Split 303 cases. What did I do wrong?

[emtjakster]

Good evening gang, need some help from the older and wiser gang here.
I started reloading .303 British and ran into a small issue with my first batch of rounds.
Out of the 20 that I reloaded 3 split. Luckily I though of this before hand and had a case extractor tool handy
I don't think I over charged the powder, the primer not being wavy is pointing me in that direction
But I did crimp the rounds and I think that may have caused the over pressure and ripped the cases
Here is my recipe and below are some photos of the damage.
I would like to know y
ou options and if I should junk the empty cases. I did check to see if the base was coming apart and there does not seem to have and ridges on the inside that I noticed
1) Remington 174gr once fired brass
2) Hornady 174gr FMJ (3105) Rounds
3) BN(c) powder 46.4gr
4) Lee single stage press and dies

Left case is reloaded and interacted, Right case is reloaded and split

Both cases are reloads and split, one cleaned the other not

Both reloaded bases, one cleaned the other not.

Two reloaded rounds that did not split, I cannot see any damage to the cases

Reloaded case, both split with the base. One is cleaned the other is not. Not that even after cleaning, 4 hours in a tumbler, the bas is still dirty

I need to figure out where the scratch came from. I did have some issues with the mag not feeding correctly

Thank you again for looking and helping
Jack

 

[yomomma]

Large chamber / head space, common problem

 

[maple_leaf_eh]

The common belief is that all cases must be full-length resized as a step in reloading. If the case was fired in your rifle, and you don't plan to fire those reloads in another rifle, full-length resizing is unnecessary. It is possible that the reloading die is specified to be the minimum industry dimensions, it is possible that your chamber is at the largest acceptable end of the specifications. If you make the case small and fire it in a big chamber, the brass is going to expand with the pressure. Those splits could be where the pressure overcame a naturally occurring weakness in the case. The solution is just neck size and be done.

BTW, one CGN'er (maybe BigEdP51 or a name like that) posted is a little *.gif of a .303 case firing, showing the effects of the firing pin moving the case, the pressure expanding the case, the case moving backwards against the bolt, and the bullet finally leaving the neck. All very instructive.

 

[rosconow]

I can't open your pics. But let me guess, they're cracked/ split 1/2- 3/4" from the bottom?

Like yomamma said, enfield chambers are very generous. Low case life is expected with incipient case head separation the likely result.

After fire forming my brass, I only neck size thereafter. I'm on 6 reloadings of herters brass with no sign of the dreaded white ring at the case base. I'm lucky though having a fairly tight chamber on my 1920 lithgow.

 

[Winchester-1897]

Neck size only on the next batch.

 

[bang_on_sk]

only thing to add, if you're fire forming, get some o-rings and put them in front of the rim, this will hold it back against the bolt face, resulting in a more effective fire forming and less damage to the casing.

Also getting the headspace checked wouldn't hurt (if you haven't already)

 

[maple_leaf_eh]

The common belief is that all cases must be full-length resized as a step in reloading. If the case was fired in your rifle, and you don't plan to fire those reloads in another rifle, full-length resizing is unnecessary. It is possible that the reloading die is specified to be the minimum industry dimensions, it is possible that your chamber is at the largest acceptable end of the specifications. If you make the case small and fire it in a big chamber, the brass is going to expand with the pressure. Those splits could be where the pressure overcame a naturally occurring weakness in the case. The solution is just neck size and be done.

BTW, one CGN'er (maybe BigEdP51 or a name like that) posted is a little *.gif of a .303 case firing, showing the effects of the firing pin moving the case, the pressure expanding the case, the case moving backwards against the bolt, and the bullet finally leaving the neck. All very instructive.

Scroll part way down the link to see what BigEdP51 was suggesting. He posted his diagrams again.

https://www.canadiangunnutz.com/forum/showthread.php/1618821-Bad-shoulders-and-recoil/page2

 

[cosmic]

Well - I don't recognize the powder (BN(c)?), but it would appear to be a hefty amount.

 

[kawicrash]

Well - I don't recognize the powder (BN(c)?), but it would appear to be a hefty amount.

I imagine he means BL C(2)

 

[cosmic]

Well - If it is BL c2 then he's at max published load, and who knows what the actual load pressure is..., add thin brass, undersize rims....

 

[leebuilder]

All good info, for neck splits. I have seen batches of bullets all recent production have neck splits due to storage in an ammonia enviroment, ie a barn. Hatchers note also mentions the effect. Loading near max will end case life for 303.

 

[Ganderite]

If that is BLC2, why so much?

Neck size only, and drop powder charge by 5 gr if you want to re-use the brass.

 

[Leeper]

Even with neck sizing, a Lee Enfield will produce head separationsin four of five loadings if heavy loads are used.

 

[porpoise]

I gave up reloading my 303. a gunsmith told me headspace was fine. The barrel looks in good shape. The rifle shoots fine. It splits cases on reloads. On ejection i could see the rim was canted but googling around i found out this is normal. Do your cases come out straight?

 

[enefgee]

I gave up reloading my 303. a gunsmith told me headspace was fine. The barrel looks in good shape. The rifle shoots fine. It splits cases on reloads. On ejection i could see the rim was canted but googling around i found out this is normal. Do your cases come out straight?

Headspace can be fine, barrel can be excellent/new and you'll still get bent cases in some rifles - it's because they made the chamber...generous (yeah, that's the word) in order to be able to reliably fire crap ammo in terrible conditions. The case has a tendency to tip very slightly in the oversized chamber and when it's fired it comes out 'bent'. The military didn't care, they don't reload. This is where the idea of putting a small O ring around the base of the case at the rim comes from. The idea is to tighten the headspace just enough that the bolt face crushes the O ring around the rim and holds the cartridge in alignment with the chamber, so that when it's fired, the cases expands in all directions to fill the entire chamber. Not only do you have less failures, but you get brass that's more likely to last longer and be more accurate. As far as max loading the 303 goes, you won't gain anything from it, 100 years of match shooting with the cartridge and rifle shows that downloading slightly from the military standard load gives better accuracy and case life in most rifles. Remember, Grandpa used to shoot 1000 yards with irons and get hits using those things.