Alpha 6BRA brass

[dbduff]

When Alpha came along with their brass it seemed that a lot of guys didn't want the .080" flash hole. The common knowledge was that .060 was best. But I have never seen the data. Who did the testing and under what conditions? I have never seen it published or even heard from someone with first hand knowledge of the testing. Even if it was done, Id bet it was in a ppc and would it even apply to the dasher or bra case with the powders we run? Alpha was on board to get me some brass without holes so we can test ANY size, so we are on board to see what can be learned.

Works for me. Let us know if you find any conclusions you can verify.

 

[johara1]

Remember these test now are in extremely cold conditions and may be different in the 80-90 degree heat. This is why the military uses the .080 flash hole in the .223..... jim

 

[savageshooter86]

@tom and @Alex Wheeler Thanks for all the data and testing y’all do. And are willing to share most of what y’all can to help us mortals do better and shoot smaller groups. Can’t wait to see what y’all conclude

 

[tom]

@tom and @Alex Wheeler Thanks for all the data and testing y’all do. And are willing to share most of what y’all can to help us mortals do better and shoot smaller groups. Can’t wait to see what y’all conclude

I personally find it fun, as it is interesting. I'm thinking I'm going to throw my shit in the truck here about the 15th or so, and go test in the desert sw in some warmer temperatures. It's either that or wait until August here lol.

I have no clue how .080" was decided for large rifle. I'm pretty sure lapua just scaled down the large ratio and rounded to the nearest metric available tooling for their small rifle stuff.....But possibly it was put through the testing and the data just hasn't crossed my path?

Tom

 

[lawman29]

For the OCD crowd:

https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=8415&context=masters_theses

So maybe test ~ 3mm or 0.10 from above

https://apps.dtic.mil/dtic/tr/fulltext/u2/a114616.pdf

 

[savageshooter86]

I personally find it fun, as it is interesting. I'm thinking I'm going to throw my shit in the truck here about the 15th or so, and go test in the desert sw in some warmer temperatures. It's either that or wait until August here lol.

I have no clue how .080" was decided for large rifle. I'm pretty sure lapua just scaled down the large ratio and rounded to the nearest metric available tooling for their small rifle stuff.....But possibly it was put through the testing and the data just hasn't crossed my path?

Tom

One would assume testing was done to come up with these specs for other brands of brass. But like you find it interesting that the small changes are making a difference on paper so far. So makes one wander how much more could be gained by changing flash hole size only on the brass. I find your data interesting. And targets don't lie. And I fully uderstand this is initial stage of testing and like you said many rounds will need to be shot and targets analyzed until any full conclusion can be made. Keep up the great work. Can't wait to get my barrel and do some testing

 

[Alex Wheeler]

Remember these test now are in extremely cold conditions and may be different in the 80-90 degree heat. This is why the military uses the .080 flash hole in the .223..... jim

Very well could be the case. But he didnt say 80 was best, just that it is also good. I do not think hole size will correlate with temps from what I have seen at this point.

 

[Mulligan]

Some might find this interesting.

https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=8415&context=masters_theses

Results showed that muzzle velocity and chamber pressure varied 1-4% from the control flash hole as hole diameter, offset, and orientation changed. The precision, particularly in the 3mm diameter and centered flash hole cases resulted in improvements of up to 28%. Variations in flash hole diameter, offset, and orientation do affect cartridge performance. Alternate flash hole diameters exist that improve powder ignition consistently as well as precision.

CW

 

[johara1]

Very well could be the case. But he didnt say 80 was best, just that it is also good. I do not think hole size will correlate with temps from what I have seen at this point.

No, I understand but so far the test is good but in the cold. I don't think the .080 is either but that is to be seen. May just have to do with the pressure it will stand. Send Tom south, he needs a tan ..... lol.... keep up the good work.... jim

 

[Ga. Dawg]

@tom you got any them Alfa brass in left hand? Askin for a friend.

 

[tom]

Well this ought to be a fun weekend! Heck, might as well blow off work the beginning of the week and really test them out!

Did I ever mention that I despise February!!

Tom

 

[STS]

Come down south to Bozeman. It's supposed to warm and calm here all week. It's coyote calling weather.

 

[Hoodoo]

Looks like we finally get some decent weather. If you need to contact me this weekend, don't. I'll be busy working hard, definitely not playing in the snow.

 

[Jud96]

I have really enjoyed reading through this thread. This level of testing and data collecting is what I love to see. Unbiased, real life testing like this is great. Good work @Alex Wheeler and @tom. You guys always share excellent information and testing results.

 

[tom]

Alpha #3 is starting to repeat as "left handed" a couple times now lol.

Tom

 

[TZaun]

Alpha 2 1/2 and 30.15 gr.

 

[Northridge]

Alpha 2 1/2 and 30.15 gr.View attachment 1232206

Lol i get it but i would actually trust the solid color 30.2 not the split not at all because they are together but because 30.2 is in full compensation.

Shawn Williams

 

[tom]

My last day for a few weeks was about as miserable as I'll tolerate for shooting! 3 above, 10 mph northeast wind, and enough snow coming down I had to strain to see I was centering up on my poa.



I feel I'm getting somewhere, with the caveat being in this one barrel with this one primer, and in very cold weather. Repeatedly Alpha 1 shoots ladders that suit my eye. Alpha 4 has shot nice ladders as well, and groups well for the conditions so far. My alpha 2s continue to look "workable", and alpha 3s have been homely multiple times now. I will be heading south for a visit with my aunt, and hopefully will see some warmer mornings when I get back home.


Also, I wanted to say thank you to @Roy H for providing some bullets for this "project". Without knowing the chances of this resulting in a "game changer" or not, he stepped up in case it is! There's a lot of components going to be expended just on the outside chance it results in an advancement of our sport. And even though your 6.5 has no chance, you're a good man that's in it for the right reasons!

Tom

 

[Roy H]

From what I see you better get a different size drill bit or my 6.5 gonna bust your ass....

 

[Northridge]

My last day for a few weeks was about as miserable as I'll tolerate for shooting! 3 above, 10 mph northeast wind, and enough snow coming down I had to strain to see I was centering up on my poa.

View attachment 1232452View attachment 1232453View attachment 1232454View attachment 1232455

I feel I'm getting somewhere, with the caveat being in this one barrel with this one primer, and in very cold weather. Repeatedly Alpha 1 shoots ladders that suit my eye. Alpha 4 has shot nice ladders as well, and groups well for the conditions so far. My alpha 2s continue to look "workable", and alpha 3s have been homely multiple times now. I will be heading south for a visit with my aunt, and hopefully will see some warmer mornings when I get back home.


Also, I wanted to say thank you to @Roy H for providing some bullets for this "project". Without knowing the chances of this resulting in a "game changer" or not, he stepped up in case it is! There's a lot of components going to be expended just on the outside chance it results in an advancement of our sport. And even though your 6.5 has no chance, you're a good man that's in it for the right reasons!

Tom

thanks Roy you old dog... takes a village to keep Tom between the guard rails. Tom I suspect your windows will hold at 50 degrees even with a possible uptick..

Shawn Williams