resizing 308 to 243

[conan32120]

just to see if I could do it I ran some 308 range brass thru my 243 die, reamed the necks with a forster neck reamer and cleared the crimp from the primer pockets. when I was done and quite proud of myself, I noticed a problem, the resized brass is .02" inches shorter than factory 243 brass. Is this normal and safe? I might never even fire this brass but I am curious about this result and how others dealt with it.

 

[CoalCrackerAl]

The brass will grow.Load a dummy round. And see if it chambers easy. If it passes that test. Load a few. I often convert 270 win to 30.06.

 

[Varminterror]

It’ll be fine. It’ll grow.

I preferentially made all of my 243win and AI brass (and 7-08rem and AI and 260rem..) from Lapua Palma brass (308win with small primers) for almost 20yrs.

 

[CoalCrackerAl]

I sized a Federal 308 into 243. It went pretty good i think. I need to see if it chambers then. My son has a axis in 243.

 

[conan32120]

I sized a Federal 308 into 243. It went pretty good i think. I need to see if it chambers then. My son has a axis in 243.

did you ream out the neck? I certainly had to as there's lots of extra brass in there now

 

[CoalCrackerAl]

No i didn't. Only the expander ball if that is considered reaming.

 

[Chuck R.]

No i didn't. Only the expander ball if that is considered reaming.

Nope, that's not reaming. One of the reasons I like going "up" rather that "down" when forming is usually getting to skip having to ream necks. Here's a good explanation:

Another application where inside reaming is frequently recommended is in forming operations that require a reduction in case neck diameter. When a case is “necked down,” which means run through a sizing op that creates a .243 caliber from a previously .308 caliber, for instance, the neck walls thicken. An appropriately-sized reamer makes the shortest work of this tedious but necessary job. Most forming die packages either include or make mention of the specific-size reamer to use.

https://mssblog.com/2017/06/23/reloaders-corner-inside-reaming-vs-outside-turning/

 

[Bcwitt]

I make 270w from 3006 just so i do not have to trim.

 

[bdb242]

Nope, that's not reaming. One of the reasons I like going "up" rather that "down" when forming is usually getting to skip having to ream necks. Here's a good explanation:



https://mssblog.com/2017/06/23/reloaders-corner-inside-reaming-vs-outside-turning/

I have 2 tite-neck old school wildcat rifles, a 6mm/284 and a 257 WSM made from a necked down 270WSM case. Neck turning is not my favorite thing to do so I can burn more powder, but they sure do shoot very well.

 

[AJC1]

I have 2 tite-neck old school wildcat rifles, a 6mm/284 and a 257 WSM made from a necked down 270WSM case. Neck turning is not my favorite thing to do so I can burn more powder, but they sure do shoot very well.

Those sound like Lazer beams. Not much for needing holdover.