Why this flyer?

The force isn't slight. If you've done any straight-wall cartridge loading with conventional dies, you will have noticed you can get a surface bulge mirroring the base location of the bullet that is only clearly apparent on one side of the case. When that happens, the uneven bulge corresponds to tilt in the bullet that pushed the side of the case in one direction and pushed the mouth in the opposite direction. That requires lateral force. Where it comes from is the tilted bullet acts as a one-sided wedge being driven into the case mouth. It bends brass easily for the same reason you can easily move heavy objects apart by driving a wedge between them. In effect, it gives you a lever arm that magnifies the downward force in proportion to how many times the wedge is taller than it is wide, and it applies that force perpendicular to the direction the wedge is driven into.

I used to get a lot of those uneven bullet base bulges loading 45 Auto on my Dillon Square Deal. I finally made a powder tube for its measure with a Lyman M profile expander so I could set bullets straight up and down in the cases for seating and crimping. That put an end to the uneven bulges. The M-die is a way people make standard seating dies seat bullets straight. Lyman even boasts about this on their site. It works very well.
 
Unclenick said:
The force isn't slight. If you've done any straight-wall cartridge loading with conventional dies, you will have noticed you can get a surface bulge mirroring the base location of the bullet that is only clearly apparent on one side of the case. When that happens, the uneven bulge corresponds to tilt in the bullet that pushed the side of the case in one direction and pushed the mouth in the opposite direction. That requires lateral force. Where it comes from is the tilted bullet acts as a one-sided wedge being driven into the case mouth. It bends brass easily for the same reason you can easily move heavy objects apart by driving a wedge between them. In effect, it gives you a lever arm that magnifies the downward force in proportion to how many times the wedge is taller than it is wide, and it applies that force perpendicular to the direction the wedge is driven into.

I used to get a lot of those uneven bullet base bulges loading 45 Auto on my Dillon Square Deal. I finally made a powder tube for its measure with a Lyman M profile expander so I could set bullets straight up and down in the cases for seating and crimping. That put an end to the uneven bulges. The M-die is a way people make standard seating dies seat bullets straight. Lyman even boasts about this on their site. It works very well.
Click to expand...

Even the M die requires you to do your part in seating the bullet as straight as possible.
https://americanhandgunner.com/gear/crooked-seated-bullets-and-accuracy/
 
l I have never done any straight walled cartridges but I have loaded thousands of .260 Rem using my .308 die and am now using the Frankfort Armory universal neither of which provide any support whatsoever for the case neck and have no major issues.

I loaded 50 of the .260's yesterday for another powder test. Then I checked all on my Hornady and found most were less than .0005 out of alignment,those I let be. I found five or six at .0015 and one at .002 which I decided to brin aa bit more into line. I straightened the .0015's down to less than .001 with the Hornady. The .002 one I had to pull, renecksize, and replace the bullet because I actually damaged the jacket it took so much force to try and get straight.

Back when I first got my arbor press I can and have seated .260 and 6mm by hand using a Wilson inline and nothing more than my bare hand to press it down rather than the arbor. Just as a experiment mind you, uncomfortable on my dainty hand but easily doable. It does not take much force to seat a bullet even with .003 compression. Certainly less pressure than it took to try and bend that neck back into submission
 
Houndawg, how do you get your bullets so consistently seated so straight? Ive been checking mine for a month or so, and only the occasional one is less than a thousanth runout, usually .0015 to .003 runout.

Unclenick, yes I agree, I have seen the bulge on too many straight wall pistol cases, and they are always irritating, especially after I've seated many with no bulge and then here comes one with a bulge, I think I want to measure some of my pistol rounds, like 9mm, 45acp,, etc. and see how much neck tension they usually have.
 
Bear in mind my cartridges never hit the ground and are being shot single fed in bolt actions which have had the ejector pins removed.

My current method of case prep consists of

Cses wiped off then deprimed using a universal deprimer

sizing is done with a Redding S type bushing full length dies, shoulders setback .002 - .003 from fired

I use a regular steel bushings sized to give me .003 compression. Recently I switched to .005 compression which is then followed by a expander mandrel to give .003 compression.

cases are then wet cleaned, annealed on a Annealeeze, chamfered and deburred, then dipped in Imperial graphite

the cases above were the first I have done with the mandrel system and when seating they seemed to be more consistent than just those sized to final dimension.


edit-

my case prep is constantly evolving. I have annealed, not annealed, body then neck sized, lubed, not lubed, used Wilson inline dies etc etc. I try things myself and see if I can tell a difference on paper.
 
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Houndawg, sounds like you have your brass prep near perfection, I have a long way to go. You didn't mention if you neck turn your brass or not, or maybe you found it to be not worth the effort. I don't own an annealer yet, but am considering one now. Another thing I saw on here today, is someone claims your accuracy can be affected by lube being left on the finished round, after sizing with RCBS lube on a pad, I wipe each one off with a napkin and it seems to me that most the lube is off, and I have checked my prepped brass that's been waiting to be loaded and I really can't feel any lube.
Have you experienced any bad groups because of not getting lube off, sounds like you do take interest in that part by tumbling your brass after sizing?
 
yes I neck turn the brass when new. The downfall of bushing dies is you always leave the jam screw backed off 1/4 turn for float which will leave the last 1/10 inch or so of the neck unsized. If you want to neck turn used brass a ful length sizer such as the Hornady Custom grade with the expander button removed is necessary.

I use Imperial graphite for neck lube, dip the neck in then wipe off the outside to keep my hands as clean as possible. I do mine after sizing and just before seating the bullet

https://www.midwayusa.com/product/1012768197?pid=614125

I am happy with my ammo's performance in matches now if I could get my wind/mirage skills and technique down and stop dropping 3-5 points per target becasue of my own screwups. Last match last target I shot 2 X's for sighters then dropped 3 in the 9 ring the first three shots. I stopped shooting, stood up stretched, took a few deep breaths repositioned myself and finished up with a 195/11X score. No doubt in my mind all my 9's are due to me screwing up, not my ammo or rifle
 
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