reloading 303.

[newcastle]

looking at the picture above - the two cartridges on teh right have a shiny area above the head, more noticeable on teh right hand case. Is this where the case has stretched and is this super bad? I've noticed this on alot of my cases.

[Edward Horton]

newcastle

Below are .308 cases, and I'm showing them as a general example because the location of the case head separation is dependent on case construction and thickness. This normally involves base diameter and case wall thickness "BUT" the quality of the brass also plays a big part.






Just as an example a new hunting rifle might have from .003 to .005 head gap clearance or "air space" between the rear of the case and the bolt face. The .003 to .005 is also the amount the case can stretch and thin in the web area when first fired.

Below is a once fired factory loaded Winchester case, it stretched and thinned .009 in the web area and the headspace on this Enfield is set at .067 and the head gap clearance is also .009.





With my RCBS Case Mastering Gauge I do not have to use the bent paper clip trick checking for case head separations, this gauge tells me exactly how much the case has thinned.

[RobD]

I agree you should segregate cases for each rifle and neck size. I have had no more case separations since I adopted this method; when I was full length resizing I had plenty of separations, even on 1st reload. Sellier and Bellot cases are awful for separations - Prvi Partisan are good cases.
If you have orphan cases, neck size them and then try them in your rifles to see which they will fit.
I use 174 grain FMJ boat tails (the cheapest supplier is the Flying Dutchman, he visits Bisley fairs a couple of times a year, see his website http://www.bold-action.com ) and 40 grains of Vihtavuori N140

[tbonesmith]

looking at the picture above - the two cartridges on teh right have a shiny area above the head, more noticeable on teh right hand case. Is this where the case has stretched and is this super bad? I've noticed this on alot of my cases.

If they're only once fired that isn't going to be a problem.Often they look a bit like that, the shiny ring that occurs before separation is not the same as the shiny band just in front of the rim, where the case begins to taper often looks a little suspect, but usually it's fine. Just do some and you'll pick up the little details as you go.
I've had 2 case separations ever in .303 reloads, and they were almost consecutive in a batch that had been reloaded about 20 times, it's not a big deal, and you'll learn how to spot it most of the time.

[Edward Horton]

looking at the picture above - the two cartridges on teh right have a shiny area above the head, more noticeable on teh right hand case. Is this where the case has stretched and is this super bad? I've noticed this on alot of my cases.

newcastle

Below is another example of once fired brass, the Prvi Partizan case on the left has a larger base diameter and the case walls are .010 thicker than ANY presently made .303 case. The case on the right is a military Greek HXP case it has a smaller base diameter and the case wall thickness is .010 less than the Greek HXP.



Please note that neither of these two cases stretched or thinned in the base web area when fired. The Prvi case did not stretch due to its larger base diameter and case wall thickness, and the Greek HXP case did not stretch due to higher quality brass.

The Winchester case below failed after three neck sizings, it is a shame but company profits are the bottom line in todays world and neither Winchester or Remington are producing ammunition at any of our American munitions depots.



ATK now produces small arms ammunition at our American Lake City Depot, if I remember correctly Remington is now owned by a French company and Winchester belongs to General Dynamics weapons division. Money talks and quality walks..............





The bottom line here is you can not always judge your cases by outward appearance.

[newcastle]

Thanks for all your advice. Now all I have to do is find time to deprime 4000+ cases, get the wife out of the house to use the dishwasher, have time to dry them all outside in the sun and get reloading.

[ireload2]

>>>In the bottom photo is a new American Remington case and it is setting over a 1/4 inch below the lip of the gauge. This means the shoulder of the case is a 1/4 of an inch shorter than standard British military ammunition.<<<
From the photo 1/4" is a bit of exaggeration. In any case (to make a terrible pun) I don't an O ring the size of a B-36 tire will correct it.

[RobD]

Ireload,
The point about stretching and subsequent separation is that it always takes place about 8 mm in from the case head. That shoulder is not weher teh case splits, strangely, and this is why: As the case expands during firing, it adheres to the chamber where it is thin (at the neck, then shoulder) and the thick part is pushed back. This thins out the case. The little O ring serves to press the case head snug against the bolt face before firing, so that it is already as far back as it can be when the expansion-adherence-stretching takes place.

[Baal]

The little O ring serves to press the case head snug against the bolt face before firing, so that it is already as far back as it can be when the expansion-adherence-stretching takes place.

I tried the O ring method a few weeks ago for the first time. Five shots, 5 O rings split in two down the middle leaving me with 10 thinner O rings. The brass looked only slightly better than without the O ring.

[ireload2]

RobD,
So tell that to the guy claiming the location of the shoulder is the problem. You have missed several thousand posts about the same subject.