Dents/Crimp on shoulder cause?

[Legionnaire]

I've found that my bolt closes easier when I do this, at least in my rifle. Also my dies were blueprinted from my fired casings.

I understand, but you don't want the bolt to close easily. P.O. Ackley designed his cartridge so that a standard cartridge fired in an Ackley Improved chamber will "crush fit." That keeps the case head flat against the bolt face when fire forming. A bit of tension on bolt closure is exactly what you want.

 

[65WSM]

I too own a 6.5-06 Ackley and found that .270 Winchester cases were too thick in the neck and produced donuts at the top of the shoulder when fired. I use Wilson dies and partially size the long neck so it centers in the chamber. Please tell me what happens when you size with the expander removed?

I think that annealing the necks might solve your problem but you might not have those tools handy.

 

[HaroldNRAEndowment]

I am pretty confident this is not from too much lube. I have seen that before, this is different in how it dented the whole circumference. Also after the first one I lubed the next two cases very lightly. Not sure if the vent hole could cause this much . The only thing I could think of, once a lube problem is ruled out is the collapsing of the shoulder, pushed too far back.

 

[tim_w]

I already stated this about it being AI and you had to fireform back on page 2. But Edd pointed out if you look at th 2506 necks before sizing its clear they do not have the gentle 17.6° shoulder of standard 06 cases but a much sharper angle. They must have been fired in a chamber with a sharper angle shoulder 35°-40°

That is why I have 2 or 3 edited posts as to not confuse people.


I think the op should take some measurement of the fired 2506 cases and see what they are. Shoulder diameter, length from base to various junction points.

To me its clear there is something buckling the shoulder maybe its too large in diameter or at a different location (setback) etc

In the end it may very well be able to expand the neck and jam a bullet and fire form. I thought a very light lube on the body might help prevent separation. But way more people with more fire forming experience than me.

 

[Reloader222]

For sure it is too much lube. If you are using Redding Die, it is not equiped with the vent hole. So in that case you need to be very careful with too much lube.

 

[tim_w]

For sure it is too much lube. If you are using Redding Die, it is not equiped with the vent hole. So in that case you need to be very careful with too much lube.

From page one:

Just cleaned the die and made sure vent hole was free. Ran another piece of brass through with no lube at all and it had the same affect.

 

[MNbogboy]

I'm with @GLTaylor. To turn a standard 6.5-06 case into an Ackley Improved case, you need to fire form the case to the Ackley chamber before FL resizing with an Ackley die.

You have a two-step process facing you, as the original brass isn't 6.5-06; it's 25-06. So the first step is, in essence, to neck up the 25-06 brass to take a 6.5 bullet; i.e., convert standard 25-06 brass into standard 6.5-06 brass. You can't do this in a 6.5-06 Ackley die. Best would be to expand the neck with a standard 6.5-06 FL or neck sizing die. Then build a fire-forming load that will convert the now-6.5-06 cartridge to the Ackley version when fired in the 6.5-06 Ackley chamber. Only then is your brass ready for FL sizing in an Ackley die.

^^^this^^^

You need a FL std 6.5-06 die to convert your 25-06, 30-06 cases as a first step.

Then load as 6.5-06 then fireform in the 6.5-06 A.I. chamber.

Then you can use the Ackley dies.

 

[GLTaylor]

Just a quick question. Earlier you indicated you had RCBS Ack Imp dies for the 6.5-06AI.
I didn't know anybody outside of custom die makers were making this cal dies. Did you have them made?
I need some, as I have a 6.5'06AI on the way!

 

[huntoregon]

Ok back to this topic. This whole deal has turned into a giant ball of confusion for me but also a lot of good info came out of this thread for rookies like me.

A little more background, my father in law was given this rifle, brass, and the dies from his uncle. So I think this turned into the telephone game.

Now my father in law is telling me the brass may already be fire formed. So I have a couple new questions:

1- What is a sure fire way for me to know if it has been fire formed? Are there certain areas on the case I can measure that would be a tell tale?

2-If it is already fire formed, I am assuming I was getting these dents because the die was set wrong and I was crushing the shoulder. What is the appropriate method for setting the die up and making sure the case fits the chamber right?

Side note I just measure the neck opening on a couple of these fired cases at 6.90mm for what that's worth.

 

[MNbogboy]

Ok back to this topic. This whole deal has turned into a giant ball of confusion for me but also a lot of good info came out of this thread for rookies like me.

A little more background, my father in law was given this rifle, brass, and the dies from his uncle. So I think this turned into the telephone game.

Now my father in law is telling me the brass may already be fire formed. So I have a couple new questions:

1- What is a sure fire way for me to know if it has been fire formed? Are there certain areas on the case I can measure that would be a tell tale?

2-If it is already fire formed, I am assuming I was getting these dents because the die was set wrong and I was crushing the shoulder. What is the appropriate method for setting the die up and making sure the case fits the chamber right?

Side note I just measure the neck opening on a couple of these fired cases at 6.90mm for what that's worth.

You kind of just answered your own question. If that 6.90mm dimension is an inside dimension (.271) that is not totally out of line for a .264 bullet but sounds large.
If it is an outside dim it is too small for both 6.5mm and the .257 of a 25-06.
Assuming that your brass is already fireformed you are crushing them with standard 6.5-06 dies.
Do you have 6.5-06 A.I. dies?
You will need them to size the fireformed brass.

 

[huntoregon]

The RCBS die box says 6.5mm-06 IMP 40 Deg.

And the 6.90mm was ID of the neck.

 

[tim_w]

Just a quick question. Earlier you indicated you had RCBS Ack Imp dies for the 6.5-06AI.
I didn't know anybody outside of custom die makers were making this cal dies. Did you have them made?
I need some, as I have a 6.5'06AI on the way!

If you do a search for that die you will see a number of placed used to stock it. Both Redding and RCBS offered them at various vendors. Maybe they had gotten enough requests they ordered and stocked small quantities? You would have to look

RCBS 2-Die Neck Sizer Set 6.5mm-06 A-Square Ackley Improved 40-Degree

Neck Sizer Dies resize only the neck of case just enough to snugly hold the bullet. This leaves the shoulder and body at their fire-formed dimensions...

www.midwayusa.com

Here is the special order list and scroll down you will see it listed

RCBS Special Order Reloading Dies | Huntington Die Specialties

Buy special order and custom dies at Huntington Die Specialties online.

www.huntingtons.com

Here is the part number and other data off that chart

56195

6.5mm-06 Improved 40°

G

3​

Hope this helps

 

[Alibiiv]

I understand, but you don't want the bolt to close easily. P.O. Ackley designed his cartridge so that a standard cartridge fired in an Ackley Improved chamber will "crush fit." That keeps the case head flat against the bolt face when fire forming. A bit of tension on bolt closure is exactly what you want.

Hello Legionnaire, thank you for your reply. I am not modifying anything by running brass through the Ackley Improved die as it will not do anything but bring the brass to conform to the .270 Ackley Improve chamber that my dies were created from, and in my opinion that is the goal of fireforming to being with. For whatever reason my chamber is extremely tight with factory .270 Winchester brass. My son and I have rifles, Ruger 77 tang safeties, that were built by the same gunsmith, his will close tightly where my rifle is nearly impossible to close. I understand the dynamics of needing a tight chamber to hold the brass back so that the firing pin can do its work whether a false shoulder or leaving the bullet seated out to touch the lands to hold the brass back against the bolt so to facilitate ignition, but this is not the case with my rifle. Again thank you for your reply back.

 

[David Emerson]

I don,t know what you are using for lube but I would try Hornady one shot.