rechamber H&R .243 to a rimmed cartridge?

[dualsport]

I've got a thing for rimmed cartridges. This is just an idea now but I'm looking at the 6mm .303 Epps wildcat. Not sensible, I know. Besides that, doable? Any other 6mm rimmed possibilities? Could a " .243 Win. Rimmed "be made reasonably? From what? The H&R design precludes setting back the barrel so there's that.

[dragonrider]

Perhaps necking down a 30-30? I have a chamber reamer for a 22-30-30 that I will get to use someday.

[KLR]

Isn't a 307 Winchester a 308 with a rim and isn't a .243 a necked down .308? Seems like you could just cut the barrel for a rim and then use necked-down 307 brass.

[rockrat]

I think the 307 brass might be a bit short, you might look into 356 win brass

[Hamish]

Standard stated case length for .243 Winchester is 2.045, .444 Marlin is 2.250. Theres your rim and you can even use the shorter LEVERevolution brass. This works, Im using it in a rimmed .308.

[dualsport]

Thanks guys. I can use those ideas. Two heads are better than one.!

[nekshot]

I got a download off the internet where a fella put rims on a rimless cartridge. It is easy and safe and very doable. I don't know how to send anything but it always shows up in a google search.

[dualsport]

I'm wondering about how much sense it would make but this rimmed .243 seems to catch my imagination. Now it's about money. I've looked at .308 Marlin Express brass for a parent case. Better availability than .307 Win. More cogitation to follow. Perhaps rechamber to some other more interesting 6mm cartridge? Magnums? I'll look at Greybeard's, they have done it all when it comes to Handi Rifles.

[chutesnreloads]

I'd figured you got the idea from Graybeards in the 1st place....but yep...that be the place to look

[leadman]

I had a Contender barrel chambered for the 225 Winchester opened up to 6mm. velocities were just under what I get with my Encore 243 Win. Then there is the 6mm JDJ, an improved 225 Win. case.

[paul h]

Given the taper of the .243 case, or rather lack thereof your re-chamber options are rather slim.

The easiest would be to just have the breach and extractor worked over to allow use of .307 brass necked down and .243 dies not to mention loading data.

If you want just a little bit more oomph, and while the smith has the barrel in the lathe... a .243 reamer could be run in and additional 0.20". You'll have to get form dies, but could neck 444 down to a rimmed/stretched .243 and use .243 dies set 0.20" proud of the press. Because of the minimum taper of the .243 case, running the reamer in deeper will only increase the dia. of bottom of the chamber 0.002" or .473" vs. .471".

Beyond that you're looking at custom reamer, custom dies, etc and IMHO the 6mm bore does quite well with the capacity of the parent .308 case.

[Artful]

I think the 307 brass might be a bit short, you might look into 356 win brass

both 307 or 356 will grow as reduced to 243 caliber, but I think this is be best choice.

[BigEyeBob]

303/243 is a very good cartridge was commercially loaded in Australia a few years ago , many SMLEs were rebarreled to this cartridge .In Sth Africa it was called the 6mm Musgrave and is still popular and loaded commercially .

[BAGTIC]

.308 Marlin Express may have better availability than .307 today but don't count on it for the long run. .308 ME is a 'boutique' cartridge and history shows they usually have a short life span. If you go that way it would be wise to buy a lifespan supply at the beginning.