The 6UM

[JDMBEND]

Anyone have experience running short barrels 16-18”?

 

[bielenbm]

I’m running an 18” and it seems to be on the slow side 3080 mv with the 115.

 

[bielenbm]

I got the 116s today. Loaded some up for tomorrow!
They look good in the 6um brass!

 

[JDMBEND]

15 rounds of 116 TMK’s
65 grn N570
ADG 6 UM-30 Brass virgin
Fed 215M primers
2.9
3093 fps
SD 10.2 ES 36.5
Barrel now has 65 rounds
1 shot to confirm zero
17-20 mph wind, 48 degrees, 3800’
14 rounds off bag PRS barricade
Shooting on a oem Tikka stock until one of my Rokstok’s showa up. Tikka action, Prefered 20” Tikka hybrid.
Shooting 8-10” plates 350-550 yards
Spotted EVERY shot. No signs of pressure. Going to load up to 65.5-66 grains and see what happens. Hope to get to 3200-3300.

 

[bielenbm]

15 rounds of 116 TMK’s
65 grn N570
ADG 6 UM-30 Brass virgin
Fed 215M primers
2.9
3093 fps
SD 10.2 ES 36.5
Barrel now has 65 rounds
1 shot to confirm zero
17-20 mph wind, 48 degrees, 3800’
14 rounds off bag PRS barricade
Shooting on a oem Tikka stock until one of my Rokstok’s showa up. Tikka action, Prefered 20” Tikka hybrid.
Shooting 8-10” plates 350-550 yards
Spotted EVERY shot. No signs of pressure. Going to load up to 65.5-66 grains and see what happens. Hope to get to 3200-3300.

Is your barrel a 30 or 40? What was your jump? I had a few issues, bipod made a volleyball size group… went to a bag and it was better (1.8 moa for 7). My Labradar was being a POS so I didn’t even get a speed…

18” 6-40
66n570 with a 30 tho jump.

I’m not exactly happy with the group hopefully I can tighten it up some.

 

[JDMBEND]

No idea what the jump is , loaded to 2.9 coal and shot it. After the barrel is broke in, I may jump in the rabbit hole.
It’s a 30

 

[ike22]

I’m running an 18” and it seems to be on the slow side 3080 mv with the 115.

I am running and 18” also and have the same exact speed as you

 

[JDMBEND]

How many rounds?

 

[ike22]

How many rounds?

150-175 and 100 weee fire forming

 

[Ryan Avery]

I am running and 18” also and have the same exact speed as you

What barrel?

40 or 30?

 

[ike22]

What barrel?

40 or 30?

40 and ace unknown cut it

 

[bielenbm]

Kinda sounds like 18” barrels are not burning all the powder up?

 

[Wprinkle]

Kinda sounds like 18” barrels are not burning all the powder up?

My barrel is 18" and I could get 3200ish but accuracy went to crap, so I backed off and settled at 3120. My next barrel will definitely be 20 or 21 and a 1:7 twist not a 1:7.5. Good new is it doesn't take long to need a new barrel lol

 

[Formidilosus]

Kinda sounds like 18” barrels are not burning all the powder up?

No. That’s not a thing.

 

[bielenbm]

My barrel is 18" and I could get 3200ish but accuracy went to crap, so I backed off and settled at 3120. My next barrel will definitely be 20 or 21 and a 1:7 twist not a 1:7.5. Good new is it doesn't take long to need a new barrel lol

How many grains of n570 were you using to get the 3200? I’m just curious

 

[Treelineasassin]

Kinda sounds like 18” barrels are not burning all the powder up?

If you go up in charge and velocity increases, you're burning the powder. If it tops out and stabilizes and doesn't increase velocity as expected, you might be at that point. I don't know if anyone has ever really experienced that, I haven't. But I typically don't run under 18-20" tubes.