Mike’s All-Metal Marvel 6mmBR
Mike’s Marvelous Mystery Gun first appeared in the Reader’s Photo Gallery, and it produced lots of interest. Well we’ve got some more photos and Mike Murphy has been kind enough to give us a report on his unique 6BR switch-barrel rig with its one-of-a-kind all-metal stock.
Mike reports. “Here’s my metal-framed 6BR with a 22BR switch-barrel laying beside it. Both barrels are Harts and they shoot great. The action is a stainless Remington 40x that was trued, and mounted in a custom sleeve that bolts directly to the stock, or what I call the frame. It has a standard 6mm BR Norma chamber with a .265″ neck. I shoot 68gr custom-made bullets in Lapua brass. It has turned out to be one of my best-handling benchrest guns. I’m still working up a good load, but that is not far away.
This 6BR is the best-tracking Benchrest rig I have ever set on bags.
This is a old 40X action with some small mods made to it. It is now a switch-barrel rig with a extra Hart 22BR barrel. The Hart 6BR barrel is a 1:14 twist, 24″ full-contour (1.250″ OD straight, no taper). I can’t claim credit for the innovative metal stock. It was made by a smith in the northwest who shall remain anonymous for now. He only makes a few now and then, and only if he is begged and you hand him your check-book. I’ve been asked not to disclose his name here because he is a master machinist for a major U.S. Government high-tech facility. Needless to say, he is familiar with building very sophisticated metal components and prototypes that go into zillion-dollar scientific assemblies. His frame design I guess you could say is trickle-down from Uncle Sam’s research programs. He has access to tools that the average smith would never have. The amount of precision fitting that went into the frame is amazing.
Many of you looking at this stock for the first time might be skeptical. Yes, it IS pretty radical. But I can tell you–this 6BR is the best tracking Benchrest rig I have ever set on bags. If you notice holes cut in the frame they are for adding weight with some attachments I have. So if you are moving to a heavier load you may want to move some weight towards the nose or to the rear as you see fit. There are also some other cut-outs made to assist frame component assembly.
Using the gun as a switch-barrel rig has worked out very well. The extra 22BR barrel shoots to the same point of aim when I swap from 6BR down to 22BR. The trigger is a 2 oz. Jewell and it breaks like the proverbial glass rod. As far as loads go, I wish all my benchrest rigs were this easy to tune. I settled on Vihtavuori N-133 and a custom bullet made by George Coleman. Unfortunately, George sold his dies and I had to track down the new owners of the dies and order a few thousand more so I won’t run out in the future. Does the gun have any glitches? None that I’ve found so far. I was worried that the metal in the forearm might expand at a different rate than the rest of the frame if I was shooting under a shed and the fore-arm got more sun than the sleeved action. Well that has not showed up as a problem yet. Overall I have been very impressed with the gun and I have to say the metal work displays some remarkable engineering. It is extremely stable on the bags, it torques less than a conventionally-stocked gun, and as I’ve said, nothing tracks better. The ability to easily change weights is another plus.” — Mike Murphy
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