Focusing in on the build differences not the performance differences as I see a lot on performance.
I have built several 308 including BA and AR10.
What do I need to change besides the barrel?
Bolt?
Mags?
Can I make brass from other carts or will I have to source them?
Any dies carry over from 308?

thanks

I’m surprised no one more knowledgeable has chimed in yet, but I can tell you that the magazines are the same.

According to SAAMI, the case head dimensions of 6.5 Creedmoor and 308 Winchester are the same, so should be the bolt faces. Checking the Internet revealed many references to forming 6.5 Creedmoor brass from 308 Winchester and possibly others. It shouldn’t be hard to find 6.5 brass, though; Creedmoor Sports has at least a couple of varieties in stock now.

quote:

Originally posted by smschulz:
Focusing in on the build differences not the performance differences as I see a lot on performance.
I have built several 308 including BA and AR10.
What do I need to change besides the barrel?
Bolt?
Mags?
Can I make brass from other carts or will I have to source them?
Any dies carry over from 308?

thanks

Dies, headspace gauges and the like are all their own thing. No crossover. I'd say even in the panic climate, not worth converting brass from other calibers, though it can be done. Most guys chose to neck up .243 when 6.5 was brand new, for what it's worth.

Whatever you do, you will want to add a good adjustable gas block. Like .30-06, factory ammo tends to use slower powder better suited to squeezing the most velocity out of longer barreled B/A rifles, which can cause headaches with shorter barrels and different gas system lengths--getting the rifle to run right; you may find it either over or under gasses depending on what barrel length / gas system length, or which powder / factory ammo you decide to use. Also a good idea to have a pin vise and a set of wire gauge drills, in case you need to open up the gas port a thou or two.

I built one for a friend: 20" with rifle length gas, and one for myself 18" with rifle gas. His ran like a champ, mine had issues. I think it was the dwell time on the 18" barrel with the slower powder. A combination of opening up the gas port a smidge as well as regulating it down a bit with the adjustable block had mine running pretty good in short order--with H4350.

I recently rebarreled a Savage 10 in 308 to 6.5 CM and all i did was unscrew the old and put the new on and set the headspace and all is good. The AICS pmags have fed fine and no bolt head change required. Now if I had more cci 450 and H4350 id be good to go!

To my mind, the two important aspects in cartridge changeover are, in order of importance, bolt face diameter and overall length.

The .308 uses what is arguably the most common botl face diameter for rifles, .473 inch, also known as 12mm. This was the diameter of the 7mm Mauser on which the .30-03 and later the 30-06 and so many others were based.

If you want to create a new cartridge, just make sure you have a 12mm rim diameter and then go to town.

I don't know much about AR builds, but I have an ARC Nucleus build in 6.5 Creedmoor. I do know that they share mags and receivers with 308/AR10 builds.

The 6.5CM is basically a necked down .30TC. The .30TC has the same head dimension as a .308 Winchester.

Can a conversion be done from 308Win? Sure. I've made a couple. Is it worth the time and energy input? Not a fat chance, especially if you're doing a lot of them. If you're set on converting, then I'd do 30TC brass or 243Win. If you go 30TC, you're stuck with Hornady brass for the most part. Nobody else makes it.

Personally, I really like Starline and Lapua. Both make small and large pocket brass, and both can take a real beating. I'm on firing #5 of my large pocket Starline and #2 of my small pocket Lapua. The small pocket Starline is still virgin for now.

I share AICS PMAGS with my .308 Win Remington 700 without issue.

I have a Redding bushing die and a LE Wilson seating die. I genuinely don't know if it's advisable to use that combo for ammo intended for a semi (there might be some issues considering there's zero crimp; I don't really know because with the primer shortage I have been worrying about pistols and bolt guns only so I haven't played with loading even just .223), but I can say that it makes for some REALLY accurate ammo.