Optimal speed with slugs.
- Thread starter Emu
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My M3 is now set up for 16gr Zans. Reg is at 130bar. My RTI is still shooting 13gr Zans at 970fps and reg is about 95bar.
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600fps-3600fps all depends on the slug barrel stock shooter and probably a few other things
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In my two rifles currently in use ( .177 ) the speed of 960 fps seem to be trending, and that is 13 grain in the Maverick and 16 grain in the Two.
Both 700 mm barrels FX Heavy and CZub respective.
But for 55 M i had to do 1 ( cant remember is scope on Two is MIL or MOA ) hold under, at a guestimated distance of 65 M i was bang on, and for 93 M i had to use 2 hold over.
And the 20 grainers was flying quite well i have to say, i will have to retest this again on my next outing even if i will also be bringing my sawed OFF use to be 700 mm Maverick that otherwise is my hard hitter now.
By then i will probably also have some 24 grain Zans to try out in both rifles. In the Maverick i will be looking to get 55 - 60 food pounds if i can.
Both 700 mm barrels FX Heavy and CZub respective.
I ran into the same on Friday, having shot all my 16 grain at 963 fps , i thought WTH and tried some 20 grain Zans, no idea what the speed of them was CUZ no chrono on at this time.
But for 55 M i had to do 1 ( cant remember is scope on Two is MIL or MOA ) hold under, at a guestimated distance of 65 M i was bang on, and for 93 M i had to use 2 hold over.
And the 20 grainers was flying quite well i have to say, i will have to retest this again on my next outing even if i will also be bringing my sawed OFF use to be 700 mm Maverick that otherwise is my hard hitter now.
By then i will probably also have some 24 grain Zans to try out in both rifles. In the Maverick i will be looking to get 55 - 60 food pounds if i can.
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Hi,
I've just purchased an Impact M3 and have installed the heavy liner and Huma barrel tensioning kit. I shot some very good groups using 23 grain Zan slugs at 50m with the 1st regulator set at 145psi and 2nd at 100psi, macro wheel at 12 and micro at 3; valve adjuster at 5. The velocity was constant at 800fps. At 100m the group opened up, somewhat more than I'd hoped. After tons of research I'm planning to increase the 2nd regulator pressure until I reach speeds of 950fps with all other variables maxed out. I then will reduce hammer spring tension on the macro until the velocity drops by approx 20fps. Then, I'll increase the macro up by 1 increment and reduce the micro wheel until the same velocity is reached. After that, I plan to reduce the valve adjuster until the velocity starts to drop. Please correct me if I'm wrong, but I believe this is the correct way to go about finding the most efficient sweet spot without hammering the working parts too hard?? The only thing that may set me back is selecting an incorrect required velocity of 950fps in the first instance. Any constructive advice would be extremely appreciated. Regards from Australia
I've just purchased an Impact M3 and have installed the heavy liner and Huma barrel tensioning kit. I shot some very good groups using 23 grain Zan slugs at 50m with the 1st regulator set at 145psi and 2nd at 100psi, macro wheel at 12 and micro at 3; valve adjuster at 5. The velocity was constant at 800fps. At 100m the group opened up, somewhat more than I'd hoped. After tons of research I'm planning to increase the 2nd regulator pressure until I reach speeds of 950fps with all other variables maxed out. I then will reduce hammer spring tension on the macro until the velocity drops by approx 20fps. Then, I'll increase the macro up by 1 increment and reduce the micro wheel until the same velocity is reached. After that, I plan to reduce the valve adjuster until the velocity starts to drop. Please correct me if I'm wrong, but I believe this is the correct way to go about finding the most efficient sweet spot without hammering the working parts too hard?? The only thing that may set me back is selecting an incorrect required velocity of 950fps in the first instance. Any constructive advice would be extremely appreciated. Regards from Australia
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Interesting thread.
I have a Maverick and barrel kits for .22, .25 & .30. I tried to get the .25 to shoot slugs MOA at 100 yards but after 2 liners, changing every possible position, torque, cf or o-ring holders, more slugs than I can count of several manufacturers and weights, I gave up!
I moved on to the .22 with the current STX liner with the 1:16 twist and as I worked through speeds with simple 5 shot groups starting at 800fps, I found that this liner has 3 harmonic nodes that allow for 1 MOA replication, shot to shot.
Those numbers are written down in my shop and id hate to miss quote them but they were at equal intervals with the fastest running at 1100fps+ but the gun sounded ugly when fired and I moved to the middle speed which was somewhere about 1000fps.
This was the most stable speed for NSA 27.5gr, .2175 slugs that allowed me to consistently make 1 MOA groups back to back with calm winds.
Charting that, I moved on to .30 and I found that this STX liner is a happy middle of the road shooter with no inclination to tighten up no matter what settings are used! It's super consistent but at 1.5 MOA at 50-150 yards but it's no laser!
Pellets, slugs, damaged skirts, any weight, boringly OK. It's shooting NSA 49.5gr slugs but it will eat JSB 49.5 pellets just the same with 1.6" groups at 100 yards.
I have a Maverick and barrel kits for .22, .25 & .30. I tried to get the .25 to shoot slugs MOA at 100 yards but after 2 liners, changing every possible position, torque, cf or o-ring holders, more slugs than I can count of several manufacturers and weights, I gave up!
I moved on to the .22 with the current STX liner with the 1:16 twist and as I worked through speeds with simple 5 shot groups starting at 800fps, I found that this liner has 3 harmonic nodes that allow for 1 MOA replication, shot to shot.
Those numbers are written down in my shop and id hate to miss quote them but they were at equal intervals with the fastest running at 1100fps+ but the gun sounded ugly when fired and I moved to the middle speed which was somewhere about 1000fps.
This was the most stable speed for NSA 27.5gr, .2175 slugs that allowed me to consistently make 1 MOA groups back to back with calm winds.
Charting that, I moved on to .30 and I found that this STX liner is a happy middle of the road shooter with no inclination to tighten up no matter what settings are used! It's super consistent but at 1.5 MOA at 50-150 yards but it's no laser!
Pellets, slugs, damaged skirts, any weight, boringly OK. It's shooting NSA 49.5gr slugs but it will eat JSB 49.5 pellets just the same with 1.6" groups at 100 yards.
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Barrels and liners have multiple amplitude nodes in a wide range of speeds between min and max, for both pellets and slugs.
Monitoring the POI is more important then talking about any specific speeds.
For example when you start with let say 800 and incrementally increasing the speed in small steps of 10 fps to a max or whatever, you will realize that the groups opens up and shrinks along the way.
The speed either 800ish or 900ish or 1000ish is absolutely irrelevant, you chose the range one that suits your game.
Monitoring the POI is more important then talking about any specific speeds.
For example when you start with let say 800 and incrementally increasing the speed in small steps of 10 fps to a max or whatever, you will realize that the groups opens up and shrinks along the way.
The speed either 800ish or 900ish or 1000ish is absolutely irrelevant, you chose the range one that suits your game.
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Hehe yeah.
But if i could go hunting i would have a even larger caliber air rifle, probably also a nice Parker & Hale powder burner like the one i " modified" when i was young.
"Them " putting air rifles in under hunting / that kind of weapon permits, just underwrite how stupid the rulers of Danes are.
But if i could go hunting i would have a even larger caliber air rifle, probably also a nice Parker & Hale powder burner like the one i " modified" when i was young.
"Them " putting air rifles in under hunting / that kind of weapon permits, just underwrite how stupid the rulers of Danes are.
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