How can a copper bullet slide down a steel barrel as easily as a lead bullet ?

[gunDriller]

Oath
http://oathammo.com/product/223-rem-match-grade-projectiles-copper/

and Barnes
http://www.barnesbullets.com/


both make Copper bullets.

Oath has a good price - 20 cents each, Barnes is a bit more expensive, 40 to 60 cents each.

Barnes has the cannelure groove, and it is a hollow point type bullet.

Oath's copper bullet is solid metal, no hollow-point hole in the tip.


What I don't understand is - how can a copper bullet slide down a barrel as easily as a lead bullet ?

It doesn't make sense.

The lead is much more easily deformed, much more 'buttery'.

Yet they are the same diameter.


I would expect the copper bullet to have a LOT more friction in the barrel, with one possible exception.

It becomes obvious when working with 40,000 psi that metals get formed very easily.

If the copper bullet is de-formed at the beginning, then it starts out resisting the pressure - which builds.

A force of 1000 to 5000 pounds will get it started, and form (or de-form) it.

Once de-formed (to reduce the diameter), then maybe it slides as easily as the lead.


Still, I wonder.

[palani]

What I don't understand is - how can a copper bullet slide down a barrel as easily as a lead bullet ?

When considering standing being under it is of lesser importance than being in front of it.

[monty]

The reason for copper jackets is to keep from leading the barrel bore. Lead bullets at higher velocities melt from the friction. The lead adheres to the bore of the barrel. 980 FPS .38 cal pistol bullets probably won't lead your barrel, but a 2600 FPS .30 caliber lead bullet will. I don't know about pure copper bullets, being lighter the wouldn't have the foot/lbs of energy a lead bullet of the same size nor will they expand like a lead bullet will.

[Neuro]

I am not sure, but doesn't copper has a greasing effect, which would reduce friction in the barrel?

[gunDriller]

imagine a steel bullet the same diameter - .224.

in a barrel that's .219 (according a guy at ar15 forums)


it would probably get stuck.

yet a lead bullet does not get stuck.


i just always thought of copper as being more like steel.

but as a bullet, it's closer to lead, in terms of deforming.

[midnight rambler]

being lighter the wouldn't have the foot/lbs of energy a lead bullet of the same size nor will they expand like a lead bullet will.

Not necessarily.

Barnes all copper Triple Shock X round, this one is 70gr/.224 caliber. Not only does it retain mass while expanding exceptionally well, it's also an excellent barrier blind round.

http://www.phossil.com/thom/Night%20Vision/Night%20Vision%20Kills/Barnes%2070%20gr%20TSX.jpg

[gunDriller]

The reason for copper jackets is to keep from leading the barrel bore. Lead bullets at higher velocities melt from the friction. The lead adheres to the bore of the barrel. 980 FPS .38 cal pistol bullets probably won't lead your barrel, but a 2600 FPS .30 caliber lead bullet will. I don't know about pure copper bullets, being lighter the wouldn't have the foot/lbs of energy a lead bullet of the same size nor will they expand like a lead bullet will.

I don't shoot lead bullets normally, so, good to know.

As the Barnes pics posted by MR illustrate ... let's say that the copper bullet, with the 4 tips curled back, the tips having razor sharp edges - it reminds me of those deli slicers.

It's like a mini deli slicer slung at about 3000 feet per second (e.g. 62 grain 5.56). Holy moly wouldn't want to get hit by that.

The RPM's are mind-boggling, 100,000 rpm +.


I would like to set up some containers of water at the 25 yard line on a slow day at the range, to look at the bullet which normally ends up in a big pile of dirt.

I guess normally I shoot copper coated lead. I went to the range today and shot 308. The best cluster I had at 200 yards was a flat-butt (no boat tail) Hornady, with the plastic tip (Hollow Point) 125 grain.