Several of us have Re-run the math shared and coming up with a similar 1.53 matching what Lloyds calc was also showing.
Mike,
It could be that we’re shooting at a much higher pressure than you. To shoot 34 grain Mk2 Heavy pellets from the 25 inch barrel at 965 fps requires 1900 HP reg pressure. And ALL THREE GUNS that the Team has drift down to 1700 psi or a little under at 2000 psi bottle pressure. That 200 to 225 psi decrease reduces pellet speed by about 30+ fps.Mike,
During that session was just taking shots & keeping track while shooting at @ 70 yards, No chrony was in use at that time.
Having done shorter sessions just over the chrony, the EPOCH as set up has shown ES values run from 6-10 fps (+/- 3 to 5 fps ) with known good pellets. I've read reports of velocity swings over the fill range, sadly not been seriously watching that being just recently getting it set up as a .22 cal
Slugs due to there bore draggy nature in general, I would doubt run that tight. Tho not tested them so a WAG
Scott, have you experimented with raising or lowering the dwell settings? If so does it affect the pellets speed much, or perhaps efficiency or even ES/SD? I have changed HP pressure up and down but have left the dwell untouched so far.Here about a week later had a bit of time today to go back into the valve and test it with some jet changes .
The OEM poppet head jet is a .035" as delivered with the .30 cal barrel fitted.
Had tested at 10% larger a .037"
Recently with data above was running jet at .039" in .22 caliber w/ 25" barrel fitted.
* Today tried Jet at .041"
Yes indeed shot is a tad snappier at same pressure & dwell setting, but did lose @ 15 fps being easily corrected with just a tad @ 30 psi shift in HP reg setting.
Jetted at .039" on @ +1750 psi we were shooting H&N 25 grain slugs @ 960 fps
Jetted at .041" a tad under 1800 psi for the same speed.
Am really liking how the gun is now sounding being a sharp yet muted "SNAP"
Dozen or so shots over the chony was +/- 2 fps being IMO really tight ES. More serious testing tho in the future
I’m just wondering if it would help efficiency or SD to lower the dwell to a point right before pellet speed starts to drop? Keep HP and LP pressures constant.
While we initially were very impressed with the low pressure output potential .... It in my eye it is so due too long dwell and big ports.
The pressure were starting to get near is more typical for the power extracted with many platforms. Yes a tad bit on the electronic dwell setting ..... as we're running currently the EPOCH is set at Dwell 25 finding set in the 18-22 range experienced random 1st cold shot misfires and a somewhat wider ES overall.
