6.5x.300 RUM
Hi folks. I have built and worked up loads for various wildcats out of .300 and
.338 RUMs. I am currently working on loads for a 6.5 x .300 RUM. I discovered
after I had started that one can save some effort by starting out with 7mm RUMs. I started out with the slowest possible powders. Because I could find no
recipes for this case I began very cautiously and was rewarded with terribly low
velocities and very large fluctuations in velocity. Just as I was beginning to get
velocities up ( 37-3800 fps with 123 SMKs and 3600 fps with 142 SMK's ) I ran out of
8700 and have been unable to find more. I worked on RE-25 and got high pressure and pierced primers at around 3575 fps with the 142s. My gunsmith/friend
recommended 5010 and Retumbo. I have been working on these and H50BMG,
H1000, US869. Right now my best accuracy is coming with H1000, US869 and
H50BMG, with 869 the best. I am starting to get some moderately hard bolt lift at around 3550 fps with the 142s and 3700 fps with the 123s. I get occasional pierced primers 100fps after that.
I know that I will have short barrel life but I will live with that in exchange for
performance that sends 142 grain bullets out close to 4000 fps. As good or
better than .22-250s or .220 Swifts with 50 grainers! I can rechamber and
save some money that way before I have to buy a new Kreiger. I don't have
the numbers with me tonight, But I have fed the data into my Sierra ballistics
program and the ballistic curve looks as straight as a tight string compared to
6.5-06s and 6.5 Creedmores and all the other so-called hot numbers. They are still supersonic and have usable energy at incredible range. I was hoping
to get it all worked out before winter and cold weather comes to our range,
but that is not going to happen, I do not think-it is snowing right now! Bummer. I work at our range however and I may still get the loads ironed out.
I will post the data and some pictures if I can figure out how to work these
contraptions. If anyone has any help for me, including where I could get lots
of AA8700, please pass it along. I am also building a wildcat .338 that I am
hoping will get a real 3200-3500??? fps. One of my primary considerations is
the availability and cost of brass and bullets. However, the primary design
consideration is being able to use an off the shelf 700 reciever and bolt with minor modifications. I do not want to even consider custom $1000 recievers.
Thanks for listening.
Hi folks. I have built and worked up loads for various wildcats out of .300 and
.338 RUMs. I am currently working on loads for a 6.5 x .300 RUM. I discovered
after I had started that one can save some effort by starting out with 7mm RUMs. I started out with the slowest possible powders. Because I could find no
recipes for this case I began very cautiously and was rewarded with terribly low
velocities and very large fluctuations in velocity. Just as I was beginning to get
velocities up ( 37-3800 fps with 123 SMKs and 3600 fps with 142 SMK's ) I ran out of
8700 and have been unable to find more. I worked on RE-25 and got high pressure and pierced primers at around 3575 fps with the 142s. My gunsmith/friend
recommended 5010 and Retumbo. I have been working on these and H50BMG,
H1000, US869. Right now my best accuracy is coming with H1000, US869 and
H50BMG, with 869 the best. I am starting to get some moderately hard bolt lift at around 3550 fps with the 142s and 3700 fps with the 123s. I get occasional pierced primers 100fps after that.
I know that I will have short barrel life but I will live with that in exchange for
performance that sends 142 grain bullets out close to 4000 fps. As good or
better than .22-250s or .220 Swifts with 50 grainers! I can rechamber and
save some money that way before I have to buy a new Kreiger. I don't have
the numbers with me tonight, But I have fed the data into my Sierra ballistics
program and the ballistic curve looks as straight as a tight string compared to
6.5-06s and 6.5 Creedmores and all the other so-called hot numbers. They are still supersonic and have usable energy at incredible range. I was hoping
to get it all worked out before winter and cold weather comes to our range,
but that is not going to happen, I do not think-it is snowing right now! Bummer. I work at our range however and I may still get the loads ironed out.
I will post the data and some pictures if I can figure out how to work these
contraptions. If anyone has any help for me, including where I could get lots
of AA8700, please pass it along. I am also building a wildcat .338 that I am
hoping will get a real 3200-3500??? fps. One of my primary considerations is
the availability and cost of brass and bullets. However, the primary design
consideration is being able to use an off the shelf 700 reciever and bolt with minor modifications. I do not want to even consider custom $1000 recievers.
Thanks for listening.