.308 to .243 brass conversion.

tappedandtagged · #1 08-22-2012, 01:56 AM

I'm about to buy another .243 rifle after my H&R Handi Rifle gave up on me and started looking at my reloading supplies. I only have 17 cases of .243 brass but 99 pieces of one fired Federal Match .308 brass. I don't even have a .308!

I know that .243 is a necked down .308, so I lubed up a .308 case and ran it through my .243 sizing die. Going nice and slow, I was able to neck it down rather easily. The .243 case and my re-sized .308 case look identical.

I seated a bullet (on an un-primed, no powder case) and stuck it in my Handi Rifle. The action was a bit still to close up, but it did close up fine. I then took my calipers to it and noticed that the neck measured out to be 0.272" where my .243 dummy round (both with the 100 grn Hornady Interlock bullet) measured to be 0.271" or a difference of 1 thousandths of an inch.

Should I smile at my experiment and then go buy some .243 brass or (being the ever frugal re-loader) re-purpose the remaining 98 cases of .308 brass?

Ivan the Butcher · #2 08-22-2012, 09:47 AM

The case capacity is your next cocearn. Put a used primer in the re-sized cases, fill with water, then weigh and compair their volumes. The 243 brass is readily avalible, don't be cheap. Save or trade the 308 brass. By the way, I,ve found that the match brass (any brand) is alot different internally than standard brass.

tappedandtagged · #3 08-22-2012, 09:49 PM

Talked to a local reloading shop today. He's willing to trade new .243 brass for my .308 once fired Federal Premium brass.

What is a fair exchange rate? I figured 51% would give me 100 .243 cases for the 198 .308 I have. Am I asking too much? Too little? His is likely going to be bulk Winchester brass.

Frank46 · #4 08-23-2012, 04:01 AM

Well if you ever fired that necked down 308 to 243 you just might have received a suprise you were not counting on. As you made no mention of either neck turning or neck reaming I would have to have you not fire any of that ammo. Why, because when you resized the 308 case to 243 where did you think all that brass was going. Your case necks are now way oversized as far as thickness is concerned. The thickness maybe such that after seating a bullet and putting it in the chamber there may no longer any room for the case neck to expand and release the bullet, pressures will no dougbt be very high and damage to you and your rifle would be sustained. Frank

growr · #5 08-23-2012, 08:21 AM

Make the trade and move on.........Frank46 is right on the neck thing as well. Unless you have the tools to correct this....get the 243 brass and make some more ammo.

Randy

brucev · #6 08-23-2012, 08:40 AM

Once upon a time in the dim dark past when the .243 was a new bird on the wire, it was not uncommon to have to rework .308 brass so that one would be able to do any serious reloading. Those who followed that route understood that either reaming or turning of the formed cases would be necessary so that upon firing the neck would be able to expand the slight amount necessary for the bullet to be released. As factory .243 brass became more available, it greatly reduced the problems inherent with such modification of brass. Exactly the same thing happened later when the 7mm-08 came on the market.

As to fair trade value, you cannot expect a retail shop to give a retail price on one-fired brass traded for new brass. In addition .308 brass is much more common than .243 brass. If the owner is willing to trade, you'll pick up a usable quantity of .243 brass. But for the long term you would likely be better served to just go ahead and buy 100-200 pieces of new .243 brass.

Now... once you have your new brass in hand... you can begin the fun of sizing, trimming to length, uniforming primer pockets and sorting by weight into batches for subsequent load development. Of course you'll want to also lay in a nice selection of bullets and powders and primers. Oh the fun of reloading! And... as I told my wife when I first began handloading ammunition... it's economical. :-)

couleeflyfisher · #7 08-23-2012, 09:36 PM

In the mid 1960's I purchased my 1st .243 and brass was not too easy to find. Lots of .308's available and a shooting buddy gave me a good supply and told me how to process into .243's. I still have the old Rockchucker which has lots of leverage and converted several boxes of .308 brass to .243. Can't remember if I reamed the necks or not but they worked fine, still shooting some of them but also over the years I acquired add'l .243 brass.