Difference between making FB and BT bullets?

H

hecksf

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I was wondering if I could get a good description of the difference between making Boat Tail and Flat Base bullets.
I suppose BT bullets require an extra dies,,,Is that correct?
Is the BT formed by a punch or is the die itself made in the BT configuration?

Thanks Ted
 
hecksf said:
I was wondering if I could get a good description of the difference between making Boat Tail and Flat Base bullets.
I suppose BT bullets require an extra dies,,,Is that correct?
Is the BT formed by a punch or is the die itself made in the BT configuration?

Thanks Ted
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Ted, making BT requires both a BT core-seat die and BT point-up punches: the primary BT forming is done during the core-seating; the BT is then 'finished', via the BT punch, during point-up. RG
 
Ted,

I think most if not all short bullet makers (the bullets, not the makers) form boat tails with the core seating operation and there is no difference in process just a different die shape. One exception that I'm aware of in long range bullets is Greg Seigmund, maker of Clinch River Bullets. Greg puts the boat tail in the jacket with a steel punch in a separate operation and squirts cores into a boat tail shape before the core seating operation. Greg believes that pre-shaping the boat tail rather than forming it during the core seating operation results in more uniform jacket thickness over the boat tail. I've shot a lot of his bullets and I think he's right. The additional operation of preforming the jacket into a boat tail shape accounts for the higher price of Greg's bullets.

This might not matter at all for short boat tails of bullets used in short range benchrest.

Greg
 
Greg, There are a number of bullet makers who do not form the boattail as a part of core seating. As to whether this is better, well, as with most things, there is more than one way to do it -- whatever it takes to get consistent, good shooting bullets.

I agree Clinch River bullets are very, very good.
 
Thanks for the info, Charles. I'm curious, who else preforms boat tails? Are you going to the banquet?

Greg
 
Greg Culpepper said:
Thanks for the info, Charles. I'm curious, who else preforms boat tails? Are you going to the banquet?

Greg
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I know R.G. Robinett has in the past, when he was making a special order bullet for a guy in Scotland. Whether the current BIBs with the short bottail are made that way, I dunno. I've heard that Brady Knight made the 200-grain 30s that way, but that was second- or third-hand.

I kind of go by trust, which includes most custom bullet makers. There are always problems -- boattail or not -- and the good guys come up with solutions.

(yes, I'm going to the banquet)

Charles
 
Charles is correct, many years back, for a gentleman over-seas, using HIS dies & presses, I made some extreme VLD tye bullets, featuring an extremely LONG BT: pre-forming the BT, as Greg described (above) was necessary. Also the core-form die pre-formed the BT, which necessitated droping the cores 'right-side-up', as opposed to either end up - another PINTA!:eek:

The relatively SHORT BTs, which are featured on the BIB bullets (Bob-Tails, as I am calling them), circumvent this pre-forming . Charles and others can attest to the quality of the BIB Bob-Tails, which are offered in .25;6mm; and .308 - relative precision of the BIB BTs has proven fully equal to the FB versions.

For the BIB ogives/meplats (form), the short BTs, featured on the new BIB BT line, as calculated via JBM Ballistics (Drag/Twist Calculations) provide fully 98% of the BC potential. ;) Shorter may just be better . . . :eek: I believe that history has proven: once [G1] BC exceeds .5, "the monkey is on the shooters back." For something which, "won't work", the original BIB 187 Gr. FB (Doppler measured .525 BC) has a pretty AWESOME record, with win/place/shows, and RECORDS in drastic disproportion to its opportunities. :eek::D

But, I'm hi-jacking the thread: making the LONG (VLD type) BTs is a PINTA! :D RG
 
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R. G. Robinett said:
The relatively SHORT BTs, which are featured on the BIB bullets (Bob-Tails, as I am calling them), circumvent this pre-forming . Charles and others can attest to the quality of the BIB Bob-Tails, which are offered in .25;6mm; and .308 - relative precision of the BIB BTs has proven fully equal to the FB versions.
Click to expand...


I can't wait to give the BIB BOB 88 a tryout in the 257TED

Ted
 
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