School me on the 338 Edge...

[Earnhardt]

OK, a couple of more questions...
Does/can a variance in size of the flash hole opening in the primer pocket effect the powder burn rate of powders?
Here's the examples in my 338 Edge
My new 338 Edge Bertram Brass has a .081" primer flash hole opening, or .0206" sq.
My Norma 300 RUM brass I opened up to .338 has a flash hole of .075" or .0176" sq.
So the 338 Bertram brass has a flash hole opening that is ~ 16.5% larger than the flash hole in the Norma brass.
Does/can that larger flash hole effect the powder burn rate in between the two different pieces of brass, if the bullet weight/type are the same as well as the same powder type and weight?
So the only variable between the 2 cartridges would be that the primer flash hole is ~16.5% larger in the 338 Bertram brass.
I have only shot with the Bertram brass so far.
But I'm getting ready to shoot with the Norma brass.
Thanks

 

[Deleted member 46119]

Does/can that larger flash hole effect the powder burn rate in between the two different pieces of brass

Absolutely. That is why Lapua Palma, 6.5 Creedmoor and others have a smaller flash hole than say Hornady.

 

[Deleted member 46119]

Bertram Brass has a .081" primer flash hole opening, or .0206" sq.
My Norma 300 RUM brass I opened up to .338 has a flash hole of .075" or .0176" sq.

Now you are making me want to get a pin gauge set.

 

[shortgrass]

You don't think a good set of number sized drill bit might work?

 

[Deleted member 46119]

You don't think a good set of number sized drill bit might work?

Yes. I'm tired. Brain fart. I have a drill full set.

 

[TwoMore]

OK, a couple of more questions...
Does/can a variance in size of the flash hole opening in the primer pocket effect the powder burn rate of powders?
Here's the examples in my 338 Edge
My new 338 Edge Bertram Brass has a .081" primer flash hole opening, or .0206" sq.
My Norma 300 RUM brass I opened up to .338 has a flash hole of .075" or .0176" sq.
So the 338 Bertram brass has a flash hole opening that is ~ 16.5% larger than the flash hole in the Norma brass.
Does/can that larger flash hole effect the powder burn rate in between the two different pieces of brass, if the bullet weight/type are the same as well as the same powder type and weight?
So the only variable between the 2 cartridges would be that the primer flash hole is ~16.5% larger in the 338 Bertram brass.
I have only shot with the Bertram brass so far.
But I'm getting ready to shoot with the Norma brass.
Thanks

I ream all mine to .083 and match them up, I use the same reamer on my WSMs also. but I only use rp and bertram brass on my edge, and win brass on the wsm's , i have bought some bertram brass for my wsm's but it isnt here yet

 

[Earnhardt]

Cool!
Great idea!
I was wondering if I should just sell the new Norma Brass I necked up to 338, but I'll just keep it and increase the flash hole size to match the Bertram Brass.
Thanks!

 

[Earnhardt]

When it comes to different size primer flash holes in different brands of brass, is this due to brand variability, or is this caliber specific?
Meaning does a 300 RUM Norma brass always have a different size flash hole, compared to a 300 RUM Hornady brass?
Or is it caliber specific, meaning that a 300 RUM brass ALWAYS has a different size flash hole than a 338 RUM brass flash hole? (or a 7mm Mag, for example)
Thanks

 

[Deleted member 46119]

When it comes to different size primer flash holes in different brands of brass, is this due to brand variability, or is this caliber specific?
Meaning does a 300 RUM Norma brass always have a different size flash hole, compared to a 300 RUM Hornady brass?
Or is it caliber specific, meaning that a 300 RUM brass ALWAYS has a different size flash hole than a 338 RUM brass flash hole? (or a 7mm Mag, for example)
Thanks

I don't have huge amounts of data to back this up. However...

It appears to be manufacturer specific.

 

[Edd]

My new 338 Edge Bertram Brass has a .081" primer flash hole opening, or .0206" sq.
My Norma 300 RUM brass I opened up to .338 has a flash hole of .075" or .0176" sq.
So the 338 Bertram brass has a flash hole opening that is ~ 16.5% larger than the flash hole in the Norma brass.

The 16.5% difference is correct but if the area of the flash hole is important to you, the math isn't correct here.

A .081" diameter hole has an area of .00515 sq in.
A .075" diameter hole has an area of .00442 sq in.

 

[Earnhardt]

I didn't doo da maff right!
Ooops...thanks man!

 

[Gregg C]

Absolutely. That is why Lapua Palma, 6.5 Creedmoor and others have a smaller flash hole than say Hornady.

So, inference here, a dirty flash hole could contribute to ES?