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Thread: Info needed on rifling bits
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August 4th, 2010, 04:45 PM #1
Info needed on rifling bits
I'm looking for info on the purchase of a rifling bit for my use.
From my understanding the way to go for the DIYer is to "button rifle" a barrell. Any other info that anyone can give would be more than appreciated.
Before anyone gets bent out of shape about what I'm doing.
I have already filled out Form 1, besides the firearm at this point can not function, but I'm close.
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August 5th, 2010, 01:31 PM #2
Re: Info needed on rifling bits
If you google "button rifling tools" you'll get a lot of hits. Also, you can check www.danjon.com they make barrel drilling tools and the such.
Ron USAF Ret E-8 FFL01/SOT3 NRA Benefactor Member
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August 7th, 2010, 12:15 AM #3Member
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Re: Info needed on rifling bits
Hmmm..You're making your own barrels? Don't suppose you're anywhere near Scranton?
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August 7th, 2010, 09:54 AM #4
Re: Info needed on rifling bits
Once you buy the Button youll only need 10K in machine to turn out your first barrel.
Good luck!
.
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August 7th, 2010, 10:03 AM #5Member
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Re: Info needed on rifling bits
are they that cheap??...LOL!! Pretty sure you need an insert for each twist rate.I've considered cheating and using an actual barrel with the right twist as the guide,but I think too much..It's easier to just buy a barrel,LOL!!Wonder how those backwoods gunsmiths did it in the dark ages? must have made a guide from two rings and two pieces of steel,and heated the assembly to twist it..Years ago,I remember seeing a show on some info channel where they had a multi piece cutter,they kept pulling it through the tube by hand,an on each cut or two,they added a sheet of paper under the cutters to make it deeper till they got where they wanted to be..Pretty sure these days,they do the barrels hot,or mandrel form them..
Last edited by ROBOWOP; August 7th, 2010 at 10:09 AM.
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August 9th, 2010, 08:12 PM #6
Re: Info needed on rifling bits
Nope, bought for scrap price out of my friends shop. Vintage lathe used for turning barrels in the '40s, has leather belts and everything. It even holds a pretty good tolerance. We bent one barrel already but that was our dumb fault. After some research I realize I can buy a barrell made already for a couple hundred more than the cost of the bit...and save alot of headache.
http://www.riflebarrels.com/products...le_barrels.htm
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August 9th, 2010, 08:42 PM #7
Re: Info needed on rifling bits
If you're going to contour the barrel, do so BEFORE rifling the bore. When you contour after rifling the bore, the inside diameter of the bore will enlarge itself when you take metal off the outside. It'll only be a couple hundredths or thousandths of an inch, but its enough to make a nice paperweight out of a otherwise good barrel.
I know that's hard for some folks to fathom, but it happens. I cant remember the physics behind it, or even how it does it - but it does happen. Which is part of the reason why H&R and other lessor rifles have inconsistent bores. ..They contour after rifling.RIP: SFN, 1861, twoeggsup, Lambo, jamesjo, JayBell, 32 Magnum, Pro2A, mrwildroot, dregan, Frenchy, Fragger, ungawa, Mtn Jack, Grapeshot, R.W.J., PennsyPlinker, Statkowski, Deanimator, roland, aubie515
Don't end up in my signature!
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August 9th, 2010, 09:21 PM #8
Re: Info needed on rifling bits
Rifling barrels is SERIOUS business. The tolerances have to be held really really tight. Sometimes you can hold them tight enough to shoot a particular load or bullet, but lots of times when you start trying to change things up, your consistency and accuracy goes all the heck. Even if you hold tight enough tolerances, sometimes you'll induce so much stress in the barrel, that it'll start walking around when it heats up. There's so much that goes into making a barrel, and pretty much unless you dedicate yourself to holding extreme tolerances and the art of barrel making, it's not worth your trouble.
Lots of times you can buy some "cheaper" barrels, and if you work hard at chambering them properly and your loads you can still have 1 MOA rifles or better. It's EXTREMELy difficult to basically drill a near perfectly straight hole through a barrel, especially one that is stress free. When you start trying to add rifling in there that holds a constant twist, or the twist increases slightly, and also has exacting dimensions on the depth of the lands and grooves. There's just so much to worry about, that most of the time it's not worth your time to try. To do it properly it takes the right machines, LOTS of practice, the right metal, and a way to stress relieve the barrels. Pretty much "do it yourselfers" and "do your own gunsmithing" people buy barrel blanks that are already rifled, and do the chambering and everything else on their own. The truth of the matter is that most professional gunsmiths buy barrel blanks made by the top manufacturers. It's just not worth their time and investment when they may not even be able to do it as good or any better than a top barrel maker. Just something to think about.
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August 10th, 2010, 12:20 AM #9Member
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Re: Info needed on rifling bits
Tomcat,you ain't kidding.I consider myself a pretty good machinist,I wouldn't even consider actually trying to make my own barrels.The variables hafta be staggering.When you consider just the heat generated pulling a rifling bit through a bore,just the starting size of the hole can change the final rifling by several thou just from the excess heat and final shrinkage.Just take into consideration also that every caliber has to have the correct twist rate,right ratio of elevation between lands and grooves..Geez.I'd bet different twist rates generate different rates of shrinkage.My buddy John is a top level benchrest gun builder.He spent something like 60 grand for a lathe just for chambering.It's mounted on a 5 foot thick concrete slab with a 10 inch thick piece of granite on top of the concrete!!He told me that no barrel is perfect,almost any barrel has a "bannana",or an uneven undulating shape to the bore,caused by the boring bit wandering.You can't try to get cute,and straighten the banana,because when you do,and recut the outside of the barrel,all kind of wacky stresses get introduced,making the barrel do strange things when it heats up.
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August 10th, 2010, 12:28 AM #10Member
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Re: Info needed on rifling bits
P89,might I ask,is this lathe for gun DRILLING,or gun RIFLING? A "gun drilling" lathe is simply a lathe made for for drilling long holes.It's not made for drilling gun barrels,[although it could be used for that purpose..]it's the name of a process.After drilling the bore in a barrel,there's another machine needed to pull the cherry through while it rotates at the rate of twist to make the rifling.I passed on a huge gun "drilling" lathe a few years ago,800 bucks,20 feet long..And useless unless I was lightening driveshafts for a submarine...
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