Max charge difference

[oldfatguy]

Been working up OCW loads with good results. The bullet maker’s max charge of H4350 for 123 SMK in 260 Rem is over 3 grains lower then that listed by the powder manufacturer. Any ideas why the difference and which one to use?


OFG

 

[El Cid 92]

Different Lawyers. Different levels of acceptance of vicarious liability.

Find a proper starting weight and work up slowly to find the max charge that your equipment will accept.

Andrew

 

[Deleted member 10043]

Show pics of your max load cases. 3 grains is a lot of difference. We can't help without more information like MV, seating, and so forth. For what it is worth I had a similar problem with 260. The fucking smith must have used a field gauge to set headspace.

 

[oldfatguy]

Pictures are beyond my skill set right now, but the primers showed no flattening at all, and the case heads show no marks.

Really not looking for the max safe charge, but a good node in the upper end.

OFG

 

[supercorndogs]

Look at the brass and primers both used. They are probably different. Specifically one probably used a much heavier brass, with less internal capacity.

 

[Steel head]

Look at the brass and primers both used. They are probably different. Specifically one probably used a much heavier brass, with less internal capacity.

This.

Different 260 brass will noticeably affect max charge.

The safe 147 load in my 260 would 100% blow primers and ruin brass if I switched to lapua or norma brass.

 

[ShtrRdy]

You're just going to have to monitor how the reloader rounds work in your rifle. I would work up toward the powder manufacturer max while doing an OCW sequence and monitor pressure signs carefullly.

 

[918v]

Look at the brass and primers both used. They are probably different. Specifically one probably used a much heavier brass, with less internal capacity.

Exactly

 

[918v]

Different Lawyers. Different levels of acceptance of vicarious liability.

Find a proper starting weight and work up slowly to find the max charge that your equipment will accept.

Andrew

While the lawyers may be different, that’s not the reason. See, there is the law and there is physics.

 

[Deleted member 10043]

I didn't read the original post correctly. Sierra tends to be very conservative but they do respond to email within 24 hours. Ask them.