6UM-30 Data

[Ryan Avery]

6UM-30
115 Dtacs NR
20" Ace barrel

I ran a five-shot string from 63 to 65 grains of VV N570. 65g will be too hot for most people. So, if we go with a round number of 3200 FPS with the 6UM30, it's around 90 FPS slower than a 6UM40 at comfortable pressures. This is data from one barrel, and more testing is needed. The data on the 40 is pretty solid, with seven different 20" barrels averaging 3290.

63g-570
3116 Average

64g-570
3190 Average

65g-570
3227 Average HOT!

 

[RockAndSage]

What's the 30 designation, vs the 40?

 

[mddat]

What's the 30 designation, vs the 40?

Shoulder angle

 

[blacktailcentral]

6UM-30
115 Dtacs NR
20" Ace barrel

I ran a five-shot string from 63 to 65 grains of VV N570. 65g will be too hot for most people. So, if we go with a round number of 3200 FPS with the 6UM30, it's around 90 FPS slower than a 6UM40 at comfortable pressures. This is data from one barrel, and more testing is needed. The data on the 40 is pretty solid, with seven different 20" barrels averaging 3290.

63g-570
3116 Average

64g-570
3190 Average

65g-570
3227 Average HOT!

Did you guys ever try n565 with the 40 or 30 degree shoulder?

 

[AZ_Mike]

So a 6UM-30 with a 24" barrel should get approximately 3300 with 64g of N570?

 

[hdc77]

I just built a 24 inch 6 UM 30, only 20 rounds down the pipe. Shoots tiny holes with 108s Bergers and 115 DTACS. Never hit pressure.

 

[AZ_Mike]

I just built a 24 inch 6 UM 30, only 20 rounds down the pipe. Shoots tiny holes with 108s Bergers and 115 DTACS. Never hit pressure.

Impressive numbers. Thank you for sharing. I have one on order, can't wait to send some down range....

 

[High Tech Redneck]

I picked up the 24” 6UM-30 from hdc77 a couple months ago. Running the coated 115 DTAC’s with 0.003 neck tension and 2.950 COL. Using Fed GM210M and N570, 64.5 grains is running 3267 fps with an ES of 14.6 and printing groups of 0.4 MOA at 200 yards.



64.0 grains N570 averaged 3250 FPS. Saw ejector marks at 65.0 grains and the groups opened up quite a bit. Stopped at 66.0 running 3358 fps, the accuracy was just not there.

Also tried H1000, at 58.2 grains it was crazy accurate, printing 0.4” groups at 200 yards, but only averaging 3089 fps. Pressure was at 61 grains running 3230 fps.