6.5x47 Lapua Brass?

[2644ever]

Well, A.Y., I never claimed the .308 family was inaccurate or weak, I just wonder about the intellectual laziness in R&D sometimes, every case that was derived from the .308 case had the same wide groove and the same shoulder angle, and even when an important change would occur,,i.e.the small primer pocket instead of the large one)the same shortcomings would remain...
Do you think the equipment to manufacture the 22-250, 6mm Rem,300 Sav,8 Mauser and 30-06 brass -all without the notorious "groove"- is different from the one used for the .308 family of cases, and that it couln't be used to manufacture 6.5 Lapua brass also? If the innards and the primer pocket section are that different, why shouldn't Lapua aim to make it right from the very start?

 

[CAB]

The fact your missing here is measured case head hardness,....
It would be dubious to say as a blanket statement, that all Lapua brass is X number of points higher on the Vickers scale than whatever other brass your using to reform from, but the case stands, as a general rule, I have seen the Lapua brass run up to to 22 points harder than some of our domestic brass.,the wssm stuff) While that isn't a fair comparison, the Lapua is still USUALLY 10 to 15 points higher than most commonly used brass produced domestically.,case head measurements)

CB

 

[JER]

Well, A.Y., I never claimed the .308 family was inaccurate or weak, I just wonder about the intellectual laziness in R&D sometimes, every case that was derived from the .308 case had the same wide groove and the same shoulder angle, and even when an important change would occur,,i.e.the small primer pocket instead of the large one)the same shortcomings would remain...
Do you think the equipment to manufacture the 22-250, 6mm Rem,300 Sav,8 Mauser and 30-06 brass -all without the notorious "groove"- is different from the one used for the .308 family of cases, and that it couln't be used to manufacture 6.5 Lapua brass also? If the innards and the primer pocket section are that different, why shouldn't Lapua aim to make it right from the very start?

Maybe you should explain how the extractor groove of the 308 Winchester design is a weakness. Start by explaining how that can be so when that feature is outside the pressure vessel.

 

[2644ever]

OK, just watch the cut out brass, every case already has some sort of a built-in weakness with the primer pocket and the flash hole.Have you alredy gone overboard with a load? What happened when the case was brand new and it fortunately wouldn't give up with a head separation but with a blown out primer? The gases went through the path of least resistance... You don't even have to blow a primer, a few hot loads will make your pockets too lax. Don't you think a little more brass in the neighborhood of the pocket would have been welcome? Maybe the missing brass doesn't weaken the case, but maybe a little extra brass wouldn't do no harm... I'm getting too old for that fashion of "just enough" and "just in time" Would you buy a barrel with deep flutes,even if past the chamber) with the lame excuse that the steel is super duper extra lothardened & waltherized ? I'm no engineer but I've worked with many materiels my whole life and I would never buy a windshield with a nick, a pipe wrench with too many holes in the handle and the shaft, and anything with unnecessary grooves or serrations...
Case closed. No pun intended. Let's move on.

Take care

 

[JER]

OK, just watch the cut out brass, every case already has some sort of a built-in weakness with the primer pocket and the flash hole.Have you alredy gone overboard with a load? What happened when the case was brand new and it fortunately wouldn't give up with a head separation but with a blown out primer? The gases went through the path of least resistance... You don't even have to blow a primer, a few hot loads will make your pockets too lax. Don't you think a little more brass in the neighborhood of the pocket would have been welcome? Maybe the missing brass doesn't weaken the case, but maybe a little extra brass wouldn't do no harm... I'm getting too old for that fashion of "just enough" and "just in time" Would you buy a barrel with deep flutes,even if past the chamber) with the lame excuse that the steel is super duper extra lothardened & waltherized ? I'm no engineer but I've worked with many materiels my whole life and I would never buy a windshield with a nick, a pipe wrench with too many holes in the handle and the shaft, and anything with unnecessary grooves or serrations...
Case closed. No pun intended. Let's move on.

Take care

There is none blinder than he who does not want to see.....

 

[jb1000br]

So let me get this straight...you think WW brass will last longer because the extractor groove is not as wide as the lapua?



IMO, you are looking at completely the wrong issue...it is the SMALL primer pocket that lets cases last longer...harder to stretch the small PP out than the large one...I have looseded lapua 6.5-284 PP's but keep pounding my 6BR's and they feel like new after 4-5 firings...

Has ANY ONE had strength problems with Lapua brass,where other brands have taken the pressure better)?

JB

 

[2644ever]

So let me get this straight...you think WW brass will last longer because the extractor groove is not as wide as the lapua?

IMO, you are looking at completely the wrong issue...it is the SMALL primer pocket that lets cases last longer...harder to stretch the small PP out than the large one...I have looseded lapua 6.5-284 PP's but keep pounding my 6BR's and they feel like new after 4-5 firings...
Has ANY ONE had strength problems with Lapua brass,where other brands have taken the pressure better)?
JB

This is not exactly what I meant, I think a 22-250 Rem case from Fed will last longer than a 243 Win Case from Fed or,probably) from Lapua because of The Groove.
You quote the lower resistance of Lapua's 6.5-284 brass, I assume it got the same factory treatment as the 6 BR brass, but it failed first... well, check the rebated head of the 6.5-284 case, this is an even worse design than The Groove!

I know Lapua's brass is outstanding, do not be mistaken, my point was: After making this brass more durable with redesigned innards, metal hardening treatment or else, small pocket primer, why stop there and not get rid of The Groove? Beats me...
Consider one of the toughest case in history, the Swift, 13 years ago a fellow named Dave Reppart from Fla created a 6PPC clone using the Swift case, the 6mm Trapper. The cases seemed to last forever and Mr Reppart attributed this fact to the case head design. Unfortunately due to his untimely death and the loss of his files, we will never know for sure.

Please do not get upset, this ain't that critical, I'll gladly live with whatever brass is affordable and...available!

Take Care

 

[chrisj]

I have been shooting high volume in numerous calibers, for decades, using every big name in brass and have NEVER had any cracks/separation/problems in the web area. Lapua has been the Bets by far for me in terms of primer pockets remaining tight.

Chris

 

[JER]

2644ever, in case you didn't notice some target sports have rapid fire as part of the match. Highpower in the US and CISM in Europe,mostly) do.

Extraction must be flawless when seconds count and a wider groove makes that easier to achieve.

 

[2644ever]

In case you didn't notice, some target sports have rapid fire as part of the match.Highpower in the US and CISM in Europe,mostly) do.Extraction must be flawless when seconds count and a wider groove makes that easier to achieve.

Well, JER, you may have a point but keep in mind that a few cartridges used in rapid fire competition don't have THE GROOVE, like the 30-'06 you use in rapid fire in the Garand, or the 7.5x55 Swiss used in various events with the StG in Switzerland... They do eject flawlessly and should it be otherwise, any jam with these 2 rifles is usually not related to the case design.
In my life I had the opportunity to use the G3, the SIG in .308 and the real M14, I certainly can't blame the case design for any malfunction that,rarely) occurred but I failed to see any improvement over a well tuned Garand...
You guys take care.