308LC to 270/308AI

[Estacado]

I purchased a Mauser that has been barreled to 270/308Ackley. A nice set of Redding dies came with the rifle. I bought 250 once fired 308LC cases. They have been resized(308). I felt it would simply be a matter of running the 308's thru the full length die. I promptly shoved the neck into the top of the cases. I kept adjusting the dies up. After destroying 6 cases here I am! I have been reloading for a year or so. Never for a wildcat. Would some of you reloaders who are experienced in case forming have an idea of what I might be doing wrong?

[skeettx]

Yes, the problem is the super sharp shoulder will not let the case neck feed into the 270 neck area.
You can start the taper with an assortment of dies

or you may get lucky with the rotate size effort

take the full length size die and with out a case in the shell holder, adjust the die to bottom out on the shell holder ALMOST.
Then take out the decapping stem of the size die.
Lube the case with Imperial Sizing Wax.
Put a case in the shell holder. Size it a small bit, lift the handle, rotate the case 90 degrees, size a bit more, lift the handle, rotate the case 90 degrees, continue on like this until the handle is full down.

Let us know how this works for you. And also after you have done 5 or so cases this way the die may be seasoned and will let you be more agressive.

Mike

p.s. How close to Amarillo are you??

[GRUMPA]

If I were you I would try different head stamped cases. All mil brass seems to be rather thick and doesn't like to be formed a lot all at once. I make a lot of different cases with the 308mil brass, and not all work well, I do get my share of bad ones.

If I had the sizer die the first thing I would be doing is doing it in stages. And by that I mean using other dies and gradually forming the case.

For reference: It takes me 5 forming operations in order to change a 32-20 into the 25-20. And what's even worse is I had to make form dies on the lathe for some form jobs.

Something else: NEVER and I mean NEVER have the decapping rod in any dies, except the very last final form operation.

Edit: Here's something else to further mess with your brain. I wouldn't be surprised if your either going to need to ream it OR turn the neck. Reaming works better.

[MostlyLeverGuns]

I had a .270-08 improved with a 35* shoulder. Size in 308 Win die WITHOUT neck expanding, size in 7mm-08 Sizing die - set die to leave enough 308 neck to set headspace, size in 270-08 AI die, sizing only 1/2 to 2/3 of the neck, finally sizing to provide a 'false' shoulder for fire-forming case. Annealing is recommended before fire-forming. You may need to turn necks, depending on chamber dimension using 308 LC brass. Using 7-08 bras would be a simpler process. I built my 270-08 improved before there was a factory 7-08 Rem. It is a pleasant and effective cartridge. Keep the neck well lubricated, feed the cases into the 270 die carefully centered and slowly into the 270-08 AI SEATING die, then size in the 270-08 SIZING die.

[Estacado]

Mike, 70 miles from Amarillo.

Grumpa, I have some of your 35 Rem brass you formed from .308LC. You made it easy for me.

MostlyLeverGuns, I am sure this rifle was built before 7-08 also. I am still "digesting" what you said. After it is sized to 7-08, run it into the bullet seating die then the sizing die?.

I have noticed the LC brass is thick. I may save the 308LC and bite the bullet and buy some 7-08 brass to start with. My thinking was that I do not like having brass that says it is so and so caliber on the head and it is not. I do everything in my power not to make a mistake along those lines.

[nicholst55]

I'll second MostlyLeverGuns suggestion to try the seating die before the sizing die. Grumpa also has more experience reforming brass than most folks alive, so the OP is getting good advice!

[Estacado]

Thanks everyone for the responses. Thank you skeettx for the PM, very kind of you. I ordered the 7mm08 cases and Imperial Sizing Wax as suggested. I'll give that a try.

[bj139]

Military brass seems to me to be be harder in the neck area than new annealed brass.
I think this is to provide better neck tension to hold the bullet in place.
Annealing before case forming might help.
New brass should be annealed very well and would be easiest.

[MostlyLeverGuns]

Your concern over chambering a 270-08 AI in a 7-08 is valid. In theory - the sharper angle and wider shoulder SHOULD keep the cartridge from chambering, then if somebody does manage to chamber the 270-08 AI in a 7-08 the smaller bullet should prevent extreme pressure issues. Getting a cartridge stuck while trying to chamber would be my expected negative outcome. Using the seating die provides another step-down in diameter before the final reduction in the sizing die. Annealing before sizing, particularly with 308 LC, any fired brass and even new brass may ease the process and should not hurt. There are some advanced long range shooters that anneal their brass every reloading, including new brass. Done properly, annealing is a plus.

[Texas by God]

You might could fireform .243s into your cartridge. The headspace should be the same. And you won't need to turn necks.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[Estacado]

Just letting everyone know how it turned out. I necked new 7mm-08 cases down to 270 caliber. Loaded up a light starting load and fire formed. The fire formed cases are perfect! Thanks for everyone's help!

Bob

[376Steyr]

Once fired LC brass has almost always been fired in a machinegun. Machinegun fired brass is often badly oversized, due to big chambers and violent extraction, so just getting it back to .308 Winchester dimensions can be an adventure. As you have found, using new 7mm-08 is a lot less hassle.