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Discussion Starter · #1 ·
Hey guys, just thinking about getting another AMD kit and making a pistol. I know plenty of others have done this...I was wondering what you guys have found is the best way other than buying a crowning tool to re-crown the barrel and smooth out the outside of the barrel(less critical). I know accuracy is definitely not a consideration here with these pistols, but I know I have to debur barrel. Thinking of using a countersink bit to do it.
 

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Actually the barrel crown counts quite a bit for accuracy. If the crown is done improperly the gases flowing past the crown can and will cause the bullet to yaw or pitch as it leaves the barel. A few hundred thousandths deflection at the muzzle (crown) can be inches downrange.

You don't want to use a hacksaw on something like this. You can use the floating type crowning tool that not only tapers the rifling at the muzzle but also cuts the crown at the same time. These are usually 90 degree or 71 degree crown cuts. If you want a recessed crown you will need a lathe.
 

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Under NO circumstances should you use a pipe cutter to straighten the end of a barrel. I've seen pictures of this done followed by a proper crowning tool and there is allegedly no problem. When no crown is cut following trimming with a pipe cutter, the barrel is pinched closed and can have disastrous results. I would never even consider this option even if it were followed by a crowning tool.

A crowning tool isn't cheap, but additional pilots can usually be purchased to allow use for a wide range of calibers. This, and a lathe, are the only way to properly cut a crown.

Here's a link showing a crown done with a large grinding stone, followed by a carriage bolt with lapping compound:

http://www272.pair.com/stevewag/bob/bob4.html

And here's the link showing how to do it:

http://www272.pair.com/stevewag/muzzle/mz.html
 

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Crowning tool= drill, low speed, brass panhead screw, and lapping compound.

Cut it with a hacksaw, then put masking tape evenly around it, then file flat.
 

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Discussion Starter · #6 ·
Thanks Rhino, that's a great link and looks cheaper than a crowning tool and lathe. I should be safe doing this way right!!??

I'm sure there are some testiomonials out here, because I have seen the short barreled pistols everyone has made. Did they use this technique??
 

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Ahem-
You plan on cutting an AMD-65 down? Better plan on moving the gas block back, re drilling the gas port, and getting a custom short piston made too. This is not a simple project. The barrel is only 12.5 inches anyway-anything shorter is going to be all about flash and blast. If you go with a short muzzle device (or even no muzzle device) it's pretty short stock.
However, if you must, the hacksaw (be sure you are cutting square here now) is OK, then true it up, and do the grinding stone/carriage bolt thing. Us C&R guys are used to it, it works great. Most folks use valve grinding compound.
FWIW, my Swiss K-31 has a muzzle that looks like it was done with this method and it's straight from the arsenal. Swiss K-31's are accurate.
 

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Discussion Starter · #9 ·
Hey Cammo, for the valve grinding compound...most I have found doesn't tell you the exact grit, so I assume use the "fine" grit right? Since the lapping compound used on the other link used 400 grit.
 

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I dont think it will be that difficult since Hotbarrel has already offered to make shorter pistons and maybe shorten a barrel? He's probably the cheapest person for labor that I know and has a lathe.
 

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Yeah, fine. The coarse is similar to getting a handful of dirt out of the yard.
Pookie: Yes, the long wooden thingys.
 
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