Lackluster speeds with retumbo and Berger 156 6.5 prc

[luckystryke]

Went to range yesterday with some retumbo and Berger 156. Adg brass virgin, fed primer. These were results. I was just checking pressure and speeds, 59-59.3 just starting to get slight ejector marks and ever so slightly flattening of primers. I might push a little further but these speeds are lackluster to say the least. The Hornady is white box match advertised at 2910 mv.

New fierce rival carbon. Has about 30 rounds down the tube. 24 inch barrel. I'm at 600 ft elevation

I'm gonna try h1000, n565 and n570 next. Was hoping for retumbo to work as I have 8 lbs of it. Any experiences?

I've read about barrel speed up but from what I gather that's essentially carbon ring causing pressure.

 

[gillettehunter]

For top velocity you might try RL-26 or RL-23. H-1000 seems to often provide good accuracy. Good luck.
Bruce

 

[Jakeweb09]

I've ran quite a bit of retumbo through a 26" bartlein in 6.5prc, however with 140s and 144s. My accuracy load was on the lower end of things but was phenomenal. 144 Berger with 56.2g of retumbo and I was at 2920fps. One of the most accurate loads I've ever had, and a good friend of mine tried it in his rifle and it hammered for him as well. I believe he was also around the same velocity. You definitely seem low, I would get around 150 rounds down it and recheck velocities

 

[Tucker65]

I've built quite a few 6.5 prc's and the best velocity was with RL-26. In a 24" 7.5 twist barrel I could push them 3000 fps which is where they seemed to like to shoot speed wise. When RL-26 became hard to get I switched to N565. Only about 25 fps slower in the few rifles I've used in in since switching but accuracy has been great and the powder has been readily available.

 

[Mike D Texas]

Went to range yesterday with some retumbo and Berger 156. Adg brass virgin, fed primer. These were results. I was just checking pressure and speeds, 59-59.3 just starting to get slight ejector marks and ever so slightly flattening of primers. I might push a little further but these speeds are lackluster to say the least. The Hornady is white box match advertised at 2910 mv.

New fierce rival carbon. Has about 30 rounds down the tube. 24 inch barrel. I'm at 600 ft elevation

I'm gonna try h1000, n565 and n570 next. Was hoping for retumbo to work as I have 8 lbs of it. Any experiences?

I've read about barrel speed up but from what I gather that's essentially carbon ring causing pressure.

View attachment 557483

Something isn't right. Those are 6.5CM speeds.

 

[SheepShapeAK]

N565 and N570 seem like slow powders for that bullet.

 

[SheepShapeAK]

Load data was showing a bunch of H4831 loads for the 147gn bullet. Didn't show any loads for a 156gn bullet. I'm sure someone with QL could run the numbers.

 

[Phil Rizzo]

I'd take a mild approach with virgin brass for the first firing.
Shoot and clean at tighter intervals for at least 100 rounds.
Sometimes they don't speed up and settle in until 150-200 shots.
Sometimes, not at all!