Chris Spiess Posted January 8, 2007 Share Posted January 8, 2007 I recently compared the velocity of identical loadings of four (4) different 9mm bullets. Two of the bullets are copper jacketed, and two are coated with proprietary polymer. Each bullet selection was compared for consistency of weight and length, the details of this analysis follows below. The following bullets where examined: Hornady HAP, 125 grains Winchester FMJ, 124 grains Masterblasters Bullets CCRN, 124 grains Precision Bullets FP, 124 grains The swaged bullets from Precision Bullets were the most consistent in weight, followed closely by the swaged Hornady HAP. It is assumed that the Winchester FMJ is also of swaged construction, although I am unable to definitely confirm this; therefore it was somewhat surprising to find that the cast Masterblasters bullets were more consistent in weight than the Winchesters. It is worthwhile to note that Precision Bullets lists their bullet as 124 grains, however, the average weight of the sample set was 125.2 grains, and is the heaviest of any of the bullets measured. Also, I discovered a 121 grain bullet in the sample set of 125 grain Hornady HAPs. I am very tempted to weigh a larger sample set from the carton to see if there are any other 121 grain bullets. This could be a nasty surprise at the chronograph; at major power velocities, the difference is worth about 5 points of power factor. Fig. 1, Bullet weight (grains) When comparing bullet length, the Winchester FMJ was least consistent in this category as well. The Hornady HAP bullets, Precision Bullets and Masterblasters bullets were all equally consistent in length. Fig. 2, Bullet length (inches) Bullet lengths were used to determine the final loaded cartridge overall length. Cartridge overall length for each bullet type was selected to provide the same internal case volume for each round. This provides very similar pressure curves beneath each bullet type, making the individual bullet types the most significant variable in each of the loads. Fig. 3, Cartridge OAL (inches) All loads used 3.6 grains on Hogdon TiteGroup, CCI #500 small pistol primers and once-fired Winchester brass. All test rounds were fired from a five inch Para Ordinance barrel over a Alpha Shooting Chrony from approximately ten feet. Fig. 2, Velocity (fps) The two polymer coated bullets recorded higher velocities than the two jacketed bullets evaluated. The extreme spread of velocities is 54.7fps. In addition, both polymer coated bullets were more consistent than the two jacketed bullets. However, both of the polymer bullet loads were much smokier than the jacketed loads, the Masterblasters load producing much more smoke than the Precision Bullets load. The Masterblasters load also being much dirtier than the Precision Bullets load. However, it has been my experience with TiteGroup that loads at this level produce smoke regardless of the bullet type. Higher pressure TiteGroup loads, around 140 power factor for example, are notably cleaner. That’s what I found; take it for what it’s worth. Personally, I am going to stick with the Precision Bullets from now on for both Production and Limited. The velocity difference between the Precisions and the Masterblasters is minimal, and it has been my experience with the Masterblasters bullets in .355 and also .451 that the coating is scraped off the bullet as it travels down the barrel leaving the bare lead exposed; this would explain the additional smoke over the other bullets examined. This information is available in PDF, Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.