Here's yesterday's results. The weather was terrible, again, so I got smart and just brought along a pop up cover to stay dry long enough to get something done. The good news is that the snow is slowly melting! Like in previous tests, 6.5mm bullets were tested in a 6.5x47 Lapua and 338s are from the 338-375 Ruger Striker. New additions this week are the 284 Win Striker to test the 7mm bullets and old faithful, the 375 Ruger Hawkeye Alaskan, to test the 375s.
375 Ruger- 260 Accubond
- Muzzle Velocity 2630fps
Impact velocity is approximately 2460 fps with retained weights of 194.3 and 203.4gr. Performance is typical of what I expect from Accubonds with good, consistent expansion. It's interesting to note that a portion of the plastic tip is still embedded in both bullets. This load was used to take a cow elk back in January at roughly 350 yards with excellent results. That bullet was a pass through double lung and not recovered.
- 270 Hornady Interlock
- Muzzle velocity 2627fps
Impact velocity is approximately 2415 fps with retained weights of 131.5gr and 208.6gr. These performed very similar to other Interlocks that I've recovered in the past with significant weight loss and lots of fragmentation.
284 Win- 162gr ELD-x
- Muzzle velocity 2298 fps
Impact velocity is approximately 2175 fps with retained weights of 131.2 and 143gr. This impact velocity is similar to a standard 7mm Mag (Rem, WSM, SAUM) at 550-600 yards with a muzzle velocity of around 2900 fps.
- 168gr Matrix VLD
- Muzzle velocity 2186fps
Impact velocity is approximately 2068 fps with retained weights of 142.3 and 147.4gr. This impact velocity is similar to a standard 7mm mag at 650-700 yards with a muzzle velocity of around 2900 fps.
- 168 Berger VLD Hunting
- Muzzle velocity 2210 fps
Impact velocity is approximately 2080 fps with retained weight of 152.1gr. I believe that this bullet hit a jacket fragment that was already in the leather, causing the irregular expansion. Only one of the two bullets fired was recovered but I believe that is also related to one of the bullets completely fragmenting after impact. I'm not certain what caused this but I'll retest in the future to see if the results are similar.
338/375 Ruger- 300gr Elite
- Muzzle velocity 1924
Impact velocity is approximately 1835 fps with retained weights of 300.0gr and 281.9gr. This is the second time I've tested these bullets with similar results each time. I can see where the nose starts to expand but then the jacket ruptures at the HP. These particular bullets must require a significant hydraulic force (more than the water soaked leather) to reliably expand.
- 300gr OTM
- Muzzle velocity 1989
Impact velocity is approximately 1905 fps with retained weights of 269.5 and 278.0gr. Both of these bullets expanded more reliably than the 300gr Hybrids did.
- 250gr Elite Hybrid
- Muzzle velocity 1814
Impact velocity is approximately 1720 fps with retained weight of 251.1 and 251gr caused by leather packed into the HP. These bullets performed like other Berger Elites that I've tested which show early expansion at the nose but then a jacket failure in the HP cavity. Like other Elite Hybrids I believe these require more fluid and/or higher velocity to perform.
- 250 Elite Hybrid
- Muzzle velocity 2599 fps
Impact velocity is approximately 2480 fps with retained weight of 192.6gr. Two bullets were fired but only one was recovered. I believe that the second bullet impacted another bullet fired into the leather and fragmented. Performance of this bullet with the higher impact velocity is much better than the low velocity impact. This impact velocity is similar to what I would expect at about 450 yards with a muzzle velocity of 3000 fps from something like a 338 Edge of long barreled Lapua.
6.5x47 Lapua- 143gr ELD-X
- Muzzle velocity 1960 fps
Impact velocity is approximately 1845 fps with retained weights of 135.4gr and 119.0gr. These performed very similar to the other Hornady ELD series of bullets I've tested so far. I will likely test these as a replacement for the 140 Berger VLDs that I've been shooting in the 6.5x47 Lapua.
- 150 Matrix VLD .040" HP
- Muzzle velocity 1854 fps
Impact velocity is approximately 1750 fps with retained weights of 138.4 and 136.7gr. Expansion was decent but the lead core slipped significantly in both bullets with one completely separating from the jacket.
- 150gr Matrix VLD .055" HP
- Muzzle velocity 1847 fps
Impact velocity is approximately 1750 fps with retained weights of 134.5 and 139.0gr. Minimal expansion compared to the same bullet at the same velocity with a smaller HP.
- 140gr Berger VLD Hunting
- Muzzle velocity 1842 fps
Impact velocity is approximately 1725fps with retained weights of 114.5 and 121.5gr. The results this time with the 140gr VLD at a very similar velocity to my initial tests lead me to believe that my initial theory on the poor performance may have been accurate. When I fired the same bullet at nearly identical velocities from a polygonal rifled barrel, it appeared that the bullet was under stabilized and tumbled on impact. The same bullet fired at a very similar velocity from a conventionally cut rifled barrel with the same twist proved to be stabilized much better, causing significantly better expansion. This result coincides with past results comparing the performance of relatively heavy for caliber bullets in both poly rifled and conventionally rifled barrels with the same rate of twist (those were also 6.5mm barrels). It's my belief that the poly rifling just isn't getting a sufficient grip on the bullet, resulting in the bullet "slipping" in the rifling similar to a slipping clutch on a car. What you end up with is an applied riffling twist that doesn't match up with actual twist of the rifling in the barrel.
This project is more work than my actual job! It takes on average 5 hours (including setup and tear down) to get the shooting done, then about 3 hours to collect data, calculate impact velocities, take pictures and get it all written up. I need to make my kids do more of this!:D It has been a great way to waste time while I'm waiting for the snow to melt so I can get to my better long range spots though. I won't be able to get to my 1500-2600 yard targets for another month at least.
