Recent Mrod 25 test 10 spring Still working on this ...

[bmazz007]

Ok I think i figured one problem after adjusting the valve when i put back on the stopper while tightening I was closing the valve. For my testing I had the valve on 4.5 the preload on 5 3/4 and the stroke all the way open. I am using heavy pellets the Barracudas which are 31.02 GN I ran out of the domes and Kings. STARTING PSI IS 3050

1 845------3050 PSI
2 843.5
3 829--------2850 PSI
4 822
5 823------2600 PSI
6 815
7 803.5------------2500 PSI
8 798
9 782.5--------------2300PSI
10 782.4
11 765
12 758.7-----------2000 PSI


  DOES THIS STINK???   i AM HERE WORKING ON THIS IN MY OFFICE I AM STAYING HERE TILL I GET IT RIGHT..

[GadgetX]

I just tested my MROD.   24 shots above 819.   So in my mind it not worthy.  I tested with Poly Mags 26.0 gr, JSB Exacts 25.4 and Benjiman 27.0 gr. pellets.  All have 24 shots above 819 fps.  Not sure what to tell you.  Only mod is #10 spring from dave at addicted2airguns.

Mike

[bstaley]

Not sure exactly what kind of tune you're looking for, but right now, you need to reduce your preload if you want a flatter shot string.

[bmazz007]

Not sure exactly what kind of tune you're looking for, but right now, you need to reduce your preload if you want a flatter shot string.

Hey Mike, I am looking for a flatter shot string and to keep the velocity in the 840 range with these 31.02. Seems to be an impossible task..


Thank  you  for the tip..

Bill

[JerryW]

The steadily declining velocity indicates too much spring preload. To get a curve, you need to back it off(CCW). It looks like you aren't going to get 840's with those heavier pellets. It would probably take lighter pellets or some valve and port mods to get there.

What are your goals for FPE? Is this for hunting or targets/plinking? What kind of maximum range are you looking for?

Jerry

edit: just saw your other threads(s). Maybe stick to posting your results on just one thread so it's not so confusing as to what's current.

[bstaley]

With those pellets, 825 is probably a more realistic target velocity for a stock gun with a reasonable shot count.

[bmazz007]

The steadily declining velocity indicates too much spring preload. To get a curve, you need to back it off(CCW). It looks like you aren't going to get 840's with those heavier pellets. It would probably take lighter pellets or some valve and port mods to get there.

What are your goals for FPE? Is this for hunting or targets/plinking? What kind of maximum range are you looking for?

Jerry

edit: just saw your other threads(s). Maybe stick to posting your results on just one thread so it's not so confusing as to what's current.

825 Is perfect for these pellets if I can maintain that for at least 16 shots. It would be for long range target I really like the challenge 80 yard to 100 yd  shooting with air rifle. A little hunting.

thank you Jerry

Bill

[rsterne]

If you're after good groups at 80-100 yards, you will need to reduce the shot count and work off the top of the "sweet spot" to reduce your extreme velocity spread to about 2% maximum (ie about 20 fps).... You can get away with 4% at 50 yards, 3% at 75 yards, and 2% at 100 yards, but not more.... From what I understand you won't get much more than 1 clip with that spread.... The good part is it doesn't take much air to top up from 2500 psi....

Bob