300 Ultra Mag Reload Question

[300 Mag]

I'm have loaded some 300 untra mags for a friend of mine. I used the 180gr. Accubonds with IMR 4350 powder @ 82.0 grains. He wants me to try some loads with Reloader 25 powder. The nosler book I have doesn't have Reloader 25 loads in it. I was wondering what the recommended load was with this powder as well as the max load with this powder. Thanks

 

[the444shooter]

Reloader 25 will give you the best velocities, but it is also one of the more temperature sensitive powders out there as well. There have also been a lot of reports about the variations from lot to lot. I would recommend Hodgdon Retumbo. Not temp sensitive and will give you CONSISTENT velocities within 50 fps of RL 25. Retumbo is the way to go, and it is what I switched to in my 300 RUM. Just a heads up for you.

 

[clambdin]

I agree with the retumbo, my savage shoots .500 moa with 180gr AB @ 3250 fps using 100.1 grns retumbo...deadly on elk ! remember start your loads low and work your way up !

 

[300 Mag]

Thanks for the info. I will give the retumbo a try. What is the MAX load for this powder w/ 180 Accubonds?? He has already purchased the Reloader25 so I guess I'll have to try it as well. Does anyone know the MAX load with this powder? I was told it was over 100 grains but I'm not sure of this and don't want to overload it.

 

[jbrbro]

DO NOT try to load 100grs of RL25 under a 180 gr bullet in the 300RUM without working up very cautiously to it! Alliants website data lists 96gr as MAX under a 180 swift A-frame and less then 90 as max under a 180 Barnes X-bullet. so start probably at 90 grains and work up slowly and you'll be ok with the accubonds. and they list velocity of the swift load at 3,250fps so that about duplicates factory speeds if I am not mistaken. with retumbo Hodgdon list start at 94gr - 3182fps and max at 100.5gr 3300fps that with a sierra 180 spitzer BT. Best of luck

Chris