WGP cocker parts diagram:

Small parts:

valve retaining nut:  5/8"-18 5/16" long hollow lock screw (jam set screw)  McMaster-Carr part number 91301A190 (alloy steel black oxide finish)

valve locking nut (located on underside of body): 5/16"-24 1/4" long set screw McMaster-Carr part number 91375A595 (alloy steel black oxide finish)
    or in stainless, McMaster-Carr part number 92311A594 (18-8 stainless steel).  Tap drill for this is .272.  Note that Merlin bodies use the same nut.

cocking rod hex knob:  5/16" OD 10-32 stainless threaded hex standoff, 3/4" long, McMaster-Carr 91115A610 (18-8 stainless, $3.59)
    or 91780A810 (aluminum, $2.00)

grip frame screw anchor:  1/4" OD 8-32 brass threaded hex standoff, 1/2" long, McMaster-Carr 91115A535 (18-8 stainless, $1.26)
    or 90308A635 (zinc-plated brass, $0.27)

grip frame hole spacing is the same as AutoMags and Sheridans - 4.125"

To remove the screw from the vertical ASA, Timberwolf says to use a 1/4" 12 point socket.

Valve retaining nut removal tool:
sergi writes:
Start with a 1/2" steel rod. I drill a 9/32 hole 3/4" deep in the end, and mill 5/16 flats on the end. I use a horizontal rotary table on the mill with a 3jaw lathe chuck on it to index 60 degrees.

In a pinch, I busted one out using a 5C collet hexagonal holder in the vise of my Sherline mini-mill.  Not quite as good of results as using a rotary table (and I had to make my cuts quite shallow), but it did the job.  -HB

Sear lugs:
Doc Nickel says:
All (or most) newer hammer kits use a 1/4"-28 x 1/2" setscrew, with the first approx. 3/16" turned down to just narrower than the 'Cocker body slot. (Itself 3/16".)

And TimeLord is right- most of the sets you get at hardware stores will be "case hard"- the skin of the steel will be hardened more than the 'core'. This makes for a tougher screw, less likely for it to break.

You can try rehardening them- heat it red and dunk it in water after you're done machining- but I'm not sure how much it'll gain you. It depends on the alloy of the screw. Good stuff will harden better than the $0.50/ton generic crap.

I know I've seen "Grade 8" sets before, but I can't recall where, and you'll probably have to order them. And grind the threads off- a hard-metal interrupted cut is tough on inserts. :-)

I know the squared lugs that RaceGun sent me are considerably harder than the cut-off-setscrew I had in the gun. I don't know if that's due to rehardening or better metal to start with.

Pre-98 vs. 98 and newer triggers:

This photo (from G3) shows two AKA trigger plates - the top one is the old style (note the point at the bottom right of the plate) and the lower one is the new style (rounded off rather than pointed).  Springs and sears will fit either the new or old frames.  Note that '98 plates and previous are supposedly narrower than the 99/2k plates.  [how to tell old/new grip frames apart?]


This photo (provided by Jeff "Yankee Workshop" Barnett) shows (from top to bottom) a stock cocker ram (circa 1983), a Clippard 3SD-1 (unthreaded), and a Clippard/J&J ram (bought from J&J at Zap Am in 1995).  Note that older cockers (probably pre-96 or so) had ram threads that were threaded 5-40 (which is actually the correct thread size for a 1/8" shaft), while newer rams are threaded 6-32 (and thus the threads are not 'full' threads, but they do work well enough (plus, 6-32 is a much more common thread size).  Also note that the only rod threading option on the Clippard 3SD-1 is for 5-40 - if you purchase one from Clippard, get it with an unthreaded rod and do the 6-32 tapping yourself.  The ports on the 3SD-1 have 10-32 threads.

All cocker rams are double acting, have a 1" stroke and have the nose threaded 5/16"-24.
The nifty little stainless mini-ram from Clippard (also sold by ANS and perhaps others) is not a standard Clippard ram - it's a special order item with a minimum 500 pc. order.  Rats.  However, Ed Kang notes that SMC has a very nice stainless cylinder available (used, in fact, on Sandridge's F5).  He writes:

The SMC cylinders used in the sandridge cockers are $17.00 per piece for 1" stroke, 5/16"-24 nose thread, 6-32 shaft thread. They are excellent rams, quick, smooth, and very attractive - more attractive than Clippard units and I would dare say more attractive than any commercial unit out there, except for perhaps the Palmer unit.

        The part number is: NCJ2B10-100-XA07

        The standard part is NCJB10-100 for 1" stroke, 6-40 shaft thread. Appending the XA07 machine code changes the 6-40 shaft thread to a 6-32 shaft thread. A perfect fit for use with the autococker.

Nose is threaded for 15/32"-32
McMaster-Carr ( ) sells a tap for this rather uncommon thread size, part # 2595A235, $27.25.  J&L Industrial ( ) has the cheapest price on this tap that I've managed to find - $11.97, part # TSP-15334-K.  Also, Ed Kang notes that ICS Cutting Tools ( has them for $12.24.

X-way shaft drawing:

Cadket .prt drawing

4-way operation (Sorry, I forget who to credit with these animations):
standard 2-ring 4-way
Standard 2 o-ring 4-way

Aftermarket 3 o-ring 4-way (i.e. Shocktech Bomb)

Palmer Quickswitch 4-way drawing:

Front block screw:
3/8-24 threads on '99 and earlier
9/16-24 threads on 2000 and later
5/8-18 threads on the bottom tube on Spanky bodies (still use a 3/8-24 screw to attach the front block).

Pneumatics regulators:
Threaded for 1/8" NPT

Disassembled view of PPS Micro Rock:

Velocity adjuster:
Threaded for 3/4-16 (only '98 and older - '97 and earlier guns weren't threaded and used a sleeve to hold the velocity screw)

Ball detent:
the electricianthe electrician notes that cocker ball detents are threaded 3/8"-24.  Use a Q size drill.

I don't recall who said this, but it was on Doc's tech forum:
"The threads on a cocker barrel are .912 (major dia.) 20 threads per inch. FYI when I cut them I single point them on a lathe, don't think you will find a tap that size."

Ed Kang found a 15/16"-20 tap (again at for $43.20.  This would give a major dia. of 0.9375", which might just be perfect for adding cocker threads to gun bodies.

Ed then did a bit more research on the subject, and called up Larry at AKA:
Just got off the phone with Larry Alexander. He offered the following information:

The tap used to cut autococker threads is:

15/16"-20, Oversize GH-7

The tap drill is 15/16" minus 46-50 thousandths.

This makes sense. 15/16" corresponds to a major diameter of 0.9375, with a minor diameter of 0.8875 at the largest. 20 threads per inch equals 50 thousandths point to point between threads, or 25 thousandths from valley to point, which means that one can cut these threads with a 45 degree cutting tool.

Fun fun fun. Now the question i have is, what does the Oversize GH-7 notation appended after the tap size mean?

Many thanks to AKA.

[HB - note that Ed said 45 degrees for the cutting tool, though I'm pretty sure he meant 60]

Aaron (the AKA in AKA) then popped in to help clear up the oversize notation a bit:
If my tired brain remembers correctly GH-7 is either .003 bigger or .005 bigger then the thread size you need. I would have to look it up again to make sure. This means that the tap would cut a bigger thread so when you industrial hard anodized it the barrel would still fit.

Aaron also notes that they get their oversize taps from MSC.  

Feed tube is 0.875" OD, 0.75" ID

Bolt o-rings are 0.1" thick, 0.5" ID, 0.7" OD
Back block on '99 and older models is 1" thick
Pre-2000 cocker bolts measure 5.25" from the bolt face to the center of the retention pin hole; 2000+ cocker bolts measure 5.125" from the bolt face to the center of the retention pin hole. P-blocks measure 4.75". (thanks to Ken Newell and Foxfire5).
Pull-pin is 1/4" dia.
Air feed port from valve chamber to bolt is 1/4" dia.

Ed the human computer recalled these spring sizes off the top of his head:
1/8" diameter x 3/4" length trigger spring (perhaps as big as 3/16" in diameter depending on the frame)
1/4" diameter x 2" to 2.5" length sear spring

Gun operation:
Click here for a copy of the Autococker animation from Worr's website.

Cutaway photo:

CAD files:

This cocker body was created by Aimn4u2 in SolidWorks and is available as the following file types:

SolidWorks (.sldprt, contains all the model configurations)
Catia (.model)
Stereolithography (.stl)
VDA Surface Data Interface (.vda)
If you don't have a CAD package, download this Windows executable - it contains the vert feed configuration and will allow you visually inspect the model.

 Gizzmo created this vert feed body in Pro/E and provided an IGES file (.igs).

Josh Coray
provided this AutoCad DWG (R14 format) file and writes "It is fairly close, and short of EXACT outside dims for those curves, and some valve internals, and the threads, it is fairly right on."

Autococking cycle times:
Punisher writes: "I've been able to cycle down as low as 12ms. However only perfect, SMALL paint will feed reliably. you're better off to shoot for somewhere near 30ms."  When asked about the means that he used for these measurements, he replied:

"I initially used a rather complicated system, tacking optical (IR) sensors to the bolt and back block, with the stationary IR source hung off the back of the gun. I had a buddy cycle it as fast as he could. I measured the resulting signals with a Tektronix 3052 digital oscilloscope. He could rip off strings of 6 to 10 at around 11 balls a second. It's truly frightening to hear a guy shoot a cocker that fast all on his own. I saw that at that speed, the bolt was open for a total of (approximately) 63 milliseconds. Now that is counted from the time the block lifts away from the body, until it actually settles home again. In reality, the bolt was only fully open for around 40 milliseconds. Once I got that much, I started whittling down until it wouldn't allow it to feed."