Fx impact mk2 shooting slugs

[spyde82]

Hi i am currently setting up my impact for slugs but have some problems with my groups.



i get good groups but there are still some flyes maybe every 4 shot or so.



How do i get a more stable fps ? 

 

[Michael]

Caliber?

FPS?

Slug size, type, weight?

 

[spyde82]

Its a mk2 .22 with 600mm slug liner shooting 23g nsa at 945 ish fps

 

[clgraham82]

I tried all recommended slugs with the same setup and got lousy groups. Testing/tweaking got too expensive...I gave up on the slugs until the prices come down.

 

[Hobbyman2007]

Have you tried adjusting the VS until the speed just starts to decrease ? Are you using the .218” or .217” size ? I’ve found the Impact to be quite bold sensitive , by that I mean if your not holding the rifle exactly the same way every time you pull the trigger the exact same way , the groups tend to open up . I figure this is mostly due to the high state of tune needed to get the bullets to fly at a reasonable speed in comparison to a lightweight pellet . 

If the trend continues , the price of bullets will go down . I cast my own so it really doesn’t affect me . There are alternatives to casting that are quite cheap . 

 

[mtnGhost]

That's probably too fast for those little NSAs given BC. I wouldn't shoot them over 920-930 personally (they also behave more like pellets in the wind vs. the heavier ammo).

 

[AirgunBill]

I am shooting the NSA 23's .218 dia. at 900 to 920 fps out of my 600 mm barrel. I'm getting one inch 10 shot groups at 80 yards. I found the .217 diameter 23's did not shoot well enough. They say with the short bearing surface of the lighter weight slugs the .218 dia. might be the ticket Bill

 

[spyde82]

Okay mine dont like to shot under 940fps, and i noticed that under 50y the groups wassent good but at 100y they where much better

 

[Hekk187]

I got a 1st generation Impact, 700mm barrel, slug liner, hammer spring on 3, regulator at 150. shooting 218 23 grain at 960 fps sub moa at 100, valve backed out to start and then in until power drops off..c3 bumper has been changed to delrin..

the fx gauges aren't very accurate, but the 700mm barrel added about 30fps.. occasional flyers, but I figure the accuracy from slugs is not going to be as good as the 25 monsters under 100.. but 200 yards all day, and this is not a mk2 impact..

only gets 2 sideshot magazines at that power, so could be more efficient..but a lot cheaper than a new fx mk2...

 

[mtnGhost]

I got a 1st generation Impact, 700mm barrel, slug liner, hammer spring on 3, regulator at 150. shooting 218 23 grain at 960 fps sub moa at 100, valve backed out to start and then in until power drops off..c3 bumper has been changed to delrin..

the fx gauges aren't very accurate, but the 700mm barrel added about 30fps.. occasional flyers, but I figure the accuracy from slugs is not going to be as good as the 25 monsters under 100.. but 200 yards all day, and this is not a mk2 impact..

only gets 2 sideshot magazines at that power, so could be more efficient..but a lot cheaper than a new fx mk2...

That's still 56 shots, which is not bad in my book! I tested my MKII for the first time Sunday, only did the TP and probe mods so far. I wanted to keep the testing at or under 150bar, and I'm able to shoot 30gr .217 NSAs at 950fps. I shot a bunch of those, and then tested 27gr and 21gr, during my day long session I think I refilled my bottle 3 times at most (it may have only been twice, I'm not sure). Shot count is