When I was looking to get a 6mm/.243 rifle, for both predator, and deer/antelope sized game, my research pointed to the 6mm Rem. I had a friend that shot the .243 Win, and he left brass on my range. I was not impressed with the short neck of the .243 Win. So with the research, and range observation, I went with the 6mm Rem. In my case, I was re-barreling a Savage Model 16(Short Action), that was a factory .22-250 Rem., that wasn't getting shot much anymore. Some of the internet experts told me the 6mm Rem., in a short action, would restrict OAL to the point that long game bullets wouldn't fit in the magazine...Well the internet experts were wrong. I have Sierra Pro Hunter 100 gr. loads, that fit well in the magazine, and shoot sub-MOA groups...Glad I didn't listen to them.
So put me firmly in the "6mm Rem. is better than the .243 Win." camp. It is probably a better cartridge for hand loaders, but there is some factory ammo offerings out there. I just saw 6mm Rem. brass(Winchester) at a local Cabelas. I have more than a couple of life time supplies of Winchester brass, when Winchester still made good brass, so I passed on then new Winchester brass, but it is still out there.
My new deer/antelope load is the 80 gr. Barnes TTSX. I did a BANG-Flop, at 320 yards, on a WY antelope a few years back. The exit hole was impressive, even at that range. I will always own at least one 6mm Rem. rifle.
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