450 Bushmaster reloading advice W/Hornady dies

[RBDMTJager]

Been reloading handgun (38/357, 44mag/44spcl,45acp, 45LC, 40S&W, 9mm) and bottle necked rifle cartridges (338wm, 300wm, 300wsm, 308win, 7mmstw, 6.5x55, 35Rem, 223/556) for about 33 years now so I am not a beginner reloader.

Although I have reloaded 10's of thousands of straight walled HG cartridges I have never reloaded a straight walled rifle case before. I have older (newest at least 15 years old) reloading manuals form just about EVERYBODY (Hornady, Lee, Lyman, Nosler, Hodgdon, and Sierra) and have read them all about reloading straight walled rifle cartridges, but essentially the only thing they all state to do differently reloading with straight walled rifle cases is to bell the case mouth per the reloading die manufacturers recommendation.

I know the 450 Bushmaster head spaces on the case mouth so I am concerned about achieving as correct of MINIMAL case belling as I can to maximize the accuracy potential of my reloads. I also plan on using a Lee Factory Crimp die to crimp each reload as I have done with all my HG and some rifle rounds.

I walked into Cabela's some time ago and low and behold they had a one set of Hornady Custom Grade four die set in 450BM along with Lil Gun and Hornady .452" 245 grain Interlock and 200 grain .452" FTX and I used up all my Cabela's points and walked out with enough powder and bullets to make several years worth of reloads.
I also bought a Lyman ammo checker for 450BM as well.

My questions are
#1 how does one determine when they have achieved the lest amount of belling of the case moth needed to seat a bullet, is it safe to assume it would be similar to the minimal case belling I do to my HG cases?
#2 Must I bell the case mouth at all
#3 Is fallowing the Die manufacturers recommendation on crimping going to yield my best accuracy results?
#4 Any other advice tips or tricks reloading straight walled rifle cartridges as well as on case moth belling or crimping to maximize consistent accuracy would be greatly appreciated.

[Hoot]

IMHO, you don't need to bell the case mouths. I did the very first time I reloaded and never since. The good news is it doesn't have much impact upon head spacing but it can have an impact upon ultimate neck tension, albeit just a small amount. The 800 pound gorilla in the room is getting optimum (meaning a lot) of neck tension. Anther good piece of news is don't fret too much about how much you taper crimp the mouths. Years ago, I determined that the cases will still positively headspace off the end of the chamber even down at .460. I don't advise or ever crimp down that far however. Usually about .474 is the most I go. With smooth sided bullets, its more like .476 but you can benefit greatly using bullets with either a cannelure to crimp down into or as in the case of Barnes bullets, crimp down into one of the grooves between the driving bands. With jacketed bullets, stay away from the heel of the bullet. IE don't crimp too near it as the heel will just distort and lets be smart, that's the last thing that touches the rifling on the way out. Always use magnum primers. Rem 7 1/2 are my favorite but CCI 450 are just as good. WSR aren't too shabby despite not carrying "Magnum" in the name. I can not speak for Wolf or Tula Magnum primers as I've never tried nor compared them to anything else. From 200gr to 300gr bullets, its near impossible to do better than Lil Gun powder if you can get it. Despite them being longer handgun style bullets, always lube your cases before resizing with a good lube like Imperial or some other kind of wax/grease combo. I have not had good luck with One Shot in any caliber. Again, my opinion is that the Hornady die set is the best bang for buck out there. Lastly, my experience has been that fastest is not always the best load. These big cross sectioned bullets are plenty lethal at modest velocities and more enjoyable to shoot, especially with "pop gun" length barrels. I like big barrels, I cannot lie. A muzzle break will help but not as much as with bottleneck calibers. The best recoil reduction investment, aside from heavier, is a good recoil pad. I use all three and i can do a 50 round range visit in my tee shirt with no impact upon my comfort all the way through the last shot.

I probably forgot something you asked but that's all that comes to mind. off now to watch the Twins.

Hoot

[RBDMTJager]

Hoot,
Thank you for your superbly written and extremely well thought out reply. I will print it out and use it as a reference material when I go to reload my first batch of 50-60 450BM reloads plan on reloading Friday.
I have all my reloading components now and all that is left is awaiting for my LGS to get my rifle in which also should be on Thursday or Friday in the AM.

Will post my results along with load data and targets.

Once again
be well and greatest of thanks.
Regards,
Arthur.