FMJ vs plated ??


July 15, 2007, 11:35 PM
I am reloading for 9mm with AA#5 and have some new Rainier 147 grain TRN bullets. I see in several different manuals as much as 0.8 to 1.0 grain of powder difference for FMJ vs plated bullets. When we are talking about the same weight bullet and extremely similar shape, what is the big difference between FMJ, plated or jacketed RN?? Aren't the plating and jackets all copper? Why would there be so much difference to get the same FPS also? Any thoughts out there on this?

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July 16, 2007, 12:02 AM
I have had unpredictable results with plated bullets, Cu is Cu and fiction should be the same but plated and copper jackets bullets can be different animals given similar weight and shape. I use the min. load for jacketed and work up if needed, some plated bullet manufactures will say to use lead data.
I have found Rainier to be the best of the plated bullets I've tried.

July 16, 2007, 01:08 AM
The difference is mainly in the amount of friction generated by the differing hardness of the two styles of bullets. A full metal jacketed bullet is harder, due to the thicker jacket, which produces more friction.

A plated bullet is swaged from almost pure lead and then given a very thin plating of copper, producing a soft bullet, which acts more like a lead bullet, but doesn't have the lead exposed to the rifling or the powder charge. This produces less friction than the full metal jacket, which is why they recommend using lead bullet data.

I've had excellent results with Berry's plated bullets and have fired thousands of them in quite a few different calibers. There are some things that are done a little differently when loading them, but they're minor.

Hope this helps.


July 16, 2007, 10:37 AM
Are there guidelines for developing loads for plated bullets where none exist? I'm thinking particularly of .40SW applications using Hodgdon powders (Universal and Titegroup so far.) Hodgdon data, and the other sources I have (few enough) list few if any loads for lead or plated bullets, but plenty of info for 155gr JHP or TC/FMJ

July 16, 2007, 11:03 AM
Check There are loads listed there for 155 gr TMJ which are plated bullets.

July 16, 2007, 11:12 AM
I routinely shoot Ranier 9MM 115 RN at 3/4 to full jacketed data with no problems. Start in the middle of jacketed data and work up.

July 16, 2007, 11:15 AM
When Berry's and Rainier listed load data on their sites, Berry advised mid-range jacketed loads and Rainier suggested using lead data values. Rainier's plating is definitely softer/thinner than Berry' can see the difference in the nose "smiley's" on a mistimed 1911. Montana Gold are even harder plating but a few more $$.

Basically you'll find a nice mid-range load that'll do fine with either...they're not Bullseye 50 yd accurate but quite acceptable at shorter distances or for general plinking. Note also that Rainier's are .451 while Berry's are .452.

Cabela's charges shipping by price with a maximum of $13.95 (last time I checked) so they're often cheaper if you're getting a decent quantity than buying directly from the manufacturer's or Midway, where they ship by weight.

July 16, 2007, 04:26 PM
Another thing- plated, like Berrys are fully encapulated in copper... so it reduces my exposure while shooting indoors. I see no difference in accuracy from my handguns. I shoot mostly 25-50 ft.

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