coated bullets Vs jacketed bullets

[Mikeinkaty]

Is max load for coated bullets same as for jacketed bullets? I cannot find load data for coated lead bullets so I figured someone here would know. Assuming .001" oversized for lead. Would this be true for both revolver and rifle?

 

[BC38]

You probably won't find much published data for coated bullets. There are only a couple of big manufacturers selling ammo with coated bullets or even the bullets alone.

The general rule seems to be start with lead loading data and work your way up. Preferably with the use of a chronograph to check your results.

Coated bullets are usually around .001" or so larger than their original nominal diameter. Of course that varies with the coating and the method that was used to apply it.

 

[Wee Hooker]

No.
For coated, use lead data.
For plated. use mid to upper end lead data.
For jacketed, use jacketed data.
As always, watch OAL and start 10% below max and watch for pressure signs in the primer.

 

[Mikeinkaty]

No.
For coated, use lead data.
For plated. use mid to upper end lead data.
For jacketed, use jacketed data.
As always, watch OAL and start 10% below max and watch for pressure signs in the primer.

One reason I asked this is that I started at max load for lead then went up in small steps to max load for jacketed. 357 mag, CCI 500 primer, Titegroup powder, 125 grn coated bullet. None of the loads showed any signs of overpressure. Primers were all fine and no case buldges. And, no leading at all. Accuracy seemed to be a little better at the higher velocities.

 

[BC38]

One reason I asked this is that I started at max load for lead then went up in small steps to max load for jacketed. 357 mag, CCI 500 primer, Titegroup powder, 125 grn coated bullet. None of the loads showed any signs of overpressure. Primers were all fine and no case buldges. And, no leading at all. Accuracy seemed to be a little better at the higher velocities.

Did you chrono any of the loads?

Personally I wouldn't rely solely on the appearance of the cases and primers to ensure I wasn't going over recommended pressures.

I've read too many posts by experienced reloaders where they said that the brass & primers looked fine but the velocities were WAY high - which pretty much equates to an excess of powder - which means over-pressure.

Not saying that you shouldn't look for flattened primers and/or sticky extraction - because if you see them that's a good indication that you're almost certainly over pressure. But you can also be over pressure and NOT see either of those indicators...

 

[gwpercle]

Coated bullets are loaded with the same data as cast lead.
The coating is just another form of lubrication that prevents leading. It does not make the bullet any harder . They are not necessarily loaded any faster. Treat them as conventional cast lead and lubricated bullets .
Some claim they can be loaded to a higher velocity without leading, and that might be true , but you still use the load data for cast bullets to get there . Jacketed and plated bullets do offer a harder jacket / skin so the data changes for them .
Gary

 

[Speedo2]

I've been playing around with a Chronie for coated (Bayou) and plated (Berry's) bullets; found that plated bullets have more friction losses than coated. Approximate average velocities for 9 mm w/ 5.2 grs AA5 from a Springfield 1911-A1:

124 TCG (Bayou) @ ~980 fps
124 HBFP (Berry's) @ ~ 920 fps

It took 5.5 gr AA5 to get up to ~980 fps with 125 RN-Plated (Berry's).

Good advice to stick with cast lead data for coated bullets IMO. -S2

 

[bluetopper]

Beware of Titegroup in upper end loadings in magnum handgun cartridges.

 

[Nevada Ed]

The plating on bullet varies per the company that makes them.

I believe that coated bullets are made in two different ways also
which would also effect what their maximum fps would be.

Lots of variables to make a difference in the fps.

 

[rwsmith]

The coefficient of friction...

The coefficient of friction between copper plating or jackets and the barrel is greater than polymer coatings and the barrel. Consequently, you get more velocity with less powder with the coated or plain lubed bullets.

 

[muddocktor]

The coefficient of friction between copper plating or jackets and the barrel is greater than polymer coatings and the barrel. Consequently, you get more velocity with less powder with the coated or plain lubed bullets.

I found this to be very true. One fine day I went to the range with some JHP, plated and coated bullets that were all loaded with the same load of powder and using the same primers. And I tried them in a model 27, a Coonan Classic and a Rossi 92 SRC. In all instances, I found the coated bullets to give the highest velocity, with the JHP coming in second and the plated trailing by just a little bit.

 

[AzShooter]

Never start at the top load listed. Always start 30% below Max and work up.
Use lead load data and you won't have any trouble.

 

[noylj]

>Never start at the top load listed. Always start 30% below Max

Start 10-12% below the max charge weight.
I wouldn't start at the max charge for lead even if I was shooting jacketed.
Next, the manual is ONLY a guideline. With different lots of powder, different bullets, different cases and primers, different COL, and even different GUNS, the MAX load changes. This is why no two manuals completely agree--too many variables.
You don't know how your variables compare to ANY manual, so you should check a couple and start at the lowest starting load.
The whole CoF is nice (if you know the CoF at pressure and velocity), but lead can also reach MAX pressures at lower charge weights, no matter what the velocity is, so . Velocity is not pressure. They are separate animals, with plated usually being more like cast lead (except for the thick plated bullets). The std. plating was so thin, it was little more than a "coating" in its own right.
So, Mikeinkaty started "his" coated lead work-up at some manual's MAX charge for lead and worked UP from there.
Thank God guns are made strong.

 

[TAROMAN]

I've shot coated bullets at 1900+ FPS from my M1 Carbine with no issues whatsoever.

 

[BC38]

I have a question about the statement that on "some" plated bullets "the plating is more like a coating". I've seen that statement in several threads.

What brands of plated bullets have such a thin coating of copper? I've used Berry's and Xtreme in several calibers and have pulled and damaged and examined a few of them. None of them had copper layers so thin that they could be accurately described as a copper "coating". None of them even cracked - even the ones with a very pronounced roll crimp.

The only bullets I have seen that fit that description are not sold as copper plated, but rather they are sold as copper-washed, and they were all factory ammunition in .22 or .17 calibers.

So who plates their bullets with such a thin layer of copper? I ask because I want to be sure and avoid those brands.

 

[ajgunner]

Myself, I load coated bullets for 2 reasons---they are about half the price of jacketed, and they are cleaner on both the barrel and handling. So while I am loading on the "cheap", why would I want to raise the powder level which in turn raises the price per round. I figure coated bullets are for plinking/casual practice, so I want them as cheap as I can make them. If/when I want full house stuff to practice with, I use the real thing---jacketed not plated/coated.

 

[Nevada Ed]

Muddoktor;

I never checked fps with plated and coated 9mm 125gr.

I just looked it up and you are correct.
The coated bullet does kick out a higher fps than the plated
bullet with the several powders that I used.

Very interesting.

 

[SLT223]

I've launched Bayou .44 240's and .357 158's at full tilt over 110, 4227 and No 9 with outstanding results. Several people here have sent them down range in rifle at twice the speed of sound. I would say feel free to try them at jacked velocities. You will probably like the results.

 

[noylj]

There were nickel "washed" bullets (a really light plating) and some with plating 0.003" or less. As the plating thickness goes up, the cost approaches, and sometimes exceeds, jacketed bullets from Precision Delta and Zero. After all, many plated bullets are using as much copper as jacketed bullets and the bullets have to be swaged ("struck") twice.

 

[BLUEDOT37]

Here is an article that compared the different types of bullet construction vs. velocity.

(The original url for it doesn't work anymore.)

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