3006 brass ? - Page 2

Bart B. · March 20, 2015, 04:27 PM

06shooter, would you like me to send you a private message about your concerns?

F. Guffey · March 20, 2015, 05:21 PM

Quote:

06shooter, would you like me to send you a private message about your concerns?

While deciding on Bart B.s request I will give you something to think about. I loaded 150 30/06 rounds on a Dillon 550B, when finished there was 17 grains difference between the lightest and heaves round. The powder charge was correct, the bullets weighed the same. The 17 grain difference was the difference in case weight, straight across the board the Winchester cases were lighter.

F. Guffey

06shooter · March 20, 2015, 07:05 PM

Quote:

06shooter, would you like me to send you a private message about your concerns?

That would be good , thanks !

hooligan1 · March 20, 2015, 08:03 PM

F.Guffey I stand here thinkin to myself,, you just touched on the reason I have so many flyers......hhhmmmm. Yep I could fly to France twice and I think you've showed me why.

If 150 cartridges have 17 grain difference in weight from top to bottom, then there a huge possibility that when I prove my data I should weigh and get the ten similar weights to prove my loads, damn and I thought it was all on me...damn...

Bart B. · March 21, 2015, 08:03 AM

I've shot the same load in .308 Win cases whose weights ranged from 150 grains to 175 grains, all in the same rifle barrel. Powder charge weights and primers were all the same a couple grains below maximum; only Sierra 168's were used. There was no significant difference in accuracy through 300 yards with them. Several 10-shot groups were used with each case weight (average in a 3 grain spread) in their comparisons; some at 200 yards and others at 300 yards. There was about a 1 MOA spread in elevation zeros across them a 300 yards; not as much at 200..

There's no reason in my mind that .30-06 cases should not perform the same across a 25 grain spread in weight.

Regarding fliers; how does one tell what caused that shot hole far from the rest of them to be there? It happens because of either the ammo being bad or the person shooting bad.

F. Guffey · March 21, 2015, 09:49 AM

Quote:

There's no reason in my mind that .30-06 cases should not perform the same across a 25 grain spread in weight.

Bart B. I reserve the luxury of not agreeing with or believing you.

There was an article, before the Internet, written by a shooter, reloader, writer in one of the fine gun type magazines. He purchased 500 cases from one manufacturer as in from one lot. He inspected, sorted loaded those cases over and over until he settled on 47 cases out of the 500. The 47 cases could be loaded and shot, the rest? required instructions.

He did find cases he sorted and found to be different were accurate if he indexed the case in the chamber. He found the powder column in those cases were not centered.

F. Guffey

Bart B. · March 21, 2015, 10:12 AM

None of the cases I've used have perfectly centered powder columns across all of them for two reasons.

None of the cases have perfectly centered powder chamber dimensions uniformly distant from their outside surfaces; case walls vary in thickness around them a few thousandths of an inch. That puts the powder chamber offset a bit from the outside shape of the case. The powder chamber's center is offset from the outside dimensional axis 1/2 the spread in case wall thickness.

None of the powder charges 100% fill the space inside the cases. Load density is close to, but never at 100% There's a small air gap at the top of the powder chamber so the center of the powder mass is a little below the center of the powder chamber inside the case. But it's pretty repeatable from shot to shot in its location. That's why the "SAAMI twist" was used to properly chamber test ammo in SAAMI spec'd pressure and velocity test barrels so each powder charge would be positioned exactly the same in each round.

Such is life with all cases and less than 100% load densities and uneven case wall thickness.

mikld · March 21, 2015, 10:46 AM

If I remember correctly, the OP asked if there was a SAAMI spec on case wall thickness. His next post confirms there aint. SAAMI specs. aren't like a speed limit; they are industry standard "suggestions" (which 99% of manufacturers abide by).

Posters who oh so quickly, post disagreeable retorts get real tiresome quite quickly...

F. Guffey · March 21, 2015, 11:14 AM

Quote:

Regarding fliers; how does one tell what caused that shot hole far from the rest of them to be there? It happens because of either the ammo being bad or the person shooting bad.

Quote:

Posters who oh so quickly, post disagreeable retorts get real tiresome quite quickly...

The writer, shooter reloader grouped cases that would be considered flyers as in causing bullets that strayed from the group. He indexed the cases, after loading again he found the cases were as accurate as his select 47, problem? the group seemed to have a mind of their own and had there own little group.

And then he rotated the cases with different indexes, the whole bunch went back to what could be described as 'all flyers'.

Again, this was before the Internet.

F. Guffey

March 20, 2015, 08:03 PM	#29
hooligan1 Senior Member Join Date: July 18, 2010 Location: Independence Missouri Posts: 4,586	F.Guffey I stand here thinkin to myself,, you just touched on the reason I have so many flyers......hhhmmmm. Yep I could fly to France twice and I think you've showed me why. If 150 cartridges have 17 grain difference in weight from top to bottom, then there a huge possibility that when I prove my data I should weigh and get the ten similar weights to prove my loads, damn and I thought it was all on me...damn... __________________ Keep your Axe sharp and your powder dry.

March 21, 2015, 08:03 AM	#30
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I've shot the same load in .308 Win cases whose weights ranged from 150 grains to 175 grains, all in the same rifle barrel. Powder charge weights and primers were all the same a couple grains below maximum; only Sierra 168's were used. There was no significant difference in accuracy through 300 yards with them. Several 10-shot groups were used with each case weight (average in a 3 grain spread) in their comparisons; some at 200 yards and others at 300 yards. There was about a 1 MOA spread in elevation zeros across them a 300 yards; not as much at 200.. There's no reason in my mind that .30-06 cases should not perform the same across a 25 grain spread in weight. Regarding fliers; how does one tell what caused that shot hole far from the rest of them to be there? It happens because of either the ammo being bad or the person shooting bad. Last edited by Bart B.; March 21, 2015 at 09:42 AM.

March 21, 2015, 10:46 AM	#33
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	If I remember correctly, the OP asked if there was a SAAMI spec on case wall thickness. His next post confirms there aint. SAAMI specs. aren't like a speed limit; they are industry standard "suggestions" (which 99% of manufacturers abide by). Posters who oh so quickly, post disagreeable retorts get real tiresome quite quickly... __________________ My Anchor is holding fast! I've learned how to stand on my own two knees... Last edited by mikld; March 22, 2015 at 11:04 AM.

March 20, 2015, 04:27 PM	#26
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	06shooter, would you like me to send you a private message about your concerns?

March 21, 2015, 10:12 AM	#32
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	None of the cases I've used have perfectly centered powder columns across all of them for two reasons. None of the cases have perfectly centered powder chamber dimensions uniformly distant from their outside surfaces; case walls vary in thickness around them a few thousandths of an inch. That puts the powder chamber offset a bit from the outside shape of the case. The powder chamber's center is offset from the outside dimensional axis 1/2 the spread in case wall thickness. None of the powder charges 100% fill the space inside the cases. Load density is close to, but never at 100% There's a small air gap at the top of the powder chamber so the center of the powder mass is a little below the center of the powder chamber inside the case. But it's pretty repeatable from shot to shot in its location. That's why the "SAAMI twist" was used to properly chamber test ammo in SAAMI spec'd pressure and velocity test barrels so each powder charge would be positioned exactly the same in each round. Such is life with all cases and less than 100% load densities and uneven case wall thickness.