25STW carbon excess

[21buck]

Just setup my Sako 25 STW with a 29" SS barrel. I am in the process of breaking in the barrel. The powder is H1000. From the very first shot, I noticed that there is an excessive amount of carbon left in the barrel. Some would suggest that there is an incomplete burn of powder, not hot enough primer, go to a faster burning powder, not loaded hot enough. What's the answer or explanation. The accuracy seems great. Your opinions please before I load up a number of rounds for the process. Thanks

 

[Dano1]

The .25 STW is a very over Bore cartridge, so H1000 just right if anything it's probably too fast of a powder. If you are using standard primers, definately go to a magnum primer. H1000 is a "dirty" powder from my experience, try retumbo or RL-22 or RL-25.

Dan