300 RUM w/ Seekins mag Loads ??

[Cross C]

I know there are plenty of folks out there experimenting with the extra room allowed by seekins bottom metal with the ultra mags. I'm about to take delivery of another beanland work of art chambered in 300RUM.

Does anyone have any loads or wisdom using Retumbo or H1000 and 210 VLDs with the extra OAL?

I know there are plenty loads out there at standard OALs via the searches through the hide, but I'm unable to find anything related to the extra capacity.

Hodgdon states 200 Accubonds @3.600" can take 95.5 grs. of Retumbo. The barrel length will be 27" so I'd like to use a slower burning powder.

Thanks!!!

 

[Cross C]

Re: 300 RUM w/ Seekins mag Loads ??

Anyone??

 

[Cross C]

Re: 300 RUM w/ Seekins mag Loads ??


Just to contribute to my own question so anyone in the future can dig this up and have a better starting point than I did. I started at 90.0 gr of Retumbo in the longer case with the Seekins BDM and worked my way up with a chrono until I reached pressure. I stopped at 92.5 as it was pushing 210 VLDs 3175 avg out of a 27" tube. I settled on 91.7 as it shot nearly one hole (5 shots) while staying above 3100 fps ( 3115 avg.).

Another Beanland work of art!!

Feel free to pm me if anyone needs any details on the load work up etc...