Case Length- Forming .243 from .308

[JaoeyP]

I recently have gotten into tinkering with .243 Win. I don't have much brass but have an ample supply of .308 brass. I've been able to succesfully form .243 from the .308 brass. My concern is the formed brass is a fair amount shorter than .243's Trim-To length. Is this an issue? The brass chambers without issue. Are there safety concerns with having too short of brass? The brass is ending up around 2.007".

 

[spclark]

Are there safety concerns with having too short of brass? The brass is ending up around 2.007".

That's pretty typical of 308 brass, I trim mine to 2.005" after two firings (and deburring flash hole, neck turning to 0.0130" thickness) before reloading.

Only safety concern I can think of is tendency for powder deposits (carbon, mostly) to accumulate ahead of case necks in your chamber which, should you then change to more typical length 243 brass (@ 2.045"), could lead to hard-to-close bolt & perhaps pressure issues at firing... unless you're diligent with cleaning your chamber before the switchover.

 

[ireload2]

Many el cheapo handloaders used to form .270 Win brass from .30-06 cases. The .270 cases are supposed to be about .050 longer than .30-06 but I never heard of any problems.

 

[dkhunt14]

Make sure you keep the carbon cleaned out in the neck area. The other thing you have to wartch is when you neck down the brass usually gets. 001 thicker. That means you lose .002 clearance. Make sure you have enough clearance or you can have pressure problems. Might have to neck turn them a little. Matt

 

[ebb]

I don't think you are even asking the right question. When you neck down the neck gets thicker. You mentioned that the brass chambers, but when it has a bullet seated will it chamber and have enough clearance between the neck and the chamber? I made some 25-06s from 270 brass it was too tight. The first 5 I fired were OK, but the 6th one was bigger and it was bad.

 

[AckleymanII]

You should get into turning necks if you are forming 243 from 308


DOUGHNUTS!!!!

 

[spaniel]

It's a straight 243....fire it 1-2 times and it will grow to the correct length. 243s are good for that. You just traded case trimming for neck turning (maybe, depending on your chamber).

 

[Someoldguy]

I agree with the above remarks concerning neck diameter. I formed some .243 brass from .308 brass once to see if it had any significant affect on accuracy, which it did not. But I also had to turn the case necks or there would have been clearance problems.
You need to know your chamber neck diameter to proceed.

 

[JaoeyP]

I don't think you are even asking the right question. When you neck down the neck gets thicker. You mentioned that the brass chambers, but when it has a bullet seated will it chamber and have enough clearance between the neck and the chamber? I made some 25-06s from 270 brass it was too tight. The first 5 I fired were OK, but the 6th one was bigger and it was bad.

I had not thought of that. I'll have to seat a bullet on one of the cases and try.

 

[243winxb]

Buy 243 brass and FL bushing die. 18 or more loadings with no annealing.

Short trim length, more erosion, worse with 68 gr or shorter bullets. Base of bullet leaves case mouth before front of bullet enters the rifling. This produces blow by before sealing. (Factory chambers)