bullet seating problems in 375 H&H

[Northman999]

Fellows,

I'm having problems seating bullets in my .375 H&H loads. I'm full length resizing using all RCBS equipment.

I can seat 300gr gamekings (boattails) , but I pulled apart one bullet (due to a powder problem) and found that the brass had really scraped into the boattail all around and actually pushed up a flange of copper. 220 gr Hornady FP's were way worse; often the case necks would bulge or sometimes even collapse right under where the bullets were seated.

I've tried using the deburring tool on the case necks, as well as lubricating them, but it makes no difference. I've also pulled apart my die and made sure that the neck sizer (expander??) was able to fit through already sized necks to see if maybe I wasn't having it set deep enough, but the sizer slides right through the resized necks. It basically seems like the damn necks are about 0.10 too small and are having a hell of a time getting over the bullets. I've heard that the neck expanders are adjustable, but I don't see how mine is and I've scoured the instructions and there's no mention of any adjustments in there. I reload eight different calibers and this is the only one I've had this problem with. Any help would be appreciated.

 

[303carbine]

That happens when case necks are tight and /or the cases weren't chamfered properly.Another brand of brass or bullets may solve this for you if it concerns you. Also some bullets are slightly bigger such as some.308 bullets might actually measure out to .309
The only time you have problems with accuracy is if the base of the bullet gets distorted,I have loaded bullets with the lead tips bent over with no loss of accuracy.

 

[Northman999]

That happens when case necks are tight and /or the cases weren't chamfered properly.Another brand of brass or bullets may solve this for you if it concerns you. Also some bullets are slightly bigger such as some.308 bullets might actually measure out to .309
The only time you have problems with accuracy is if the base of the bullet gets distorted,I have loaded bullets with the lead tips bent over with no loss of accuracy.

Thanks for the info 303carbine, I'll certainly keep that in mind.

I think I just found out how to adjust my neck expander however. After removing the neck expander/decapping pin from the die, I snapped a pair of vice grips on the shaft of the pin and grabbed on to the cone shaped neck expander with heavy pliers and managed to turn it a full turn more than it originally was. I then tried a piece of brass on it (by hand) and it seemed noticeably tighter on the neck. One more turn and I could not get the expander through the neck by hand. I gave it one more full turn (those damn bullets really didn't want to go in there) and reassembled my dies...well, I just loaded a box of shells and everything went smooth as silk and I checked each round in the rifle and they're all just as slick as you like. So it sounds like, I'm good to go.

Thanks again!