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Vectan powder?


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Guest cookoff013

I use 21 grains of Vectan AS for 28/30 grams shot in 12 gauge and 24 grains of Vectan A1 for 32 grams shot in 12 gauge. Works great for me but always verify data.

 

what he said and +1

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no i haven't the only thing is with 21 grams is you get a small amount of unburnt powder due to low pressure but that doesen't bother me still kills well. i haven't got a chronograph but if you could load a couple and try them i would be interested to know how they perform.

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Iv used 18.5 grains with good results,

I settled with 19.5 grains - 27 gram showing 1350 fps,

Before anyone starts ,This was tested on two chrono's :good:

Bta

 

Isn't this the 'special' AS you were telling me about though :whistling:

 

For the record I used to record around 1250 fps with 21 grains under 28 grams of shot with a cx2000 and a z24.

Edited by sitsinhedges
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no i haven't the only thing is with 21 grams is you get a small amount of unburnt powder due to low pressure but that doesen't bother me still kills well. i haven't got a chronograph but if you could load a couple and try them i would be interested to know how they perform.

 

I bet the velocities are all over the place with such low pressure a bit more powder may make for a much better shell.

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  • 2 weeks later...

Ok fellas, I see some on here seem to advocate a PT case with a cx2000 and 21g of AS under 28 gram with a plastic wad (as per C&G).......has anyone got a tried and tested formula for a true 65mm PT case with cx2000 using AS and a 28gram load using a card and fibre wad?

P1

 

P.S. I note C&G 70mm 28 gram card/fibre wad formula advocates using 24g AS.

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And shorter shells will create more breech pressures so be careful

Can you explain why shorter cases give higher pressure I used to load 21 grains of Vectan AS with a Z24 wad in a 70 mm case with 28 grams of shot.

 

I also use the same load but with a Z 21 wad in a 67mm case never found any difference with the load

 

 

Deershooter

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Can you explain why shorter cases give higher pressure I used to load 21 grains of Vectan AS with a Z24 wad in a 70 mm case with 28 grams of shot.

 

I also use the same load but with a Z 21 wad in a 67mm case never found any difference with the load

 

 

Deershooter

 

I would guess less space for the gases to expand in to before the shell opens. I just proofed two identical fibre loads one 70mm and one 65mm. The only difference was the shorter wad in the 65mm case. It came back with a 300 bar increase in pressure although I think the wads were more compressed in the shorter case which again would decrease any space for the gases to expand in to. I'm not saying it will but that it may as in this example.

 

How would you notice any difference in breech pressure without a pressure gun?

Edited by sitsinhedges
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Guest cookoff013

i guess there would be less volume in a 65mm case compared to 70mm for the gasses to compact the wad, i`m not sure its always going to e a 300bar increase, but its going to increase.

 

no you wouldnt notice the extra pressure. i have had loads come in within saami specifications but failed the cip. and they just shot like normal.

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Guest cookoff013

i also did a proof load with plastic and fibre.

 

the fibre wad load came back toasted, and not as fast.

 

i think the 10% rule was to load up to speed regardless of pressures (which we can only measure with a proofgun )

 

normal bvarrels and proof barrels produce different speeds.

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I would guess less space for the gases to expand in to before the shell opens. I just proofed two identical fibre loads one 70mm and one 65mm. The only difference was the shorter wad in the 65mm case. It came back with a 300 bar increase in pressure although I think the wads were more compressed in the shorter case which again would decrease any space for the gases to expand in to. I'm not saying it will but that it may as in this example.

 

How would you notice any difference in breech pressure without a pressure gun?

Surely there would be no difference in the space for the gasses to expand in! a weighed 21grains of Vectan AS powder would take up exactly the same space

under the wad (behind the gas seal!) whether it be loaded into a 2 1/2" case or a 3 1/2" case? so how could the pressure increase?

P1

Edited by panoma1
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Guest cookoff013

its all to do with compressability and volume before the crimp gives way.

the fibre wads phisically have a "different" volume that the powder can expand into, maybe both fibre and plastic compress differently.

 

@ panoma

21grains of AS regardless of whether its been weighed or dropped from a machine will perform differently in either applications that you state.

 

the powder charge is only one part of the shell.

 

i`m not even sure if this totally applies to "low" pressure loads and switching to fibre or plastic.. AS isnt slow by all means,

mine was with my fast powder and i had a few loads come back toast. even the 21gram load.

 

same as i always have faster speeds with plastic, less friction, better speeds.

does the fact that fibre gets more pressure mean its a better at sealing? at the P1 that argument should be yes. but at the muzzel, speed dropped off, so no. or even "maybe"

 

i put my money where my mouth is. bang off a few at proofhouse.

 

i had one load comeback nearly right (it did fail, but only "slightly")

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The object of any wad is not solely, but primarily to provide a gas seal, yes? the actual gas seal is (or should be!) made at the point

where the wad (in this example a card OP wad) sits on top of the powder, so any part of the wad column (of similar type/weight) above this

OP card(assuming the gas seals integrity holds) should thusfar, in theory have no impact on pressure on ignition!

 

I can see when a plastic wad starts to compress (on ignition) into the voids between the wad cup and the gas seal will have some

effect.

 

But I am talking about the same weight of a given powder (AS) under a similar width solid card OP wad (the gas seal!) under a solid fibre

wad, the same primer in the same structure/type (Reifenhauser) case (whatever its length) the same shot load (28g) all held in by a

6 point crimp closure.....I still can't see where the case length should make any difference?

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