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I'm new to the 303 British and am seeking guidance over checking overall length after full length re-sizing.

I regularly reload .223 and .308 but they are both rimless and use LE Wilson Case Gauges. It occurs to me that as the 303 is rimmed I dont quite see how I would use the .303 gauge from Wilson.

With the 303 the headspace is not shoulder to base so can you just use the Wilson gauge for overall length? Or is there a better way? I was wondering about a dial gauge as an easy and quick way to check.

Advice and guidance please

Norman

There is a maximum case length and a trim to case length. 2.202" is the trim length and 2.222" is max overall length. You should be fine with just measuring this length with calipers.

Can't answer your question directly but its usually better to only neck size 303 cases as they last much longer. Its important though to only uses cases you have fired in your own rifle.
I use the Lee case length gauge for mine.

A set of callipers is a easy way to check over all length. Every reloader should have a set on the reloading bench.

@Alpha 1 is quite correct. I also made a guage for the max cartridge length and after a shoot I put all my fired cases through it with a seperate bin for those that need trimming before reloading. Digital calipers are so cheap now that there is not excuse for not having a set.

Have got calipers but was wondering if there were options.

I use the case gauge and make sure I trim to the maximum length of the gauge and the ammo shoots fine.

shotgun sam wrote:I use the case gauge and make sure I trim to the maximum length of the gauge and the ammo shoots fine.

Which case gauge please

If you are only measuring the length of the case all you need is a caliper you don't need a gauge. If you want to measure cartridge over all length accurately buy a Hornany overall length gauge and a drilled case. Or visit the shooting shed and check ovenpaas offerings out.

Another vote for a vernier calliper. You can find them for not much more than a fiver in some of the discount shops through to a couple of hundred pounds for top end stuff however they all do the same sort of thing and for the most offer similar accuracy when used carefully. Downside of the cheaper items is they have an auto shut down which can be frustrating on occasion. I personally use Mitutoyo digitals however I also have Mercer and M&W analogue and I sat down and compared them all to the cheap Lidl's models the Viking uses for measuring envelope thickness and similar and all of them read to within .001" however the cheaper ones were noticeably coarser to operate when new, these days they are nigh on as smooth as my Mitutoyo models.

Do remember a vernier calliper gives an approximation and is no substitute for a decent micrometer. Having said that you do not always needs a calibrated micrometer that reads to .00005" and at such levels of accuracy ambient temperature of the measuring device and work piece have a big impact on the final measured dimension. You can prove this by using a cold micrometer and work piece, determine the diameter or whatever then pop the work piece in your pocket for the morning and measure again. This is the reason I always do my most critical jobs in the afternoon when the machines and workshop have warmed up.