.460 S&W Magnum Primer Question

[EddieCoyle]

I posted this over at the S&W forum, I figure I'd try here too:


I loaded up about a hundred .460 Magnums with 240gr Hornady XTP Mag bullets, 46.5 grains of H110, and CCI large rifle primers.

The velocity (measured about 15' from the barrel) ranged anywhere from 1749 to 1990 fps. The powder charges are very consistent, as were the crimps (I measured them after I began to notice the wide velocity variations). I trimmed all of the cases to the same length before I started to ensure that I'd get good consistent location on the crimps as well.

Here's my question:

Should I be using large rifle Magnum primers instead of large rifle primers? Would this help to stabilize the velocity?

 

[EddieCoyle]

​

Anybody?

 

[Grumulkin]

There is no reason a 460 S&W cartridge should need a large rifle magnum primer but if I were you, I'd try a magnum primer anyway. In loading for a 357 Herrett with IMR 4227 I've found a definite accuracy advantage using large rifle magnum primers. In loading for a 7mm Remington Magnum, I use large rifle primers as opposed to magnum primers and get excellent accuracy. What primers work best, doesn't always make sense.

Another point, if you're getting good accuracy with your loads, don't worry about a little variation in velocity. You might also get better accuracy/velocity consistency with heavier bullets.

 

[NavyLCDR]

The loading manual says to use large rifle magnum primers, that's why I do.

I found 46-46.5 grains of H110 to be too light. Up around the 48 grain range worked better for me. I also switched to Lil' Gun powder and definitely won't go back to H110, I think Lil' Gun is mucho superior.

My preferred load is 47.5 grains Lil' Gun behind 250 grain Hornady HP/XTP with large rifle magnum primers. I don't have a chrony but the groups are very tight and the recoil seems the same as Hornady factory ammo.

 

[EddieCoyle]

Thanks NavyLT! I'll try bumping the charge up a bit.

 

[EddieCoyle]

You use the XTPs and not the XTP Mags? The people at Hornady told me not to drive the regular XTPs faster than about 1500 fps.

 

[NavyLCDR]

Yes, that is correct, I use the regular XTP's. I only use mine for target shooting and only shoot at an indoor 30 yard range. I think the concern for the regular XTP's is expansion characteristics, so what I load may not be suitable for hunting purposes, but it puts accurate holes in targets and is a hoot to shoot!

I clean the gun after each range session and have noticed no leading or jacket shedding in the gun and no forcing cone erosion. We've got probably 400 - 500 rounds through it.

Don't try a copper plated bullet, though. Those will leave the copper plating behind jammed between the cylinder and the forcing cone :banghead:

BTW, to get the info on the brass length and primer info from data.hodgdon.com, you have to click on the Print button. Then you will get a nice table with all the proper info at the top, whether or not you print it.

 

[jethro75]

The way I read about the difference between the XTP and XTP magnums is not to do so much with the expansion issue, they would be fine for say hunting with a 45 long colt, but more of how they hold up with the higher velocities of the 454 and 460.