reloading - can roll replace crimp finish

[Doriboy]

I have found that normally the only reason 3 1/2" RTO loads won't cycle through autos is if you use a frangible disc, change this for a thin OSC. Problem solved.

[sitsinhedges]

What doesn't make sense? I use no. 4 steel with no. 2 steel on top. I also use BB steel with T on top. 80% of the load is the smaller shot size.

 

So how does that work then? What's the point of having 20% of useable shot at range when it has no pattern because there isn't enough of it? What's the point of having extra small shot at close range where the pattern would be dense enough anyway. All I can see it managing to do is create a huge shot string that you could drive a bus thru.

[motty]

I don't know of many people that do it, but it is a recognised technique. The theory is that the there is a drafting phenomenon created where the bigger pellets 'drag' the smaller pellets and keep them at a higher velocity than had they been flying by themselves.

I obviously do not know if this works, but I killed a few pinks with the 10 last season with the BB/T combo.

I have also loaded a few 2+BB ( for the 10) for rangey mallard. This doubles as a good goose load if one suddenly appears and there is no time to change shells.

[motty]

 

So how does that work then? What's the point of having 20% of useable shot at range when it has no pattern because there isn't enough of it? What's the point of having extra small shot at close range where the pattern would be dense enough anyway. All I can see it managing to do is create a huge shot string that you could drive a bus thru.

I'm certainly no expert or a scientist, but I didn't dream up the concept by myself - I read about it in reloading manuals. I'm unsure if there is any huge benefit in using duplex loads, but I have found they can be effective.

[Tedward]

Roughshooter,

which case trimmer would you recommend?

cheers, Tedward.

[sitsinhedges]

I'm certainly no expert or a scientist, but I didn't dream up the concept by myself - I read about it in reloading manuals. I'm unsure if there is any huge benefit in using duplex loads, but I have found they can be effective.

 

I think you would have more success by using one sized pellet optimised for a killing pattern at your maximum range, so the pattern is still just dense enough at that and just accept that the pattern is going to be smaller in size at closer ranges albeit more dense. That way you'll be using the largest shot possible and kill well at any point up to your maximum if you're on target.

[pestcontrol1]

a 3 1/2" 12g case is normally 89mm - if you are doing an rto finish then I will trim the case to 83mm which give the same oal as a crimpred 89mm shell

Regards

Graham

Chers Graham i know if i was to trim the case down i can get them to fit what i was getting at was the half grain powder drop or increase

[edenman]

I have found that normally the only reason 3 1/2" RTO loads won't cycle through autos is if you use a frangible disc, change this for a thin OSC. Problem solved.

In my very humble opinion if your using steel shot your better with a frangible disc as it's waterproof.

[kent]

I'm certainly no expert or a scientist, but I didn't dream up the concept by myself - I read about it in reloading manuals. I'm unsure if there is any huge benefit in using duplex loads, but I have found they can be effective.

Like you have said "drafting" occurs and creates a sort of slipstream as race car drivers are well aware. I think this and how the pattern develops from your gun are the reasons why one might do this over any advantage on quarry of a few outsize shot (personally speaking).

Some haven't the wit or intellect to try anything they see as out of the ordinary, it either works for you or it doesn't however there is no harm in testing it. If your talking about actually reading peer reviewed published data though you have already lost a fair few early stages though LOL

 

Factory loads will not do this mixing and stacking of shot sizes as its too time consuming (the other reason why RTO fell from favour)

[Mick Shaw]

Like you have said "drafting" occurs and creates a sort of slipstream as race car drivers are well aware. I think this and how the pattern develops from your gun are the reasons why one might do this over any advantage on quarry of a few outsize shot (personally speaking).

Some haven't the wit or intellect to try anything they see as out of the ordinary, it either works for you or it doesn't however there is no harm in testing it. If your talking about actually reading peer reviewed published data though you have already lost a fair few early stages though LOL

 

Factory loads will not do this mixing and stacking of shot sizes as its too time consuming (the other reason why RTO fell from favour)

What about just mixing two shot sizes ? Any adverse effect ?

[Doriboy]

In my very humble opinion if your using steel shot your better with a frangible disc as it's waterproof.

Funnily enough I did think the same thing, and the grey coloured OSC really aren't much good once they get wet they tend to go quite soggy. I stopped using them for steel a while ago and instead use the ones with a shiny finish to them, they are far more water tight and durable in wet conditions and as I'm sure you know RTO gives a very good seal. Much better for goose loads as they tend to sit in my pocket a lot longer than duck loads do.

[kent]

What about just mixing two shot sizes ? Any adverse effect ?

Dunno never tried it, be hard to get consistency without stacking I suspect though

[edenman]

Funnily enough I did think the same thing, and the grey coloured OSC really aren't much good once they get wet they tend to go quite soggy. I stopped using them for steel a while ago and instead use the ones with a shiny finish to them, they are far more water tight and durable in wet conditions and as I'm sure you know RTO gives a very good seal. Much better for goose loads as they tend to sit in my pocket a lot longer than duck loads do.

Not sure if we are talking about the same thing? The ones I use are clear see through?

Edited October 16, 2013 by edenman

[sitsinhedges]

Like you have said "drafting" occurs and creates a sort of slipstream as race car drivers are well aware. I think this and how the pattern develops from your gun are the reasons why one might do this over any advantage on quarry of a few outsize shot (personally speaking).

Some haven't the wit or intellect to try anything they see as out of the ordinary, it either works for you or it doesn't however there is no harm in testing it. If your talking about actually reading peer reviewed published data though you have already lost a fair few early stages though LOL

 

Factory loads will not do this mixing and stacking of shot sizes as its too time consuming (the other reason why RTO fell from favour)

I doubt a few large shot would create any meaningful slipstream in the same way a line of cars travelling in a line would. Certainly if you want to get your shot there quicker or with more remaining energy get rid of those few oversized shot and just use their equivalent weight by upping the size of the other shot in the cartridge which is proven to work instead of relying on some vague unproven theory which doesn't hold water.

[kent]

I doubt a few large shot would create any meaningful slipstream in the same way a line of cars travelling in a line would. Certainly if you want to get your shot there quicker or with more remaining energy get rid of those few oversized shot and just use their equivalent weight by upping the size of the other shot in the cartridge which is proven to work instead of relying on some vague unproven theory which doesn't hold water.

 

And you know that about drafting, how? because published results are available to study that show a different tale. We are talking stacking loads though not just mixing shot sizes and there are variables not least gun to gun. unproven, a bold and maybe rash statement perhaps? One should never dismiss anything. It is not my personal practice but I do not dismiss it as it seems to work for others and the tech bit is sound, we feel this "drafting" when a large vehicle passes by us in the street. Colanders don't hold water but like ammo they aint actually supposed to. Its not all about energy and velocity and its very often used in Turkey loads I read as pattern is said to be improved in some guns

[sitsinhedges]

 

And you know that about drafting, how? because published results are available to study that show a different tale. We are talking stacking loads though not just mixing shot sizes and there are variables not least gun to gun. unproven, a bold and maybe rash statement perhaps? One should never dismiss anything. It is not my personal practice but I do not dismiss it as it seems to work for others and the tech bit is sound, we feel this "drafting" when a large vehicle passes by us in the street. Colanders don't hold water but like ammo they aint actually supposed to. Its not all about energy and velocity and its very often used in Turkey loads I read as pattern is said to be improved in some guns

It's just quack ballistics with no proven data as far as I can see unlike the ballistically proven effects of going up a shot size with a standard load. What exactly are you expecting to achieve?

[Doriboy]

Not sure if we are talking about the same thing? The ones I use are clear see through?

The frangible discs are clear see through. OSC are normally the grey 'rough' finish type or the 'shiny' finish type. I use the thin shiny ones

[edenman]

The frangible discs are clear see through. OSC are normally the grey 'rough' finish type or the 'shiny' finish type. I use the thin shiny ones

Ahh good we are on same wavelength

[kent]

It's just quack ballistics with no proven data as far as I can see unlike the ballistically proven effects of going up a shot size with a standard load. What exactly are you expecting to achieve?

 

perhaps you should look some more and do a little reading up on the subject? there is quite a bit of published work on this. I have published data a plenty

[Guest cookoff013]

i kinda have a few problems here.

 

the first being the add x grains to a roll turn shell... with my recent loadings, even 1/2 (ok 0.6gn) can really make things toasty. so dependent on the original shells pressure please be cautious and do try and stick to published data.

 

the second, is these odd analysis comparing ballistics to something completely different things. i can come up with some crazy stuff, "all shot should be shaped like f1 cars because they are fast."

 

"shot should be soaked in jagermeister / bombs to give the shot monster energy"

 

its all rubbish, absolutely rubbish.

 

shot duplexing was really popular in the 60s with lead. it was done a lot. the added advantage was, if one lucky large pellet got on target it might work, but the disadvantage would be you are shooting doves (american) with BB shot and at close range, "unsprouting."

 

but thats not totally the extent of duplexing ratios and weight. #9s over BBB shot? or #7 and #6 blend.

do i do it? no, i cant be bothered even to test. there is nothing better than having a decent shotsize, for said application. is there any need to do it? well if that floats your boat then do it.