6.5 x284 concentricity challenges

[gene so]

Hello,
In resurrecting a target rifle for competition, I have an older, but nearly unfired 6.5x284 barrel, cases etc. I remember it shot well, but not spectacularly, and I realized I had some loaded ammo concentricity problems from years ago.

Now I note in developing a load for 6,500 feet where I am retired, that the rifle is responding, but loaded ammo is measuring "out" about .002 on the concentricity gauge with a 1/10,000 dial. I know that is not bad, but I want to make it better, if possible. I note the cases, when being resized with the die, seems to leave marks on the case neck area on one side only of the fired brass. I do have at least thee different resizing dies for this caliber, and know my attempts to solve this problem , back then, never were resolved.
I would deeply appreciate any sound advice as to how to arrive at more concentric reloaded ammo since this weapon will never be used for anything less than 600 yards.

Thank you in advance,

Gene So

 

[CMaier]

does this mean you are pulling a button thru the necks after sizing ??
that would be my first change, go to a neck bushing and no pull thru button.

 

[alinwa]

Hello,
In resurrecting a target rifle for competition, I have an older, but nearly unfired 6.5x284 barrel, cases etc. I remember it shot well, but not spectacularly, and I realized I had some loaded ammo concentricity problems from years ago.

Now I note in developing a load for 6,500 feet where I am retired, that the rifle is responding, but loaded ammo is measuring "out" about .002 on the concentricity gauge with a 1/10,000 dial. I know that is not bad, but I want to make it better, if possible. I note the cases, when being resized with the die, seems to leave marks on the case neck area on one side only of the fired brass. I do have at least thee different resizing dies for this caliber, and know my attempts to solve this problem , back then, never were resolved.
I would deeply appreciate any sound advice as to how to arrive at more concentric reloaded ammo since this weapon will never be used for anything less than 600 yards.

Thank you in advance,

Gene So

You will hear dozens of ideas and can try hundreds of things, but.....

There is 1 way to make straight ammo.

ONE way.

all other ways fail to pass truly scrupulous scrutiny.

First you must fireform virgin cases correctly, very hard to do but easier for you than for most. For YOU, you start with unfired .284 cases, don't even consider pre-made cases.....Remove the expander mandrel from a 6.5X284 sizing die......now you unscrew a 6.5X284 die and use it to neck some cases down, slowly work it down until you can chamber the cases firmly......now back the die off just a tiny bit and tighten the lockring. You want your bolt to close FIRMLY on the new brass.

Run 5 cases thru.

See if they chamber, tightly.

Load them with a stout load of fast powder and a light bullet. You only get ONE chance to move the brass properly the first time and fast powder works easier.

Now you fire these five cases 3-5-7 times WITHOUT RESIZING... either just setting the bullet in the neck or using a neck-only die.

Once the cases get to "exactly where you want them" set two aside.

Now fire the other three until they get tight.

Carefully mark these cases, save one of each for yourself and send the others to a good diemaker and have a custom sizing die made.

Now you can MAKE straight cases with proper fireforming and MAINTAIN the concentricity via the fitted sizer.

Of all the ways....

There Can Be Only One

This is it

al

 

[gene so]

wow!

You will hear dozens of ideas and can try hundreds of things, but.....

There is 1 way to make straight ammo.

ONE way.

all other ways fail to pass truly scrupulous scrutiny.

First you must fireform virgin cases correctly, very hard to do but easier for you than for most. For YOU, you start with unfired .284 cases, don't even consider pre-made cases.....Remove the expander mandrel from a 6.5X284 sizing die......now you unscrew a 6.5X284 die and use it to neck some cases down, slowly work it down until you can chamber the cases firmly......now back the die off just a tiny bit and tighten the lockring. You want your bolt to close FIRMLY on the new brass.

Run 5 cases thru.

See if they chamber, tightly.

Load them with a stout load of fast powder and a light bullet. You only get ONE chance to move the brass properly the first time and fast powder works easier.

Now you fire these five cases 3-5-7 times WITHOUT RESIZING... either just setting the bullet in the neck or using a neck-only die.

Once the cases get to "exactly where you want them" set two aside.

Now fire the other three until they get tight.

Carefully mark these cases, save one of each for yourself and send the others to a good diemaker and have a custom sizing die made.

Now you can MAKE straight cases with proper fireforming and MAINTAIN the concentricity via the fitted sizer.

Of all the ways....

There Can Be Only One

This is it

al

Wow, after writing for precision shooting magazines for years and setting two world records, I have found someone who really far exceeds my knowledge in reloading for accuracy. Your precise steps are unlike any case prep I have ever done. All this fora barrel which will last 800-to 1,000 rounds and then be replaced by a .284. I am in your debt and so appreciate your level of expertise. Thanks

 

[alinwa]

Wow, after writing for precision shooting magazines for years and setting two world records, I have found someone who really far exceeds my knowledge in reloading for accuracy. Your precise steps are unlike any case prep I have ever done. All this fora barrel which will last 800-to 1,000 rounds and then be replaced by a .284. I am in your debt and so appreciate your level of expertise. Thanks

I guess if you're just looking for commiseration and people with whom to discuss your situation without resolving it, maybe you should list your credentials and explain your position before asking a question of people who actually are driven to help......with answers.

Enjoy The Day

And The Holiday Season

 

[CMaier]

big al,
i think he does not appreciate you at all.

strange that with his "experience" he has such issues.

writing must be hard on dies and bbls.

 

[JerrySharrett]

If you have the proper relationship between the chamber and the loaded round 0.002" runout will not negatively effect accuracy. Having SAAMI chamber and SAAMI spec ammo where there is up to 0.010" clearance(maximum chamber/minimum cartridge) would not be desirable though.

..

 

[JerrySharrett]

Hello,


Now I note in developing a load for 6,500 feet where I am retired, that the rifle is responding, but loaded ammo is measuring "out" about .002 on the concentricity gauge with a 1/10,000 dial. I know that is not bad, but I want to make it better, if possible. I note the cases, when being resized with the die, seems to leave marks on the case neck area on one side only of the fired brass.

Thank you in advance,

Gene So

Where is this 0.002" runout you are measuring? Is it at the bullet tip. At the ogive/body intersection, or at the bullet body/case mouth intersection? Big difference.

If you feel or know the barrel is in good condition, making new brass, as al suggests, certainly can't hurt.

Bottom line though, how does it shoot now? Example, will it make 3 bullet holes touch at 100 yards in mild conditions? If not, could be your load needs to be adjusted.

.

 

[alinwa]

Where is this 0.002" runout you are measuring? Is it at the bullet tip. At the ogive/body intersection, or at the bullet body/case mouth intersection? Big difference.

If you feel or know the barrel is in good condition, making new brass, as al suggests, certainly can't hurt.

Bottom line though, how does it shoot now? Example, will it make 3 bullet holes touch at 100 yards in mild conditions? If not, could be your load needs to be adjusted.

.

Good Catch Jerry!

I'll back up this 'big difference' thing about WHERE it's measured, adding that depending on your tool, your method and where/how the apparatus is supported that ".002 out" could mean just about anything......including the fact that if it's banananana'd such that the .002 reading is in the middle, then IMO the actual reading is more like .004 out.....