Cartridge Counter Grip Mod

[sheepherder]

I'm going ahead with a left-side 'cartridge counter' grip & magazine. I'm planning on using an extended follower pin/button for the indicator.

I didn't have a spare Mec-Gar mag, so I ordered one from Greg Cote. I pressed out the base pins with an arbor press. There seems to be a correct way to do it, as shown in pic. After moving ~3/32", they popped right out.

Magazine base and follower are plastic, so I'll have to make metal replacements.

Locating the follower pin hole [cartridge indicator] in relation to the body, both 7-round [full] and one round [end of proposed slot]. 'Full' pin location is with top cartridge under tension from breechblock.

[sheepherder]

The magazine body needs to be securely clamped to mill out the slot, so I need an insert and outer relieved clamps (because of the ribs). I had a special mill cutter left over from a similar project [coff, coff] so I used that to contour the front of the insert. I used aluminum. The clamps are also aluminum, with 1/4" milled grooves for the rib clearance. A slot was milled in the clamp for end mill cutter clearance and observation. I chamfered it for better vision.

The magazine body can now be securely held and clamped for the milling of a 1/8" slot for the follower pin/indicator.

All this for an operation that will take less than 5 minutes to perform...

[sheepherder]

Boy, was I wrong about the five minutes!!!

After spending two+ hours today, I have the mag body slotted! A long tedious chore, with one broken 1/8" 4-flute end mill.

It just wouldn't take the feed. (BTW: Mec-Gar mags are not hardened). I ended up doing it all by hand, very slowly.

I made a relief cut in my tube insert, then clamped the mag tube + insert in my 'sandwich' and indicated off the tube front for my slot. I used a #31 drill bit to zero my 1/8" end mill and sank it into the hole. Then it was one cut up the tube to open the slot up. After that, it was just climb and conventional milling each side to open it up a bit, as I'm planning on making my button pin 1/8".

The first end mill broke off when I was ~5/8" into the power feed, as slow as my Chinese feed could be set. It left a jagged edge that cleaned up with subsequent cuts. A bit wider slot than I wanted, but them's the breaks [bad pun].

Next up is the follower.

[sheepherder]

Now that I have the body slotted, I need a metal follower and a metal bottom. G.T.'s bottoms are the best, and Gerry was able to fit me into his busy schedule and make one for me.

That left the follower. I had a chunk of brass left from the other magazine project so I made my follower out of that. Battery in my digi-cam was depleted, so no brass milling pics. Sides are relieved; bottom is spot-milled for spring header.

To drill G.T.'s mag bottom, I had to make another mag body insert <sigh>. Using my previous clamps and the new insert, I was able to spot the mag bottom holes and drill them through. G.T. graciously instructed me how to do it, and for a one-time-only procedure it came out OK.

I still need to make my extended follower button, so I have not pressed the bottom pins in yet (just Cotter pins holding it in place).

I'm not thrilled with having to make an extended follower button. Micro-machining is not my strong suit.