Some reloaded .303 prevent bolt from closing/turning.

[Ignition Override]

These are my first complete reloads, any ammo.

With about twenty rounds of once-fired Prvi. the bolt would not quite go all the way forward, or maybe it closed a few times, but will not rotate. These rounds were all fed from the same old internal magazine (extractor engaged), but the other 12 or so worked fine.
This has never happened with new Prvi or very old surplus ammo.

After comparing side by side with a new Prvi from the box, can easily see that the shoulder taper on Both these problem reloads and the successful reloads is about one half the taper length of the new Prvi, and the taper begins at a slightly longer distance (fwd) from the case rim.
All of these reloaded cases appear identical.

My only sizing was with the necks, as advised by many LE owners, for extended case life.
Might not even have a full-length resize die, but don't know if that is the solution.
Both the new and once-used Prvi cases were only fired in the exact same
LE #4.

Will be out of town a few days. Am so very fortunate that some very lucky contacts allowed me to acquire a heap of surplus ammo.

 

[Steve C]

Might not even have a full-length resize die, but don't know if that is the solution.

You don't say what die set you are using but it should indicate if its a full length die or neck sizing die. If you are using a Lee collet die it is neck sizing only.

Enfields have a tendency to stretch the case because the bolt isn't as tightly locked in place as the Mauser type actions. There's quite a bit of variation between rifles and their chamber dimensions. You need to keep the brass segregated by which rifle it was fired from to have much success with neck sizing only. Any pick up brass or brass that's been fired from another rifle often will not fit. If all the cases you reloaded came from the same rifle then that's not an issue as long as you properly sized the neck.

Check the bullet and the case after you attempt to chamber the shell and see if you can see a shiny spot where its impacting causing the stoppage. You could also smoke the case and to find the same thing if no marks can be discerned.

You could have the bullet set out too far and its catching the rifling lead before the bolt can close, could be the case neck needs trimming or it could be the shoulder has to be set back a bit which would require a full length sizing die.

 

[counterclockwise]

I think the .303 is a flanged case, which would naturally head space on the flange, not the shoulder. If the case is a bit loose, the fireformed case could grow so the case spaces on the shoulder and binds up between shoulder and flange face.

Were the once fired PRVI from your rifle, or some other rifle?

Lee-Enfields are notoriously tricky for reloading because of the springy bolt and typically loose cartridge-to-headspace with large amounts of stretching from new to fire-formed case condition. With this condition, about two reloads are all you get out of case life. Neck forming only may extend that life a bit, but then neck forming only does not provide any resizing of case at all.

I think that a full sizing die that is teased so it just barely bumps back the shoulder, and squeezes down the case body just a bit to let the bolt close might do the trick. Of course you want to pull the bullets and dump the powder of your first tries to do this.

 

[NCsmitty]

I'm glad that you have completed your first reloads. Now it's time that you learn from your first issue of ill fitting cartridges.
Steve C's recommendations basically mirror my thoughts on the situation.
If these cases were fired in rifles other than you own, you should always full length size them back to proper dimensions. Once you fire them in your rifle and attain your rifle's chamber size, you generally can neck size them a time or two before having to FL size them again or when they start causing hard chambering.
I'm guessing that you have the bullet seated to the recommended COAL so that it does not interfere with the chambering.



NCsmitty

 

[Ignition Override]

Thanks.
They were used in either my LE #4, or #5. All of my equipment is from the "Lee Anniv. Kit", except the neck-size die, from Midway.
The collet die only sizes the necks, and have never used a full-length type.
NC: yes, each is slowly measured in the Lee caliper and all rounds are under the max. length of 3.075 in the Lee diagram.

The powder measure scale is locked at 39 grains of IMR 4064, though each loading takes time to add/subtract several grains.

I could have mistaken which of the two rifles they came from, because something earlier made me go try the six rounds in my Jungle Carbine's action, via the magazine.
All six allowed the bolt to close normally and lock, then eject. It felt normal-what a surprise.

If this is the only cause, for now, then better (colored baggies) separation of once-fired cases could stop this.
If this was the problem, in the long-term, would ordering a full-length sizing die from Midway for one resize, allow more loads from many of the cases?

Some people claim to only neck-size, others to allow full-length just once, either during the first reload, or later.
Once I try full length sizing and sort this out, then the Yugo Mauser might be an easier Next Project months later-if cheap 7.92 bullets could be located.

 

[FROGO207]

You will probably find that full length resizing or at least bumping the shoulders back with that die will be required after every couple reloads anyway so purchasing the die-dies now will be a good idea. I would get the lee set of FL dies as the other seater could be used with a different bullet size and you will not need to adjust your single seater with every bullet change. Just label them as to which one they are set for.I did that with all four of my seating dies.BTW I find that I need to FL size and trim every three reloadings with light loads in my 303.

 

[Ignition Override]

Will follow all advice on here.
Appreciate it.