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Bullwolf
01-13-2015, 03:02 AM
Read an interesting article on the web tonight comparing the differences in velocity while shooting cast, jacketed and commercial coated boolits.

How Fast is your Bullet? (http://38super.net/Pages/How%20Fast.html)

http://38super.net/Smart%20Figures/CoverFigureHowFast.jpg


http://38super.net/Pages/How%20Fast.html

The article somewhat confirms that cast boolits tend to travel at higher velocities than jacketed and plated ones, but there's some interesting data as well using moly, poly, and bayou coatings.

Figured the folks that hang out here would enjoy the read.



- Bullwolf

Maximumbob54
01-13-2015, 07:44 AM
Interesting read. I didn't know plated ran so slow. I guess the copper/no lube plus filling out the grooves means the most friction. This also makes me wonder about the types of coatings available that might be slicker in the bore. There are several powder coatings with PTFE added to them that might speed things up some. Food for thought.

Lead Fred
01-13-2015, 08:14 AM
Cast: 230gr RNPB .452 @ 940fps

Have not shot anything else though it

Gunslingerdoc
01-13-2015, 10:52 AM
Interesting read. I didn't know plated ran so slow. I guess the copper/no lube plus filling out the grooves means the most friction. This also makes me wonder about the types of coatings available that might be slicker in the bore. There are several powder coatings with PTFE added to them that might speed things up some. Food for thought.

The Teflon 'Evil' or "wonder coating" may in fact be more myth than anything - the original KTM or KTW aka cop-killer bullets were only Teflon coated to decrease barrel wear (per the makers) since they were using tungsten bullets that were ruining barrels. IIRC, the designers stated that the coating while saving the barrels resulted in a 20 or 25% decrease in penetration. Not trying to start a fight.

The Teflon craze I think got way overblown by the media as they ASSUMED the great penetration was related to the PTFE vs the tungsten bullet. Also, there are 8-10 states that made 'teflon' coated bullets illegal as a result of ignorant fears over 'cop-killer' bullets 'flooding the streets' so depending on ones local....

SlippShodd
01-13-2015, 04:54 PM
Interesting read, however there was one bit of data that I would have liked to seen as well: Average diameter of each of the bullet types used, and maybe a slug of the test barrels.
We constantly preach "fit is king" so it would make the test more complete, I think, if those measurements were included.

mike
----> maybe not...

runfiverun
01-14-2015, 05:55 PM
it's friction...
lead is a lubricant.
most jackets are not copper but are 5% zinc the same as a cartridge case, the zinc acts like lead in the mix.
and plated is pure copper which is a bit draggy in the barrel.

you also have to deal with engraving pressures the jacketed spikes the pressure more and thus gets things booted along allowing it to beat the soft lead copper plated one.