Tuning 1004 fps? Really??

[Khornet]

Following the method of starting with the hammer preload screw backed out on my .22 700 mm PP Impact, and gradually increasing preload while changing nothing else, I found that my top speed was 1004. Sure enough, any more preload caused speed to drop, and I was far from max preload. Using 23 gr H&N .218 slugs with regulator at 115. That's about 50 ft-lb. Well more than I intend to use, but I'm surprised to get that energy from a slug with the reg at only 115.

 

[Corvid_hunter]

Impressive power. If you put pressure on your hammer spring (with your finger) and slowly turn the power wheel between MIN and 1, do you hardly feel any movement (between MIN and .5) of moving the dial?

 

[dizzums]

Sure why not .. I'd keep adding weight to see how much it could push down to about 900 myself .. 30g squirrel smackers would be nice lol ..

 

[Guest]

Keep those danger distances in mind when shooting up into trees with slugs. A kilometer is a long ways.

 

[Khornet]

Nah, any tune between 880 and 930 is hot enough for a 23 gr slug, provided the accuracy and efficiency are there, for the reason Cornpone stated. Not shooting upward unless my target is against a trunk anyway. But I am surprised how low a reg setting I need for that. Shows the effect of a big plenum, I guess.

 

[qball]

PP impact has a lot of power. At 115 bars I was shooting 34 grain .25 slugs at around 900fps. It’s a beast of a gun. 


23 grain slugs even at lowly 830 FPS absolutely destroyed a lot of meat on a good sized cottontail, looks like HMR round hit it.