Case seperation on a .303

[Sailct41]

I reloaded some S&B brass for the first time and one of the cases separated when fired. I inspected the other S&B cases and they had no obvious faults. The load was a 150 grain Sierra bullet with 40 grains of Varget. This is by no means a max round so I am unsure what happened here. Is it just a question of cheap brass? How dangerous is this in a .303 enfield no1 mark III? I did full length resize them before I reloaded and none of the other hundred had any problems. It would seem to me that if it was a hot load the primer would look bulged but it looks normal. Not sure what happened. Could someone help a newbie reloader.

Thanks, Scott

 

[joustin]

The Enfield is well known for crazy head space issues and case head separations

 

[Edarnold]

If you full-length sized these cases before loading them, you may have set the shoulder back too far. In most cases, the case fire forms to the chamber, the base of the case expands to grip the chamber and the brass stretching at the forward end. Sometimes the front of the case slides forward and the stretching occurs at the base, resulting in in a rupture such as you experienced. The cure is to only neck-size the cases now that they have formed to your rifles chamber. Back off your sizing die so that it just touches the shoulder of the cases, and your cases will last much longer.
Battle rifles like the Lee-Enfield were made to be reliable with dirty or corroded ammunition, so the chambers were 'generous' in dimension, compared to the cartridge shape. If the fired case was bulged or distorted compared to its original shape, it didn't make any difference since it was discarded. We are treating the ammunition in a way the gun was not designed for when we reload, so we must treat the cases as customized to our particular gun. In a rimmed design such as the .303, a case separation is usually not a big deal since the case head and rim seal the chamber and there is no gas escape. Not something you want to have happen often, since it could gradually damage the chamber at the point of separation.

 

[243winxb]

http://s338.photobucket.com/user/joe1944usa/media/Firearms and Reloading/303.jpg.html?sort=3&o=32. Neck sizing may help.

 

[jeeptim]

For the 303 S&B is hands down the worst!!!!!
I have a j/c I love to shoot and shoot a lot. hxp I have found to be the best neck size only and even at that three reloads. s&b I find right in the scrap. If you cut a shell in half long ways its clear what's happening. For some reason s&b fails near everytime.

 

[Sailct41]

Thank you so much for the help!

Thank you for the help, I ordered a neck sizing die on your recommendation. this a common problem with other sizes? I have a couple of other rifle sizes that I reload, 8mm, 7.7 Jap, 7.62x54r. Is

 

[243winxb]

Old Military Rifles and Headspace.

[/URL][/IMG] This one happens to be in an old militay surplus rifle. These guns can have mismatched bolts, causing excess or tight headspace. Play it safe, have headspace checked by a gunsmith. Excess chamber headspace can be helped by Partial Full Length Resizing, if done correctly.

 

[Walkalong]

As posted, the .303 Enfield is bad about having excess headspace. Size the case to fit the chamber.

http://www.thehighroad.org/showthread.php?t=734058

http://www.thehighroad.org/showthread.php?t=504759

It won't help on the first firing with new brass though. If you are getting separations on the first firing with new brass, you need to take the rifle to a gunsmith. If you are getting them with once fired brass, adjust your sizing to fit the chamber. It is the shoulder position you need to worry about.

 

[Edarnold]

Of the cartridges you are reloading for, the 7.62x54r is the other example of a rimmed military cartridge that can have the same issues as the .303: depending on who made the barrel the chambers can be tight to very loose. The same technique applies when reloading: avoid pushing the shoulder back, and you minimize the stretching of the case. While a neck-sizing die ensures you touch only the neck, just backing off your full-length sizing die so it just touches the shoulder works just as well in most situations.

If normal or light loads never show protruding primers in your rimmed-cartridge rifles, you can assume the headspace is OK. Remember that headspace on a rimmed case is just the space between the case head and the face of the bolt. How much the front of the case expands is irrelevant to the gun maker, as long as there is enough room to not bind. When you neck-size the fired cases in reloading, you are making the case shoulder part of the support as the case is fired, just like a rimless cartridge. Just be aware that your rimmed reloads from one rifle very likely will not properly fit another rifle of the same caliber, due to variations in the chambers. This is different from rimless cartridges, where a properly reloaded cartridge will always be correct in a rifle of that caliber that has correct headspace.

 

[gamestalker]

Sounds like you have one with generous HS, not unusual for those old war relics.

When you FL sized them it probably bumped the shoulders back excessively for that chamber, in which case I would closely inspect those that didn't separate to make sure they haven't thinned out too much at the web.

GS

 

[Sailct41]

Just ordered some brass from Graff and sons, I will toss that S&B I think I only had one box anyway. Don't need to invite trouble. Thanks for the information and the 7.62x57r too. I have been reloading mostly straight walled cartridges like the 38, 45LC and Beowulf. thanks again, I love this forum

 

[351 WINCHESTER]

Get yourself a broken shell extractor or two and keep one with your rifle. I've found S & B to be too brittle I think as they will give way quicker than any other brass in the .303.

 

[Comrade Mike]

The head spaces issues are the reason I will never buy a Lee Enfield.

Pretty much what everyone else said though. Don't full length size. Only size enough to get the brass to chamber. After the initial fire forming this well help keep the thinning at the base of the case to a minimum.

 

[Curator]

S&B brass SUCKS! I have seen incipient head separation after the initial firing. This doesn't mean anything except what I already wrote. S&B brass almost always has incipient head separation after 2 or 3 reloadings regardless of your rifle's headspace. I suspect this is due to two factors; the brittle nature of their brass alloy and that they are made intentionally undersize so one size fits all. Try some "quality" brass like R-P or FC or even better Privi and fireform with the case head kept hard against the bolt face for the first shot. Afterwards, neck size and keep pressures on the mild side. Brass should last 15 to 20+ reloadings.

 

[RNG]

I had the same problem with S&B brass in my .303 enfield. As previously posted, it is the WORST IMHO as well.

 

[gamestalker]

If you find that the chamber has excessive head space, try seating your bullets so they push against the lands, this will keep the head against the bolt face. This will help the brass to fully stretch to your chamber on the first loading. Then once you've done that, only bump when needed, and only enough to fit the chamber. This should extend the life of the brass if you do it right.

GS