Reamer input

[Mikecr]

I don’t have any dies yet. I wait till I fire the Brass three times then have them made.

That's right. Your chamber is your #1 and best die.
Reloading sizing is merely per your plan, easily adjustable.

The Ackley design allows for use of the parent (nonimproved) cartridge. It provides a slight neck-shoulder crush fit for the parent cartridge, so that it fire forms correctly to new design.

 

[KRP]

I am confused now.

Headspace dimension from the prints you posted above:

6.5x55 SAAMI is 1.7834 min to 1.7934 max

6.5x55 Hansell is 1.8110 min

7x57 SAAMI is 1.7947 min to 1.8047 max

7x57 Hansell is 1.8330 min

Both improved cartridges are designed to headspace with the parent cartridge go gauge -.004 as written on the print. The confusion comes from that gauge referencing a different point than the headspace datum in the improved chamber due to the different shoulder angle.

 

[unclebob]

I would measure the inside dia of your full length sizer, you can not use calipers.

I don’t want to hijack a thread but some of you seem to be very familiar with this
We inherited a Remington 722 that was marked 257 Roberts on the bbl and we bought some factory ammo but when we shot it we could see that it was an improved chamber
From the scope, mounts, and the person that originally owned the rifle it was probably rechambered in the early 1950s. What should I do to get a set of dies that will fit this chamber
Thanks

 

[KRP]

I don’t want to hijack a thread but some of you seem to be very familiar with this
We inherited a Remington 722 that was marked 257 Roberts on the bbl and we bought some factory ammo but when we shot it we could see that it was an improved chamber
From the scope, mounts, and the person that originally owned the rifle it was probably rechambered in the early 1950s. What should I do to get a set of dies that will fit this chamber
Thanks

Measure fired cases and see what sort if "improvement" was made. 257 Roberts Ackley dies are available off the shelf if it seems they may work. If not send fired cases to Whidden or somebody and have custom dies made.

 

[unclebob]

Measure fired cases and see what sort if "improvement" was made. 257 Roberts Ackley dies are available off the shelf if it seems they may work. If not send fired cases to Whidden or somebody and have custom dies made.

Thank you

 

[Justice1327]

Headspace dimension from the prints you posted above:

6.5x55 SAAMI is 1.7834 min to 1.7934 max

6.5x55 Hansell is 1.8110 min

7x57 SAAMI is 1.7947 min to 1.8047 max

7x57 Hansell is 1.8330 min

Both improved cartridges are designed to headspace with the parent cartridge go gauge -.004 as written on the print. The confusion comes from that gauge referencing a different point than the headspace datum in the improved chamber due to the different shoulder angle.

Thank you.
So is my headspace too long or too short?

 

[KRP]

Thank you.
So is my headspace too long or too short?

No, not according to the prints. It's up to whoever is cutting the chambers and loading the ammo to make sure it functions properly though.

 

[Justice1327]

So I took some advice and I had JGS change my reamers. On some of them, I reduced the neck size and the 200 data line.