243 pressure issues

i apologize for the long post, and let me thank you in advance for taking the time to help/share your knowledge. i want to clearly explain every little detail in order to help narrow down the cause of this problem. i am fairly new to reloading as i have only been in it only one year and have only gotten my information through reloading manuals as well as forms like this. i understand that despite hundreds of hours researching the subject of reloading, it doesnt leave me much more than tired and having to sort through the true and speculated information. i have reloaded a few thousand rifel/pistol rounds without any issue but have recently run into an issue while trying to reload 243 win for my girlfriend's savage 99e. I started reloading for this rifel when the reloads (unknown recipe) she was shooting from an experienced family friend started splitting the cases in half approx .365" up from the base of the cartrige on two occasions.

load #1) I started with clean mixed once fired brass (primarily rp and win) all trimed to 2.035" and used a rcbs 243win die, and started loads straight out of the hornady reloading manual 8th edition for the correct bullet (100 gr sp interlock 243). All these loads used fed 210 primer per hornady. I started with 31.5 gr imr 4064 and a col of the published 2.630" with a very very slight crimp. when i went to test these rounds, i found that on occasion some cases were again separating in half in the same spot as the other reloads, and sometimes the primers would back out or flatten or both. other times the cases seemed fine, other than a shiny stress line all the way around and sometimes a fracture 2/3 or all the way around the case would show in the same spot the cases were splitting.

after this i measured the headspace using a resized trimmed case that i cut a slit into the neck and just slightly seated the 100 gr interlock and chambered the uncharged/unprimed round to measure where the bullet be pushed back in the case and would contact the lands. the col of this test was 2.810" which i assume to be a bit long.

I then reloaded a few different loads of different amounts of imr 4064with several col for each change of powder weight. all of these loads produced similar results indicating high pressure. all loaded brass was checked and the correct size in all dimensions. each powder charge was hand weighed on a rcbs manual scale calibrated correctly. none of the following reloads had any crimp.

all loads used once fired mixed brass cleaned and trimmed (after resizing) to 2.035" using imr 4064 and fed 210 primers in the same rcbs dies on a single stage rockchucker.


#2) 31.5gr, col 2.710" fired 3 rounds, one primer flattened and backed out slightly, the other 4 had slightly flattened primers and all 5 have small dimples rising up from bolt face and all are slightly cratered around firing pin dent

#3) 31.5 gr, col 2.805" fired one round, flattened primer with cratering and split the case in two separate pieces. didnt want to fire the rest of these.

#4) 32.6 gr, col 2.633", 3 rounds. backed out primers with very slight cratering. all had stress line all the way around cases.

#5)32.6 gr, col 2.710", 3 round. all backed out primers. two with slight cratering and one with more obvious cratering, all had lines around case which were less visible than load #4.

#6)32.6 gr, col 2.810", 3 rounds. one backed out primer and cratering with stress line around case, two flattened primers with cratering, one with cracked case 2/3 around and one with two stress lines all the way around case. the first was in the same .365" up and the second was .665" up from the bottom.

#7)34.2 gr, col 2.633" 3 rounds. all flattened primers with cratering, all with stress lines at .365"up from base

#8)34.2 gr, col 2.710" 2 rounds. two flattened primers with cratering, one of which was backed out.

#9)34.2 gr, col 2.810" 2 rounds. both had flattened primers with cratering and one had cracked case all the way around in same spot as others, the other case had a stress line around case in same spot.

the min published load with imr 4064 per hdy is 31.0 gr and i started with 31.5 gr. and went up from there to max load of 34.2 gr. my original thought was that the .2" gap the bullets traveled was causing a pressure spike when they would hit the lands but changing the col didnt help even with the col set to 2.810" where the bullet is just touching. or for some reason there was some sort of under pressure issues causing the backed out primers. i got confused by the flattened primers and the backed out primers as well as the splitting cases as t thought they showed contradicting signs. before i start over with cci primers and/or different powder and risk blowing myself up anymore i'll wait to see what you kind folks can come up with (which i should have done in the first place). and yes i realize that this was dangerous testing these loads now that i know my original suspicions were incorrect.

thank you so much and any help would be greatly appreciated as well as needed. dont be afraid to hurt my feelings as i am open to learn any way i can.

thanks for the heads up longhorn. thats something i read about on another forum but i guess it wasnt too accurate. the reccomended col from hornady was used in the origional load that first brought the problem to my attention. i forgot to mention that the rifle shoots fine with factory loads.

thanks guys! anyone know of a decent smith in northern ca? the closer to the bay area the better!

thanks folks. and strongbad- all the brass was once fired im pretty sure all out of that same gun.

all brass was once fired and then FL sized to where the die was touchong the shell holder at the top of its stroke. actually when the shell holder had camed over from the top of its stroke. thanks Centaur 1. that was going to be my next question. it is a great feeling to have the assistance from so many people here. i wish everyone in the world was as helpfull to others.

my next questions are... when i resized these cases, i did about 300 of them at the same time and primed them as well so once i found an accurate load i could load up a bunch. i guess all those are trash now? or just give them to my girlfriends dad to shoot out of his 243s? i dont want to fire form them back with these kinds of pressure signs.

also, this 243 is a lever gun, which to my understanding has less mechanical advantage than bolt action. is it very dangerous to just neck size when reloading for a lever action? the last thing i want is to have a round not chamber all the way when a 300lb boar is charging my girlfriend? although that could be better than having chunks of metal and hou gasses flying in her face from too much headspace.

for pistol powders i have- titegroup, h110, only about 1/4 lb of win 296, tons of hs-6, blue dot, pistol power, an old 3lb can of Alcan Al-5, and an old 15lb cardboard drum of hurcules (now alliant) red dot which is still good

i just got done comparing these reloads to ppu 100 gr sp which was the only facory loads i have laying around. everything seemed dead on with those and i checked all dimensions given in the hornady reloading manual from the illustration with out anything being out of spec. the only measurement i could not take was to confirm that the angle of the shoulder was 20 deg. the only thing i could find is at the bottom of the case shoulder the ppu ammo was much more rounded where the shoulder starts where mine is not very rounded. more of a clean change to the shoulder angle.

I also compared the fired reload cases to some of the loads i didnt fire but from the same batch. everything was the same except the case body just before the shoulder starts was a few thousanths larger dia on the fired brass than the unfired, the neck of the case was quite a bit larger dia on the fired brass and the fired brass was stretched a bit but distance from the case head to where the shoulder starts and stops seemed the same although i was eyeballing it with a caliper.