Thread: Chamber run out issue

If you had a perfect chamber and put crooked ammo in it, would it shoot any better. At least with the crooked chamber the error is always in the same direction--- Food for thought

Quote: Originally Posted by Bnhpr Geez, I thought all the gun drills had counter rotation? I'll have to run the traps on that one? Ben Some or all of them may now. A few years ago not so. Douglas used to have a video on their web site but I can't find it now. Check it out and let us know. It was in the 1970's when I was working on projects like deep hole drilling.

To: TRA The Interapid indicator described is made to operate with a 2.750" stem with a resolution of .0005" on the dial. To: Shooter53 I'm following the principles described by Gordy's video on barrel alignment. Bore alignment only at the chamber area, what the muzzle is doing is not critical. To All: I have made a few changes to my setup: 1) Made the alum. split ring holding the barrel in the chuck thinner. Last...

I have posted a procedure in the past on how toactually check your work, what criticle areas to indicate to verify that all of the criticle surfaces do indeed run reasonably true with one another. You mentioned .003 runnout. That is extreme. But, if the Rifleshoots at a competitive level, then who knows. In reality, while a lot of runnout might not affect accurcy, it does start to manefest it's self in other areas, such as difficult...

tr, I don't think any of us can answer your question. Butch

I am not sure why counter rotation works, but when the subject came up, some time ago, in a discussion on this same topic, with an experienced machinist/machine shop owner, he told me the following story. He and his partners were involved in the production of close tolerance aircraft parts, hydraulic cylinders of some sort, that required accurate deep hole drilling. After struggling with producing the parts to the required tolerance, he...

AZLarry, Sorry, I'm not familiar with Gordy's method of barrel alignment. My reference is from Darrel Holland's 2 video set "Custom Barreling" from AGI (American Gunsmithing Institue), The Gunsmith Machinist by Steve Acker and " The Complete Illustrated Guide to Precison Rifle Barrel Fitting by John L, Hinnant. Good luck with your project.

When you drive into a tunnel you do not worry where the exit is, as it does not matter, hitting the entrance straight does. A bullet would be the same, the best chamber is the one that starts the bullet true to the entrance of the bore. Indicating the exit would be a waste of time. the bullet has to follow the bore. From an engineering and a machining standpoint, the entrance is all that matters, no consideration about what the exit is doing...

Quote: Originally Posted by JerrySharrett Much of this wandering could be eliminated if the barrel maker would build a machine where the barrel and the drill both rotate.. Hi Jerry, How would the rotation of the barrel and the drill improve the bore straightness? I would think the barrel material would see the same cutting edges, flute support, and speed rates, so I am having a hard time finding a difference that would achieve improved...

We have to split the differences when necessary. Bores are not perfectly straight so we have to deal with it. Boyd..The answer to your first question is yes, that is why I don't use the pilot. you are just adding another variable to errors that you will encounter. Gordy Gritters has a method too get this area running true by adjusting the outboard end of the barrel too correct it. Another way to skin the kitty. As for your second...