416 Barrett Bolt Gun Performance

[BCadvantage]

Any members with first hand experience of this cartridge ? I have been working with the 416 gr. Lehigh projectile and very large amounts of wc 872 powder @ 3400 fps. Accuracy currently @ 0.75 MOA with ability for more powder.

 

[Sling]

Most dropped that cartridge and went with 375 Cheytac or IMP version.

 

[ELR Researcher]

BC:

Bravo! 3400 and .75 MOA is excellent. Which rifle (or rifle components) are you using - especially barrel length and twist? And how much 872 to get to 3400? I'll PM about my .416 Barrett-base project.

 

[BCadvantage]

BC:

Bravo! 3400 and .75 MOA is excellent. Which rifle (or rifle components) are you using - especially barrel length and twist? And how much 872 to get to 3400? I'll PM about my .416 Barrett-base project.

This platform is a major change from my normal short and mid range BR chamberings of 220 Beggs , 30 BR, and 6 Dasher. The rifle is a newly purchased Barrett Model 99 Single Shot with a 32" barrel which currently wears a 12x - 42x Nightforce for load development purposes. Load development has all taken place within a 100 yd. indoor benchrest range utilizing standard BR rests and benches so as to minimize influence from hold and weather conditions.
Inspection of the new barrel with a 21" Hawkeye borescope left me impressed with the quality of bore finish and chamber concentricity in relation to the rifling for a production barrel. Powders utilized to date have been Hodgdon US 869 and military surplus wc 872 , both being ball or spherical as manufactured by St. Marks Powder (SMP). I have not worked with any of the "stick" powders in looking for maximum load density at this time.
My maximum accuracy node currently is 209 gr. of wc 872 powder for a PVM-21 chronograph velocity of 3410 fps and 14 ES. The ball powders are burning "clean" due to the upper pressures being obtained. As noted in my original post the bullet being used is the Lehigh 416 gr. solid brass projectile. Have also used the Barrett 398 gr. bullet which is very similar with close to same performance. Must note that a long drop tube is used in dispensing the powder to case for bullet seating. US 869 has also performed well at lower charge weights due to its faster burn rate.
Can provide more detailed freebore and seating depth info in a PM if needed. There is no doubt of the rifle fired when you touch this thing off.