Background: I have impact with 700mm .25 superior heavy liner. I found at around 820fps the 29 grain and 33 grain NSA slugs seem to shoot very well. However, because I can’t leave good enough alone I wanted more POWER! But after 3 boxes or 1000 slugs later my next 100 meter groups at any speed higher than 850fps are around 2-4 inches at best and most are far worse, like 10 inches worse. As with long thin straw like barrel I am sure it’s harmonics or barrel vibration is kicking my behind. After some calculation the Nsa slugs have stability factor is 2.6 and higher with superior heavy which also confirms that the slugs have more than enough spin to stabilize and harmonics of the barrel is spraying them like a shotgun. Expensive and frustrating to say the least. One day I saw Ernest’s video on the carbon sleeve and I had a eureka moment because my favorite powder burner has full carbon wrapped barrel. It’s no fully carbon wrapped barrel but it should be a heck a lot better than that metal straw. I immediately ordered it and got it earlier this week. I degreased the barrel and carefully glued the sleeve on with 2 part epoxy, I want it to be as stiff as possible.
This morning I drove up the hills into near by national forest and found a nice flat road that dead ends into private property so shouldn’t have traffic. Setup my targets and started by shooting the 34 grain heavies I happen to bring as baseline. My best group is just under an inch with the heavy at 840 FPS, not hugely different than before but noticeably tighter by about half inch. Got my scope dialed in and it’s slug time! I immediately noticed that the groups aren’t amazing but most of the groups are 2-4 inches at 100 meters, 2-4 inch groups were my good group before!!!!
Then at 930 FPS the 29grain slugs decided to be nice to me!
I’m getting about 1-1.5 inch groups! I ven got a few cluster of them touching! Keep in mind that it was pretty cold up higher elevation so I was shooting from back of my SUV on top of a cooler. Feeling good about the groups I put some small walnut sized rocks on top of my target box and I just about hitting them at will, the few times I missed I noticed it was me. also noticed that even though the impact chassis is very stiff at that distance and power it is still hold sensitive. At lower power I didn’t notice the hold sensitivity, I still have a lot to learn about precision shooting obviously.
This group really made my day! Even though it looks like 2 groups but I remember the bipod slipped just a little and the can’t could be off a little, new bipod is still in the mail.
That is THE BEST group I’ve ever shot at 100 meter or 111 yards! It shows the gun is very accurate and I’m the limiting factor.
back to the main subject, did Ernest Rowe’s carbon sleeve work for me? From my experience today on my Impact, it worked tremendously well! I’ve shot the same slugs at the same speed before and the groups were 2-3 times the size. Harmonic tuning is still needed but I don’t think it’s anywhere near as sensitive as before, hell it was so sensitive on my gun I never found a tune above 840FPS that would even consistently knock over a soda can let a lone head shots on a squirrel or hit something size of house sparrow at 100 meters!!!
Ernest, you are my hero and savior!!!
edit: Ernest, you better make a crapload more of these liner sleeves, I need more!!!
Ernest’s carbon liner sleeves can be purchased feom Newman at https://910airguntuningandrepairsllc.com/
This morning I drove up the hills into near by national forest and found a nice flat road that dead ends into private property so shouldn’t have traffic. Setup my targets and started by shooting the 34 grain heavies I happen to bring as baseline. My best group is just under an inch with the heavy at 840 FPS, not hugely different than before but noticeably tighter by about half inch. Got my scope dialed in and it’s slug time! I immediately noticed that the groups aren’t amazing but most of the groups are 2-4 inches at 100 meters, 2-4 inch groups were my good group before!!!!
Then at 930 FPS the 29grain slugs decided to be nice to me!
I’m getting about 1-1.5 inch groups! I ven got a few cluster of them touching! Keep in mind that it was pretty cold up higher elevation so I was shooting from back of my SUV on top of a cooler. Feeling good about the groups I put some small walnut sized rocks on top of my target box and I just about hitting them at will, the few times I missed I noticed it was me. also noticed that even though the impact chassis is very stiff at that distance and power it is still hold sensitive. At lower power I didn’t notice the hold sensitivity, I still have a lot to learn about precision shooting obviously.
This group really made my day! Even though it looks like 2 groups but I remember the bipod slipped just a little and the can’t could be off a little, new bipod is still in the mail.
That is THE BEST group I’ve ever shot at 100 meter or 111 yards! It shows the gun is very accurate and I’m the limiting factor.
back to the main subject, did Ernest Rowe’s carbon sleeve work for me? From my experience today on my Impact, it worked tremendously well! I’ve shot the same slugs at the same speed before and the groups were 2-3 times the size. Harmonic tuning is still needed but I don’t think it’s anywhere near as sensitive as before, hell it was so sensitive on my gun I never found a tune above 840FPS that would even consistently knock over a soda can let a lone head shots on a squirrel or hit something size of house sparrow at 100 meters!!!
Ernest, you are my hero and savior!!!
edit: Ernest, you better make a crapload more of these liner sleeves, I need more!!!
Ernest’s carbon liner sleeves can be purchased feom Newman at https://910airguntuningandrepairsllc.com/
