Saturday, February 18, 2012

A mag for the Hi Point drum

I got tired of being jerked around by the local sheetmetal shops, so I decided to buy a new brake. A quick trip to Harbor Freight and I saw they had a simple 36" brake (identical to one I used to have) for $300, but it was on sale for $220. I had a 20% off coupon in the truck, so I picked up the brake for about $175.
I mangled a couple of pieces of 4130 sheetmetal in the first few attempts to get a mag built, but finally found a method that worked to get a mag bent and functional.
For the record, that 4130 sheet is a PAIN to bend with a non-hydraulic press brake, even when the sheet is annealed. This is .040" 4130 sheet, and there is no comparison to .040" mild steel. I was bending 6.5" lengths, and I had to muscle it a little bit to get it bent on the brake. There is no way the spring pressure from the drum will bend the feed lips even in the annealed state, and if I harden them via oil quenching, they will stay where I put them.

The mag fits really tight, unlike the sloppy factory mag. This is a plus, as far as I am concerned. The feed lips are not formed yet, but I'll get to that soon.

I also got a mag in for the Bren parts kit. That let me set the spacing between two of the cut portions on the old receiver. This is handy to have, even if it will be a while before I get to this project.

I hope to have some more drum towers made soon, and I'll get this one I made welded onto a drum pretty soon so I can get it up and running.

More projects coming down the pipe

I won't divulge everything about this one, but I'll toss some pics out here and let everyone guess what is going to happen.
The barrel to the left is a .45 caliber barrel, 16" long. Good for all kinds of interesting stuff.
(Ignore the longer barrel, that's a .30 cal barrel I am going to machine a bull barrel out of for a friends Remington 700 .300 WinMag. )

 Now, these may look a little rough, but familiar.

Those are 0% AR 15 lower and upper receiver forgings. Great for building.........whatever you want to.
This project is a month or so away, but it should prove to be pretty interesting and fairly challenging. The forgings are oversize, so before anything can be done they have to be milled to correct size, then drilled and built into the final project. I will be using an off-the-shelf  FCG, with the standard hammer/disconnector/trigger. I will likely also use a standard C.A.R. stock. Other than that, it's all going to be made by me.

Any guesses as to the finished product?

Tuesday, February 14, 2012

Some new tooling and a couple new projects

Well, I finally got another new-to-me mill. It is the same model as the one I had when I lived in west Texas, so it should be fairly intuitive. I got a great deal on it thanks to Craigslist, and only had to drive to Denton (north of Dallas about an hour) to pick it up. The mill came with a few end mills and some other random tooling, so it seems that the irony continues. When I moved out of west Texas, I had an identical mill and identical lathe to what I do now, and when I sold both of them I included all the tooling I had for them as well. I had amassed quite a bit of stuff for them, and wish I had kept some of it, but that's the way it goes, I suppose.

 Here it sits next to my lathe, waiting for me to do some wiring and get it all working.
 Now that I have a milling machine again, I can get some other stuff done I've been waiting to finish.

Since I have a mill and since I saved some money on the purchase of the mill, I picked up a couple parts kits that I have been wanting. First off is a 1942-dated Bren MK1 machine gun that has been demilled according to current ATF specs. If you zoom in on the pic you can see the torch cuts in the receiver. I spent part of the afternoon today grinding down the slag on the torch cuts and seeing if the receiver could be salvaged in order to build a legal semi auto out of it. So far, it appears the magazine well area took a hard hit with the gas axe, but that is really the worst area and can be rebuilt. Everything else looked really bad at first, but upon aligning it on the lower receiver, it looks like I can make a few filler sections and weld it up with relative ease. I have a gas regulator and magazine on order from Apex and a barrel on order from Centerfire. It does look a little incomplete without those parts at the moment.

The other parts kit I picked up is a Polish RPD machinegun. This came complete with everything I need to build a semi auto rifle out of except a receiver. I am going to try and pick up a demilled receiver and attempt a re-weld on it. There are prefabricated semi auto receivers on the market, but most of them cost almost what I paid for the parts kit itself. If I can, I'd prefer to machine a new receiver out of a block of 4130 or 4140 so I can have it heat treated. Thankfully, this rifle is chambered in the 7.62x39 cartridge, and the receiver really doesn't have to be all that tough to withstand that round.

It may be a bit before I can start working on these projects, but they are here waiting on me. I'm still waiting on word back from a couple sheet metal fab shops about the magazines for the Hi Point drum assembly. The first shop I spoke with said they could replicate the mags somewhat, but instead of bending a radius in the mags, they would only be able to bend 45 degree angles in the nose of the mag. This would work but it's not really what I want.(For the record, I had them bend me up one and I tried it. It fit the magazine well fine, it just doesn't look as nice as the radius-ed nose magazines)
The other shops I spoke with had to do a cost analysis of tooling and work up a price on each part in small lots or in bulk. I only need a couple for now so I can get back to work on it and perfect it. Once I know I have a working product I'll be more inclined to buy several mags at a time.

For those still following this drum project, my advice would be to go ahead and buy a drum or three now while you still can relatively cheaply. This election coming up looks to be a repeat of the last one, so start amassing ammo and high cap mags while they are still on the market. The worst case scenario is that you wind up with a couple drums you can either sell down the road to a Suomi owner or to someone who wants to experiment with building a drum for another 9mm firearm.
IF, and only IF I get a working product out of this project, and IF I do decide to make/sell any of the completed drums, the drums would be done on an exchange program. I don't have the capital necessary to buy and stock a whole bunch of factory Suomi drums, so I would require each person to send me a drum for modification. That keeps the price of modifying them at a constant rate, and no one would have to worry about the price going up due to a shortage of drums or the price of drums going up. Again folks, if you can, buy drums now. You won't regret it either way.

That's about all I have for now. I do have some more updates on the drums coming, but I don't want to let too much out of the bag yet, not until I know that I have a steady supply of magazine towers.

Wednesday, February 1, 2012

New Toy.

Well, my trip to Macon went well. A friend accompanied me along the way, and we made it from Dallas to Macon and back in right around 32 hours, including loading the lathe in the back of the truck. So, now I'm back in business with a real lathe, which will help a LOT with some of the upcoming projects.

Here is the new-to-me Enco 13x40 lathe

How else could I build a SBR'd SKS, or a suppressor or five?

I've got some new tooling coming in soon that should help with building the Hi Point drum mags. It doesn't seem to matter what I do, every time I build a mag out of thicker material, I wind up goofing up the design or it winds up not having enough internal room to allow the rounds to feed right.
I plan to build the mags out of .04" thick 4130 sheet this time. This is only slightly thicker than the factory .03" mag material, but it is 4130 so it can be oil quenched and hardened.
Barring that working, I also have some .035" 4130 sheet on order. If it comes down to using that, I can make a mag to factory specs but weld on an extra set of plates in the feed lip area to keep the drum spring pressure from bending the lips outward. The more room I have inside the magazine, the easier the rounds will feed upwards, and the less amount of friction I can get away with, the better.
The problem is not width so much as it is depth. The rounds have to travel up the magazine at a slight upward angle, and in the last few mags I pressed and welded they would bind up and keep the top round from pointing upwards enough to load properly. This has been my biggest hindrance in building a functional magazine.
I am also considering building a radius brake that would allow me to press these out quicker. The press brake die I built prior to my move does work, but it takes a while to align the sheet metal correctly and then use the hydraulic press, all the while keeping the sheetmetal exactly in place. This is time consuming and makes bending a mag tougher than it should be.

I used to have a simple brake like Harbor Fright and others sell like this one.
but it is only good for simple bends and is not good for building boxes or pans.
However, the design would be easily replicated such that instead of bending on a sharp edge, a radius could be used as an upper forming edge and the mag metal wrapped around that radius using the lower brake finger. Prior to that, I could bend the rear edges of the mag inward, so that after forming the radius on the front, I would simply insert an aluminum welding form inside the completed mag, squeeze the mag together the rest of the way, clamp it tightly, then weld the seam on the rear of the mag. The aluminum form on the inside would prevent warping and ensure perfect repetition of a completed part.
I'm having to MIG weld the mag assemblies together at the moment until I can acquire another TIG. Anyone familiar with welding knows that the MIG process puts a lot more heat in the weld area than does TIG. There is also a lot more grinding to be done to the finished product when MIG welded as compared to a TIG weld. Once I get the money together to purchase a new TIG, those mags will benefit from thence on.

Prior to making a brake, I have to get a new milling machine so I can machine the parts necessary to build it. Thankfully, I have a new mill picked out and hope to acquire it later this month as funds allow.

That's it for now, more as I get to it.