Powder test with short barrel 30 Nosler

[lancetkenyon]

Not a typo.

Thanks a lot...you just cost me about $7k...

Did Axisworks build this with Charlie's reamer?

 

[thaught]

Thanks a lot...you just cost me about $7k...

Did Axisworks build this with Charlie's reamer

I did the build. My reamer is from JGS

 

[thaught]

How do you get an ES of 2.8 fps unless you are measuring to the tenth on fps?

The Garmin chronographs measured to the 10th

 

[Buttermilk]

I recently built a new 30 Nosler, opting for a 22-inch barrel instead of the longer 26-28 inch barrels used in my previous builds. This rifle is equipped with a TBAC Magnus suppressor. While researching potential loads and powders, I initially assumed that a faster-burning powder would be more suitable given the shorter barrel length, as it would facilitate a complete powder burn and yield better velocity and standard deviation (SD) values. My bullet of choice was the Berger 215-grain, and I began my testing with H1000 powder. This initial load demonstrated decent accuracy and SD, with a velocity of 2,890 fps at 82 grains.

Next, I tested Retumbo, which provided significantly higher velocity, reaching 3,104 fps at the first signs of pressure, along with slightly improved SD values compared to H1000. I then tried 4831sc, which produced a velocity similar to H1000 but resulted in worse SD values. Finally, I opted for N570, the same powder I use in my other 30 Nosler rifles, and found an optimal load at 86.2 grains, achieving a velocity of 3,007 fps with an SD of 1.2 (2.8 fps extreme spread).

Contrary to my initial expectations, the shorter barrel performed better with slower-burning powders. Based on this experience, I conclude that for heavy bullets in any given caliber, slower powders yield better performance regardless of barrel length. Anyone else have similar or differing experiences?

I do a lot of short barrel guns (Contenders, Encores, XP-100's). Rule of thumb is the same powders that get the fastest velocity in long barrels also produce the fastest velocity in short barrels, generally speaking.

I have two 30 Noslers, one 18.5" bbl, the other is 19.125" bbl. Both shoot very well with H1000, and RL26. I've not tested Retumbo yet, but have had plans to do so. Just hard to move on from RL26 with B210VLDH's at 2850 fps with 1/2 MOA accuracy. I would expect Retumbo to net me perhaps 50 fps more, but based on your testing, perhaps a bit more.

 

[thaught]

I do a lot of short barrel guns (Contenders, Encores, XP-100's). Rule of thumb is the same powders that get the fastest velocity in long barrels also produce the fastest velocity in short barrels, generally speaking.

I have two 30 Noslers, one 18.5" bbl, the other is 19.125" bbl. Both shoot very well with H1000, and RL26. I've not tested Retumbo yet, but have had plans to do so. Just hard to move on from RL26 with B210VLDH's at 2850 fps with 1/2 MOA accuracy. I would expect Retumbo to net me perhaps 50 fps more, but based on your testing, perhaps a bit more.

I wish I had talked to you first. Haha. I went through a lot of powder and bullets but the experience and what was learned from it was cool. I thought for sure a faster powder would be the best, but I was very wrong

 

[Beluebow]

Not a typo. The targets seem to really like it out to 1380 yards. What I learned from this is that not only did the slower powders produce higher velocities, but the nodes were all around max charges, give or take .5 grains. I did forget to mention there is .200" of freebore which gives a little more room.

Your photo shows 9.5 SD for five shots.....A 1.2 SD for 20 is amazing.

 

[thaught]

I wish I had talked to you first. Haha. I went through a lot of powder and bullets but the experience and what was learned from it was cool. I thought for sure a faster powder would be the best, but I was very wrong

Correct. That screen shot is with Retumbo not the n570 load

 

[7.62 Gunner]

Not a typo.

Did you fire those cases several times with that load? I can guarantee you pressure was up there.

 

[thaught]

Did you fire those cases several times with that load? I can guarantee you pressure was up there.

With Retumbo, I was on my 2nd firing and I did have signs of pressure, but not excessive. For my rifle, it was safe but I did not exceed that charge.