Powder choice and long barrels

[WillyG]

Hi guys, I'm new to the Highroad. I have Savage 6.5 Creedmoor with a 27" Criterion barrel. Nathan Foster of Ballistic Studies talks about different powders for long and short barrels in other calibers. I see the #1 powder listed is always H4350 for a creedmoor. I have Varget and IMR4350, and haven't tried H4350. Do any of you notice a difference with powders based on the length of the barrel in a rifle, say 22" and then longer ones? Thanks for any input.

 

[gotboostvr]

The vast majority of the time, whatever load is fastest in a long barrel, will be the fastest in a short barrel.

 

[WillyG]

Ya, thank you for confirming what I already thought. I was 2nd guessing.

 

[Charlie98]

That doesn't necessarily mean it's the best powder...

For example, I load for .348WCF, one of the recommended powders for it is H4831. Under normal circumstances... a rifle-length barrel and a 200grn or heavier bullet... it would probably work pretty well... but not so much in my 20" Browning's barrel. A starting charge of H4831 under a 200grn bullet gives me crazy muzzle blast and concussion... and poor accuracy. A switch to a faster powder... IMR3031 in my case... gave me better velocity (because I was able to come up off the starting charge,) and a smaller SD, with better accuracy. It's a better fit for my shorter barrel. I know in your case you are talking longer barrels... so the slower powder(s) will be of benefit for you, most likely.

 

[jmr40]

With 140 gr and heavier bullets H4350 is considered the holy grail of 6.5 CM powders. Of course every rifle is somewhat different and it may not work out best in every rifle. In theory IMR4350 should be very similar, but I just don't know of anyone who has used it enough to say for sure. Varget is probably OK with lighter bullets, but wouldn't be my pick for the heavier (longer) high BC bullets most people want to shoot in the 6.5.

H4350 is what I use, but I did experiment with Ramshot Hunter at one time when I was low on H4350 and couldn't find any. I didn't spend a lot of time with it after I found a good supply of H4350, but the results were promising. I've read several posts where guys also had good luck with R16 and 17. By all accounts they are picking up some speed with R16. I've seen some load data posted online from some of these guys, but have not been able to confirm any of it from a loading source. I don't mind "borrowing" someone else's loads if I can confirm them with book loads. But I won't blindly use another's load otherwise.

 

[WillyG]

I use a 140 grain Sierra Game King bullet in my 6.5 cm. Once I finished my H4895. I tapped into my IMR4895, more or less, to run out the 1 lb. bottles. The IMR4895 shoots fantastic, and I really can't see how I could improve on accuracy with anything. Based on what I had read, I picked up some Varget, a 2nd choice, only because it was available at the time. I haven't tried it yet.
I will make some ammo using some IMR4350, H4831sc, and Varget and see how it goes. That H4350 is always on my mind as a must have.

The fast and slow is what trips me up, so now, even though I've read it before, it makes sense. That explains why my switch to a 26" barrel on my .270 shot so erratic with the same H4831 load. Once I dialed it in, it shoots lights out and even more consist on paper than the IMR4350. I seem to have good and bad days shooting the IMR, and it really does seem to do with the outside temps.---For sure a batch of Nosler brass using IMR showed more signs of pressure than the 4831 after a couple of reloads.

I've wondered about the R-16 and R-17 and read some good info on them, too. One thing I notice in my old Hornady #9 manual is that their data is different from what Hogdgon publishes on their website. That's a whole other thread. Thanks for all the input.

 

[Charlie98]

As a general rule, H powders are more temp stable than IMR, and more so than RL’s.... so it’s not just you.