Lee seating die depth or am I measuring wrong

[CopperSkink]

I might get someone up at the club to measure the stuff aswell - just to make sure I'm not going nuts

[alexham]

CopperSkink,
I am confused as to what exactly you are trying to measure and also by the comments you have had so far. The critical measurement is the distance from the bolt face to the point on the bullet which touches the rifling when the round is chambered. That measurement will be different for each type of bullet you use. The OAL of the fired case is irrelevant and the finished cartridge OAL is a different measurement too, so it is best not to bring them into consideration at this stage.

I am trying to visualize what you are doing, so correct me if I am getting it wrong. First, you use a Hornady comparator to measure the distance from the bolt face to the point on the bullet which just touched the rifling? Is that right? Then you adjust Lee seating die to load rounds to that measurement and the loaded rounds are different. Why? Adjust the seating die until they are the same.

Then you load different weight and shape bullets and the comparator shows different measurement. Of course it will if the ogive is not the same.

Are we talking the same language or have I misunderstood you?

Alex

[CopperSkink]

Hi Alex,
Yep - It is confusing.

First, you use a Hornady comparator to measure the distance from the bolt face to the point on the bullet which just touched the rifling? Is that right?
Yes you are correct.

Now taking the 55gr SP Only into account

Now the problem is that the distance from the boltface to rifiling (measured with the bullet comaparater to ogive) is 1.812" (taking the 55gr SP for example)
I cannot get the seating die down to that level - the lowest I can get it is 1.842"
If I want to get 0.02-0.04 off the lands (as I measured) I would need to get the seating die down to 1.792" which I can't do.

Now forgetting all the seating die side of things and just looking at the numbers themselves:
Measuring to the ogive on a few factory rounds (HTM is all I have) which I would assume are close to SAAMI spec I get 1.905" which is way more than I'm measuring.
The bolt closes easily when chambering the factory rounds so I am assuming they are NOT touching the rifling - I could be wrong.

This tells me that the 1.812" that I am getting from measuring with the Hornady comparator is wrong and if that was the case all SAAMI spec rounds would be jammed into the rifiling.

Hope this makes a bit more sense
Braden

[Alpha1]

If the factory rounds measured at 1.905 chamber OK then your measurements have to be wrong.
Have you miked the diameter of the bullits are you sure they are the correct size.

[CopperSkink]

That's what I'm figuring - but how hard is it to use a OAL Guage :?
Pretty simple - I'm going to take the rifle and guage to the store where I got the guage and get them to do the measurement - just to prove I'm not going stupid

[rox]

The only thing that springs to mind is: Are you zeroing the calipers after mounting the comparator and insert?

It's worth getting someone experienced with the gauge to confirm your measurements. Additionally you could refer to one of the video tutorials to see if there's something you've missed, such as this one:

http://www.youtube.com/watch?v=3lppK2jJ3XE

That's what I'm figuring - but how hard is it to use a OAL Guage :?
Pretty simple - I'm going to take the rifle and guage to the store where I got the guage and get them to do the measurement - just to prove I'm not going stupid

[alexham]

Hi Alex,
Yep - It is confusing.

Now the problem is that the distance from the boltface to rifiling (measured with the bullet comaparater to ogive) is 1.812" (taking the 55gr SP for example)
I cannot get the seating die down to that level - the lowest I can get it is 1.842"
If I want to get 0.02-0.04 off the lands (as I measured) I would need to get the seating die down to 1.792" which I can't do.
Braden

From what I understand from Hornady advertising The Comparator was intended for comparison of seating depth in a batch of cartridges, which is not what you are using it for. So, lets leave the comparator for for the moment and concentrate on the Lee seating die.

You say that when you try to seat the bullet you run out of adjustment - the seating stem bottoms out. Is that right?
If so, remove the seating stem from the die and check that it has the correct insert - see pictures in the attachments. If that insert is missing or is for the wrong calibre, then you need to take it back and get a replacement.

My guess is that the seating insert is missing.

Let us know what you find and then we will talk about the comparator.

Best of Luck,

Alex

[CopperSkink]

Hi all,
What I do is exactly what spuds video says - so yes I am getting the proper seating depth to the ogive and that measurement is the 1.812".
I also checked my seating die - first thing actually ages ago - and its all there and is the correct caliber. But when I get home tonight I'll definately check the caliber again.
I have been seating bullets to 2.210" on the 55gr SP (measuring base to tip - before I got the OAL guage) - never been able to get them lower.
As I said before when using the bullet comparater on factory rounds I get 1.905"
I'm off to the store/gunsmiths tomorrow - to double check stuff

Thanks to everyone here for the help, your a great bunch of people
Braden