Quote:
Originally Posted by Karl
This is an evaluation of 9mm polymer coated bullets based on a comparison between:
Acme polymer coated 115 grain, round nosed bullets, and Rainier Ballistics plated 115 grain, round nosed bullets. The charge was 7.0 grains of Blue Dot powder. Every effort was made to provide accurate and equal loads. The Acme bullet has a more rounded profile, and as a result is about .010 shorter than the Rainier Ballistics bullet. Consequently, I seated the Acme bullets .010 deeper, for and OAL of 1.150 instead of 1.160 to provide the same filled-case volume. Both bullets were given the same medium crimp.
Test gun was a Luger with a new 6" barrel. I fired 20 rounds of each bullet at a 4" bull at 50 ft. I used a two-hand hold with the wrist supported on a sandbag. Note that my eyesight is not all that good.
Velocity: Acme coated bullets average velocity was 1239 FPS with and extreme spread of 145 FPS; Rainier Ballistics plated bullets average velocity was 1163 with an extreme spread of 99 FPS.
Accuracy: Acme coated bullets had an extreme group size of 5 1/4" with 11 of 20 within the 4" bull. Rainier Ballistics plated bullets had and extreme group size of 4 1/8" with 17 of 20 within the 4" bull.
Other notes: I fired with 5 rounds per magazine. Using the coated bullets the holdopen only functioned once (out of 4 magazines); using the plated bullets the holdopen functioned every time. Using the coated bullets there were two jambs (perhaps a result of the shorter OAL); using the plated bullets there were no jambs. The coated bullets are also a pain to load. The coating flakes off easily requiring substantial case expansion to seat the bullet without shearing off the coating.
Conclusion: Polymer coated bullets may prove superior in the future but not yet, at least for this brand.
KFS
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Hi,
I'm working on a rush job now at work, but would like to follow-up with you in the near future.
From what you are telling me, your loads are in the +P range for a Luger, as original military pistol rounds were 123 grains at 1076FPS (four inch barrel). Hot loads are not good for your Luger's health, nor are they accurate or particularly functional.
Blue Dot isn't a particularly accurate powder in a Luger either.
More Later
Sieger
