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Rocky mountain bullets

16 Mar 2018
@ 06:14 pm (GMT)

John Mitchell

I scored big time in the Alaska draws this year. Bison, any Ram in an area that has big rams and a caribou tag that will be an interesting pack raft hunt. I have a 375 ruger with a load developed for the 350 grain Rocky mountain uld. At 500 yards I'm getting moa. I'm thinking the 325 grain with a little extra velocity might be better in the ruger. I've talked to George and read Nathan's 375 articles and RM bullet discussion. I realize that the 375 ruger might not be ideal for bison but the state thinks any 200 grain bullet out of a 30 cal is ok. My rm 350 is going just under 2400 fps. Anyone have any experience or thoughts on the 325 vs the 350 . George said it's best to shoot the heaviest bullet you can but that in the ruger the 325 might work better. Thoughts?


26 Mar 2018
@ 06:27 am (GMT)

Lane Salvato

Re: Rocky mountain bullets

I don't know why the 375 Ruger would not be ideal for Bison. I don't understand your statement. I think it would be ideal. I've been working on a load myself using the 338 Win. Mag. at lower velocities with a large, soft projectile. In my case I've been using a 285 grain ELD-M bullet traveling at around 2450 FPS. This is somewhat the same principle as using the Rocky Mountain bullets at longer ranges.

I also just finished killing a Nilgai Antelope with a 250 grain Swift A-Frame factory load out of my 338 Win. Mag. It expanded very well but kept it's base together. Penetrated to the vitals and killed him dead.

In my mind you could go with the largest slow moving bullet you can find from Rocky Mountain if you're planning on shooting longer range and you can't go wrong. At closer range your velocity being lower will help keep the projectile from being overstressed so it doesn't break up before entering the vitals.

Remember about a million of these animals were killed with 54 caliber musket balls moving slow. I'm no expert on this but I really believe in the big, soft, slow moving bullets.
26 Mar 2018
@ 08:44 am (GMT)

Nathan Foster

Re: Rocky mountain bullets
Hi John, OK, lets get into the guts of this.

To kill in style, it will be best to be at or above 1800fps.

1600fps is fine, but 1800fps will have more clout and less human error including wind error.

Note that the BC you are getting is probably around .8 at that speed. You will already have an idea of this based on current drops.

As is, you will be good to 600 yards / 1800fps.

If you want to shoot further or if you are finding the trajectory out to 300 yards or so to be too steep (time lost with dialing when shots should just be taken), then sure change to the 325gr. BUT TAKE NOTE: To increase down range impact velocities over the higher BC 350gr bullet, you will need a significant increase in speed. Otherwise the slower bullet will produce the same impact velocities as the faster bullet via BC's. There will also be an effect on BC (range parameters) between the faster and slower loads that cannot be factored in until you have tested both. Another rabbit hole.

This subject matter is not covered on this website and requires a different approach as per the cartridge book walls etc. The two factors in the paragraph above are your first port of call. Penetration will be what it will be. Impact velocities will be low with either and will aid penetration. I am sure you are well practiced at working a bolt handle quickly and getting back on target.

You must be near to seeing the first signs of spring. Hope all is well in your neck of the woods John.
28 Mar 2018
@ 05:22 am (GMT)

John Mitchell

Re: Rocky mountain bullets
Thanks Lane and Nathan
I'm happy to stay at 500 and under on a bison. Your comments confirm my load development with the 350 rm. My bc seems a bit under .8 and is accurate to 600 yards. Think I'll stay with the 350 since I can avoid another round of load development.
And yes the sun is no longer skimming the horizon here and the bears are coming out. All good here hope the same there.


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