Success...Sorta

[JohnH]

Decided to try some changes in my 375 JDJ today, first I wanted to cut back on the lube I was using. I had been filling 3 grooves, 2 seemed t do well enough, figured I would only have to clean up some lead if 1 groove didn't work....but it did, rather well in fact. It also created an interesting fit situation. The Lyman 379449, when filling the first lube groove only doesn't completely enter the die. This leaves the first driving band unsized, and while the fit is tight in the throat, (requires a bit of pressure to make the case/bullet seat) the load improved the accuray of the 7383 load I had been using. I tried it with several other loads, and it didn't help them, in fact it hurt the 4895 load.

The bullet drops from my mold at 379. After seating in a seperate die, I remove the bell with the crimping die, but that die lightly touches the bullet and sizes the exposed driving band to 378. 379 won't seat in the throat, but 378 will with a little effort. Been thinking on a 377 die, guess I'll have to get one now to see how it pans out.

This bit of difference (I had been sizing the bullet to 375) has reduced my group by an inch and completely eliminated the weird flyers I was seeing every group. Not sure why it didn't help the other loads, but I'll take what success I can get.

[Bass Ackward]

Not sure why it didn't help the other loads, but I'll take what success I can get.


John,

Many people believe that the .... "choke" provides for better alignment only. What it also does is that it requires time to size down which aids ignition for those powders slow enough to require it. So it aids inertia. Above that "ramp up" speed level, it still creates bullet distorting pressure. Depends on many factors obviously and why there is no set rule. Choking can eliminate the need for fillers or the shooters misdiagnosis that they should use a filler. But this only goes so far because lead sizes relatively easily. My guess is that your fliers were ignition related as opposed to lube.

44man writes of case neck tension to do the same thing. Retard the bullet until everything gets burning consistently.

So sometimes it works, sometimes she don't. Make sense? Bet that if you cut that 4895 load back, the groups would come back.