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Old February 15, 2009, 04:58 PM   #12
Bart B.
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Join Date: February 15, 2009
Posts: 5,385
1991 USA Palma Ammo Stuff

Nick says about the 1992 Palma ammo:

"This case’s weight averaged about 156 grains instead of the more usual 170 grains or so, and was headstamped "PALMA" (should anyone got confused)."

As one of the earlier US Palma Team members, I was asked to help develop loads for Sierra's new Palma bullet. Winchester had made some prototype cases (weighing about 166 - 168 grains) but they weren't uniform enough ineck wall thickness. Winchester had to retool/reset their case making dies to get 'em near perfect.

We were asked to use new cases weighing between 165 and 170 grains to do our load development with different powder types and charge weights. I called Western Cartridge Company's plant in Alton, IL, to ask 'em about using dies like the ones making the famous WCC58 cases for the US Olympic Free Rifle Team. The engineer there I talked to said they still have that set of dies preserved and tucked away in a back room but didn't dare use them as those perfect 150-grain cases they made were too thin for liability issues of the 1990's; and lurking lawyers sometimes get called about such things.

Winchester finally got their tooling just right and the cases made for the 1991 preliminary match (Rocky Mountain Palma Match, International Division) and 1992 World Palma Matches were headstamped "PALMA 92." Bob Jensen's crew in Tucson, AZ loaded them on two Dillon 1050's; a few hundred thousand rounds. I shot that ammo in the 1991 RMPM scoring the high 5-day aggregate of those long range matches. Weighed some empty cases and they were all about 169 grains, not 156 as you mention. Same for many hundreds I used afterwords. The load used was 45.3 grains of metered (not weighed) IMR4895 with a Federal 210M primer. This load shot 20 randomly selected rounds into 2.7 inches at 600 yards all rounds fired in 15 minutes.

Winchester made another batch of cases a few years later headstamped "PALMA" without any date shown. Those cases were lighter than the original PALMA 92 ones and were used for the tryouts for the 1996 US Palma teams. Maybe this batch is what Nick's referring to.

Last edited by Bart B.; February 16, 2009 at 07:18 AM.
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