Trying the Oryx chassis on the 12 FV 6.5mm Creedmoor

[CFJunkie]

I bought an Oryx chassis for the 12 FV .223 so I could eliminate the hidden magazine that made loading a chore. But the Oryx chassis allows a Savage short action to drop right into the frame without any further adjustments, so I figured that I would pull the Oryx chassis off my 12 FV .223 and try in on the 12 FV 6.5mm Creedmoor. The 12 FV 6.5mm Creedmoor has a NightForce 8-32X56mm Benchrest scope with a 30mm tube mounted on it and the large front objective required high rings to let the front objective clear the barrel. I figured it was worth a test to see if that configuration would work with the no-drop Oryx chassis. I had to lower the cheek rest on the Oryx chssis to the minimum setting to be comfortable getting my eye on the optical plane. I loaded 4 different bullets, all with loads that worked well with the factory stock and figured that a comparison of the results would allow me to decide: Whether the Oryx stock would eliminate the stock flexing I was feeling with the factory plastic stock. Provide a comfortable platform that allows a consistent set up. Improves the accuracy over the factory plastic stock. The following are the results shot in Northern Virginia on Monday afternoon, July 8th at 100 yards. Temperatures were from 74 to 76 degrees with winds from 5 to 8 mph with moderate to heavy rain for most of the afternoon. Altitude of the range is 250 feet above sea level. I was serving as range safety officer for the afternoon and normally I would not shoot when there were any shooters on the range, but the weather was rainy and everyone stayed away. With the range all to myself, I got out the 12 FV 6.5mm Creedmoor and shot 100 rounds with the Oryx chassis with 4 different loads using 4 different bullets. All rounds were shot using Lapua brass and CCI BR-4 primers. All loads were set up to match the 12th reflection time of 1.360 msec. for the 26-inch barrel with a 0.040 recessed crown. The action screws were torqued to 60 in.-lbs. per the Oryx directions prior to this session. The load description field shows the powder and charge, the O.A.L., the trim length, and the bullet exit time from the 26-inch barrel. # Grps Load Description Bullet Weight Velocity Average Median St Dev 1 2 3 4 4 IMR4451 38.9 gr 2.845 1.903 wf 1.360 * 79/74 deg. F. 60 in.-lbs. Oryx CCI BR-4 Sierra TMK #7430 130 2701 0.331 0.345 0.031 0.244 0.343 0.346 0.350 4 IMR44451 38.8 gr 2.823 1.909 wf 1.360 * 75/76 deg. F. 60 in.-lbs. Oryx CCI BR-4 Hornady ELD-M #26331 140 2666 0.337 0.334 0.052 0.284 0.301 0.357 0.394 4 IMR4451 39.0 gr 2.835 1.912 wf 1.359 * 72/74 deg. F. 60 in.-lbs. Oryx CCI BR-4 Sierra SMK #1742 142 2665 0.339 0.359 0.061 0.254 0.337 0.380 0.386 4 IMR4451 38.8 gr 2.358 1.906 wf 1.359 * 77/75 deg. F. 60 in.-lbs. Oryx CCI BR-4 Hornady ELD-X #2635 143 2658 0.335 0.327 .038 0.297 0.324 0.329 0.388 16 0.335 0.340 0.042 Comparison of Factory Stock with Oryx Chassis Factory Oryx Chassis Bullets Weight Avg. Median St Dev # Grps. Avg. Median St Dev # Grps. Sierra TMK #7430 130 0.357 0.352 0.056 31 0.331 0.345 0.031 4 Hornady Match # 26331 140 0.373 0.355 0.081 35 0.337 0.334 0.052 4 Sierra SMK #1742 142 0.304 0.306 0.045 11 0.339 0.359 0.061 4 Hornady ELD-X #2635 143 0.375 0.369 0.069 39 0.335 0.327 0.038 4 0.363 0.345 0.062 116 0.335 0.340 0.042 16 The average of the results with the Oryx stock shows a 7.6% improvement over the factory stock with the same bullets. However, I have a tendency to take a session or two to get accustomed to a new configuration before I get the most out of it, so I think it may take more than one session to see the benefits of the Oryx chassis. The Oryx chassis did eliminate all the flexing that occurred with the factory plastic stock and the platform was incredibly stable through recoil. I could hear the chassis twang a bit, almost like the sound of an AR recoil spring after the initial bang. The removal of the flexing of the factory stock was the primary reason for trying the Oryx on the 6.5mm Creedmoor.