Measuring cartridge overall lentgh.

[ovenpaa]

I expect a repeatability head to ogive on the same cartridge to be better than .0005" and I could not get such repeatability with the off the shelf systems which is why I started building my own 3P systems. I am also looking for at worst case a thou variation head to ogive from cartridge to cartridge for match ammunition however this is only one measurement and is far from the be all end all of accurate reloading, really it is just one of a few final checks to be made.

Also I would say minimising vertical dispersion is the most important goal in reloading, if you can build ammunition that holds a quarter at 600/1000 yards you have one less variable to worry about which means you can get on with reading the wind with absolute confidence.

[zeroveez]

Ovenpaa, I suggest that no ammunition used during the TR world Championships performed to your standard. Your ability to make custom measuring kit allows you to reload to these tolerances. I am not convinced that they are necessary, again, particularly with reference to TR. The Berger amnual itself quotes tolerances of plus or minus one thou. Can I ask what dies you use to better a half thou tolerance?

[zeroveez]

Sorry Ovenpaa, I misread your tolerances; is the one thou round to round plus or minus half a thou or one thou to give you the one thou difference ? I read it as better that .0005" when that was a one round measurement.

[ovenpaa]

First test is how repeatable is your measuring system. Check the same loaded cartridge 5 times head to ogive and it should repeat to better than .0005" if it is not then the integrity of the measurement system is in doubt. Now check 5 separately loaded rounds in the same manner, I would expect to see them at .001" worst case and move them to a different box at .0015"

One of the issues I see is dies are not always fully compatible with modern high BC bullets or neck turned cases so these are areas for improvement when seating. I use/used Forster ultra micrometer seater die dies I modified myself amongst others however that was for my F Open 7C rifle that I gave up on maybe a couple of years ago. Christel also uses Forster dies modified by myself for her 22C which shoots OK, in fact typical run out for her is .0005" to .0000" measured with one of my systems and a Mitutoyo. Fair to say her loaded rounds always come out incredibly well.

As an example Tim (ENS) expects to get quarter minute verticals at 1000 yards with Wilson dies so it is certainly not down to one particular make of dies, equally I have a Lee seater with minor modifications sitting in a dedicated press that returns 600 metre .308 loads for my AI that are consistently 2.800" +/- .0005"

[Alpha1]

Interesting. tesnews

[zeroveez]

Interesting indeed! I have just bought some Berger 215 grain hybrid bullets and am about to make some base to ogive measurments using the Stoneypoint system in a Krieger barrelled Match Rifle. I won't make any claims about plus or minus's until after the said measurments. However, some years ago there was a tip to using the Stoneypoint guage for improved accuracy which came, I think, from a Precision Shooting article. This involves passing a stiff rod down the bore from the muzzle and "feeling" the jam of the bullet against the Stoneypoint rod and the lands. I have always used this technique. Anybody else?

[rox]

I have always used this technique. Anybody else?

Yes.

..

[zeroveez]

Well now, some measurements. Using my very best touchy feely technique, using Berger 215 grain hybrids into a Krieger match rifle chamber, the numbers for case head to ogive comes out at plus or minus three thou with the Stoneypoint system. I have to say that the chamber/bullet interface has a slightly soft feel to it; I'm not happy about that, but it's there with Sierra 200 grain bullets as well. Bullet seating is another issue, as the Redding seating die can do better than plus or minus 1 thou.

[Alpha1]

I had another question but I have forgotten what it was now I went back to the beginning and re read this thread by the time I got to the end of it I had forgotten what my question was I suspect tomorrow I will remember what it was.

I have found this thread very informative and I am not finished with it yet. I still have lots of questions.

[EagerNoSkill]

I had another question but I have forgotten what it was now I went back to the beginning and re read this thread by the time I got to the end of it I had forgotten what my question was I suspect tomorrow I will remember what it was.
I have found this thread very informative and I am not finished with it yet. I still have lots of questions.

Aaah the dreaded combo of Tech Speak + Old Age = Reloader Confusion
sign01 :lol: