my FTP came from Mellon yesterday . this one has a white derlin piston. i like it! makes it easier to see the o-ring . just a couple more things and i will be ready to do the valve pinning and re-assemble the gun.
Quote from: Spooner on April 13, 2021, 11:54:22 AMmy FTP came from Mellon yesterday . this one has a white derlin piston. i like it! makes it easier to see the o-ring . just a couple more things and i will be ready to do the valve pinning and re-assemble the gun. Would you like to do mine too?
You'll do fine, Robert. Just don't get in a hurry, and if you get frustrated, put it away for a bit.Looking back on my notes, which were not very good back then, I believe the pivot was reinforced at the same time the valve was pinned.I was not very good at doing just one mod at a time...Wyo
If the alignment is just slightly off then it's normal, just back it off a little.Should be fine unless you plan on really pushing it past 2K psi.You can use a 90 duro seal between the valve halves and or Teflon tape the threads.Pro tip: Scribe a line on the valve when the valve halves are aligned.
While you're at it consider replacing the stock grip frame screws with hex head screws.The stock front screw only engages about 3 1/2 threads and strips out too easy.A 1/2" long screw will grab 6 1/2 threads.Another option is to use a long set screw and acorn or locknut.This gun is drilled and tapped for a 10-32 screw.
had to cancel the drill press vice part of my harbor freight order. they had no idea when it would be back in stock? ordered an x-y drill press vice from eBay. it cost a little more, but i will have it by Wednesday and finally be able to at least get this valve pinning over with and the bottom half assembled while waiting for the Max Flow TP from Alliance. those of you replacing your OEM 1377 hammer springs for a stronger one, can you tell me which spring you are using for this?i appreciate all the help everyone. i am learning more and using so many of the ideas shared here in this build. i am also realizing the mistakes i made on my previous 1377/1322 builds.
I use Magnum Air Power springs.He has 3 tensions, but I always favor the .038" one even on my PCP builds.
Well done, Robert... It looks great!Next mod a larger TP?...If/when you install the larger diameter transfer port, you’ll need to enlarge the barrel port as well or it may not be very helpful. If you’ve already got this covered then disregard…The stock valve port is .156” (5/32”) and is a pretty good starting point for a modified 1322. The stock transfer port and barrel port are both .140” (9/64”) and can strangle the air flow in a 1322 (shooting faster than 450 fps). So both would need enlarged, and again.. .156” is a good place to start…Drilling the barrel port:Get a .25” wooden dowel and profile the end so it matches the barrel leade-in taper. It should extend past the barrel port and have a really tight fit to the barrel i.d….This will ease the break-thru of the drill and lessen the tear-out. You’ll probably still have a burr but it’s easy enough to fix… roll up some 600 grit really tight that is just over the barrel i.d. Rotate it into the bore in the direction it was rolled. It should be hard to get in. Rotate and work in and out. When you feel that it stops cutting, reverse direction and repeat…This will remove the burr and polish the leade. Flush with WD-40 (or similar), blow-out with air, and pull a couple of patches and it’s good to go… just one way to do it, hth-Wyo
Great reading and great advice. I will follow this thread since I may find some free time at some point. For now, I'm too new to even understand one tenth of the things you folks are talking about but I'm willing to learn. Keep 'em coming and @Spooner, great job and good luck with the rest.