Benjamin Some Prod (and 1701P) ❤️❤️❤️
- By weevil
- PCP Airguns
- 28 Replies
Lots of high end AGs lurking around but sometimes it’s nice to do some work on one of the old faithful. In this case, a P-rod that has been out on loan for a few months, working on some rats with a neighbor. Time for a refresh, squeezing out a bit more accuracy, efficiency and noise reduction, the latter of which was attacked from the action end as much as the muzzle.
This little pellet shooter has already come a long long way from stock with a reg, lightweight hammer, .42 spring, PEEK striker, porting and a pretty dress. For the latest revision, added a PEEK poppet with a 2mm diameter stem, increased porting to .140, shimmed the stock Crosman barrel to fit more snugly in the breech, polished the crown and added a combination shroud/moderator (which won’t be discussed here in keeping with forum rules).
The reg was bumped up to 120bar, with the goal of getting 24 shots from a 220bar fill, shooting the 15.9grain Hades. Knowing the way this lady sings from all the previous work, I figured that the setting should net a peak speed of ~750 fps, which would be dialed back to 725, around 18fpe.
That turned out to be very close with peak speed of 745 fps. The hammer was then dialed back to get the speed settled at 725fps. I then added a 2mm PEEK shim to increase tension on the valve spring, dropping the speed to 720fps. That added a noticeable snap and gave a very nice string from 3100psi (scuba tank really needs a refill…):
722, 718, 718, 724, 721, 716, 720, 722, 717, 720, 721, 719, 722, 720, 716, 722, 719, 719, 720, 718, 719, 717, 712, 693
Just dropping off the reg on shot #23, but should be good with a 3200psi fill. Kind of an arbitrary goal of getting 3 x 8-shot mags. Silly, considering that I just ordered two new 10-shot mags. The originals seem to have gotten a little gritty.
Anyway, as those in the know will know, the PEEK poppet is a real winner here, dropping the requirement for hammer and yielding a really snappy and quiet shot cycle. The shimming of the barrel into the breech seems to have tightened up the poi in the horizontal plane.
Here she is, sporting the Optisan 6, sat on her favorite rice bag. I’m expecting big things from this little gun in the accuracy testing tomorrow.
This little pellet shooter has already come a long long way from stock with a reg, lightweight hammer, .42 spring, PEEK striker, porting and a pretty dress. For the latest revision, added a PEEK poppet with a 2mm diameter stem, increased porting to .140, shimmed the stock Crosman barrel to fit more snugly in the breech, polished the crown and added a combination shroud/moderator (which won’t be discussed here in keeping with forum rules).
The reg was bumped up to 120bar, with the goal of getting 24 shots from a 220bar fill, shooting the 15.9grain Hades. Knowing the way this lady sings from all the previous work, I figured that the setting should net a peak speed of ~750 fps, which would be dialed back to 725, around 18fpe.
That turned out to be very close with peak speed of 745 fps. The hammer was then dialed back to get the speed settled at 725fps. I then added a 2mm PEEK shim to increase tension on the valve spring, dropping the speed to 720fps. That added a noticeable snap and gave a very nice string from 3100psi (scuba tank really needs a refill…):
722, 718, 718, 724, 721, 716, 720, 722, 717, 720, 721, 719, 722, 720, 716, 722, 719, 719, 720, 718, 719, 717, 712, 693
Just dropping off the reg on shot #23, but should be good with a 3200psi fill. Kind of an arbitrary goal of getting 3 x 8-shot mags. Silly, considering that I just ordered two new 10-shot mags. The originals seem to have gotten a little gritty.
Anyway, as those in the know will know, the PEEK poppet is a real winner here, dropping the requirement for hammer and yielding a really snappy and quiet shot cycle. The shimming of the barrel into the breech seems to have tightened up the poi in the horizontal plane.
Here she is, sporting the Optisan 6, sat on her favorite rice bag. I’m expecting big things from this little gun in the accuracy testing tomorrow.