The 6.5 Something NOW Has A Name!

[David Emerson]

I agree on the straighter walls decrease back thrust but .01 to .015 taper per inch will still decrease back thrust. In the article they used a 22 250. That is extreme taper. Seems the 338 lapua or the norma mags don,t have a problem.

 

[can1010]

you have a body tpi of 0.16711 on your drawning most Ackley imp are 0.084 the most common is 0.090 - 0.100 for more reliable extraction with upper end loads. your shoulder dia. is .5165 you could go to .5295 and stay in the safe zone for extraction

 

[GLTaylor]

you have a body tpi of 0.16711 on your drawning most Ackley imp are 0.084 the most common is 0.090 - 0.100 for more reliable extraction with upper end loads. your shoulder dia. is .5165 you could go to .5295 and stay in the safe zone for extraction

The drawing is JGSs' first rendering.
That is why I posted this request. All I've ever done before is take a standard cartridge and improve it. This is all new ground to me. All suggestions are appreciated!

 

[25WSM]

Personally I would leave it as is. Also I'm not a big fan of way over bore cartridges. I can't justify in my head using 50% more powder to gain 10% in velocity. But as far as your situation is concerned I would just get bushing dies and save time and money. You can change the taper and shoulder angle all you want and it's just going to be marginal gains and lots more money on dies and fire forming brass. Your time and money worth the extra gains is up to you. Have fun with it.
Shep

 

[GLTaylor]

Guess I'm just nuts. Seemed like a good idea at the time.

Think I'll just leave well enough alone. Still thinking about making a 6.5 on the regular Blaser case. Just leave the angles and shoulder alone. Don't like the case stretch, but oh well.

I'll still have 257 Wby case volume, bit no belt. Found a source for dies, I think......

 

[25WSM]

Should be a good one. The 6.5x257wby can get 140s to 3300.
Shep

 

[GLTaylor]

I may still name it the 6.5 THOR.

That was a good name suggestion!
It ought to shoot Absolute Hammers like a laser!

 

[highdrum]

Going from a 30° shoulder to 40° and removing a lot of taper will shorten your necks by 10-15k. Personally I'd go with a 0.007/inch case taper and run a 30° shoulder. This mimicks the sherman short tactical line. You'll want to have 5k total clearance back at the 0.200" line to a new case.

 

[David Emerson]

You have about the same capacity as a 264 win mag. It seems everybody has a hate on for belted cases. After the first firing they headspace on the shoulder as the rimless do. A 264 throated right will run. ADG 7 mag brass necked down. Easy.

 

[bdyal1972]

You have about the same capacity as a 264 win mag. It seems everybody has a hate on for belted cases. After the first firing they headspace on the shoulder as the rimless do. A 264 throated right will run. ADG 7 mag brass necked down. Easy.

264wm, 7 rem, 338wm, 300wm/mark248

Don't know if I EVER had a case need replaced in less than 7 or 8 reloadings!!!

Never worried about it really 1/2 to 3/4 moa at 500 yards on range for 5rnd group impacting with more than 2200fps, more than 150 grains, more of EVERYTHING than 30/30 at muzzle....


THE WAY I LOOK AT IT....

MARK248 MOD 1 IS THE 300 WIN MAG ON STEROIDS AND FINICKY

300 WEATHERBY DOES EVERYTHING THE MK248 DOES EASIER

300PRC DOES EVERYTHING OF THE PREVIOUS 2 AT A GENTLE WALKING PACE BETTER

SAME FOR 6.5 PRC


EFFECTIVELY SAME FOR 6.5CM LOADED WITH HIGH BC MONOS VS 308 AND 06 CUP AND CORE.....

BELTED MAGS ARE HARDER TO TUNE
BUT NEWER CASE DESIGNS WITH PROPER CHAMBERING WITH FAST TWIST BARRELS JUST ARE MORE EFFICIENT....

SAW THIS FIRST HAND AT ABERDEEN PG IN THE EARLY 90S AS MK248 WAS SO DARN FINICKY WITH 220 SIERRAS

THE 30 DAKOTA, LAZZERONI SHORT 30, 300 WEATHERBY ETC


NEW 30" BARREL CHAMBERED WITH BULLET AS FAR OUT NECK AS POSSIBLE....
MADE THE MK248 LOOK LIKE A TURD....

 

[David Emerson]

They need to keep coming up with new to keep everybody buying.As far as the new being easier to tune? Not so fast. The best group I ever shot in my life at range was a long throated 264 win with matchkings out of a hunting rifle. I shot the 7 mag here on Friday. 25 inch lilja with my throat and R22 with a 140 absolute hammer. 3400 with a group in the 2,s. second load up the pipe. For ultimate precision with the F class or PRS crowd I agree. But for hunting? Pfffft

 

[25WSM]

I don't think belted cartridges are any less accurate at all. Most any cartridge cut straight in a good barrel can shoot tight. If you set up your dies correctly the belt doesn't do a dang thing anyway. That little extra brass might keep primer pockets tight a little longer but I can't confirm that. Most of my brass gets shot 10 to 12 times. I guess I'm not a speed freak and typically don't run above max pressure in my rifles. I big the highest comfortable node and tune and shoot what it is.
On your new 6.5 I would do a bore rider throat on it. Normally good for an extra 100 fps on a 264 win mag.
I use it in my 6.5x257wby too. Well ok the truth is I put the bore rider in almost every gun I own. I like it.
Shep

 

[David Emerson]

Thank you. As you say centered chamber and everything true I would wager on belted vs non.

 

[Joemac6324]

I don't think belted cartridges are any less accurate at all. Most any cartridge cut straight in a good barrel can shoot tight. If you set up your dies correctly the belt doesn't do a dang thing anyway. That little extra brass might keep primer pockets tight a little longer but I can't confirm that. Most of my brass gets shot 10 to 12 times. I guess I'm not a speed freak and typically don't run above max pressure in my rifles. I big the highest comfortable node and tune and shoot what it is.
On your new 6.5 I would do a bore rider throat on it. Normally good for an extra 100 fps on a 264 win mag.
I use it in my 6.5x257wby too. Well ok the truth is I put the bore rider in almost every gun I own. I like it.
Shep

What is the "bore rider" Shep? I'm not sure I have heard that one before. Curious though.