A Spare Magazine for an Aeron B96 Part-2 Final

Back to the Aeron magazine.

Bolted a couple 1-2-3 blocks together and placed the original mag against the soon-to-be. This arrangement kept things relatively square while I marked the angle across the corner. The angle appears to be for ease of insertion into the mag carrier on the gun. Not shown: milled and finished the angle.

I set up the original mag in the milling vise and used it to set up the quarter round cut. The depth of this cut indicates the mag in the carrier. I used a depth micrometer set against the lower fixed jaw on the vise to position the work in the same location.

Used a 4mm end mill then test fit the mag in the gun. It was a good fit in the carrier. A bit tighter than the original.

Not exactly an epiphany, but I've been thinking a lot about how to mark off the pellet hole spacing on the mag. It occurred to me that I could simply remove the barrel...
and just use a transfer punch to mark directly though the breech.

Put some layout fluid on the face of the mag, then slid it home.

Lucked out and had a punch that fit the breech like it was made for it.

Tap, cycle the carrier manually. Tap, cycle the carrier...

Testing: Drilled some aluminum with various sizes of bits then tested .177 cal wadcutters in the holes. No real surprises here, but I settled on a #16 bit for final size.

A pointed indicator is used to locate the center of the hole...

then it's replaced with a bit and through drilled.

Then back to the indicator for the next hole. Slow, but it worked.

Opened the holes up to #16 (0.1770").





Used a #15 bit in a pin vise to chamfer the breech side of the mag to allow the pellet skirt to seat flush.

A small groove cut with a 1/4" ball mill marks the side to load.

Front view. Test firing was surprisingly uneventful. The darn thing functions and the pellets go into a little tiny single hole on the target--??? I am utterly astonished that this even cycles--let alone works. Oh, the bottom mag is the new one. I'm absolute proof as to the old saying about blind pigs and acorns.

A Spare Magazine for an Aeron B96 Part 1

Nervous about posting part one before the mag is finished. There's still so much that can go wrong--and if it all goes down in flames, I'm not likely to tackle this again until I buy a proper milling machine.

Been looking around on the usual airgun classifieds, gunbroker, ebay...looking for a spare mag for my Aeron B96. They just aren't out there. Apparently, none of the importers ever had spare mags in any kind of quantity, either. The gun came with one single-shot and one five-shot mag. Gotta tell ya, when this gun comes out to play, 5 shots lasts about 2 seconds. In a perfect world, I'd have five or six spare magazines for this gun--OK, sure, I'd probably have ten. As I have to do this manually, I'm going to attempt to make exactly one.

How precise does the mag need to be to function correctly? That's my biggest concern. If the mag body isn't square, or the holes not the exact diameter, or parallel, or the height is off... I don't know if I have five thou of leeway or none. Will it shave lead off the pellets as they jump to the breech? Will it leak CO2?

The mag holds five .177 cal pellets and fits into a carrier on the pistol. The carrier indexes the magazine for each shot. The mag is just along for the ride.

Cut a piece of scrap aluminum to approximately the same length.

Set up the milling attachment and squared the milling vise.

For a change of pace, I used a homemade fly cutter instead of an end mill .



The fly cutter holds a lathe knife at an angle and swings it through an arc. The edge just skims across the work leaving a nice, flat surface in it's wake.



All I wanted for the first step was a flat side. The fly cutter did it in one pass.

I turned the piece around and zeroed the opposite side. My hope was that the fly cut side would make for an accurate base when milling the magazine to final width. There's a 1/4" HSS blank tool bit in the vise as a parallel--needed some stand off, otherwise the surface to be cut would be recessed in the jaws.

Milled the piece to 0.273"--the width of the mag.

Rotated the piece 90 degrees fly cut the face, then milled the opposite side, making the piece 0.280" in height.

A bit of clean up on the edges and corners then the ends were milled square to a final OAL of 1.687"

I guess part one should've just been titled: "Derrick makes an aluminum rectangle". Give me a few days, I'll let you know how it goes.

Magazine for a Crosman 118--Part 2 Final

Back to the 118 magazine. Searched three hardware stores for a suitable spring. No dice. Gotta make the spring. Bought some various gauges of music wire. Lacking a power feed on the lathe, I opted to wind the wire along a piece of all-thread to make the coils. A foot of #10-24 is about the correct diameter. Ideally, the coils would be further apart, but I'll make do and stretch the spring out. As I needed to anchor the wire at one end of the rod, I cut a slot and chased the threads. Wire lays in the slot. Nut threads down and locks the wire in place. Wind the wire into the valleys of the thread. Need to keep constant tension on the wire--or it just unwinds. This is over two-and-a-half feet of music wire. I found out the hard way that the wire will not set to the size of the thread by itself. Gently clamped the wire to the rod with a vise-grip so it couldn't unwind. Heated the wire with a torch for a moment then quenched. Removed the nut and unscrewed the spring. I pulled and stretched it out a bit to get the necessary length then finished the ends. The small piece of material on the right is delrin (or acetal--if you prefer). I turned it to 0.230" to fit inside the magazine. Then, turned about half the piece of delrin down to 0.160" to fit inside the spring. Left a shoulder for the spring to bear against. This will be the magazine follower. Made some comparisons to the original 118 mag and measured the amount of follower protrusion. Marked the spot on the new follower for the stop pin that will allow the same extension. Drilled about 3/4 of the way through with a #43. That drill size was chosen to allow a pin diameter that would slide freely through the milled slot in the magazine body. Chucked a piece of 0.125" brass rod and turned down to 0.090" diameter. I'll cut off the end to make a tiny rod for the follower stop pin. Cut a groove near the end of the magazine. This engages a detent inside the 118's receiver, holding the magazine in place. Knurled a piece of 0.500" drill rod to start the end cap for the mag. Squared up the ends and machined down one end. Cut a defining edge up to the knurl. Spotted Drilled just shy of an inch deep. Didn't break through. The bottom of the hole will serve as the seat for the follower spring. Eyeballed a good spot for a couple tiny retaining screw holes in the end cap. Countersunk Wire brushed the old finish off the body, then transferred the holes from the cap and drilled with a #50. Tapped #2-56. Test fit. The end cap secures with opposing #2-56 stainless steel screws. I'd been pondering (agonizing?) how to lock the follower back to load the pellets. The original 118 mag uses a spring clip to hold the follower. The spring releases the follower automatically by simply inserting the mag into the gun. Mine won't be quite as complicated. I went back to the milling set up and cut a forward slanting angle at the rear of the follower pin slot. The follower pin can now be pulled back, then turned slightly to lock in the rearmost position. After inserting the mag into the gun, it should take just a thumbnail flick to unlock the follower. Had to play with the height of the brass follower stop. If too high, it won't slide into the gun. Needs to be flush with the diameter of the mag body. Test assembly. A few different angles. Disassembled for finishing. Blued the cap and body with Birchwood Casey Perma Blue Paste. Follower locked back. A better pic of the loaded magazine. Ten .22 cal Crosman wadcutters fit perfectly. The 118's receiver has a slot to show remaining pellets in the mag. Clever. I'm absolutely dumbfounded that the "prototype" mag functions perfectly. Ten shots as fast as you can work the bolt and squeeze off the shots. As I didn't want to disassemble the original mag for measurements, it was a nice surprise that this worked without endless tweaking and re-work.