303 British sizing - problem or not?


Cellar Dweller
October 7, 2003, 02:28 AM
Lee Pacesetter dies.
S&B brass.
Lee Challenger press.

After following the instructions on how to set-up the full-length sizer die, I can only get within approx 1/4" of the shellholder. I tried playing around with the decapping pin and crushed one neck, so I stopped. The mostly-sized brass will chamber in my #1Mk3 (of course, it fit before I sized it as well). The neck diameter seemed proper; the angle of the shoulder compared to a factory loaded S&B round is less sharp (fireformed to my chamber?). How should I correct the problem or is it NOT a problem?

I also used 7.5 Swiss Pacesetters on new Norma 7.5 Swiss brass and it was able to cycle down to the shellholder, as does all my handgun brass with their respective sizer dies, so that is what I am used to.


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October 7, 2003, 11:41 AM
Your using the same set-up I'm using, except I like my hand press, and I don't have that problem. What are you using for lube?

October 7, 2003, 01:59 PM
A bit of advice with 303 brass. You are better neck sizing because the Brits made their chambers oversize for the purpose of reliability especially in the neck area. Full length resizng leads to case head separation after 2 or 3 reloads. Neck sizing or using a Lee Collet die will slow this down. Headless case extractors for the 303 may still be available from SARCO.

Cellar Dweller
October 8, 2003, 12:15 AM

Lee, straight from the tube applied with a swab on the inside of the neck AND with fingers on the outside.

Lee, diluted with water, applied the same way.

Unknown, from my father-in-law, possibly RCBS liquid, applied the same way.

Relubing and trying again gets me a bit closer, but still not down to the shellholder (and therefore full-length sized).

I'm not too worried about only getting 2-3 reloads from the brass yet, because I've only run 40 rounds so far and have another 100 NIB. I'm still working on getting my feet wet with reloading for rifles (Note to self: neck dies in the future, if I start shooting more). I don't have a problem buying 3 boxes a year if that's all I'm gonna be shooting - the nearest rifle range is 2 hours away so I don't get out much :(

October 8, 2003, 11:29 AM


Instead of using the Lee from the tube (I assume you're talking about the water based stuff, one of few Lee products I DON'T care for), go to Wally World and get a bottle of their Tech2000 Oil treatment for ~.98 -AKA "STP oil treatment".

Either use a lube pad, or about a teaspoon on a folded up piece of paper towel, or shop rag. (I recommend a lube pad. Mine is an RCBS I bought in 1972 while in high school !)

Very sparingly lube the neck and base of the cartridge, avoid getting more than a trace. This will allow you to size most of the case, though, for .303 you really don't need/want to size that last 1/2" above the rim.

If you use too much lube and/or size down too far you'll get case neck dents. Not a real problem unless done to the extreame, but are unsightly and others who see it (reloaders) will consider it "sloppy reloading".

For the VERY BEST in sizing lubes, use Imperial Sizing WAX. That stuff is Eiery smooth/slick !

Also, it sounds as if you haven't read enough manuals yet. I suggest you invest a few evenings reading one or more loading manuals for additional background info. Then spend time here for the "Rest of the Story".

Been reloading for 33 1/2 years, and I still learn something new every week here.

October 8, 2003, 11:52 AM
This sounds like your die wasn't reamed deep enough. No.1 Mk III chambers are usually tighter than No.4 Mk I. As for shoulder angle, we once sorted fired brass by it. Some had sharp angles, while the rest had a body - shoulder angle rounded off like a Weatherby radius. Hot loads will finish off cases in 3 reloadings even with neck sizing.


October 8, 2003, 03:27 PM
I haven't tried it yet, but I hear good things about Hornady oneshot lube. At least I think that's what it's called. It's the aerosol in the black can. I wouldn't rule out the possibility that you have a defective die. I'm using te same dies with Hornady case lube, both the paste and the oil based, and I've never dented a case. Although I will say that the S&B is some very hard brass to size, but on the flip side, I tend to get more loads out of it.

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