Building magazines..


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Trent
December 27, 2012, 11:20 AM
Magazines for my SCAR17S are reaching "unobtainable" status. I'd never seen them in stock anywhere since purchasing the rifle - always "late to the party" when small quantities became available. They're selling for close to $100 now.

Going to see if I can fabricate something in my garage. I fully expect my first several attempts to fail miserably. These magazines look far more difficult than an AR-15 or AK-47 magazine. The entire mag body is one piece, rolled to shape and crimped on the back; not two halves which are formed to a whole and welded.

Anyone else ever made a magazine from scratch before? Any pointers? :)

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CraigC
December 27, 2012, 11:45 AM
I bought five for Dad's rifle about a month ago at $50 each. Unless I'm remembering it wrong, there was a magazine on the market that could be modified to work.

JustinJ
December 27, 2012, 11:52 AM
Without specif tools i think it may not be feasible. Altering existing mags, if possible, would certainly be a better option.

Caliper_RWVA
December 27, 2012, 02:03 PM
Certainly should be feasable. The hardest part is likely the feed lips, both shaping them so they release the round at the right time and heat treating them if needed.

You can probably make a wooden buck to form the ribs in the side of the mag against and some sort of rounded punch to beat the sheet metal into shape. Having the right rib depth will be important as well.

Follower and spring aren't going to be easy either, can they be bought easily?

Andrew Wyatt
December 27, 2012, 02:07 PM
http://fnforum.net/forums/fn-scar-17s/15242-fal-scar-17-mag-conversion.html

Geneseo1911
December 27, 2012, 02:21 PM
I've been thinking about buying/building a 3D printer, and this is one of the reasons why. I'm pretty confident that with enough experimentation you could print a magazine body that would work reliably. The technology is there.. Even if you couldn't get a plastic as good as P-mags, a guy could surely make something that would work once and be disposable...like the original M-16 mags were planned to be.

Trent
December 27, 2012, 02:30 PM
My friend (who's a welder by trade) and I are researching making our own springs. Pretty deep subject, that.

Initially, I'll scavenge springs from a similarly sized magazine - Cetme, M14, FNAR, etc (I have many potential suitable 308-cartridge donors)

The follower, similarly, we'll "borrow" from an existing design; if we don't find one that we can make to work, I'll machine a set of dies and we'll just hydraulically press metal ones. (The cheaper the better, in each case; I'm hoping to reclaim CETME parts, as I have several dozen 20-round CETME mags).

I'm not married to exactness of the magazine design or follower; etc. In fact, I don't believe I can even re-construct the magazine as it was built, without building a great deal of tooling to do it. So I'm drafting up a new design, which will be dimensionally accurate but easier to construct.

The best I can tell, the SCAR magazine is constructed from a single sheet of metal which is run through a forming process involving rollers, folded, and the final "seam" is formed on the rear right edge of the magazine. The magazines body is a single piece that is crimped together, not welded.

A length of steel insert is also present (spot welded to) the inside of the rear of the magazine which serves to make the magazine body more rigid as well as provide a notch for the follower to travel along. The rear of the follower (the notched part) is exposed through a U shaped notch in the top of the rear of the magazine, allowing the follower to activates the bolt-hold open lever.

The feed lips are rolled over at 90 degrees (probably by ramming the assembled mag in to a forming die hydraulically). I can machine a die and insert (to keep the magazine body from fexing) and replicate that process. After bending the lips, the top opening will need to be profiled the front and rear of the lips will need to be tig welded for strength (this is where my welder friend comes in... that's an artform.)

We'll plasma cut the floor plate and trim to fit by hand.

So...

Starting with the appropriately sized sheet of steel;

#1 roll the ribs
#2 cut the magazine catch notch and punch the stop
#3 Fold the floorplate catches
#4 Fold the magazine "rear"
#5 Fold the magazine "front" (completing the "box")
#6 Mig weld the seam on the right edge (where there is additional clearance on the SCAR receiver for a "rib")
#7 Spot weld the rear notched insert in place (this will require a pass on the mill to cut the notch on the strip of metal)
#8 Trim the bolt hold open notch (dremel)
#9 Insert mag body in to retaining blocks, clamped together, hydralically press the feed lips to the appropriate radius
#10 tig weld the feed lips front and rear, clean up welds
#11 trim follower to fit.
#12 cut (or adapt) floorplate to fit
#13 assemble and test.

We'll be missing the plastic part on the bottom of the mag that "levels" it out, but I don't mind.

Trent
December 27, 2012, 02:33 PM
http://fnforum.net/forums/fn-scar-17s/15242-fal-scar-17-mag-conversion.html

Interesting, although I don't have any FN-FAL magazines to test with.

Still going to try to make my own.

Learning like this .. could be useful. :)

(Also I'd rather screw up a mag with a stupid mistake than a firearm receiver, which is my next winter project)

Owen
December 27, 2012, 02:50 PM
The mag bodies are actually FAL mags with most of the rear rib removed, and an M16 style notch added to the side.

Trent
December 28, 2012, 01:47 AM
I found an FAL magazine tonight. :)

I bought a "lot" of magazines from an estate sale.

http://i.imgur.com/KBXCA.jpg

17 H&K G3 aluminum mags
5 Norinco 30 round AK-47 magazines (2 of which were still wrapped in paper, flawless, looks like they just got off a Chinese boat)
8 Norinco 20 round AK-47 magazines
2 German bake-light AK-74 magazines
12 Norinco 40 round AK-47 magazines
and...
*1* FAL magazine!

(My cost worked out to $13.33 per magazine; $600 for the Qty 45 magazine lot.)

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