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| <Sgtdonf> |
Just a silly question, but can you finish a prefit barrel by hand with a finish reamer? If so, what would be the quality? | ||
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| one of us |
You can, if you have a barrel that is "short chambered". The quality can range from good to poor depending on the care you take. I have found the best way is to buy or make an extension that will allow you to ream it while on the receiver, otherwise you end up reaming a little, reinstalling the barrel to check headspace and if it is still not right starting the processs over again. Be sure to get the proper head space gages before you start and make sure the chamber is absolutly clean before each time you check headspace. I do not recomend trying to create a chamber from a blank without a lathe. | |||
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one of us |
Do it in a lathe or you risk egging the chamber. | |||
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| one of us |
"Prefit" as used by Pac-Nor indicates a long chambered, threaded, contoured blank. To fit it you remove material from the shoulder, with a lathe until the headspace is correct. Typically that amount will be only a couple of thosands. No reamer needed. Short chambered barrels can be finished off with a hand spun reamer. Screw the barrel into the receiver and snug it up. Use 3/8" drive socket wrench extension to spin the reamer with a tap handle. Go slow , use pleanty of tap magic or similar. Tip of the day.....DO NOT remove a reamer while you are turning it. To do so invites sticking chips under the flutes and marring the chamber. Never ever turn it backwards. Clean the chamber thoroughly and check the headspace. Cut some more, repeat the above until the headspace is correct. Carefull, an unseen chip on the shoulder can cause a falsely short headspace measurement, causing you to mistakenly cut to deep. Quality......same, that is how most are done. I can see one reamer not cleaning up all of the last reamer's cut. Probably has no effect though.
quote: [This message has been edited by scot (edited 12-17-2001).] | |||
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| <Sgtdonf> |
Hey, thanks for the help. Here is one more for ya. What about doing an Ackley from a standard chamber? Is it something that could be done easily with a finish reamer? | ||
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one of us |
Use a Lathe! Since the British used to build doubles with just a file ( or so I'm told), I suppose you can do anything if you are carefull enough with simple hand tools, however just the thought of trying to set back a barrel shoulder with a dremel tool and lapping gives me the cold sweats! I'm not doubting that it can be done, nor dissing someone who has done it, but this is the reason God invented the Lathe! I don't even try to ream out a pre-fit barrel by hand because if you do it in a lathe then you will produce a concentric(non-egg shaped chamber) and the gun will most likely shoot straight. If you don't believe me, then make a cerrosafe chamber cast and measure/eyeball it carefully. You will see why a Lathe is important! All this proves is that you can make anything go Bang,but I'm not getting my head anywhere close to something that might just be dangerous. My .02-Rob | |||
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| one of us |
It may be terribly old school, but I'll stick with the advise of Fred Huntington and Bob Brownell when they say "When you get within a few thousandhs of the finished chamber, take the barrel out of the lathe and ream the last few thousandths by hand." I figure they made a few accurate rifles in their day... | |||
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Moderator |
quote: With much shagrin I'll admit that I did use an even cruder meathod to set back the barrel on a $40 8mm mauser w/ excessive headspace, undoubtebly due to the miss match of the bolt to rifle. It was a great learning experience, and after welding a 1/2" bolt filed to the shape of a butternife bolt handle, shortening to 17", and installing a $3 butt pad, I ended up selling it with some Egyption mil surp for $100. I cannot highly enough recomend against such a practice! Finishing a chamber by hand is one thing, but setting back a shoulder with a file or dremel is entirely another. If you don't have the requisite measuring equipment to do the job properly, lathe or not, the cost of such equipment would fund having the job done properly. Butchering a junk gun is one thing, but starting with a new barrel is another. We all learn from these endevors, just be sure you fully understand the risks and pitfalls of such a project before proceding. | |||
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| one of us |
Sgtdonf Ackley Improved chambers must be headspaced to a factory go guage MINUS .004 inch. Therefore the barrel must be set back to achieve a minus HS reading. | |||
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| one of us |
At the risk of offending the working smith's on this forum, I know of one very talented smith who hand chambered several rifles. He tells me it is less time consuming now for him to have them sent out, but he has completed several, it just isn't something you do in a hurry, or while watching ESPN. I was discussing this subject with another friend of mine recently, and he reminded me of an article in Guns and Ammo where Craig Boddington was having a rifle hand built by the esteemed firm of Purdy and Sons. In that article there was a photo of his custom rifle barrel, mounted vertically in a vise with a gunsmith reaming the chamber, by hand. Now I am sure that the smith at Purdy was a skilled, competent employee. I am equally sure that with a little practice, patience, and elbow grease an adequate chamber can be cut with out the benefit of a lathe. Good luck and good shooting | |||
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