Fixing SMG 68 Aluminum Magazine?

[Tominator]

I've been trying to figure out a solution to the stock aluminum magazine of the SMG 68 deforming after sustained use.
Has anyone had success in addressing this problem? I've seen photos of people flipping the magazine around and remaking the holes on the unused end, but has anyone made a more permanent solution?

I messed around with the idea of making some sort of an adapter of a stronger material. I don't have anywhere near the machining capabilities to do something like this myself though, and it looks like it would be pretty expensive if I wanted someone else to do it. The unique cross section of the magazine is throwing me for a loop. Every other aspect of the marker runs flawlessly, and it's an absolute thrill to use when the magazine opening is actually functioning.

[RuleOfSines]

I had considered making something out of steel, like what you have there, but my motivation to do so was seriously lacking.

[Tominator]

I was gung-ho about it for the past couple days, but the hypothetical price tag hit me like a brick wall

[Carp]

BretG netsurferdude2 COB

[COB]

A solution to the self destructing magazine could allow these gems to see the field again. BretG found a way to breathe new life into the SMG60 and 68 Special with his valve mod. A new Mag or Mag Adaptor could make this gun the beast of the field again. I have 2 begging for help.

[Tominator]

Alright folks, I went ahead with the adapter idea. Gonna make the rest of the magazine out of some aluminum square tubing and drill the rest of the needed holes into the adapter. I've been simultaneously modifying the valve for HPA, and I'm getting close to what I need. I will report back with either incredible success or epic failure.

[Axel]

Did you bite the financial bullet and have it machined from billet?

[Tominator]

William The Third recommended a website called Fictiv, which is what I ended up using. I removed a lot of the features I could do myself so the cost came down to about $120.

[Tominator]

It's in a pretty rough state aesthetically, but the whole feed mechanism is working properly. Picked up a 1" x 1" aluminum square tube and some brazing rods from Home Depot to craft the magazine. First time trying that so the joints were a little rough. I have plenty left though so I might mess around and make a 10-rounder or cut a nice big slot on the side so you can watch the clips advance.

[AOD14-Marcos]

If you don’t mind me asking, what’s the thickness of the 1’’x1” square tube?

[Tominator]

The thickness was 0.06" It's slightly larger than the opening of the original magazine, so I had to angle the inner faces of the adapter I made with a file so the clips would slide in.

[russc]

Awesome!!! I'm impressed that they managed to machine those features so cheaply. Is it milled or is it sintered metal?

[Tominator]

I tried my darnedest to find any other information on how they made it, but the website just says "CNC Mill." I don't really care what kind of magic they ended up using though cause the part works like a charm.

[Ecapnation]

Is it milled or printed?

You actually did just give me a killer idea. I totally forgot the company that I use for my emek body printing offers stainless steel SLS printing. If I design that exact piece that you did I might be able to recover the mess that is my as my smg68

[Tominator]

Don't worry about it. I'll throw up a link to a folder that has the two files I messed around with.

[RuleOfSines]

Isn't that ridiculously expensive? I vaguely remember getting a feed adapter priced from shapeways and it was more than the whole marker I was making it for.

[Ecapnation]

Steel it's $100

Aluminum..... Yeah 220

[Tominator]

Here's a link to the files I used for the adapter: https://drive.google.com/drive/folde...Ah?usp=sharing
The "Simple" one was what I sent to Fictiv. The other has every feature as measured from the aluminum magazine that came with my SMG68.

[russc]

My suggestion if you are getting an laser-sintered part made...don't keep the full length pocket that the pawl sits in, and add wings that add some rigidity. Tippmann made it full length so it could be extruded, and it contributes more to the weakness in the part than anything else, and gets directly smacked by the valve.

[Tominator]

Absolutely. Another thing is the giant slot cut out for the magazine spring and its screw. It could be possible to cut a hole instead of that giant slot to avoid removing all that material. Only problem with that is you would have to put the spring and screw in after the magazine. If you designed an adapter to more closely mimic the SMG60 instead, you could have the spring attach to the side instead of inside, which would remove the necessity to have any sort of cut there at all.

[Tominator]

Had a little fun with it. The aluminum looks much better under a quick coat of spray paint.

[RuleOfSines]

Nice work, cool to see this idea actually come to life!

Since failing mags and 68 Special conversions probably limited how much use these got, I'm curious what the next failure would be. My bet would be on the receiver cracking at the breech, all that removed material to fit the 68 round makes me uncomfortable..

[Ecapnation]

Okay!

So I made some subtle (ok major tweaks) and have one being printed in SLS 70/30 nylon carbon fiber..... Going t test it once it comes in.

If it's ridged enough and takes at least 4000 rounds I'll consider it a win. Costing me $25.00 to print.

[Tominator]

After a year or so hiatus, I'm finally working on the SMG again, and coming back to this post I'm curious if you ever got this made and if it worked out. Would love to see pictures and what not!

[russc]

Nice work, cool to see this idea actually come to life!

Since failing mags and 68 Special conversions probably limited how much use these got, I'm curious what the next failure would be. My bet would be on the receiver cracking at the breech, all that removed material to fit the 68 round makes me uncomfortable..

I think a barrel core sample is more likely to cause a failure here than fatigue due to the valve impacting.