Another case of me wondering what happens...

[Mr_Flintstone]

Polymer coating cast bullets results in reduced friction, slightly lower pressure, and slightly higher velocities, so would the same apply to jacketed bullets? If a person poly coated a jacketed bullet, would it result in lower pressure or higher velocities? Just wondering.

 

[film495]

no idea, but glad to see I'm not the only one who wonders about things ..

 

[kidneyboy]

How do you get the coating to stick? How much does the coating increase the diameter of the bullet?

 

[buck460XVR]

Would seem to me, the cost and effort for the little bit of velocity gained in handgun ammo would make it prohibitive. As for rifle, odds are the velocity would cause the coating to melt off and foul the barrel. Would the increased slipperiness take away accuracy? My guess is, someone out there has tried it, and yet, we haven't heard or read anything about it.

Just sayin'.....

 

[fxvr5]

This article found the polymer coated bullets shot a little slower when tested side-by-side with the same bullets traditionally lubed . . .
https://www.ssusa.org/articles/2017/3/7/coated-bullets-the-future-of-lead-bullets-for-handloaders/

Are you comparing coated to traditionally lubed cast bullets or coated to jacketed bullets?

 

[mdi]

To answer the OP's question, no jacketed bullets have more barrel friction then lead or PCed lead, but I remember several years ago "Moly Coating" bullets (molybdenum disulfide dry lubricant https://www.google.com/search?q=mol.....69i57j0l7.7070j1j7&sourceid=chrome&ie=UTF-8) was popular for bench rest type shooters and it reportedly aided accuracy and reduced friction (?), but the down side is more difficult barrel cleaning and moly "residue" in barrels. Power coating is baked on (a powder is melted forming a coating) and adheres quite well. One of the tests for home PCers is to smash a coated bullet with a hammer to make sure the PC won't crack or flake off (mine don't). PCing is not done for added velocity from lower friction, it's for clean handling, clean shooting cast lead bullet coating, but some have driven their PCed bullets above normal cast bullet velocities. Home PCing only increases the bullet diameter by .001"-.002" and most home PC users size the bullets post PCing. Commercial PCed bullets are sized appropriately, as per advertised, mainly to cast bullet "normal" diameters. I have PCed 30 cal rifle bullets and shot them to over 2,000 fps with no coating melting or barrel fouling.

There's a bit more involved in a plain cast and lubed bullet vs. a PCed bullet. Lube on bullets is much more than just lubing, making slicker, the bullet. One thing is when fired a lead bullet will compress and the lube groove shrinks and the lube is "compressed" and acts like an o-ring to aid in sealing the bullet/bore.

For some good basic every day info on PC coating check here; http://castboolits.gunloads.com/forumdisplay.php?184-Coatings-and-Alternatives

 

[reddog81]

I agree with what mdi said.

I don't think the PC does much for velocity either way. I seen people say it goes both ways versus traditional lube.... The copper jacket on a bullet is very hard and much more difficult to size versus your normal lead bullet. Adding a layer of PC isn't going to change the hardness of the underlying copper. I don't think powder coating or polymer coating s jacketed round would make much of a difference or provide any benefit.

 

[kcofohio]

There are self lubricating bronze bearings with graphite embedded into the metal. It would seem to me that embedding graphite into copper would make more sense than to try and add a coating to the copper.

 

[mdi]

There are self lubricating bronze bearings with graphite embedded into the metal. It would seem to me that embedding graphite into copper would make more sense than to try and add a coating to the copper.

The reason moly coating was tried was because it was easier to apply and worked better than graphite. But you could easily try. Normally moly was applied in a tumbler (wobbler) so dump a couple tablespoons of graphite in your tumbler, add a hundred bullets and tumble until the graphite was embedded in the copper/bronze...

I'm not an expert on moly coating and I've only PCed about 1,200 of my cast bullets. The PCing is a little more involved than lubing/sizing cast bullets and does most of what it is said to do. I did a bit of research on jacketed bullets a few years ago when I got a good bolt gun in 308 and used jacketed bullets exclusively. Most of the info I posted was from researching texts on the subjects and my personal experience with PCing (I have purchased several hundred Hi-Tek coated bullets for my 45 ACP and they work quite well)...

 

[kcofohio]

The reason moly coating was tried was because it was easier to apply and worked better than graphite. But you could easily try. Normally moly was applied in a tumbler (wobbler) so dump a couple tablespoons of graphite in your tumbler, add a hundred bullets and tumble until the graphite was embedded in the copper/bronze...

I'm not an expert on moly coating and I've only PCed about 1,200 of my cast bullets. The PCing is a little more involved than lubing/sizing cast bullets and does most of what it is said to do. I did a bit of research on jacketed bullets a few years ago when I got a good bolt gun in 308 and used jacketed bullets exclusively. Most of the info I posted was from researching texts on the subjects and my personal experience with PCing (I have purchased several hundred Hi-Tek coated bullets for my 45 ACP and they work quite well)...

I don't disagree with you. And I, even less experience. In fact today was my 1st time smelting some scrap lead and pouring a few ingots. I'm only starting to read up on powder and powdered coatings.

My thoughts did not give consideration to plain PC on a bare cast bullet.

IIRC, Federal came out with their Nyclad bullets about 12 years ago. The original "blue pill" you could say.