GTA

All Springer/NP/PCP Air Gun Discussion General => American/U.S. Air Gun Gates => Crosman-Benjamin Air Gun Gate => Topic started by: JMJ in NC on November 22, 2011, 05:06:34 PM

Title: Crosman 1377/PC77 rear stock (PN: 1399) modification
Post by: JMJ in NC on November 22, 2011, 05:06:34 PM
I posted this on the CAPOF the other day, but thought I'd post it here as well for anyone using the 1399 rear stock on their Crosman pistols.

The Crosman 1399 rear stock on my carbine has always moved a tiny bit a no matter how much I tightened down the grip screws. Even though accuracy is unaffected, I decided to remedy the situation.

I measured back about 1.88" from the "nub" at the bottom of the grip frame and drilled a pilot hole through the rear stock until I hit the grip frame. Next, took the rear stock off and cross-drilled a large clearance hole for the screw to go into. I got lucky and hit the grip frame right on centerline.

Then, the rear stock went back on and I used it as a drill guide to drill the though-hole for the minor diameter (.106") into the clearance hole. Then removed the rear stock again and tapped  with a #6-32 tap. Next I drilled a clearance hole (.140") in the rear stock using the pilot hole as a guide, then used a countersinking tool to make a proper countersink (.280")  for the added screw.

Last, I switched all screws (2 old, 1 new)  to a black-oxide finish flat head 6-32 x 1/2" and reattached the rear stock. Stability is excellent - no more clunk, and it looks nice. Only 1 additional screw to remove for mod's, so a fairly painless change. Also included a picture of the carbine sporting it's new Leapers 3-9x40 scope.

JMJ
Title: Re: Crosman 1377/PC77 rear stock (PN: 1399) modification
Post by: SAADE on November 22, 2011, 05:10:35 PM
Nice Mod JMJ, simple is always better.
Title: Re: Crosman 1377/PC77 rear stock (PN: 1399) modification
Post by: Crosshairs on November 22, 2011, 07:08:37 PM
Sweet looking rig i like your work.  8)
                              Mike