I posted this over on the small caliber site but I would try over here, knowing the 303 still is used regularly. I think of getting a H&R Ultra Varmint now chambered in 243win to 6mm-303 or the improved epps chamber. Just trying to get a little insight on this round.
Cheers Bill

I think the 303/6mm was late on the scene, very close to the introduction of the 243Win so it was never very popular. I think the Wildcats book from Wolfe publishing had some data on it?Ballistics should be close to 303/25.
Cheers...
Con

There were a few 303/22's around here (and around Rushworth where I grew up) many years ago.

Quite a few 303/25's as well. I was given a SMLE rebarreled to that calibre a quite a few weeks ago. It was fitted with the side mount so I put a 3 to 9 on it that I know is good and shot a few roos on permit with it.

Accuracy was nothing to write home about.

But now I must get out "Cartridges of the World".

I wouldn't get over keen on one as the couple of 303/22's I used many years ago were not really crash hot. I cannot remember hearing of too many foxes being shot with one.

I know that the two farmers over in Rushy who had them got rid of them when they had a chance to get a .222 and one in particular, a cousin Anthony, raved over the .222 compared to the 303/22.

Yep. The action has a fair bit to do with it. The gun smith who fits the barrel. And reams it. The bloke reloading the ammo (and Anthony wasn't the most fastidious or reloaders). Cleaning the barrel. It all impacts on accuracy.

But thinking about it, there are too many other great accurate rounds available commercially that I wouldn't worry one made on the 303 shell.

Heaps of other very accurate wildcats if you want something different.

I know that the 303/25 I have will probably not have another shot put through it by me.

Must look up P O Ackley's two manuals

My two bits worth.

Ross

P O Ackley Page 309 Volume I

Ballistics similiar to the 243 Winchester. No real feeling either way about its worth.

Sirwilliam, maybe its worth a go.

Who knows, with modern powders, it may do great stuff.

Thinking about it, if you have the money and time, try it, I guess.


I wonder how it would go with a powder like the AR2213SC (I have had a bit of experience with this one with ) or the newer AR2225 or AR2218?

I used some AR2213SC in our 204 with the 50 gn Berger projectiles (24 gn but don't try this to start with).


Groups were lousy but the same with every other powder with the 50 grainer Berger. The twist rate of the Ruger cannot stabilize this weight so I ain't blaming the powder. (I think).


I just used the 50 grainers just to see what it would do on roos. the 22-250 is a far better bet.

ANYWAY, getting back to the topic, with slow burning powders like the above, could probably outdo the best velocities from the .243 Win using the 303 case as the base you are working from. It has the capacity to hold more grains of powder than the likes of the 243 Win or the 6 MM Rem. Just guessing.

I have never shot a 6 mm Rem or owned one.

My next wish rifle is another Ruger in .25-06. I have used one a bit but I don't own one at the moment. The deals are fantastic at the moment.

GBB,
I was chatting with an older fellow (ex-pro shooter) today about my Bill Marsden 303/25 built on a P14. Two of his mates back in woop woop days owned rimless versions of the 303/22, loaded to the gills in P14s with a 48gr projectile. Culling roos, they averaged a barrel a season for a couple of years. Well, they finally retired the rifles when they got sick of turning off rims and cutting an extractor groove, particularly when a groove was accidently cut too deep, leading to some excitement. But ... in the 90's they pulled them out and ran their loads over the chronograph. Seems they were exceeding Swift velocities with ease. A mate of mine pulled out an old 303/22 Falcon for a laugh before a spotlight hunt. We chronographed its 50gr at just over 3500fps. There is still life in the 303based wildcats, but its a labour of love given the hassles involved.
Cheers...
Con

I had a chance to fire a 303/22 built on a Martini action a few years back here. It shot ok just using 55 grain bullets. A friend of mine is the local gunsmith and he built it. The 303 is still going strong in this part of the woods. I have a #4 Mark 2F my self that shoots very well. I was going to go the 303/6mm just because the chamber on this 243 is large and reloading case life sucks.