Author Topic: What makes conicals different fm sabots primer wise ?  (Read 472 times)

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Offline preventec47

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What makes conicals different fm sabots primer wise ?
« on: November 02, 2008, 03:49:38 AM »

Regarding This quote by Busta: Re: ANOTHER 25 ACP conversion ...
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I use CCI 400 small rifle primers for all but Blackhorn 209. The
CCI 450 small rifle magnum primers will work for some saboted
bullets and BH209, but no joy with the conicals or FPB's using BH209.

/////////////////////
What is is about the mechanicals of loading or combustion that
would make conicals less reliable than sabots for any given primer?

I assume during loading the powder would be compressed with
the same force.... right ?   Could it be due to the starting
resistance being lower and back pressure not increasing
rapidly enough to sustain combustion ?

Offline Busta

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Re: What makes conicals different fm sabots primer wise ?
« Reply #1 on: November 02, 2008, 05:20:04 AM »
Looks like you have answered your own question, again. Blackhorn 209 needs a lot of fire and pressure to maintain the burn. It is a progressive powder, not your typical Black Powder substitute. That is why Western ony recommends the hottest 209 primers and a breech plug with a sealed primer pocket. Slip-fit conicals need to be spanked at upset to obturate into the rifling, filling the bore. That is also why I used at least two .060" thick x .518" diameter fiber gasket wads, if you don't get a seal the conical will just get pushed out the barrel as the charge bleeds off pressure.

This is what can happen shooting conicals out of the Huntsman/Sidekick with BH209 and the right breech plug, that doesn't include the standard NEF plug or the .25 ACP plug. This was done with a custom 209 breech plug.





Left to Right: Standard NEF breech plug w/carrier, .25 ACP breech plug, Custom 209 primer breech plug.

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Offline preventec47

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Re: What makes conicals different fm sabots primer wise ?
« Reply #2 on: November 02, 2008, 06:14:26 AM »
Busta, thanks for leading the development program for
the NEF shooters.
In the custom 209 plug, does it require the equivalent of
precise head spacing to achieve a compression seal of sorts ?
Somewhere along the way it occured to me with all the
proposed custom threading of inserts etc that it would
be possible to achieve some adjustable compression that
might  help with sealing blowback and yet allow easy
removal after firing much like a typical brass cartridge.

In your photo of breech plugs, Is the custom 209 plug
shown the one available from Hubbard or is it one of
the few that a guy hand made and isnt making
them anymore?

I am still puzzling over the fact that 209 shotgun primers
are used when shotguns never see more than 14,500 psi
as opposed to pistol and rifle primers that see 40, 50 and 60
thousand psi.     It must have something to do with ease
of insertion and removal.
Busta, reading back I can see you have been at this for
about half a year now.   Considering there seem to be
at least four or five other muzzle loader models that
have solved the blowback and ignition problem,
do you think a standard off the shelf solution is near
for NEF shooters?

I cant tell whether the 209 primers in breech plugs
or the large pistol and rifle primers in brass cases
offer the most promise at this point for NEF shooters.
Which way are you leaning ?