Wednesday, December 29, 2010

More on the Bill Holmes-ish .50 B.M.G. rifle

Been a couple weeks since I updated, I know. I have been pretty busy with the Christmas holidays,  with work (had to work the holidays, I don't think there have been too many holidays I don't wind up working. All part of the job.) and family in town and a whole list of other stuff to keep up with, I just haven't had much time to sit down and type up an entry.

Well, at my last update I had a more-or-less complete receiver sitting in my garage, a bolt that had had its outer diameter turned, a fire control group, and a few other odds and ends. One thing I lacked was a buttstock of some sort. I looked at the rifle for a few days trying to figure out what would work best and look like it fit the overall rifle.

This in itself was pretty difficult, because there are a number of stocks on the market that look good on most homebuilt rifles, such as the M4 collapsible stock, or the standard A2 buttstock from  a m16 or AR15. I had a couple of each of these laying around, and held them up to the receiver for mockup, only to quickly shelve them again. The 2.25" outer diameter of the rifle just didn't look right when paired up with the roughly 1.375" outer diameter of the collapsible M4 stock, and the A2 didn't look right at all.

I went over to Google and typed in "tubegun" to see what else was popular or available so maybe I could get some ideas. I found several that made use of AR15 and M16 stocks of many different manufacture, such as some seen on this site. In fact, those stocks look great on those tube rifles, but on my large receiver, an AR stock was just absolutely goofy looking. I feel that if you are going to build a firearm, it is important to at least try to make it look proportional.With that, the AR stock idea was shelved.

I couldn't very well use the exact stock method Holmes outlines in his book, as it is nothing more than a piece of tube with a flat plate attached. It really wasn't very flattering, although I realize his idea was more to have something utilitarian than pretty. After all, the buttstock does not decide whether the gun goes bang or not. After banging my head against the wall for a few days trying to decide what to do, I finally threw something together out of a few pieces of scrap material I had laying around. With the idea that I would build something similar to what Bill Holmes designed, but with a bit more eye appeal. I started with a piece of seamless DOM tubing that was about 1.375" OD, then cut off a 10" long chunk of it and chucked it in the lathe. I then knurled the tubing in the lathe after squaring off the ends. I had a small section of 4130 2" OD round rod left, so I bored it out for the DOM tubing so the tubing would sit perfectly centered in it, then fired up the welder and burned it in place. Once that was done, I cut a plate from .375" plate in the shape of an AR buttstock so that a buttpad meant for an A2 stock would fit and look right. I drilled and tapped 5/16" holes in the 4130 round stock I had previously welded to the DOM tubing, then drilled 11/32 holes in the end of the rifle receiver to match the drilled and tapped holes in the 4130. When the button head bolts were installed to attach the stock, it pulled the whole thing in tight, and the bolt would move all the way back in the receiver and bottom out on the buttstock, providing full access to the ejection port. It came together so well, there's no way I could have ever planned it.

Still, after looking at it, I still didn't like the large tube to small tube transition, and figured if I was going to use what I had thrown together, I needed to add a little bit to it. I dug around in the scrap bin and found some .5" 1018 round steel rod. I cut a good 14" section of this off, did some simple bending on it, then welded it to the bottom of the buttplate going forward to the 4130 round stock that fit into the receiver. I took another chunk of .375" plate and cut out a rectangular section that was welded to the bottom of the 4130 piece. I welded the .5" round rod to this to complete the buttstock for the moment. I then cut a slot in the bottom of the rifle receiver directly below the buttstock mounting area for this flat plate to slide in to place. This filled in the gap behind the AR pistol grip and the round rod on the stock I made. After all that, I cut up some .125" plate to fill in the gap between the DOM and the .5" round rod that the stock was made from. Bolted it all together, bent up a piece of that .5" round rod and threaded one end to attach it to the rifle bolt as a start for a bolt handle. I managed to completely botch this piece, (the bolt handle), but left it on for the time being, mainly so I could get a feel for the way everything looked together.
I threw some rattle can black spray paint on the parts, and threw it together to see where I stood. Ignore the bolts in the rear of the receiver, I had misplaced the button head bolts I bought for this purpose.

I'm still not entirely happy with it, although I do have a couple ideas how I can make it look a little better. I am going to bore 3 sequential 1.375" holes through the .125" plate I had welded in and then I will sand all the welds and other odds and ends down. If I am still not happy with it........

To hell with it then. I will just make it a pistol. A reaaaalllly looooooong pistol.

I got a bit farther than this with the rifle build before the holidays, but have had two separate things going on to take up my time, one concerning the .50 cal rifle and the other concerning another project waiting in the wings. More on that later.

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