Coated bullets vs lead

[Trapper6L]

Rather than have a bunch of bleed thru in Spudmeisters post about the 185gr lead bullets he tested with, I'm asking the questions here. Coated vs lead bullets. Does the coated bullets seal with the bore better? Does a coated bullet eliminate any debris being left in the steel of the bore like a lead bullet can if pushed too hard? And, does a coated bullet yield more velocity over the same load using a lead bullet? I've looked on Google for these answers but all you get are opinions and no facts. Anybody have actual data and know the answer? I'm shooting mostly coated or plated bullets since I don't like the cleanup of the lead bullet lube. I don't care for the smoke either. I do shoot some lead with wheel gun plinkers though.

[The_Shadow]

Hey Trapper, It is my understanding that the polymer paint coated bullets only provent lead alloy to bore contact. 
Does it seal better?  Not sure, I would imagine just like lead alloy bullet the size plays an important part to seal the bore.
Does it eliminate debris being left in the bore?  The PC coating may break down and actually foul the bore with the coating.  Some powders are known to react with the coatings as well.  I have read where some people saw wear due to the carbon in some colors of the PC.
Does the coating yield more velocity?  I can not say one way or the other.  There is a certain amount of slickness, lubricity to the PC bullets depending on the specific PC properties.

I have considered the PC process, but I continue to use cast/sized/lubed bullets and I do push them pretty hard without leading. 

[Spudmeister]

Hi Trapper,

I had done much of the testing you are asking about a few years back.  Sadly, the coating part was just an afterthought and did not get recorded.  But I did do a series of tests with lighter loads in my G29 and G20 with both the 200 gr WFN Montana bullet coated and the traditional lubed version.  The range was 40 yards and it was offhand.  I thought accuracy was about the same with both OEM and aftermarket barrels.  Or let's say it was about the same inside my error of margin. 

But there are tons of variables that can make a bullet go from champ to chump very quickly.  Most 10mm Glock's prefer a .401" cast bullet diameter.  While technically oversize the bullet (if it's not to big too chamber) will seal in the bore better than a smaller cast bullet.  And it's important for a bullet to obturate (expand with pressure) to fill the grooves in the barrel.  It seals the bore from all the gas behind the bullet.  If, for any reason, that seal is not there you get gas cutting and it leaves lots of lead in the barrel.  All this stuff is a science in itself. 

Back to your questions.  IME the coating seals the bore better if the bullet is otherwise not ideal.  However, I have shot tens of thousands of rounds of .357" 9mm hard cast bullets in a Glock aftermarket barrel and never had a leading issue.  Frankly I do not have the nerve to do that with an OEM Glock barrel.  I just bought a few thousand SNS Casting 147gr bullets that are coated but are sized to .356".  While I would normally consider that .001" too small for a lead bullet, the coating seems to seal the OEM and aftermarket barrel just fine.  Accuracy was equal to the larger cast bullet too. 

I do not know if the coated bullet goes faster or slower than the traditional cast bullet.  I do not know how fast you can push a coated bullet.  Probably as fast as you can push a properly fitted plain based cast bullet of proper hardness and that is pretty fast.  When you shoot good cast bullets, 98% of the "lead" in the barrel is just lube.  Sure does make some smoke but the lube really helps seal the gas behind the bullet.  However, the coated bullets leave a coating of the plastic in the bore.  It does no harm I know of.  It does typically take some scrubbing to get out though. 

As you can tell, most of my experience is with traditional hard cast bullets.  When you get it right, 500 rounds a day and 2000 rounds between cleanings is easy in a non Glock OEM barrel.  IMO the greatest single advantage a coated bullet has over a cast bullet is it is more forgiving of things not being just right.  And that's a big deal IMO. 

I'm sure other guys here have more coated bullet experience than I do... and they'll be along.  Good luck.

[Taterhead]

Correctly coated, sized and loaded cast bullets do not lead the barrel. I can push my powder coated 10mm bullets hard with great results. E.g. a 201 gr WFN at 1250 fps out of a G20.

I do see some additional velocity, too. Probably 50 fps greater than the similar bullet lubed traditionally.

I see no advantage to traditionally lubed bullets in a 10mm vs coated lead or even plated. Pretty much all I load any more for 10mm is coated cast bullets that I make at home for about 1.5 cents each.

[cwlongshot]

I shoot powder coated playing bass bullets through my 450 bushmaster at close to 2000 ft./s with zero following in the Bohr.

I don't think you could push a handgun fast enough to create an issue with a properly powder coated lead bullet no matter how soft it is. Yes it's a bold claim but it's proven true and everything I've shot for the past year and a half

CW