Slow creedmoor

[padom]

Something else is going on, thats pretty low for H4350 in my 6.5cm's. My load is 42gr with 139L Scenars and 42.6gr with 140 Hybrids out of 26"Bartlein. Both shoot in the 0.1s 2776 with the 140 Hybrids no pressure (thats all with Hornady brass). I never made the switch to lapua as I was an early adopter of 6.5cm and have over 1500pcs of Hornady brass.

 

[Rob01]

Yeah there is something going on if you are getting a carbon ring that fast. I have gone matches and not cleaning for hundreds of rounds and no issues. Might just be that factory barrel.

I only use Hornady brass also as I have a ton of it since 2008 and it works just fine for me. I have loaded up to 43.2grns of H4350 with no pressure but also in Bartlein custom barrels from 26-28” in length.

 

[moe africa]

Yeah there is something going on if you are getting a carbon ring that fast. I have gone matches and not cleaning for hundreds of rounds and no issues. Might just be that factory barrel.

I only use Hornady brass also as I have a ton of it since 2008 and it works just fine for me. I have loaded up to 43.2grns of H4350 with no pressure but also in Bartlein custom barrels from 26-28” in length.

I suspect its because N555 is a bit too slow and leaving deposits
I've never cleaned the carbon ring whilst using n555 the entire barrel life , it was alway pretty consistent but the h4350 in my gun was a bit
Erratic
First 4 of h4350 (41.5 gr)
2682
2687
2679
2671
The following 15 confirmation
2641
2652
2673
2648
2660

2725
2671
2691
2689
2690

2741
2747
2744
2732
2726
Last 8 after iosso with 7mm brush in chamber

2607
2637
2645
2656
2650

2665
2634
2650

 

[William Vogel]

I get 2750-2740 with Hornady brass, 147ELDM, 42.3 grains of IMR 4350 and Rem 9 1/2 magnum large rifle primer. It’s a Christiansen Mesa Long Range with factory 26 inch barrel.

 

[chuckshooter]

Is everyone running the same twist rate? I don't see one post that mentions twist rate.

 

[Rob01]

Mine have always been 8 twists.

 

[padom]

8 twist here

 

[moe africa]

Mines is 8 as well

 

[rijndael]

Is everyone running the same twist rate? I don't see one post that mentions twist rate.

From the test results I've seen, it was tested by Litz I believe, it's has a minimal impact on velocity. It was something like 1.3 fps for every twist change (whole number - 1:11 to 1:10).