Problem Sizing 303 British brass

[kujuak]

I reload lots of calibres, but this is my first try at reloading 303 British. Loading for No4Mk1 Lee field innexcellent condition. Usoing RCBS FL sizer die. I plan to neck size only next 30-4 cycles. Problem, sized brass with die set 1 full rotation from bottoming out. Sized brass does not seat flush in my Wilson Case gauge. Unfired ammo fits gauge perfectly. What is the problem??

thanks!

 

[SSL]

Just a thought...are you sure your decapping stem isn't contacting the case head before the case is fully entering the die and sizing? That would prevent fully sizing the case and moving the shoulder back. Would be important if you have a little excess heads pace. Those old Lee Enfields often developed headspace issues. That's why they issued bolts of varying dimensions for quick field repairs.

 

[kujuak]

Thanks, but I thought of that. I took the decapping stem out to see if that was the problem. No dice.

 

[Will Henry]

The Lee Enfield chambers are often a little long in the head to shoulder dimension. I have even seen some with a radiused shoulder. So it is no surprise that it doesn't seat in the wilson gauge, with the die one turn out. The thing is, it doesn't need to fit in the gauge; it needs to fit in the rifle. WH

 

[whatsupdoc]

You are one rotation away from the shell holder, screw the die further in.

Edit: I would never ever neck size a 303.

 

[DGP4]

Buy a Lee full length sizer die. No problems. RCBS dies in my experience are nothing but problems.

 

[Adam in WI]

Ignore the case gauge and listen to the rifle

 

[Martin52]

I agree with Posts #4 & #7 - the case needs to fit the chamber. The chamber in my No4 Mk2 is also long, the worst thing to do is to push the fired/stretched cases back too far - results in case separation due to overworking the brass (you probably already know this as you say you reload for other calibers). Minimise shoulder set back and use the chamber as the test.

 

[Curmudgeon]

It’s not a bolt but a bolt head that comes in varying sizes. The only trouble I had with reloaded rounds was when I full length sized. The case head thickness is what varies. The case needs to fit rifle. Get a Lee neck sizer. Your cases won’t reach barrel dimension that captures bullet. The 220 round nose might reach if loaded long. These cases space off case head or rim if that is easier to understand. The chamber doesn’t fully support the entire case. Fired cases do best job filling this space. Full length resizing diminishes that support. Set a number of cases on a flat surface and see how many lean one way or another. There are ways to try and fix this but in my experience accuracy with these rifles is achieved by learning how to pull the trigger and keeping the rifle pointed at your x. This info is just my experience. I shoot an Enfield from WW 2 that was worked on by Holland & Holland so it has a scope, primitive but still glass. If I’m careful it will shoot 10s and Xs. These aren’t target rifles, they were meant to shoot center mass. Anyway it’s fun and easy to load for this rifle.

 

[762plinker]

fat long chambers make IT TUFF TO RELOAD FOR
most of my brass did not expand uniformly because the chamber was so big, and then the throats tend to be long.
a challenge

 

[Ray123]

unfired cartridge fits gsuge fine because it's supposed to fit every rifle in that 303 caliber...when you fire it, the case expands the whole case not just the neck...
So ya have to turn the die down to fit your chamber, not necessarily the gauge, could be the same but not always. Go down to the bottom of tbe shell holder back off a quarter turn, try in your rifle keep going down 1/8 turn until it chambers with no resistance in your gun...you can check with the gauge to see the difference. But if the resized case now fits easily in your chamber no use pushing the shoulder back any farther...and always size there...where it fits your gun.

 

[big5ifty]

... sized brass with die set 1 full rotation from bottoming out....

Why not all the way in ?

You may be one rotation from bottoming out, but the die mouth has a bevel on the inside, so you are one rotation plus the bevel height unsized at the bottom.

 

[Curmudgeon]

If you are inserting a case into the chamber and then closing the bolt you can feel resistance as the extractor reaches around the rim to allow closing. This is a controlled feed round. Try pushing the round part way into magazine then guide case mouth into chamber as you close bolt and you will feel less resistance as bolt closes. Different than push feed action.

 

[243winxb]

303 factory vs fired Buy a neck size die.

 

[FNSafari]

303 factory vs fired Buy a neck size die.

Or just don't screw your full body sizer all the way down onto the shellholder. Just back it off a few turns until you get enough neck sizing to hold a bullet.

 

[243winxb]

If done very carefully, the 303 may be neck sized using a full length die.

The case body has a lot of taper. .455" to .401"

 

[Unkl Chuck]

I've had 'passable results' with a Lee Collet die, but it was years ago. My Enfields have been safe queens for quite some time.

 

[kujuak]

OK, first attempts at reloading 303 Brit. Full length resized cases got 2" groups at 100yds, better than RP new fmj ammo. Then I tried neck size only, got random results 2 shots less than 1" apart next shot 8" high and ,6' wide, 10' high then a shot close to the first 2 closely placed shots. Used Lee Collet neck sizer and then Lee taper crimp. The neck sized ammo was the worse "grouping" ammo I have ever reloaded in 30+ years of reloading.Seriouzsly thinking of selling Lee Neck sizing die.

 

[Martin52]

How does the headspace on the fired brass compare to the new unfired brass ?

 

[JohnW...ski]

I am by no means an expert on .303 British but there are a few things to consider with this cartridge.
It is a rimed case and headspaces on the rim, the cartridge was developed as a war cartridge and the shoulder is pushed back for a reason. During battle a soldier could drop his ammo in the mud or where ever and still be able to chamber the cartridge in the rifle during a life or death situiation. The cartridges were developed for battlefield conditions and never was reloading considered.

Reloading brings with it other considerations. Technically since it is a rimmed cartridge and the headspace is on the rim it doesn't matter where the shoulder is. However every time the cartridge is fired in this condition the brass streaches to fill the chamber and fully form the shoulder. This brass has to come from somewhere, it usually streaches from just ahead of the web. That is the reason a line just ahead of the web can often be seen in cartridges that have been reloaded several times. After a few reloadings the cartridge will seperate at this line. By keeping the shoulder close to the chamber dimension case seperation should not be a problem after several loadings. I would think that since the shoulder on this cartridge is not used for headspace and is not critical, that the shoulder length probably can vary between different rifles so the shoulder dimension you develop for your rifle may not work in every other Enfield.