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Making The full length Sizing Die For My 338 Lapua Ackley Improved.

jackieschmidt

Gold $$ Contributor
I decided to give this a go. I patterned this after a Redding “S” Die.
I got a piece of O-2 Tool Steel. I had to hand grind a boring bar to bore the hole on the correct taper plus form the 40 degree shoulder.
I used the taper attachment. The taper is .020 in 2 inches. I think I got the taper size correct.

I still have to make a decapping stem. The die is bored for standard Redding bushings.

After everything is fit, I will case harden it.

IMG_0697.jpegIMG_0696.jpegIMG_0700.jpegIMG_0701.jpegIMG_0703.jpeg
 
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I built one for a buddy and it's probably one of the most accurate rifles I've put together. This is a 500 yard target with fire forming loads using 300gr Sierra's. These loads were only going around 2850 fps. He's since got all the brass formed and is using 300gr Berger's going just a little over 3000 fps. and accuracy is basically the same if not better.

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I built one for a buddy and it's probably one of the most accurate rifles I've put together. This is a 500 yard target with fire forming loads using 300gr Sierra's. These loads were only going around 2850 fps. He's since got all the brass formed and is using 300gr Berger's going just a little over 3000 fps. and accuracy is basically the same if not better.

View attachment 1654687
They have been the most accurate big cartridge I have experiance with. What you saw is no fluke.
 
Are you using this to case harden it?
81-003-001 Main Image
 
I made the bullet seater by taking a Redding 338 Lapua Competition Seating die and simply boring out the sliding sleeve to fit a sized Ackley Improved case as Redding does not list the 338 Improved. The sleeve is not hard.
There are a few more mods, but it’s Pretty simple stuff.
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Ya gotta love it when a plan comes together.....I can't wait till you get some rounds on it.
 
Probably Cherry Red. It basically does the same thing.
excuse me. but I would like to point out that O2 steel has plenty of Carbon to harden to 63-65 HRC without the use of either casenite or cherry red compounds. additionally, it is a through hardening steel, so you are not likely to get a hard case using either compound, but you are likely to crack the die you have put a lot of work into building.
 
Why did you use O1 if you are going to case harden it?
It’s 0-2. We use it to make slotting tools for our two vertical slotters that we use to cut large keyways. It doesn’t tend to chip on the back drag like harder HSS.
But, I was wrong. It does not case harden that well.
I just talked to my buddy over at the shop that does the hardening on our slotter cutters, and he said he would fully hardened it for me just like he does those. They use small electric ovens for this type of stuff. Minimum distortion and no oxide on the surface.
 

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