8x57 Lapua to 6mm AI?????

[Phil]

Has anyone used Lapua 8x57 to form 6mm AI brass before???

I`m thinking i could go from 8x57 to 7x57 then 257 Roberts and them 6mm Remington and on to turn necks, anneal and fire form, does this sound doable or am I leaving out a step????

Phil.

 

[std7mag]

If they make 7X57, you could drop a step.
But, yes.
Very doable.

 

[Pawnee Bill]

I have used RWS 6.5x57 Mauser for 6mm Rem. Try Huntington's,

 

[ckrifles]

I have used 8x57 lapua to make 257 roberts brass. Way cheaper than RWS brass.

 

[AckleymanII]

Just remember that Web dimensions can vary greatly in CIP spec European brass and SAAMI spec American made bass for which most reamers are ground for.

 

[KMart]

Sounds like a bit of work up front but it should last forever.

Do a few first to verify AckleymanII's comments.

 

[AckleymanII]

Many, including me, have been busted HARD by using brass too large in the web vs what the chamber was cut for. This issue is worse than bolt clickers. For instance, I have some brand new PMC brass in 308(very tough brass) that will not go in my match chamber...brand new brass. Lapua 22/250 and 243 brass will not work with my reamers that are made for SAAMI brass.

 

[rickiesrevenge]

Just curious, who made your reamers?

 

[Ringostar]

The 8x57 is longer base to shoulder then the 7x57. Since you’re willing to size cases back this way, but the web size could be an issue, then you have other options. You can size back good quality 30-06 brass with your same methods.

 

[Phil]

The 8x57 is longer base to shoulder then the 7x57. Since you’re willing to size cases back this way, but the web size could be an issue, then you have other options. You can size back good quality 30-06 brass with your same methods.

Same dies and steps, just change the parent brass??

 

[AckleymanII]

Just curious, who made your reamers?

JGS and Dave Manson, Specify CIP for European Brass

 

[Ringostar]

Same dies and steps, just change the parent brass??

Yes. You will need to trim the case length though. I’ve done it just as an experiment. I wanted to see what a case would look like at 8x57 size but in a 6.5 with longer neck. I removed die internals first. Then ran a few cases into an 8x57 die. This moved most of the shoulder to that length. Then a 7x57 die adjusted up, so that it wouldn’t move the shoulder back more. This sized the neck down to 7mm, and the rest of the shoulder that was missed by the 8mm die. Then I adjust up a 6.5x47L die. This took the neck down to 6.5 and gave it a 30 degree shoulder just slightly shorter then the 8x57, because of the difference in shoulder angle. Then I trimmed the cases to a 0.340 neck length. Overall it created a case slightly less then a 6.5x284 but more then a 6.5x55 all with a longer neck length closer to the 7x57, 257 R, and 6mm R.

 

[Plumsask]

Same dies and steps, just change the parent brass??

I've done the 8x57 method, had no problems.

 

[johnmyers]

I just finished doing 50 Lapua 8x57 to 6 Remington turned and trimmed ready to fireform to 6 Rem AI. Chamber smooth and make nice looking cases. 4.5 gr heavier than ones done with 7x57 Norma

 

[Plumsask]

I just finished doing 50 Lapua 8x57 to 6 Remington turned and trimmed ready to fireform to 6 Rem AI. Chamber smooth and make nice looking cases. 4.5 gr heavier than ones done with 7x57 Norma

Did you turn necks on them?

 

[johnmyers]

Did you turn necks on them?

Yes in original post said turned and trimmed

 

[AckleymanII]

I just finished doing 50 Lapua 8x57 to 6 Remington turned and trimmed ready to fireform to 6 Rem AI. Chamber smooth and make nice looking cases. 4.5 gr heavier than ones done with 7x57 Norma

By the second or third firing, you will know what you have in terms of brass dimensions and chamber size.

Best wishes and good luck!

 

[johnmyers]

By the second or third firing, you will know what you have in terms of brass dimensions and chamber size.

Best wishes and good luck!

Thanks

 

[wildcatter]

missed this, but 8x57 Lapua brass I lost one case out of 100 early, but 7x57, 257, then 6mm Rem, the big thing your going to see is just how much this thickens the neck of the brass! In my no turn 6mm Rem. AI chamber I had to trim nearly .009" for .003" clearance. But have 100 finished cases that are weight matched to within .15 grains of each other!

I chose to fire form before turning, just used 14 grain of bullseye, and filled my cases with corn cob polishing media, then sealed them with zest bar soap, bees wax, or paraffin. Then turned the neck's with my K&M nk turner w/ inside donut cutter pilot, one step done,, was all within max length, and after the first firing with loaded ammo, trimmed to uniform length of the entire lot of precious new cases!

 

[SweaterDood]

Would any of you happen to know the webbing measurement on new Lapua 8x57 brass? Looking to do the same for my 257 Rob AI and the US brass is too small for the chamber. Hoping this cures my issues.

If not, the barrel will be set back and rechambered to 25x47L...