Advice Needed for .303 Brass

Your comments show that you're on the right track.

I've used the .303 British for over fifty years with great satisfaction; right now, I'm down to "only" three .303 rifles. These are two new-condition #4 rifles and a Ruger #1... all are great!

Due to the cost of factory ammo, I'd prefer starting with unprimed new brass.

My first firing of that new brass would have the bullets (cast or jacketed) seated out far enough to firmly engage the rifling. This would allow the SHOULDER of the case to move forward without causing the rear of the case to move back....which is the cause for early failure of .303 cases due to head separations.

Then, just as you said, neck-sizing will ensure that subsequent firings don't damage the brass in the head area.

I find that a .308 Winchester sizing die will size the necks very nicely, and the .308 die will NOT contact any part of the case except the neck.

Of course, if one doesn't have .308 dies, the regular .303 dies will also work.

Good luck with that #5..... I still believe I saved my life with a #5 against a bear back in '65.

Yep, we have to take it where we find it, for sure. I'd be glad to find some more .303 brass, although I do have a reasonable amount on hand.

hat #5 is about the most usable military rifle there is for a civilian, without needing any modification at all.

What part of Minnesota do you call home? I grew up in Northwestern Ontario, just north of the Boundary Waters Canoe Area. Nice country.

You can go either way really, but I've found that buying brass is expensive. I usually buy Prvi Patisan (PPU) factory ammo and reload it once I've shot it. Hornady came out with .303 brass awhile back but I haven't seen any myself.

Your real challenge may be finding proper bullets currently. Most desirable .311-.312 bullets are out of stock everywhere.

I usually fire every case the first time with an O-Ring placed at the rim to promote forward stretch of the case and hopefully mitigate or eliminate case head separations in .303. I have 3 loads plus the factory firing on my PPU brass and it seems fine but I'll give it a good check.

Good luck with your #5.

303 lots of fun. The brass and reloading the best and longest lasting is HXP head stamp the worst is S&B. My advise is neck size when you can. Enjoy

Hornady makes a "Vintage Match" load that shoots very well in my No. 5.....it is pricey but the brass is top notch. I still haven't found a handload that will top that Hornady stuff. I believe SGammo has it in stock.

I also got lucky and found 300 rds of non corrosive surplus stuff a few months back. That stuff is also accurate.

Also BTW, a little padding on the shoulder is recommended with this gun! Especially after 20 or 30 rds.

PPU/PRVI ammo is about as cheap as it gets for good quality loaded ammo in larger rifle calibers. If Inwere in your situation I'd invest in 100-200 rounds of that and reload the brass. In my experience it will give you a good baseline for what your rifle is capable of. Then you can set a goal on what you'd like you hand loads to do. The Hornady ammo or others may shoot a little better, but at twice the price.

Do a search on this and other sites about loading for the .303 British cartridge. If you do decide to shoot factory ammo instead of buying new brass, Privi is real good but NOT "Sellier & Billiot! Also consider using a thin "O'ring around the case head in front of the rim for the firing to keep all the case expansion forward.

the biggest problem is finding bullets.try to keep at 150gr .311 for less recoil i like when you can find them speer 150gr hcsp. they have a flat base and mild recoil. never had a problem with boat tail bullets out of my no.4.the only issue i've had is fine grained powder needs mag primers. 303 is a joy to reload for. now just give us bullets please!!!!!!

http://www.thehighroad.org/showthread.php?t=591979&highlight=jungle+carbine

info on taming the recoil of a #5mk1

https://www.apexgunparts.com/index.php/cPath/30 here is a sight with orig british 303 headspace gauges. there should be a number on you bolt face.find out what it is and see if the next higher number is available for spare

You can use the original British field gauge if you want.....but I found it to be too generous.

My No.4 passed the British headspace test (but not SAAMI). I don't shoot it anymore because it leaves signs of imminent head separation (and it already has a #3 bolt head, #4 bolt heads are as rare as hen's teeth).
As it stands, I am waiting for Criterion to start producing replacement No.4 barrels so I can rebarrel the thing, the rest of the rifle is beautiful.

Edit: my No.5 headspaces fine with SAAMI gauges and consequently leaves no signs of head separation.

@ Bainter1212
There is no reason to retire the LE with excessive headspace, If you Reload.
I had a Mosin Nagant with .012 " headspace.
It would split the shoulders on steel cased ammo.
But once Brass cases were fire formed in the rifle, and only Neck Sized for reloading the rifle was fine. and the reloads could be done up to max loads with no signs of seperation, and reloaded many times.
A Rimmed case is very forgiving for fire forming and then using the shoulder as the Headspace Datum point.
You also have the option of having your barrel Reset or Set Back like two turns and the chamber reamed again to correct the excessive headspace if you cant find a Barrel.