Tuning Impact MK1 Compact, 30 cal tuning and speeds help

[madmunki]

I am trying to get my MK1 .30 Compact (500mm barrel) around 850 FPS using JSB 44.75 pellets. I have installed the MK2 PP.

I am starting with hammer max, port at 4 bars.

At 100 bar I get around 750 FPS, as I move the reg up to 125 bar I am in the 790-800 range, but any pressure beyond that, the FPS starts to drop.

I am going to inspect the Impact and check probe alignment to barrel, not sure what else to check. It is an older impact, so maybe hammer and spring needs inspecting?

 

[Glem.Chally]

Tighten the little pretensioning screw on the hammer spring slider, you should be able to get more power out of it. 

 

[madmunki]

I took it apart and the cap of the valve rod just came out, it wasn't attached to the rod! I checked the spring and everything else, and just put it back together and used locktite blue to hold the cap threads this time! Cant wait for the locktite to dry a bit before I test fire it! I am pretty positive this is the issue!



@Glem.Chally, the hammer spring adjuster and screw are maxed.

 

[Glem.Chally]

Awesome, good catch. I would back out that screw quite a bit and work your way up. Because everything maxed might over-drive the hammer causing lower power.

Let us know your results please. 

 

[madmunki]

I had everything "maxed" trying to diagnose the problem before I took it apart. If I am able to adjust the reg from 125-150 and see a huge performance (I expect I am since discovering that issue!) Ill tone everything down, and properly turn it back up.

 

[madmunki]

I let the lock tite sit long enough! Here is a few adjustments I was making from 100-125 bar on the reg 

Shot count: 24
Low: 814
Hi: 858
Avg: 840
Spread: 44
STD Dev: 14.5
814
817
821
814
828
821
835
823
833
847
842
849
858
851
856
851
854
854
851
849
847
847
847
842

 

[Vetmx]

You have a bell curve like an unregulated gun. Put your tuning gloves back on.

 

[Glem.Chally]

You have a bell curve like an unregulated gun. Put your tuning gloves back on.

I think he was adjusting the reg during the string haha.

Madmunki don't post a string like that lol.

Try 140 and adjust your screw up with the wheel on Max, then once you find max speed then back it off a full turn or so.