stubblejumper

Totally different situation.The oil in your engine does reduce friction but it also carries away heat created by friction which is what will destroy your bearings and pistons.On the other hand the bullet is only in the barrel for an extremely short period of time so other than in the throat area,virtually no wear takes place.

By the time any significant wear due to friction takes place,the throat will be non existant,so wear due to friction is not a factor in barrel life.

Roskoe

Dritfrider explained this real well . . . . the copper jacketed bullets going down the steel barrel can eventually wear it out, but I'm guessing it would take 50,000 rounds. The throat and rifling immediately ahead of the throat is where the erosion takes place.

I built a local prairie dog shooter a .221 Fireball bench gun about 14 years ago. We used a full profile blank 27" long. About every two years, he comes back with a shot-out gun. Each time, I set the barrel back about 2.5"; re-thread it and re-chamber it. It seems to shoot as good or even a tad bit better each time we do this. Last time around, the length was just under 18" - so its about last dance for this Shilen 1:14 - that now has close to 25,000 rounds through it.

driftrider

The friction in an engine is a totally different situation. First of all, the cylender, pistons, connecting rods, bearings, journals, etc...ar all made of similar hardness metals, usually iron or aluminum, but because their hardness is similar a lack of lubrication, coupled with both the persistant heat of conbustion and the heat generated by friction, combined with the heavy force loads, will cause an engine to wear out. How fast it wears depends on how hard its run. A piston or cylender is nowhere near as hard as the steel in the barrel of a smokeless firearm, not even close. At the same time, the copper or guilding metal over a lead core, or even a pure copper bullet, it much softer than even iron or aluminum. Not to mention the fact that many metals, like copper, lead and brass, are "self-lubricating" to a degree because they are so malleable and ductile (ever hear of a brass bushing? Copper, brass and lead also will not emit sparks when rubbed on another metal, if you'd even been inside the turret and powder magazine of a WWII battleship you'd see that just about every metal-on-metal surface is brass to prevent metal sparks which could ignite the powder bags). With a copper jacketed bullet, the copper yields to the steel, not the other way around. Like Roskoe said, and I will concede this point, like any other surface to surface contact, the copper will eventually, over many tens of thousands of shots, wear the rifling a tiny amount, but the time it would take to create any detectable wear is generally well beyond the service life of the throat of any barrel. The throat will erode thousands of rounds before the rifling further down the bore erodes, and will have the greatest negative effect on accuracy. Once the throat is shot out, the barrel is toast unless it is a straight taper barrel like the one Roskoe mentioned. If bullets were made out of iron or anything other than the mildest steel, then actual bullet wear would be a serious issue. In fact, many eastern bloc countries used actual mild steel jackets for their bullets for lack of copper and zinc to make guilding metal. However, to preserve barrel life the bores were usually chrome plated. Chrome is much harder and wear resistant than mild steel, which meant the barrels would last beyond a few hundred rounds.

If you don't believe me, go find a gunsmith with a borescope and have him show you how a bore erodes. You'll see that while the throat is gone, the rifling just 2-3 inches forward of the throat shows no detectable wear. It's the truth, go see for yourself.

Mike

DM

It's true, the bullet itself does very little to wear the bbl. out! Guilding metal is much softer than bbl. steel.

I once read about a guy who fired some unbelievable number of bullets through a bbl. useing compressed air instead of gun powder, and he STILL didn't wear out the bbl.!!! He did it to study bbl. wear.

I forget the number but i think it was something like 100,000 bullets, and then pretty much gave up!!

Bbl. wear comes mostly from generated heat in the throat area of the bbl..

Drilling Man

Hunter06FlKy

i have some of the accelorators but i have yet to shoot them. the ones i got were like 28 bucks a box. the 125 remingtons shoot very well. but you can try them and see what you think.