Long story short, been trying to finalize my TX200 setup for the WFTF Worlds in few weeks
Ran 50 shots of 8.64 pellets over the chrony giving 780 fps avg @55 degrees F, yielding 11.68 ft lbs. Shot that string at 4500 ft ASL
Now I'm a bit panicked.
Phoenix is at 1086 ft ASL, Im at 4500 ft. The usual number given for Springers at different altitudes is 1.5% change for every 1000 ft gained or lost. So in my case that a 5.2% increase in efficency going to the lower altitude. Strelok Pro also says I can expect 3.7% change in every 15 degrees of temp--but it doesn say if thats an increase or decrease. Checked for the average Novemember temp in Phoenix. 75ish degrees. Rounding off for easier math., thats 7.4% change based on 55 to 80 degrees change.
One thing I cant calculate is the effect of air drag in the thicker air at the lower altitude.
And really not wanting to switch to a heavier pellet this close to the match......
If it were any other match, Id just beg out and not go. But this is most likely the only Worlds match I'll ever attend, and Ive paid for everything except gas already. Dont want to get there and be over the 12 ftlbs before even starting to sight in......
My questions are.... Am I over thinking it? meaning, the math will work out and i'll still be legal. If not, then what are some options to keep it legal at the speeds and altitude I think the gun will be performing in?
much thanx in advance
dan
Ran 50 shots of 8.64 pellets over the chrony giving 780 fps avg @55 degrees F, yielding 11.68 ft lbs. Shot that string at 4500 ft ASL
Now I'm a bit panicked.
Phoenix is at 1086 ft ASL, Im at 4500 ft. The usual number given for Springers at different altitudes is 1.5% change for every 1000 ft gained or lost. So in my case that a 5.2% increase in efficency going to the lower altitude. Strelok Pro also says I can expect 3.7% change in every 15 degrees of temp--but it doesn say if thats an increase or decrease. Checked for the average Novemember temp in Phoenix. 75ish degrees. Rounding off for easier math., thats 7.4% change based on 55 to 80 degrees change.
One thing I cant calculate is the effect of air drag in the thicker air at the lower altitude.
And really not wanting to switch to a heavier pellet this close to the match......
If it were any other match, Id just beg out and not go. But this is most likely the only Worlds match I'll ever attend, and Ive paid for everything except gas already. Dont want to get there and be over the 12 ftlbs before even starting to sight in......
My questions are.... Am I over thinking it? meaning, the math will work out and i'll still be legal. If not, then what are some options to keep it legal at the speeds and altitude I think the gun will be performing in?
much thanx in advance
dan