I've recently had shooting sessions to check the sighting of two different rifles, a Marlin 39M and a Ruger 77/22R. In each session I fired over a CED Millennium chronograph. I used two different versions of the Remington Golden Bullet for each session, the first some 10-12 year old round-nose solids and the second some newly purchased round-nose hollow points. Both batches are bulk ammo, the first 350 rounds in a mug, the second 550 rounds in a Bonus Pack.
I was very pleased with the accuracy of both guns. I was also pleased with the reliability and accuracy of both types of ammo. I fired two 10-shot strings of the old solids from each gun and three 10-shot strings of the new hollow points. I experienced only one failure to fire, in the Ruger and with the new HP. No damaged cases, no extraction problems, no squibs from either type, and each string was acceptably consistent and uniform in its velocities.
Shooting conditions were very nearly identical for both sessions, low 50s, overcast, wind from the NE at less than 5 mph. The chronograph never gave an error message and as far as I could tell was working perfectly normally. I shot all the strings off of sandbags on the hood of my Jeep.
Both the Ruger 77/22 and the Marlin 39M have 20 inch barrels. The Marlin has 12-groove Micro-Groove with a twist rate of 1:16". The Ruger has a more traditional 6-groove rifling, with the same 1:16" rate of twist.
Now, I told you all that in order to tell you this. In going over my numbers afterward, one thing stood out... the Ruger fired both old solids and new hollow points almost 100 fps faster than the Marlin. Every string showed the same thing, higher velocity for the Ruger.
I don't have the company data which came with the old solids, so I don't know what velocity was claimed for it. Remington claimed 1280 fps for the new hollow points, but I wasn't actually expecting that speed because 1) I was using a 20" barrel instead of the 24" Remington used, and 2) all ammo companies exaggerate. I did expect both types of ammo to shoot the same from both guns, though, and I have no explanation why they didn't.
Is there something obvious I'm missing? Is it because one gun is a bolt action and one a lever action?
Could differences in the rifling make that much difference? Anyone else run across this?
Spence
I was very pleased with the accuracy of both guns. I was also pleased with the reliability and accuracy of both types of ammo. I fired two 10-shot strings of the old solids from each gun and three 10-shot strings of the new hollow points. I experienced only one failure to fire, in the Ruger and with the new HP. No damaged cases, no extraction problems, no squibs from either type, and each string was acceptably consistent and uniform in its velocities.
Shooting conditions were very nearly identical for both sessions, low 50s, overcast, wind from the NE at less than 5 mph. The chronograph never gave an error message and as far as I could tell was working perfectly normally. I shot all the strings off of sandbags on the hood of my Jeep.
Both the Ruger 77/22 and the Marlin 39M have 20 inch barrels. The Marlin has 12-groove Micro-Groove with a twist rate of 1:16". The Ruger has a more traditional 6-groove rifling, with the same 1:16" rate of twist.
Now, I told you all that in order to tell you this. In going over my numbers afterward, one thing stood out... the Ruger fired both old solids and new hollow points almost 100 fps faster than the Marlin. Every string showed the same thing, higher velocity for the Ruger.
I don't have the company data which came with the old solids, so I don't know what velocity was claimed for it. Remington claimed 1280 fps for the new hollow points, but I wasn't actually expecting that speed because 1) I was using a 20" barrel instead of the 24" Remington used, and 2) all ammo companies exaggerate. I did expect both types of ammo to shoot the same from both guns, though, and I have no explanation why they didn't.
Is there something obvious I'm missing? Is it because one gun is a bolt action and one a lever action?
Could differences in the rifling make that much difference? Anyone else run across this?
Spence