I just thought this was noteworthy. I was shooting my M14 yesterday at 300 yards which has the 22" Lothar Walther 4-groove ICR rifling barrel. My son was using his own M14 with a 22" Criterion 4-groove conventional rifling barrel. We were shooting the exact same load and shooting on the exact same electronic target.

The velocities are recorded in the gray box on the right of the screenshot with the final average velocity recorded in the pink box.

My average velocity was 2215 FPS for 10 shots. His average velocity was 2137 FPS for 10 shots. That's a 78 FPS velocity spread!

I can't compare the 600 yard data as I was shooting a different load than him.





Just posting this for posterity.

Tony.

Are these barrels cut rifled or button rifled? Or is it a completely new and different technology? I know the Lothar Walther barrels used on the first generation of LaRue Tactical rifles are renowned for their incredible accuracy.

I'm curious how is the MV being measured, it looks like the scoring system is doing it? Technology?

quote:

Originally posted by Lt CHEG:
Are these barrels cut rifled or button rifled? Or is it a completely new and different technology? I know the Lothar Walther barrels used on the first generation of LaRue Tactical rifles are renowned for their incredible accuracy.

I made a post about these barrels a couple of months ago. They are button rifled barrels.
https://sigforum.com/eve/forum...500085215#4500085215

ICR rifling means "Internal Curved Radius." The CEO finally told me what it means. I also have permission to post pics of the rifling. From John at LW:

"If you look at the rifling there are no sharp edges just a radius on a radius. We have been making this type of rifling for 5 to 6 years, just haven’t advertised it. We just make barrels for the industry and don’t advertise or post anything on the internet."

This is after a couple hundred rounds from my Vintage Sniper competition rifle. There was minimal fouling in the barrel and it cleaned up with two wet patches, a few strokes of a bore brush with Bore Tech copper cleaner and three more passes with dry patches. There are just tints or stains of copper at some points and no actual copper fouling.






Here's a muzzle view of the rifling.


For those that didn't see my posts before, I got a 45 FPS velocity gain over conventional 4-groove rifling and it even shot faster than one of my 5R barrels. I got 2705 FPS out of a 22" barrel with ICR rifling while getting 2650 out of conventional rifling with ammo from the same box and the same length.

This is also the same barrel that shot the 0.6 MOA groups at 300 yards with 155 grain ELD-M's.





Here's a description of what radius over radius means.You have the groove radius, which originates from the centerline of the barrel and the land radius which originates from outside the barrel.

quote:

Originally posted by hrcjon:
I'm curious how is the MV being measured, it looks like the scoring system is doing it? Technology?

I measured the velocity at the muzzle a while back and they are launching out of my barrel at 2775 FPS. The target has electronic sensors that pick up the placement and velocity of the bullet as it passes through the target. The position and velocity at the target is then displayed on your mobile device.

Tony.

I guess my question really was what do you think the accuracy of the target measuring velocity system is?

quote:

Originally posted by hrcjon:
I guess my question really was what do you think the accuracy of the target measuring velocity system is?

It's pretty accurate. I ran the numbers in JBM and using the BC and MV of 2775 FPS, the ballistics software says they should be running about 2202 FPS at 300 yards.

The target system measured the velocity at an average of 2215 FPS, which is pretty close to what JBM says it should be.


Tony.