Brass forming questions?

[PNW_Steve]

Hey Everyone,

I started tinkering with my first "wildcats" this year. I am having a ball. So much to learn and try.

I have two cartridges for my AR's based on 6.5 Grendel necked down to .224 and .243 and started thinking about a bolt gun project. I was considering having a .243 LBC barrel made for a bolt gun. Then I started looking at some other options. I looked at the 6 mm Creedmoor and saw a comparison with the .243 Winchester. Then I came across the .22-243.....

Down the rabbit hole I went.............

I see folks necking .308 brass down to .243 and .243 brass to .224. what sort of issues would you likely run into if you took .308 brass down to .224?

I use a 6.5 Grendel ,Redding S type bushing die to form my brass using successively smaller bushings to achieve the desired neck diameter.

Would it be reasonable to do the same thing with a similar die in .308 to form .243 and .224 neck cases?

What do you all think?

[dh2]

I looked down this rabbit hole and ended up building a 22-250 AI giving me very good results, and using a brass that is easy to get. No matter what you build I dont see getting that bullet much over 4000 FPS

[PNW_Steve]

I looked down this rabbit hole and ended up building a 22-250 AI giving me very good results, and using a brass that is easy to get. No matter what you build I dont see getting that bullet much over 4000 FPS

One of the 22-243 guys claims 4200fps with a 55 grain bullet. My interest lies more to 88 grain ELD-M.

Regarding brass availability, I have a secret connection that can get me. 308 brass reliably. Don't tell anyone :)

[PNW_Steve]

My question is whether I can produce brass for those two cartridges the same way that I do for my 6.5 Grendel based cartridges, except for the different sizing die and bushings.

[dtknowles]

Steve, how you form your brass depends on the dimensions of your chamber. I don't know if there is a standard 22-243 chamber but if there is it is probably sized to work with .243 brass so if you have that chamber and you use 308 brass you might have to neck turn or ream. You should not need many bushings, you probably could just run 308 brass right into the 22-243 sizer. You might or might not need to anneal the brass and maybe you could use a 243 sizer or a 260 sizer as an intermediate step.

Tim

[yeahbub]

Regarding expected issues when necking cases down to smaller calibers, the first thing that comes to mind is how overbore is it? Necking the .308 Win to .224 is a lot of fire through that throat and overbore conditions generally leads to gas erosion and shorter throat life. The .220 Swift at full throttle was known for this, but those who backed off their loads and didn't demand 4000 fps from every shot were rewarded with long term accuracy/barrel life. Neck length also plays a part. Longer necks reduce the erosion that takes place over time. The rate of erosion increases the hotter the steel is in the throat. In semi-autos that some habitually like to chatter off magazines with as fast as they can pull the trigger aren't doing their barrels any favors for long term accuracy.

One of the AR calibers I've been hearing that cast shooters are exploring is the .30 Rem (rimless .30-30). Given the long neck, lower SAAMI pressures and the unliklihood of rapid-fire use, I'd expect that one to last a long time.

[dirtball]

You can do anything you want with a given piece of brass. With what it sounds like you are trying to achieve I would go for the 243 case, two reasons, 1) it is longer than the 308 and therefore more case capacity, 2) you can use Lapua brass in 243 and not have to turn the necks to be able to control neck tension and have brass that will last longer at higher presure. You could go to the 243 improved and neck down to 224, but I warn you, use ball powder, if not you can get "Neck Damming" and create unacceptable chamber pressures. I have a 224X6mm Remington improved that will push an 80gr SMK at 3500 fps. The 243 weather regular or improved will allow you to use a readily available die i.e.: Redding type-s bushing dies and then uses smaller bushings.

Dave

[Phat Man Mike]

Why not build a 458 socom bolt action and load Some battle ship 700 grain boolits ?