how to get to 17FPE in a Prod?

how to get to 17FPE in a Prod?

Joined: July 24th, 2009, 4:33 pm

October 10th, 2011, 7:04 pm #1

With a 15.9 grain JSB Jumbo I'm at 14 FPE now (634 FPS). My adjustments are maxed out. I also want to start with a 2600 PSI fill pressure as that seems to be where the grouping tightens up (higher fill pressure seems to cause a slight scatter effect). Is it a combo of a stronger hammer spring and a slightly larger transfer port? I figure just a larger transfer port. Am I in the right direction?
darryl
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Joined: March 10th, 2011, 8:09 pm

October 10th, 2011, 10:01 pm #2

Just remove port and drill it out to either 1/8 or .110 those are the 2 best choices for more power/but you will lose shot count. you can go to heavy pellet if speed is causing your groups to scatter, but i thought 850 fps was the area were some pellets get unstable. you may just need to clean barrel real good. when my prod groups grow i clean and they tighten-woody
Last edited by captwoody on October 10th, 2011, 10:04 pm, edited 1 time in total.
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Joined: July 24th, 2009, 4:33 pm

October 11th, 2011, 12:20 am #3

opened the port up to 0.09375 (3/32"). A little more power (wait for the chrony), but hoping for a decent number of shots. FIlled to 2700, shot one magazine and saw the pressure had dropped to 2150. Not too bad. More testing tomorrow. not greedy for power above a good number of accurate shots. I can always go larger if the urge hits me. Easy to take metal away. Thanks for the tip, Woody. I agree I don't want pellets getting unstable due to speed. Shot placement is more important to me than raw power.
darryl
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Joined: March 10th, 2011, 8:09 pm

October 11th, 2011, 3:02 am #4

only other thing i can think of is a hammer spring upgrade,but that will hurt shot count too.
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Joined: July 24th, 2009, 4:33 pm

October 11th, 2011, 11:24 am #5

hey Woody,
I'm not wanting to lower my shot count (appreciably). If I can retain creep up on power and not expend a great deal more air, then I'll be good. Might as well be focused on an end goal, which I am: about 16FPE with 15.9 grain pellets. I may be close now. Have to do the tests to see.
darryl
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