My 3D Printed Extended Magazines
A little over a month ago I finally got the money together to buy/invest in my first 3D printer. The learning curve is kind of steep but I've finally gotten to where I've started getting some decent prints out of it; not perfect prints just decent usable prints.
Thus far I've managed to design and print some new peep sights for my Umarex Gauntlet PCP air rifle, Peeps sights for my break barrel air rifles along with a replacement shroud/suppressor for one of these break barrel air rifles and now I've started in on some extended magazines for my K31 Swiss rifle. If I measured correctly it should have a capacity of between 10 to 12 rounds depending on how much room my mag-spring takes up; possibly one or two more rounds.
I printed the first prototype yesterday. The finish on it was actually very good but, I found out when I went to try to insert it into the magazine well that the K31 magazine is tapered toward the front end. My mistake was measuring the width at the back end and thinking that the front end was the same dimension. A rookie mistake if I ever saw one.
You realize how incredibly frustrating that was when you factor in the time it took to finish that print. My second prototype is printing even as I write this initial post. Would anyone care to guess how long it takes to print just the main body of the magazine? Anybody?
It took just under 7 hours to print just the main body of this extended magazine. I haven't made up the follower yet but I have finished the floor plate and the slip-on bottom cap. I'm wanting to first get the main body fitting right and then fiddle around with the side latch until I get that just right so that it stays put when the mag is inserted. I'm going to have to make my own mag-springs for this so that's going to take some trial and error to get it right but, that's just par for the course. I'm sure there's a mathematical formula for this kind of stuff but I SUCK at math so I'm stuck with trial and error.
I really hope I can get this home made magazine to work reliably cause I'd like to make one for my Lee Enfield as well. A short little banana-type of magazine for my Enfield shorty would be just the ticket to make it look unique. I was afraid that the weak link in such a 3D printed magazine would be the very thin walls of these plastic magazines but when printed at 100 percent infill they are actually fairly rigid. In order for it to break you have to make a concerted effort to break it. I'll also be making up a set of 3D printed Peep Sights for this same K31 as well. I need to find some exact measurements of one of those aftermarket Bolt-On scope mount for the K31. I want to use the same type of securing method that attaches to the right side of the reciever. I've found photos online of this scope mount but nothing that I can get any good measurements off of. If any of you guys have one of these laying around perhaps you'd be kind enough to send me some closeup pics with measurements mainly of the area where the screw goes through and attaches.
I'll post some pics once I get farther along. I've already posted a few pics of my 3D printed air gun projects over on the air guns section of this forum. If you get a chance you can take a look. I'll generally post my CAD renderings just to show what I was aiming for and then after I've had time to fine tune my 3D prints I'll post the finished product.
I'm not printing these things for sale. It just takes to long to print up anything I've designed so a profit motive of things I've made is out of the question but at some point I do intend to start offering the STL files for sale to other like minded 3Ders who are also gun enthusiasts.
Sorry to leave you with no pics this time around but they will be forthcoming.
HollowPoint
Schimdt Ruben K31 12 Round 3D Printed Extended Magazine
My second attempt at 3D printing my K31 12 round extended magazine needed alot of tweaking via a file, some sandpaper and some foul language. I got it to work but my real objective was to get a useable print straight out of the printer with a minimum of post-print work.
I've made the needed tweaks to my CAD models and I'm thinking that the third time will be the charm. The problem with my second print attempt was that I hadn't allowed for the slight curvature on the underside of my K31 right where the magazine well is. The filing and sanding and cussing took care of that problem.
I do think I'm going to have to make my mag spring out of a slightly larger diameter of music-wire but other than that all of the other components appear to be working with only a minimum of post-print cleanup. The three images below include two of my CAD Renderings (as this project was intended to look) and one image of the second 3D print attempt. The plastic powder/dust sprinkled on some of the darker components was due to me being in to much of a hurry to get these pictures posted so I could get back to work.
The problems I encounter with projects like this are generally always due to me being in to much of a hurry. I can't help it. My spare time is at a minimum most of the time so I have to hurry up or I may not get the chance to do any projects outside of my income producing work. I'll be glad when I can retire. Maybe I'll have a little more free time then but, I won't be holding my breath on that. Most of the guys I know who are retired tell me the same thing whenever I see them.
"I'm busier now than I was before I retired."
This project is looking like it might very well work out for me. I mentioned before that I'd like next to print up a good set of peep sights. I was thinking about just using the same design I used on my air rifles but now I'm thinking I can just as easily reproduce a copy of those over priced "St. Marie" adjustable peep sights. If that works out for me too I'll offer the STL files for free to anyone who may be interested in printing up their own set of peep sights. I prefer my own design because several of my rifles have this type of peep sight and I've become accustomed to using them. My only reason for doing a copy of the high end Peeps is due to an arrogant comment made by the schmuck over at the Swiss Rifle forum when I enquired about the mounting method used by them and any other maker of after market scope mounts and peep sights. They seemed to find it humorous and somehow offensive that I would dare to ask about such things.
HollowPoint
My 3d Printed Extended 12 Round Mag Is Done
It turned out that, "The Third Time Was NOT The Charm." It actually took a fourth attempt after tweaking and re-tweaking my CAD models. I finally got it to work. :-D
I mentioned in my previous post that I had identified a potential weak link in the design. That was the thin area of the latch-claw where it catches on the reciever to hold the loaded magazine in place so as not to slide downward and out of position to align the cartridges for the bolt-head to push forward. I've tested several magazines full since posting this video; not actually firing the rounds, just cycling the action. So far it seems to be holding with no breakage or signs of ill-effect on the plastic claw.
This is a low quality and very short video that I had to butcher up even further to get it to fall within the time parameter restrictions for uploading to my Instagram account. I suck as a videographer but it's good enough to prove my concept and to prove that it actually works for me. I'm loading the magazine with some reloaded cast lead 6.5x55 Swedish Mauser cartridges. Some of you may remember about a year and a half ago I got a wild hair up my butt and decided to re-barrel and rechamber my K31 in the Swedish Mauser chambering. I liked the mild recoil so much that I bought a Tikka rifle in the same chambering so now I'm thinking of returning the my K31 back to its' native chambering.
I still have all the original components in my storage closet so it should be a snap to put it all back to original. I don't really need two different rifles chambered in the same cartridge. I'm sure this 3D printed Extended magazine will work just as well with the slightly larger diameter 7.5x55 round as it does with the Swedish Mauser cartridge; probably even better cause one of the down sides to these thin walled plastic mags is the fact that with the magazine itself out of the rifle and full of cartridges, the walls of the magazine tend to expand. This spreads the mag-lips just enough to allow the smaller diameter shells to want to push up and out under the pressure of the mag-spring.
I'm fairly sure that the very slight difference/larger dimensions of the native K31 cartridge will not allow the loaded rounds to want to creep up and out of the plastic magazine on their own. If they did still tend to want to do that, simple thumb and fore-finger pressure at the top of the magazine as it's being loaded into the mag-well will keep it from happening. The magazine's outside dimensions are such the they are just a fraction smaller than the inside dimensions of the mag-well. Once the magazine is locked into the mag-well I've had virtually no problems.
I'm thinking that 3D printing this same magazine design with one of the more rigid yet flexible filaments like the carbon-fiber type, should make this an outstanding combination. That type of filament is more expensive and I'm chronically cheap so unless I find this type of "Better" 3D print filament for a cheaper price, I'll stick with ABS for now.
HollowPoint
https://youtu.be/b2VP5cp9W6g