics this time. I shot three through the same hole, left on the pic, but a two inch group at 100 so went on. Shot the three through the same hole again, right on the pic, and heard THE sound, you know the sound the gun makes when it is tuned properly, then shot the sub MOA 100 yard group in the pic. I then found my barrel loose so tightened it up a bit. So, I was very apprehensive about shooting the second group and for good reason as you can see it sucks. I cleaned the barrel and ended up pushing out a half inch sliver of lead shaped like rifling! Mosquitoes attacking and it's getting dark so I had to retire for the day. I am sooo... close to nirvana I can taste it. But I will leave it for another day. 

I have gone through near four hundred slugs both NSA 36gr Dimple and HP and VK 34gr Large HP thus far so this tune is getting spendy. Shot some pellets through the barrel as well the JSB Heavy MKII 33.95s sub MOA to two inches at 100yards with just a hint of a breeze blowing. I was shooting in 3-5MPH winds with the slugs I hardly noticed it. Oh guess I forgots to say this is a .25 liner.





Douglas Ridge Rifle Range



Three shots through these holes at thirty yards.



Sub MOA group at 100 yards after single hole three shot group.



This group was shot immediately after the one above it. I pushed a 1/2 inch sliver of lead out of the barrel and found it loose as well later on so probly was the problem here. 


 
Well looks like I finally got this thing dialed in it took three tries and over 500 slugs to get it done. Here are the results of all of that werq. Mostly sub MOA with little wind at 100 yards. These are the best of the groups although the better part are close to these unless there is wind.



VarmintKnockers 34 gr HP





NSA 36gr dimple nose I shot three shots and could not see them from where I was so I dialed in some elevation and shot three more. ;^) !!!





NSA 36.2gr HP a sighter low cuz I changed slug types.





JSB MK ll 34gr pellets This was a five shot group the high shots, in the single hole, were not part of it. One of the best I have ever shot there was no wind at all when I shot this group. Mostly the gun prints 1-2 MOA with sorted and weighed pellets at this range.

Edit; There were three pellets in the single hole high on the target so I started shooting lower so I would not mess the, once in a lifetime, group up.





Almost fergot my 150 yard group. I wasted 30-40 rounds getting the scope set up to shoot this far and actually hit something. The target is a three inch shoot and see and I shot a whole magazine at it but only got close or hit it 11 of 16 shots. Think I see some keyholing here






 
Biohazardman,

i know your pain. I am been experimenting with NSA and VK slugs in .22. Got it dialed it or so I thought for the 24 grain then turned to a shotgun pattern. 1/2” 5 shot group to 2-3” group. It definitely frustrating and expensive. Looks like all your hard work paid off. I have it power tuned in the basement. Once I can find range time hopefully I can be dialed in and done. 
 
Endeavor, velocities for the 34gr were in the mid 940s, high 920s to low 930s for the 36gr. I just ran it over the chrony today after all that tuning. I was surprised by the accuracy when it said 740ish but depressed cuz now I gots to start over again. My gun is almost stock. I oval ported the barrel and probe and added a 1.25 mm brass washer for hammer weight and to increase spring tension slightly. Running at 150bar or so my Huma gauge says.