7.7x58 Arisaka

[Jim Watson]

lowering the die 1/16th of a turn would be the same as lowering the die 4.43".

Amazing.
Easy to see why you shouldn't use unconfirmed load "recipes" off the www.

[44 AMP]

another that has the mum intact but was nicely sporterized and has a scope mount squarely over the mum...

over the mum is the best place to put it...

[5whiskey]

Jim I caught that too. My math tells me .00446 although he’s mostly correct if he moves the decimal 3 spaces left. I wanted a little head clearance. .005 is plenty. Actually a smidge more than I really want but holy cow I’m not shooting the rifle in bench rest comps. And smoothness/reliability is more the goal not tiny groups. Let me hit the 20” gong with irons at 500 and I’ll be tickled.

[F. Guffey]

I do not know if you used a forming die and or the full length sizing die. lowering the die 1/16th of a turn would be the same as lowering the die 4.43".

Forgive, I did that, I have no ideal where that came from. It should have been .0043". Wait, I was using a Construction Master 1V calculator, there is a chance I took a short cut without my glasses

F. Guffey

[F. Guffey]

I do not know if you used a forming die and or the full length sizing die. lowering the die 1/16th of a turn would be the same as lowering the die 4.43".

I have no ideal where that came from.

We have reloaders that convert degrees of rotation based on 360 degree equals 1 turn. We also have the group that does fractional turns based on one turn equals .071".

I use a height gage when measuring the height of the die above the press. I go straight to thousandths. And I have another choice, I can back the die whole measuring the gap between the die and shell holder with a feeler gage.

Always left out when lowering the die, there is a good chance lowering the die will not work with the feeler gage (for me) because of the cases ability to resist sizing.

F. Guffey

[5whiskey]

When sizing cases for no-go length chambers I adjust the die off the shell holder .004". to get go gage length cases. If I want no go length cases I adjust the die off the shell holder .008".

Guff, as always and as you know... it depends on your chamber and how bad off the headspace is. For my gifted Type 99, it wasn’t that bad really. I started about a half turn off the shell holder, then kept slowly sizing until lo and behold I could force it to chamber. I didn’t check with feeler gauges but I was probably a couple thousandths from the shell holder. The “little more than 1/16th” extra I gave it put the die in contact with the shell holder on the top stroke.

[F. Guffey]

Guff, as always and as you know... it depends on your chamber and how bad off the headspace is.

How bad is the head space? All I want to know is the length of the chamber from the shoulder/datum to the bolt face, I do not perceive head space as being good or bad. I do not have many rifles with short chambers, but if I did I can size cases for short chambers.

Again, a shooter just west of Ft. Worth, TX was interested in cases for his Japanese rifle. I contacted him off line to offer help. I had no ideal how much clearance his rifle had with minimum length/full length sized, over the counter factory loaded ammo; so I formed cases for his rifle that measured field reject length, no go-gage length, go-gage length and minimum length/full length sized cases, after forming and sizing I mailed 80 cases to him with instructions.

The minimum length/full length sized cases should chamber without resistance, the go-gage length cases should chamber with a slight resistance to bolt closing and the no go-gage length cases should not allow the bolt to close. The field reject length cases should not allow the bolt to close.

As luck would have it the minimum length/full length sized cases allowed the bolt to close and the go-gage length cases allowed the bolt to close with a slight resistance to closing.

At that time I suggested he sized the no go-gage length cases to minimum length from the shoulder to the case head and then check the length of the case from the end of the neck to the case head; the same advise applied to the field reject length cases. He had to trim the neck of the cases that were formed to field reject length.

He came for a visit at the next gun show, he had additional questions about other matters. He did not get all of his answers from one individual.

F. Guffey