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Time to make the donuts....

What do you, with your extensive experience, think about the bleed in the video? I can't get it to be uniform around the entire circumference, no matter what core seater diameter punch I use.
I don't think the punch is oval-shaped. Could it possibly be a difference in the thickness of the jacket?

These are .30 caliber jackets with a length of 1,270".

I sectioned them to better assess the bleed.



View attachment 1731789
My assumption has always been it is jacket wall variation
When I have ran into this and have gone to a different jacket using the same punch this went away
 
Lacking a bore scope, that's a nice way to get a good eye on the bleed by.

Is it an illusion or is the top of the core slightly dome shaped....are the cores dome shaped on both ends or flat? The core also looks to have a raised nub in the center?
Al
Yes, I made some conical (domed ?) punches, as they seemed to give better results.

Yes, the cores are also domed on both ends.
About nub, I believe is a optical ilusion
See punch attached picture
 

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    coned punch.jpeg
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Liseo, domed/concave faced core-form (convex on both ends of core); flat/perpendicular core-seat punches will eliminate a fair amount of head scratching. It appears that you have the ability to make this happen.;) Think flow dynamics.

Perusing the OLD J4 prints, for 1.300" long jacket, the J4 print displays [T.I.R.] tolerance of 0.0003" wall-thickness variation @ 0.150" from the inside-base, then, at 1.175" from inside-base, 0.0007". The tapered section begins at 0.31" from the base, and runs to the mouth. The taper is specified as 0*-34', with angularity tolerance of +/- 30 minutes. Note: for wall-thickness variation, T.I.R. is poor terminology: both inside and outside walls may be perfectly ROUND, but not concentric, thus creating variation of wall-thickness = center-of-gravity offset.

Rigidly mounted misaligned punch(es) can also cause your issue, as can/will relatively small diameter flat-ended cores, which are free to tip/tilt once under pressure, thus flow to the least resistance. If you're not doing so, as opposed to locking punches rigidly in place with punch-nut, try o-rings, between the punch-head and the lock-nut faces, just finger tight, to secure the punches. RG
 
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liseo

What did the target say?
I always ask a friend, who is a good shooter, to test them. He has several rifles assembled by Borden.
In the last test, we did 5 groups of 5 shots with each bullet at 100m, comparing 30 caliber bullets produced by me with those by Berger( Juggernaut.)
On average, my bullets produced groups that were slightly better.
But I wish they were noticeable better.
I would like them to group like some BIB bullets I acquired a few years ago (high expectations, I know,,,lol)
 
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Randy's advice on 'o' rings is nugget of pure gold.

On my Blackmon core seater setup, the addition of an 'o' ring between the seater punch and the lock nut effectively acts like splitting the difference between punch sizes. (in terms of bleed by). I've A-B-A'd this many times and the results are always the same, no matter what punch diameter I work with. Whether it's vertical or horizontal, the same principles of self centering apply. Like the concert documentary of Led Zepplin: 'The Song Remains The Same'. :cool:

For tightness of the nut, a .015 gap between the nut and the punch holder on this setup is a perfect balance of self centering and enough tension where the nut doesn't back off. When changing punches, a .015 feeler gauge makes it so easy......even a poor white kid from the wrong side of the tracks (like me) can do it. :eek:

TGafuUbl.jpg

dPMh36Ql.jpg
 
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Randy's advice on 'o' rings is nugget of pure gold.

On my Blackmon core seater setup, the addition of an 'o' ring between the seater punch and the lock nut effectively acts like splitting the difference between punch sizes. (in terms of bleed by). I've A-B-A'd this many times and the results are always the same, no matter what punch diameter I work with. Whether it's vertical or horizontal, the same principles of self centering apply. Like the concert documentary of Led Zepplin: 'The Song Remains The Same'. :cool:

For tightness of the nut, a .015 gap between the nut and the punch holder is a perfect balance of self centering and enough tension where the nut doesn't back off. When changing punches, a .015 feeler gauge makes it so easy......even a poor white kid from the wrong side of the tracks (like me) can do it. :eek:

TGafuUbl.jpg

dPMh36Ql.jpg
I like your safety tip on that punch;)
 
I make 30 cal bullets only and on J4 jackets the punch selection is usually between .2690 and .2693 for 117-118 bullets- what is generally the punch sizes for making 112's on a .925 jacket?
 

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