16.5” vs 18” 6 creed

[TxLite]

Im shooting 16” 1-7 twist OMR barrel on a Falkor Defense receiver, YHM Nitro 30 suppressor. Shooting hand loads with Peterson brass, RL16 powder, LR CCI primers and 115 bergers, pushing them around 2925 on average with a very low ES. Measuring velocity with Garmin Xero C1 Pro Chronograph.

That’s some crazy speed out of that 16”

My 18” is at ~2950 with a max load of h4350 and 108 Berger elite hunters

 

[cal30_sniper]

Im shooting 16” 1-7 twist OMR barrel on a Falkor Defense receiver, YHM Nitro 30 suppressor. Shooting hand loads with Peterson brass, RL16 powder, LR CCI primers and 115 bergers, pushing them around 2925 on average with a very low ES. Measuring velocity with Garmin Xero C1 Pro Chronograph.

That’s called overpressure. My 6-284 barely throws 115s that fast with an 18” barrel, and even those loads (Retumbo) are over standard accepted pressures.

 

[khuber84]

Lapua and alpha brass along with a well built rifle won't show traditional psi signs till you're north of 70k psi. Keep this in mind. If you want to know if you're safe, pour a bottle of water through your mag, then shake it out by hand and then fire that wet ammo through your rifle. This is what would simulate hunting in rain/melting snow.

 

[khuber84]

There are ejector marks on almost every one them cases, primers cratered. Peterson holds the least amount of powder of all brass manufacturers.

 

[cal30_sniper]

This is the setup, no sticky bolt and little primer cratering and no ejector pin marks. I know a little about hand loading not my first rodeo. I’ve blew a few primers in my time pushing it passed limits.

Holy ejector marks. Those are probably pushing 80ksi.

 

[JRay]

Just received my 6CM Tikka barreled action from PVA. I went with 18" (1:7 twist) for this one since it's my first. Won't be able to shoot it until a few weeks from now unfortunately though.

Please report back when you do. This is then route I’m considering

 

[JRay]

Sorry... late to the thread.

18 inch 6mmCreed (ultra7 suppressor)
108 eldm, 2865fps at 40deg F.
N555/lapua brass
1/8 twist

My son took 3 critters with it in 2024
Black Bear 400 yards
White Tail Buck 325 yards
Cow Elk 550 yards

*** this is a very lightweight setup compared to most. Barrel was done by LRI, heavy fluting brought it down to about 24oz. Whole rifle weighs just 4lbs 2oz (bare). But it still shoots moa, and my kids can hit my 720 yard gong first shot.

Have you detailed your build? Your listed weight sounds fantastic for a pack rifle.

 

[Kimber7man]

Shot my 18” today. Factory Berger elite hunters averaged 2708.

Sounds about right, the factory Berger 105 hybrids shoot 2,750-2,760 in my 20”