.243 into a 6mm Creedmoor how hard is it?

Barrel swap. Done.

Ya barrel swap, I'd think you would have to set the barrel back so much there would not be much shank left.

The twist of an older 243 isn’t likely to be ideal for the Creedmoor. That’s one more factor that favors replacement vs rechambering.

horsemen61 said:

older model 70 in .243 Winchester

Click to expand...

Older? Like how old, Pre-64? If so don't change anything.

In a hunting rifle, I don't see the 6mmCM offering anything that you can't get with the 243 and you can use the money you'd save on a barrel swap on a nice scope.

Olympus said:

In a hunting rifle, I don't see the 6mmCM offering anything that you can't get with the 243 and you can use the money you'd save on a barrel swap on a nice scope.

Click to expand...

Faster twist and room to load longer heavier VLD bullets. Whether that is useful in a hunting rifle is a personal choice.

mcb said:

Faster twist and room to load longer heavier VLD bullets. Whether that is useful in a hunting rifle is a personal choice.

Click to expand...

I understand the differences between the two calibers. But in practical hunting terms, the differences are splitting the hairs that have already been split! Now if we're talking long range shooting, then yes the longer, heavier bullets of the 6CM hold a definite edge. But if the OP is talking about an older Model 70, that doesn't sound like a 1000 yard target rifle to me. That sounds like a sporter hunting rifle, in which case the intended use is probably not long range shooting. So I see no reason to rebarrel unless you've just got plenty of fun money burning a hole in your pocket.

I'd also price barrels and installation before even considering it.

Probably going to come in cheaper just buying a new 6mmCM.

Before rebarreling I was shooting a .243 using AICS mags with Berger 105 Hybrids without an issue. I had the gun rebarreled in 6mm SLR using a short throat-ed reamer for mag length and still don't have an issue with OAL and the SLR is .243 length. Biggest problem the .243 is going to have is the slow twist, IF you want to stretch it's legs, and if that's the case I wouldn't use a stock M70 anyway. By the time you get done with the barrel a suitable stock etc. you're adding up $$$.

For a deer rifle I'd probably stick with .243 also.

Push feed I'm guessing? if so you can use a Ruger American barrel and nut. I screwed the barrel off my .300 RAM into my SILs pushfeed m70 and had it been a magnum action it would have run fine.

Might save you some time and cash depending on what barrel you want, and how available/costly smithing services are.

LoonWulf said:

Push feed I'm guessing? if so you can use a Ruger American barrel and nut. I screwed the barrel off my .300 RAM into my SILs pushfeed m70 and had it been a magnum action it would have run fine.

Might save you some time and cash depending on what barrel you want, and how available/costly smithing services are.

Click to expand...

Very interesting, I didn't know that! Post-64 M70s are all over GB for cheap, and the action seems like a pretty well thought out design.

I had an SC built modern M70 in .243, and liked everything about it except for the 1:10 twist rate. It shot great with 70gr, 85gr, 90gr bullets and decent with 95gr BTs but really didn't like anything longer than that. These days, I'd want a faster twist to have more modern bullet options that really let the caliber shine. Instead of going with a custom twist .243, I'd personally just go standard 6mm Creed, so I can certainly see where the OP is coming from.

I bought my first 243win about 20 years ago. Within a year, I had rebarreled to a fast twist. Within 3 years I was shooting 243AI in custom fast twist barrels. I bought what I expect to be my LAST 243win about 4 years ago, a Savage Striker specialty pistol. I have replaced the rest with 6mm Creedmoor’s, and will order a barrel within a few weeks to replace the barrel in that Striker to become 6 creed. The 6 creed is everything the 243win really should have been from the beginning.