Guys are still having trouble with various cases with too thick of sides. The thick sided case have enough brass material to thin up sides and stretch them way out to 4 or more inches,,And they'd work with proper slow powders, we are working on a 458 HSM experiment, with case holding 400 gr ball powder under the bullet. ED
More about our 416 HSM from BMG brass, and our 416 HE & 460 HE from our 585 HE cases Got reamers for 375 HE, 416 HE and 416 HSM,....
460 HE & 460 HSM are all spec'd, got HE reamer soon have HSM reamer...Our HSMs have a Wea type radius on the shoulder..
The fellow that set up our 416 HE in an ELR rifle and got 1/4 min accuracy, They got some game out west over 1400 yds.. .Here is the gun they set up. Using a K&P 34" barrel on a BAT action.....Ed
And have got a 460 HSM figured out, and the impetus for that is some asking about one and the great line of 458 bullets CEB now has. It will hold more powder than the 416 HSM.....Ed..
The guys that did the super accurate 416 HE did another 416 HE that has an 8" longer 42 inch K&P barrel..
Used a Stiller action and same load with 475 gr bullet, as in first gun and and gained about 200 fps with good accuracy. 3065 fps. Tested 2 groups of 3 and less than 1/2 min moa.
And loads they used are not the highest speed loads the cartridge is capable of....Here is print with specs for the 416 HE reamer chamber ....Ed....
More about he guys that did the accurate 416 HE, they did a 416 HE that has an 8" longer 42 inch K&P barrel..
Used longer barrel and the same load with 475 gr bullet, as used in the first gun and and gained about 200 fps with good accuracy,. 3065 fps. Tested 2 groups of 3 and less than 1/2 min moa.
And loads they used are not the highest speed loads the cartridge is capable of....Here is picture.......Ed....
Here is print with chamber reamer specs for the 416 HSM chamber..There are 3 base sizes we have, depending on actions used. Got reamers for all 3.. Got cases for all of them.. Our cases are public domain, so that is why I post info and specs. Manson makes reamers I use,,, Ed. [Linked Image]
Here is reamer print with chamber reamer specs for the 460 HSM chamber .Couple guys getting set to do 38-40 inch heavy 458 target barrels...Ed.... [Linked Image]
With 40 inch barrel 416 HSM ,475 gr, get 3650, over 13,000 ft lbs muzzle energy. Got guys getting set to have 38-40 inch 458 barrels made for 460 HSM.Ed..
More info on this gun, we did it for testing 416 HSM with a rebated rim, to check in intermediate size actions, with the longer, stronger, bolt lugs, Ed..
Here is experimental action for 416 HSM in a heavy stock....We lengthened port a little, set bolt stop back , opened bolt face fit the 416 HSM rebated rim. Ed. [Linked Image] Here is comparison of Montana PH to Pierce action we modified to use for rebated rim 416 HSM testing..Ed. [Linked Image]