Closing meplats & Jeunke measuring...

C

Charles E

curmudgeon
There was a report -- I think by Lynn -- that some guys were experiencing distortion of the bullet, as measured with a Jeunke, after closing the points.

Which kinda scared me, as I've been doing this as of last year. So I got out the Jeunke & measured 20 of the repointed 187 BIBs I have left over from last year. 12 showed 2 unit deviation or less, 8 showed between 2 and 4. Ran the Jeunke at a fairly slow speed, so the needle was allowed full swing. Well, 20 is a real small sample size, but it is completely consistent with the the numbers I get with an unaltered BIBs.

[Aside: Since I had the machine out, I ran 300 unaltered BIBs during the game last night. All 300 showed less than 4 deviation units. So as not to waste my time, I grouped them according to the absolute measurement, which is another way of measuring the bearing surface. Again, I used a 4 unit increment to sort by. Got one big group, two smaller groups right next to it (probably not necessary), and a few outliers.]

Anyway, back to pointing: I trim first, then point, then trim again. Nothing fancy, and I doubt my technique is superior to anyone else's. It would be interesting to hear the details of bullets that were deformed when repointed.
 
Vern, you'll have to ask the people who weigh. I'm sure they have a reason. Why not start another thread? I'd like to stay on topic with this one.
 
Charles I still don't get it about trim, point and trim again. Thats probably the BC. you can't find. Just seems redundant to me. Pointing is all that needs to be done! Just once.

Joe Salt
 
charles,In my experience pointing bullets,the base will distort first on bullets with i4 jackets, and the noI use the hoover pointer and thru trial and error trying to close up meplates this is will i noticed where the bullet distorted. The hoover die has different punches to be used on different makes of bullets, i try using different punches to achieve closer of the meplat.I trim, point and trim again also, but I end up with a bullet that was longer then before any pointing without any distorting. I use a comparator to check before,and during pointing to check for any distorting.I Ruined alot of bullets before learning what to do and what not to!
 
slw said:
charles, In my experience pointing bullets, the base will distort first on bullets with J4 jackets, and the no [????]

I use the Hoover pointer and thru trial and error -- trying to close up meplates -- this is will [s/b where?] i noticed the bullet distorted. The Hoover die has different punches to be used on different makes of bullets, I try using different punches to achieve closer [??] of the meplat.

I trim, point and trim again also, but I end up with a bullet that was longer then before any pointing without any distorting. I use a comparator to check before, and during pointing to check for any distorting. I Ruined alot of bullets before learning what to do and what not to!
Click to expand...

I had a little trouble with your post, but I think I figured it out. You're saying the base will distort before the nose, right?

I think I'm all right. After reading your post, I went back & checked the bases of the 20 BIBs I'd pointed up that were left over from last season. They were all within 5 deviation units, both relative & absolute. I then went & checked 20 "untouched" bullets, and they were the same way.

For the heck of it, I then checked some 300-gain Berger .338s I'd pointed up. That bullet takes the most force to point up... after all, it is about 1.75 inches long, longer than a PPC case. They too were all fine. It's amazing how well Berger controls that massive bullet.

* * *

As it happens, I use a Tooley meplat trimmer and a Whidden point-up tool. The Whidden also has several point-up punches, but not as many as the Hoover, I'd guess. I would doubt the tooling matters.

One thing I do, a tip picked up from Greg Sigmund, is to bang the bullet up sharply after I've got it centered. It probably takes less total force to do it this way. Greg points up his Clinch River bullets this way (as opposed to our little effort in "repointing.")

Anyway, I'm curious what you think caused the distortion -- I know it's almost impossible to say with certainly, but having stumbled onto a way that seems to work, I don't want to stumble the other way through sheer ignorance.

Thanks,

Charles
 
You must log in or register to reply here.
Back
Top