7mm 423 dakota wildcat

[7x57]

I contacted Hornady's custom die dept. and they require chamber reamer prints and a couple of parent pcs. of brass. I believe the price they quoted me was $177.00 for a set. Swamplord has done a lot of development on the 423 Dakota brass format. He calls it the "PRO" lineup. He has everything from 6.5 caliber to 50 cal. I think. I'm just in the starting stages of my build. From the looks of it he has got a complete set of reamers, dies, brass, etc. Hopefully he chimes in on this again.

 

[CHARLIEDUECE65]

Just ordered forster 338 norma mag die set.....do I need an intermediate die to get it sized down all the way or am I good to go? Im going to run the standard 338 norma mag chamber.

 

[IdahoCTD]

I built some dies using a 338 Lapua reamer and it is fairly easy to get down to there. Trying to get from there to 30 cal is a bit of a challenge. I have a 30-338 Norma Imp. that I'm using the brass for. It might be easier with 338 Norma and 300 Norma dies but I don't have either. I have a friend with 300 Norma dies I will borrow next time I see him to try for better results as I lose a few every time I form brass. I have to turn a bunch off the necks for my chamber as well. The necks end up about .021-.022" thick and I have to have .015" or less for my chamber.

It is really easy to get it down far enough for a .375 caliber cartridge.

 

[CHARLIEDUECE65]

I got my 338 norma mag dies in today. Tried sizing a few cases but they didnt work out. The cases pushed in at the neck junction. I think I will try to find an intermediate die. Wish I knew what the 375 norma specs were going to be. If its just the 375 cal neck on the 338 case I will have a die made. Thanks for any info.

 

[Edd]

When you are forming cases, you should reduce the diameter about .050" per step.

 

[CHARLIEDUECE65]

Thanks, I'm going to try to get a 375 norma mag bushing die made.

 

[IdahoCTD]

I got my 338 norma mag dies in today. Tried sizing a few cases but they didnt work out. The cases pushed in at the neck junction. I think I will try to find an intermediate die. Wish I knew what the 375 norma specs were going to be. If its just the 375 cal neck on the 338 case I will have a die made. Thanks for any info.

If your going to use this brass and have custom dies made then it doesn't matter what the official 375 Norma dimensions are. Make the reamer and dies to the same dimensions and carry on.

I used 4 steps to get them to 338 so I can see where you'd crush them trying to go straight to 338. I still lose a case or two out of 20-25 when I'm sizing them. I use 3 bushings in my .30-338 Norma Imp to get them from 338 to 30 to minimize case loss because they don't have support at the shoulder like they would in a 300 Norma die.

 

[IdahoCTD]

When you are forming cases, you should reduce the diameter about .050" per step.

When you've necked a 423 case to 338 or smaller I would go to half of that or less. The necks get so thick already at 338 and 30. Trying to shrink them more puts a lot of pressure on the shoulder of the case.

 

[harfman99]

yes to get them down to 7mm I had to inside neck ream after I had them down to .375. I also had to go down in steps of .025 otherwise I would ruin cases.

 

[Edd]

I size Ultra Mag cases from .528" down to .355" in 3 steps. Then I ream and turn the necks and go down to either .342" or .318" in the fourth step.

 

[harfman99]

By the way this Fat little round is amazing! it is kicking my 7 ultra's *** in every way possible. running the same or more powder with less pressure signs and getting as good or better velocity. this rifle round combo is printing well under .25 moa and running average of 3260 in a 30" benchmark barrel.

before and after fireforming

 

[CHARLIEDUECE65]

I talked with whidden about dies. They can make a custom die however they dont make bushings to fit. Jim Carstensen will modify my Forster 338 norma mag sizing die to a bushing die and make a 375 bushing for it. If I take this route should I have him make .400,.375, and .350 bushings also?

 

[IdahoCTD]

I would do that. You can buy some bushings so you may not need him to make you all of them (I'm thinking it might be cheaper to buy them rather than have them made).

 

[CHARLIEDUECE65]

Ok....what size of bushings are standard for the 338 norma. Did a search and couldnt find any info for standard bushing sizes or size range. Thanks.