6mm SAUM ??

[hemiford]

People are building 6.5 SAUM's with good results.

Am I just being silly considering a 6mm version ?

I had a plan to build a 6mm-6.5 Rem Mag, so I thought
well as long as I'm considering that, what about a slightly
more extreme version ?

 

[AZShooter]

It would have a short barrel life. The 6mm-284 is considered a barrel burner. The case capacity of the 284 vs the 7 SAUM parent cases is 66 vs 73.6 grains of water.

There was a 6mm-264 win mag AI that was called the Mach IV. The case capacity of the parent case, the 264 win mag is 82 grs.

Ross Seyfried wrote an article where he made one calling it the 6mm mach IV. He stated that he could get 4205 fps with IMR 7828 and 70 grain nosler BT and 4150 fps with 75 grain x bullet. IIRC this article was back in the 1990s.

He talked about it being the closest thing to a death ray he had ever used. He had an issue with a hard carbon like substance building up on the first barrel due to not cleaning it every dozen rounds or so. IIRC he had to throw away that first barrel.


I wore out my 6mm-284 with its bartein 5R barrel in approx. 1100 rounds with casual shooting over several years of use. You can decide if the performance vs cost is worth an even shorter barrel life.

If you do make one be sure to share the results here!

 

[Frank in the Laurels]

I agree 100%...there's no way the barrel could last all that long in the throat Ares. If the 6mm/284 is bad the 6 SAUM would be considerably worse with almost 10 grains more powder...but if you could pull it off it would be fast, not sure the 100+ bullets would stay together at those speeds..3500+ would be achievable with ease ...I'd like to see the trajectory chart at those speed..point and shoot..?? 450 yards... I'm sure this has been tried many times before..I even remember reading something about it before, maybe someone who has already tried it will chime in on what happened.

 

[elkaholic]

I have not done that with my SS case for that very reason. If you want to pay for a reamer and do it, it would be a screamer. I can have dies made for it.......Rich

 

[TXAoudadKlr]

I feel you would be limited to a small amount bullets that could handle the speed of it. I very well could be wrong though

 

[hemiford]

Thanks Gents.

I think it would be easier to form 6.5 Rem Mag brass into 6RM
and it appears to be easy to find.

With 6mm-7SAUM, just the opposite, harder to find brass and
more steps to form.

Barrel life is what it is.

 

[elkaholic]

I have SS Norma brass and have no problem getting and have no problem getting it on line......rich

 

[IdahoCTD]

I built a 6-300wsm. I ran 105 Amax's at 3600fps in a 28" barrel using Retumbo. I'm sure a ball powder, R-50, R-33, etc. would have got more velocity.

 

[adam32]

We used the 6.5 Rem Mag case for our 6mm wildcat...

 

[TXAoudadKlr]

Would a 6-6.5 GAP4s be a viable option? Gap has Hornady making them brass.

 

[elkaholic]

Would a 6-6.5 GAP4s be a viable option? Gap has Hornady making them brass.

don't know why not

 

[Trickymissfit]

It would have a short barrel life. The 6mm-284 is considered a barrel burner. The case capacity of the 284 vs the 7 SAUM parent cases is 66 vs 73.6 grains of water.

There was a 6mm-264 win mag AI that was called the Mach IV. The case capacity of the parent case, the 264 win mag is 82 grs.

Ross Seyfried wrote an article where he made one calling it the 6mm mach IV. He stated that he could get 4205 fps with IMR 7828 and 70 grain nosler BT and 4150 fps with 75 grain x bullet. IIRC this article was back in the 1990s.

He talked about it being the closest thing to a death ray he had ever used. He had an issue with a hard carbon like substance building up on the first barrel due to not cleaning it every dozen rounds or so. IIRC he had to throw away that first barrel.


I wore out my 6mm-284 with its bartein 5R barrel in approx. 1100 rounds with casual shooting over several years of use. You can decide if the performance vs cost is worth an even shorter barrel life.

If you do make one be sure to share the results here!

Build whatever you like, but remember the results you see with the 6mm Ackley present the case for overbore. Ackley said the case capacity of the 6x57 case was just about max for the 24 caliber bore. With that in mind we then know the 6mm AI is in overbore, but not by a great amount. Why it does better with 90+ grain bullets. Yet the 6mm Vias is built off an improved 6.5x55 case that has the shoulder pushed back roughly .050". It will push a 70 grain bullet to 4150fps while having a slightly smaller case capacity than the 6mm AI. Precision Shooting tested this round and found these values with very little effort.

Gun powder's not cheap these days, so why waste your money?
gary

 

[hemiford]

IdahoCTD,

6mm-300WSM is very impressive to me.

How did you work the case down to 6mm ?
Did you start with a 300 or a 270 ?

 

[IdahoCTD]

I used 270wsm cases. The first step was 6.5x300wsm through Lee dies in that caliber. They were a standard die at the time, I'm not sure if they are now. Then I used a 243 WSSM die backed off to get them to 6mm.