A friend of mine and I were discussing a custom rifle I was planning as a moose gun and I plan on a very simple one he asked what the largest diameter bullet is that could be placed in a 243/308 case. I'm planning on rebarrelling a 30-06 to 35 whelan same bolt head not really a lot involved. He's thinking because he has a 243 in a savage to rebarrel it to a larger bullet. Some have said that the 35 whelan has barely enough shoulder to headspace so is it advisable to go larger the a .358 bullet? He plans on just opening up 243 necks to take larger bullets and have a suitable barrel installed with the correct twist rate to stabilize the weight of bullet he can load. The purpose would be for deer at close range and as a fun project more then anything. Any ideas or suggestions? He doesn't want or need to buy another gun he simply wants to convert this action to something not common. Sorta just downsize a real cartridge to a close range plinker
how much can a 243 neck be opened?
- Thread starter brybenn
- Start date
Necking .243 brass up to .358" or higher is a huge gap and I think you would be better off using .338 Federal cases. You could go up to a .375" off the .308 case, it would have to have almost no taper and a very steep shoulder angle in order to headspace though.
$700 tikka hunters in .338 win mag at prophet river, on a somewhat related note.
Pudelpointer
CGN frequent flyer
- Location
- Lethbridge, Alberta
Is he just looking to use all his 243 brass, or is he looking for a thumper of a deer cartridge based on a 308 case?
If the former, then stretching those necks much past 7mm (and likely even then) is going to leave them mighty thin. If the latter, then do as Dogleg suggests and get it rebarreled to 358 Win.
If the former, then stretching those necks much past 7mm (and likely even then) is going to leave them mighty thin. If the latter, then do as Dogleg suggests and get it rebarreled to 358 Win.
He just wanted to go to a bigger bullet with keeping the same action and bolt head. Is the 338 federal the same bolt face as a 243? I tried to talk him in to a 7-08 (because I've never shot one) but he wants a bigger diameter. 9.3 would be awesome if it were possible on 243 brass.
.243 Winchester, .260 Remington, 7mm-08, .308 Winchester, .338 Federal, .358 Winchester all share the same case body dimensions. Only the neck portions of the cases differ, depending on the bullet diameters. There are wildcats in the series, using the same body dimensions. .25, .270, etc.
.243 cases can be readily opened up for .260 and 7mm. Going beyond this is just silly. Just start with one of the cases that is closer to begin with.
.243 cases can be readily opened up for .260 and 7mm. Going beyond this is just silly. Just start with one of the cases that is closer to begin with.
Don't get stuck on the 243, just because that is what the Rifle will have been in a past life.
it is a short action rifle (I assume) with a standard bolt face, and can be chambered for ANY of the similar cartridges based on Length and base diameter.
some things to think about.
How much can you safely increase diameter?
How available is brass, bullets...
308 Winchester would be the most readily available for brass, so How much can you neck it up without issue?
338 Fed, 358 Win, brass will probably cost you 3x what 308 would
just a thought... Then the cost/availability of bullets.
BUT a .375x2" would be a Fun cartridge. I think it was JD Jones who built one and said he could safely get 2250fps from a 270gr bullet. No Moose will stop that
it is a short action rifle (I assume) with a standard bolt face, and can be chambered for ANY of the similar cartridges based on Length and base diameter.
some things to think about.
How much can you safely increase diameter?
How available is brass, bullets...
308 Winchester would be the most readily available for brass, so How much can you neck it up without issue?
338 Fed, 358 Win, brass will probably cost you 3x what 308 would
just a thought... Then the cost/availability of bullets.
BUT a .375x2" would be a Fun cartridge. I think it was JD Jones who built one and said he could safely get 2250fps from a 270gr bullet. No Moose will stop that
257Roberts
CGN frequent flyer
- Location
- Peterborough ON
How about a 8mm/308. Uncommon, no brass and dies would be special order.
Other than that, I am really starting to admire my 358.
Other than that, I am really starting to admire my 358.
Thanks guys. He decided to go with a .358 diameter and for some reason I thought the 338 fed and 358 win had bigger cases. So in essence he will have a short action 35 and ill get a long action 35. Thanks for all the help guys. And a 375x2" would be a sweet lil round
On a side note your friend could use a .284 win case which holds more powder than the 308 based case(holds the same ammount as the long action) so in essence making a short action with the same horsepower as your long action. I built a 6mm/.284 from a .243win without doing anything but a rechamber. The .284 case is just a little fatter and just a little longer but fits and feeds perfectly in the short action rifle with absolutely no modification whatsoever. Of course its a true wildcat and would have to reload and obtain dies for it. Maybe too much messin around but it's cool to own a wildcat.
some feedback I found
http://www.go2gbo.com/forums/index.php?topic=85269.0
