Originally Posted by MontanaMan
Originally Posted by antelope_sniper
Electromachining has it's place, for the low end home gamer but not the best option for high end production barrels.


Electropolishing, if that is, in fact, what they were using, is not electromachining, per se'.

Electropolishing is intended for burr removal & rounding of sharp edges. It is done in a concentrated sulfuric acid + concentrated phosphoric acid bath using the part to be "polished" as an anode with inert or lead cathodes.

It produces a very highly polished, very low surface finish depending on the exact SS alloy.

It is very difficult to ensure perfect current density distribution (i.e., stock removal) over the entire surface being affected, especially at the ends as the effective current density applied to an electrode is always higher at its ends that in the middle; the amp meter can only measure & adjust the average total current, not the uniformity of its distribution.

If that makes any sense to you......................

MM


Like wavelengths or harmonics to sense surface finish? Since inside a bore, you can not use a surface finish gauge. Very interesting stuff MM. What surface finish do they say is optimum? 64-40 finish, or is that too smooth?

Here's an excerpt from Lilja, from an article they wrote about "what makes a rifle barrel accurate":

" It seems as though some experienced shooters and gunsmiths tend to place too much emphasis on one single characteristic of barrel as it relates to accuracy. For example, some gunsmiths look at not much more than how straight a barrel is in evaluating its potential before chambering it. Others look at internal finish or bore diameter. We had experience with one customer that paid a business that checked twist rate deviation to examine all of his barrels.

In our opinion this is putting the blinders on, a case of being myopic. All of these properties are important and a serious problem with any single one of them could cause accuracy trouble. But the point is they’re all important. To sum up the critical factors we’ve mentioned, they include: a straight hole of uniform diameter and correct size for the intended caliber; a smooth and uniform surface finish that lays parallel to the rifling; a uniform rifling pitch; stress-free steel; adequate stiffness for the type of shooting it will be used for; and a first-rate installation job with special attention paid to the throat. An accurate barrel is the result of a happy marriage of all of these."

I believe this is what you guys are saying about getting the right guys to do the final barrel work. Lilja has been known to put out some exceptionally accurate rifle barrels.

Originally Posted by raybass
I try to stick with the basics, they do so well. Nothing fancy mind you, just plain jane will get it done with style.
Originally Posted by Pharmseller
You want to see an animal drop right now? Shoot him in the ear hole.

BSA MAGA