rsterne
12-05-2014, 07:42 PM
http://i378.photobucket.com/albums/oo221/rsterne/Hayabusa%20PCP/HayabusaLogo.jpg (http://s378.photobucket.com/user/rsterne/media/Hayabusa%20PCP/HayabusaLogo.jpg.html)
Today was quite a day.... After a couple of years of planning and a year of work, I shot my Hayabusa .457 for the first time today, and saw over 550 FPE.... I tested three kinds of ammo, found the maximum that the gun would do at 3600 psi with all three, and found two great shot strings.... The bullets used were a 143 gr. roundball, and two Lee bullets, a 216 gr. RN and a 336 gr. FN.... In order to find the velocity plateau I had to use the two 3" hammer springs like I did on the .410 shotgun, and here are the maxed out results....
143 gr. RB - 1101 fps (385 FPE)
216 gr. RN - 993 fps (473 FPE)
336 gr. FN - 859 fps (551 FPE)
Needless to say, all the work and frustration has paid off and I've got a pretty big smile right now.... I put the 4.5" long 0.072" wire spring back in and shot the following strings....
http://i378.photobucket.com/albums/oo221/rsterne/Hayabusa%20PCP/Hayabusa457_zps4c23b7a5.jpg (http://s378.photobucket.com/user/rsterne/media/Hayabusa%20PCP/Hayabusa457_zps4c23b7a5.jpg.html)
With the spring just shy of coil bind the roundball showed the first shot fastest at 1070 fps.... The 216 gr. RN had the 2nd shot fastest at 960 fps.... Both bullets had 5 shots before falling more than 4% below the peak.... With the 336 gr. FN bullet I got a very nice 7 shot string peaking at 815 fps (496 FPE).... That string averaged 800 fps (477 FPE) with an efficiency of 0.96 FPE/CI.... I then backed the preload down a turn and shot another string with the 216 gr. RN and got 8 shots peaking at 929 fps (414 FPE) and averaging 913 fps (400 FPE) with an efficiency of 0.99 FPE/CI from 3600 psi down to 2400....
To say I'm pleased with this performance is an understatement.... I was hoping this gun would break 500 FPE, I never though it would break 550, nor did I think it would give me 8 shots at 400 FPE on a fill.... Time to just bask in the glow of satisfaction for a while.... I need a break.... and a drink....
Bob
Today was quite a day.... After a couple of years of planning and a year of work, I shot my Hayabusa .457 for the first time today, and saw over 550 FPE.... I tested three kinds of ammo, found the maximum that the gun would do at 3600 psi with all three, and found two great shot strings.... The bullets used were a 143 gr. roundball, and two Lee bullets, a 216 gr. RN and a 336 gr. FN.... In order to find the velocity plateau I had to use the two 3" hammer springs like I did on the .410 shotgun, and here are the maxed out results....
143 gr. RB - 1101 fps (385 FPE)
216 gr. RN - 993 fps (473 FPE)
336 gr. FN - 859 fps (551 FPE)
Needless to say, all the work and frustration has paid off and I've got a pretty big smile right now.... I put the 4.5" long 0.072" wire spring back in and shot the following strings....
http://i378.photobucket.com/albums/oo221/rsterne/Hayabusa%20PCP/Hayabusa457_zps4c23b7a5.jpg (http://s378.photobucket.com/user/rsterne/media/Hayabusa%20PCP/Hayabusa457_zps4c23b7a5.jpg.html)
With the spring just shy of coil bind the roundball showed the first shot fastest at 1070 fps.... The 216 gr. RN had the 2nd shot fastest at 960 fps.... Both bullets had 5 shots before falling more than 4% below the peak.... With the 336 gr. FN bullet I got a very nice 7 shot string peaking at 815 fps (496 FPE).... That string averaged 800 fps (477 FPE) with an efficiency of 0.96 FPE/CI.... I then backed the preload down a turn and shot another string with the 216 gr. RN and got 8 shots peaking at 929 fps (414 FPE) and averaging 913 fps (400 FPE) with an efficiency of 0.99 FPE/CI from 3600 psi down to 2400....
To say I'm pleased with this performance is an understatement.... I was hoping this gun would break 500 FPE, I never though it would break 550, nor did I think it would give me 8 shots at 400 FPE on a fill.... Time to just bask in the glow of satisfaction for a while.... I need a break.... and a drink....
Bob