Donation

All Springer/NP/PCP Air Gun Discussion General > Machine Shop Talk & AG Parts Machining

Crosman 700 Pellet Master

(1/3) > >>

JPSAXNC:
The gun was shooting 430-460 fps. with a 17" barrel from 70-85 degrees f. I made a Condor style poppet for it, tapered to seal on the inside of the donut. This let more gas through 514fps. @ 61F. The only thing limiting power now is the short .195 hammer stroke, If the internals could be put in a new tube with a longer hammer stroke??

Rob M:
fascinating gun , ideal for a cane gun really.. Im sure you can get it to 600 fps or so.

JPSAXNC:
I bored out the donut in the valve and went about .150 deeper, but that lost power because it brought the hammer and poppet closer together shortening the hammer stroke. I noticed that the hammer could be pushed further forward and could get a longer hammer stroke if the trigger/sear could be moved forward. So I glued a dowel in the trigger/sear pivot pin hole in the stock and re-drilled the hole about .80 further forward, gaining about 30% more hammer stroke. The velocity went from 515fps. to 630 fps. @ 84f. and 660 fps. @70f. a little valve lock at higher temps.

JPSAXNC:
Correction, I moved the pin hole .080 further forward.

Rob M:
awesome .. i looked at some detailed pics , and see what you mean about the hammer stroke..

Navigation

[0] Message Index

[#] Next page