XRe Posted May 12, 2008 Share Posted May 12, 2008 Before or after resizing? They definitely get shorter when you fire them, but resizing them should fix that. Look forward to your testing results. R, One of the things I'm going to do is section a few - at the beginning, and part way through testing - and measure for variance... The supposition I've heard is that at least some of the material that expands outward upon firing (shortening the case a tad) is then pushed straight in (and somewhat down) upon resize (and not pulled back out in the fashion that happens w/ a rifle case). It'll be one of the theories I've heard and somewhat seen anecdotally on my own that I can finally test for, one way or the other... Roy is being kind enough to provide me with a few Starline TJ cases. Now all I need is a 2nd brand of regular Super and I'm rolling... Link to comment Share on other sites More sharing options...
Jack Suber Posted May 12, 2008 Author Share Posted May 12, 2008 Just a little note...the brass that I measured (both SC and Super) were new/unfired. Each were resized prior to measuring. I am loading our Super on a 650 using a Lee U-Die. The more I think about it, the more I am concluding that the shorter length of the SC after resizing is causing less powder to be dropped because it is not pushing up as far on the powder funnel as the longer cases are. That has to be the reason for the variances in powder weight. I guess this should have been put under the reloading forum, huh???? My bad.... I have to admit this Open thing is new to me...(I have been shooting LTD/L10/Production since I started in 1996). I shot an Open gun in a match for the first time 3 weeks ago. I classified initially in Open with a Limited gun!!! Link to comment Share on other sites More sharing options...
XRe Posted May 12, 2008 Share Posted May 12, 2008 Different length brass is not just an Open phenomenon, though, Jack Not something you'd typically see with one, though, except when switching brass. However, in the iron sight calibers, with everyone's habit of buying used brass, the various mixed head stamps will all show variations of length, diameter, rim dimensions, etc... Link to comment Share on other sites More sharing options...
Jack Suber Posted May 12, 2008 Author Share Posted May 12, 2008 Different length brass is not just an Open phenomenon, though, Jack Not something you'd typically see with one, though, except when switching brass. However, in the iron sight calibers, with everyone's habit of buying used brass, the various mixed head stamps will all show variations of length, diameter, rim dimensions, etc... Quite right about the Limited brass. However, I have never experienced this much of a difference in PF with mixed .40 and 9mm brass. Link to comment Share on other sites More sharing options...
shred Posted May 12, 2008 Share Posted May 12, 2008 Just a little note...the brass that I measured (both SC and Super) were new/unfired. Each were resized prior to measuring. I am loading our Super on a 650 using a Lee U-Die. The more I think about it, the more I am concluding that the shorter length of the SC after resizing is causing less powder to be dropped because it is not pushing up as far on the powder funnel as the longer cases are. That has to be the reason for the variances in powder weight. How much case mouth belling do you have? Unless it's a very small amount, I don't know how the powder throw itself could change since the belling kicks in after the powder stops. Link to comment Share on other sites More sharing options...
Jack Suber Posted May 12, 2008 Author Share Posted May 12, 2008 Just a little note...the brass that I measured (both SC and Super) were new/unfired. Each were resized prior to measuring. I am loading our Super on a 650 using a Lee U-Die. The more I think about it, the more I am concluding that the shorter length of the SC after resizing is causing less powder to be dropped because it is not pushing up as far on the powder funnel as the longer cases are. That has to be the reason for the variances in powder weight. How much case mouth belling do you have? Unless it's a very small amount, I don't know how the powder throw itself could change since the belling kicks in after the powder stops. Shred, I bell my cases very little...just enough to get the bullet started (allow the bullet to sit on the case without falling off). I am of the belief that too much belling adds more "wear" to the case. Link to comment Share on other sites More sharing options...
L9X25 Posted May 12, 2008 Share Posted May 12, 2008 (edited) I'll add another observation to the mix... I load 9x25 on a 1050, so I have the opportunity to add a few extra procedures in the loading process. I decided that, since my 9x25 sizer die could not be adjusted to full length resize the brass without relocating the shoulder, I would add a 10mm resizer to the mix. The 9x25 die resizes the first 85% of the case and places the shoulder exactly where it needs to be, then the 10mm die resizes the remainder of the body all the way to the extraction groove. I take my first batch of ammo to the range and expierence lots of jams resulting from the shoulder being too long to chamber completely. Remove the 10mm sizer and all is well again. Conclusion ... slightly bulged brass DOES get longer when you resize it completely. Edited May 12, 2008 by L9X25 Link to comment Share on other sites More sharing options...
G-ManBart Posted May 13, 2008 Share Posted May 13, 2008 Before or after resizing? They definitely get shorter when you fire them, but resizing them should fix that. Look forward to your testing results. R, One of the things I'm going to do is section a few - at the beginning, and part way through testing - and measure for variance... The supposition I've heard is that at least some of the material that expands outward upon firing (shortening the case a tad) is then pushed straight in (and somewhat down) upon resize (and not pulled back out in the fashion that happens w/ a rifle case). It'll be one of the theories I've heard and somewhat seen anecdotally on my own that I can finally test for, one way or the other... Roy is being kind enough to provide me with a few Starline TJ cases. Now all I need is a 2nd brand of regular Super and I'm rolling... That'll be cool info...look forward to your results. Man, I'm such a geek....lol Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now