Resizing .243 brass

[TheHunter]

I don't know if anyone can shed any light on a issue I have noticed while resizing .243 brass.

 

As I use a Lee resizing rod\cutter-head while the case is in the holder, I have noticed that some cases only get trimmed on one side of the mouth!

 

This would suggest that the mouth of the cartridge has expanded in a non uniformed manner! I use Lapua brass which I know is top quality but can't see a reason why this would happen.

 

The loads do differ and hotter loads expand the case more but why is there a deformed mouth after firing some rounds (I never exceed max loads)

 

Has anyone had the same issue or know why it happens?

[wy111]

Ok, you may not me as pedantic as me, but this is the way I go for neck resizing…. Decap (Not resize), clean primer pocket, scrub inside of neck, tumble…..Lube outsideof neck(I still use a pad) and inside of neck with a lubed cotton bud (More important than a lot of reloaders realise) then neck size.

Next, using a rechargeable drill, shell holder and cutter, check all cases for size. Those that do not cut, I just use a quick touch with chamfer tool and put to one side, those that do cut, before I chamfer, I neck size again, check length and then chamfer.

Tumble all cases again to get rid of lube.

RELOAD

 

I use Remmy cases for 100 gn’s(Roe) and Winchester cases for 70 gn’s (Fox /seals)(Just thought I’d keep em different)

Am getting onto 7-8 reloads with the Winnies at the moment, I did notice offset cutting at first, from once fired, but now, length cutting doesn’t seem to be a problem. I think cutting by hand can cause some non-uniformity.

Another thing, that’s way I am saving my Winnie cases(Most used), I think that it is time for the necks to be annealed, as constant resizing hardens the brass and will not be resize correctly.

When you say hotter loads….how do you know? Have you chrono’d them, or just figures from manuals?

[marky123]

Hiya

The cartridge case isn't forced to 'grow' evenly,ie the same length all the way around the mouth.

MARK

[Browning]

Case wall thickness will also cause uneven growth. Turning the your necks may help but it's probably not worth it.

 

I've run standard Lapua cases and neck turned Lapua cases through my .243 with no appreciable difference in acccuracy.

[macca]

Hi,

Purchase a Lee neck collet die. Trim your brass after firing and before resizing. Clean the outside of the neck and then resize with the collet die. Clean primer pocket. Reload. Next time you reload you should not need to trim as a collet die sqeezes the neck in and does not stretch it with a button.

Cheers

[TheHunter]

So far i have always de-capped and resized first using a Lee neck sizing die, then cleaned the primer pocket followed by case length and finally de-burr and chamfer. Case is now ready to re-prime and load.

 

I took this process to be the norm? am i wrong?

 

Fister it is only on the odd one or two so i may have been guilty of not using enought lube inside the neck so will be very carful from now on.

[macca]

Hi

the following is from the lee web site

"There is no loading system that will load more accurate ammunition than Lee Collet Dies. We guarantee it in writing with every set. No one but Lee has ever dared to make a guarantee like this "Smallest group size or your money back." A collet squeezes the case neck against a precision mandrel for a perfect fit with minimum run-out. No lube case is needed. Cases last ten times longer, so the savings on only 35 cases will pay for the dies."

The guys who shoot long distance target rifle in our club (300 - 800 metres) usually use collet dies rather than button dies as they give greater consistancy accuracy and case life for the calibres they shoot.Collet dies are usually quicker to use than button dies.

Cheers