Welcome Guest!
Do you full length or neck size?
- Thread starter BriarPatch99
- Start date
rmp
Senior Member
My mistake. I’ve got a box of 308 win Norma. I’ll get some data up in a bit.
rmp
Senior Member
Measured a few with a Mitutoyo dial caliper so there is that.
Norma 308 Winchester factory ammo is my 0.
Fired cases are +.004” to nearly +.005”
Sized with Redding FL sizer to cam-over in a Rock Chucker press. -.004” but never -.005”
I’d say an average of .009” movement.
My Whidden bushing die moves a piece of Lapua .003” average.
Norma 308 Winchester factory ammo is my 0.
Fired cases are +.004” to nearly +.005”
Sized with Redding FL sizer to cam-over in a Rock Chucker press. -.004” but never -.005”
I’d say an average of .009” movement.
My Whidden bushing die moves a piece of Lapua .003” average.
rmp
Senior Member
Not a dumb question at all. Base of case to shoulder.
Bobby Bigtime
Senior Member
I full length resize mostly because I usually load for multiple rifles in the same caliber. It also is handy if someone needs some ammo that I have on hand. But in very few cases like my 6.6x55 where I am loading for one gun only I tend to neck size as it is specific to that chamber and shoots 3\8 of an inch. And no one in the gang is slinging those slugs except me. In short, I like to keep things as universal as possible.
rosewood
Senior Member
I do think the video is a bit confusing. He keeps asking if they full length or neck size. Technically I think they are between the 2. To me, pushing the shoulder back a couple of thousandths isn't really full length sizing (you are stopping short). You are using a full length sizing die, but I think full length sizing is running the die all the way to the shell plate. It may just be semantics, but for a new hand loader, it can be confusing.
Rosewood
Rosewood
Jester896
Senior Clown
most likely they are using a F/L bushing die of some type or a body die and a bushing neck sizer. There is a difference between a F/L bushing die and a F/L die same as there is a difference between a bushing neck die and a NK die.
It wouldn't matter if the die touched the shell holder or not if it bumped the shoulders back... but I believe in most cases you are going to have to touch the shell plate, shell holder or what ever your press uses to achieve bumping the shoulders back.
if you don't run the die down to the shellholder then you do what you believe they are doing which in reality is a form of neck sizing with a F/L die. If you are not careful doing that you can make the case longer than it previously was depending on the chamber the case was fired in.
rmp
Senior Member
The Sinclair and Whidden gauges do in fact measure at the datum line. There isn’t really a closer or further because you are measuring base of case to shoulder at the same points and adjusting to keep case movement to a minimum. The shoulder is your datum.
rmp
Senior Member
Most of my FL size dies never touch the shell holder. This includes some RCBS, Redding, Hornady, and Whidden. The exceptions being Weatherby mag cases with RCBS dies.
Edit to add, If you are bumping shoulders, you are sizing the body to some degree. You can check it with your micrometer but you can also feel the resistance while sizing.
Edit to add, If you are bumping shoulders, you are sizing the body to some degree. You can check it with your micrometer but you can also feel the resistance while sizing.
Last edited:
Jester896
Senior Clown
I always understood the datum line was half way between the neck and the case body on the shoulder. The Sinclair tool measues from where the neck meets the shoulder doesn't it?
rmp
Senior Member
It doesn’t. Directly on the shoulder.
rosewood
Senior Member
That is kind of my point. He gave only 2 options with his question, neck size or full length. He didn't really explain what they were really doing.
You can bump the shoulder back without the die touching the shell plate with a standard full length die. I do agree, it is similar to neck sizing, but you are still pushing the shoulder back and sizing most of the case to some degree.
Rosewood
rosewood
Senior Member
Does it really matter as long as you do it the same way every time?
rmp
Senior Member
By definition, as long as you can get accurate measurements to move shoulders. The datum in this case, pun intended, is for measuring case base to shoulder and it’s relation to headspace.
Last edited:
Jester896
Senior Clown
I read the instructions for the tool since I wasn't familiar and see now that it does work like the others. I had a different understanding prior to that.
No, it doesn't matter if you do it the same way every time. I have the Hornady version and use it when I don't have a Mo's gauge for the caliber I am working with. Even if you turn over a 9mm case and measure, as long as you do it the same every time with the same case you will get the same information. Whidden has a similar gauge to Mo's as well as RCBS.
@rosewood if the datum/shoulder area of the die doesn't come into contact with the datum/shoulder area of the case how does it push the shoulders back? Doesn't the die have to come into contact with the shell holder to do this?
rmp
Senior Member
rosewood
Senior Member
Maybe we are not using the same terminology.
You can bump the shoulder back without pushing it all the way back. The die comes in contact with case shoulder before the die bottoms out on the shell plate. You can easily size without the die touching the shell holder (but not completely size). Your press is still completing the stroke. Back your FL die out a bit so it doesn't touch the shell plate and resize and see if it doesn't push the shoulder back still. I believe this is what some of those "professional shooters" are doing that are not using those neck bushing thingys.
Rosewood
rmp
Senior Member
Rosewood, you can accomplish the same thing with a FL die or the FL bushing die. It the same process for adjusting to bump the shoulder but one gives better control of neck tension.
The Type-S die was named after BR shooter Speedy Gonzalez. If I’m not mistaken, he’s the one that figured out FL sizing (shoulder bump) in conjunction with bushings for neck tension. The best of both worlds rather than neck sizing and bumping shoulders every few firings.
You’re right though. Contact with the shell holder doesn’t happen often.
The Type-S die was named after BR shooter Speedy Gonzalez. If I’m not mistaken, he’s the one that figured out FL sizing (shoulder bump) in conjunction with bushings for neck tension. The best of both worlds rather than neck sizing and bumping shoulders every few firings.
You’re right though. Contact with the shell holder doesn’t happen often.
