Shot sizes

[stuartyboy]

If you were to follow a 'recipe' for a home loaded catridge but to subtitute a shot size ie the data is for No.4 shot but you used a different size; for example, No.6, would this have any impact on the safety of the cartridge in regards to pressure etc?

Obviously, keeping everything else identical, just changing the shot size.

Sorry if this is a daft question, New to this and still learning

[saddler]

As long as the weight is the same...and volume occupied in the wad not too dissimilar.

[stuartyboy]

Thanks Saddler

[Guest cookoff013]

i also think /presume this is too.

i do draw the line when a cartridge has obviously, been designed for clays ie 28 gram job, i wouldnt even bother thinking about putting #SG in there. my cut off is birdshot numbers.

 

as for steel, its a different matter. but i tend to stick with bigger shot sizes because of the density differences. all steel shot should be at or below the top of the wad.

[Smokersmith]

all steel shot should be at or below the top of the wad.

 

I disagree with this ...... loading 2 to 3 pellet rows over the wad has never caused me any issues, and the shot wads show how setback during firing leaves the steel well below the top of the wad, and safe from any risk of barrel contact.

[rbrowning2]

all steel shot should be at or below the top of the wad.

I disagree with this ...... loading 2 to 3 pellet rows over the wad has never caused me any issues, and the shot wads show how setback during firing leaves the steel well below the top of the wad, and safe from any risk of barrel contact.

Interesting, but how is the setback working given that steel shot does not deform like lead? is setback not the result of the lead shot being crushed?

[motty]

Interesting, but how is the setback working given that steel shot does not deform like lead? is setback not the result of the lead shot being crushed?

Setback certainly happens with steel. Check out a fired steel shot wad. You will notice the imprint from the shot.

[Smokersmith]

I'm not sure of the science ... but it the effect is real.

[rbrowning2]

Ok so the wad has dimples but would that allow 2 or 3 pellet rows above the top of the wad to move within the wad when fired?

[Smokersmith]

Yes 100%

 

There's no evidence of any shot pushing against the sidewall at the top of the petals. If I find an old fired wad kicking around I'll post a pic.

[Guest cookoff013]

all steel shot should be at or below the top of the wad.

 

I disagree with this ...... loading 2 to 3 pellet rows over the wad has never caused me any issues, and the shot wads show how setback during firing leaves the steel well below the top of the wad, and safe from any risk of barrel contact.

 

i`ve got to disagree with this statement, because dependent on shotsize the 2-3 pellet rows could be substantial. it may not happen for #7steel, but T and F? different ballgame.

i`m not stating that setback does not happen. but i doubt it is that substantial to allow 2-3 rows of big shot (wildfowl loads). the abc of reloading suggests its about 1/8" setback.

please post pictures.

could you post a picture of the loaded wad and the fired wad?

[Smokersmith]

I collect my wads after I've been pattern testing so might have one kicking around in the truck ... if I do then I'll post it.

 

I don't have any other pics, and will not be loading any steel in the short term .... but when it get's nearer to September it'll not be a problem. I do think it's worth doing this as those less experienced may be surprised by the results.

 

Clearly bigger shot = more height = I take less risk

[Guest cookoff013]

I collect my wads after I've been pattern testing so might have one kicking around in the truck ... if I do then I'll post it.

 

I don't have any other pics, and will not be loading any steel in the short term .... but when it get's nearer to September it'll not be a problem. I do think it's worth doing this as those less experienced may be surprised by the results.

 

Clearly bigger shot = more height = I take less risk

+1

[Smokersmith]

Here's a 4.8mm load that was just over the petals when loading.

 

You will clearly see how far it gets 'setback' ....

 

This is why I do not adhere to the advice that no steel should be over the wad at the loading stage.

 

[Continental Shooter]

For lead 2 shot size difference doesn't matter in terms of pressure/speed.

 

If you go above that either ways you can have higher pressure with smoller pellets and lower pressure with bigger pellets: say you have a shel with 32 g lead #5 if you go 7 you're fine, 8's will start to increase in pressure as it offers less space for the gases to go through; vice versa, with 3 you're fine with 2's you have less pressureas the bigger pellets leave more space for the gasses to escape.

this could cause the shells to pattern differently; but not substantially different; although in certain shells (i.e. Magnum or long range) you always need to ensure the patterns are similar to the shell you want to change to ensure the same performances.

 

You might also have to adjust the wad to suit the different column space occupied by the different pellets.

 

For steel: teorethically the wad should not expand any more than the internal diameter of the barrel (i.e. ensuring ther e are no escape of gases when the shell is fired.

Steel wads are made of a harder polymer and are thicker than normal wads which makes them even less prone to expand.

 

So, given CIP rules, the internal diameter of a 12 bore barrel should be 18,1 mm - 18.5 mm; allowing for some expansions we can assume that the wad stretched 1 dm, while in drawback, bringing the size of the wad to somewhere between 18 mm and 18.4 but dependng on wads you might not even get a decrease of the base thickness as some have their own shock absorber.

 

Based on the above I doubt that the area of volume of the wad will be suffcient to absorb 3 lines of pellets; It would also be intersting to know what diameter your barrel is, what gun it is, what choke you use and how many sells you shot to draw conclusions

[Smokersmith]

With reference to the wad above... barrel of Remington SP10, terror .705 choke, and I guess I have looked at about 100 wads over the years. Get your calculator out if you want, but the hard evidence is in the picture.

That's my ending thousand words .... Hopefully it may have helped someone.

Edited April 12, 2017 by Smokersmith

[Guest cookoff013]

i`m just wondering where set back happens?

is it in the chamber (i think, which is bigger than the bore,) ? or in the bore?

 

thanks for the picture.

[rbrowning2]

i`m just wondering where set back happens?

is it in the chamber (i think, which is bigger than the bore,) ? or in the bore?

 

thanks for the picture.

Or the forcing cone?

[Guest cookoff013]

could be.

[UK fowler]

Im with Smith on this one even gamebore do it in some of there US fast steel loads . I dont go mad but I am quite happy with a row of smaller steel shot just above the wad , for the record cookoff your steel load with A1 powder fits much better with 26 grams of shot much better crimp 95 pellets in 4mm from memory

[wj939]

Couldn't the imprints be as a result of thermal energy rather than kinetic? Just a thought.

[Continental Shooter]

could be.

 

Would the forcing cone, being few dm smaller than the bore itself, force the pellets out of the wad by compressing the wad?

Edited April 12, 2017 by Continental Shooter

[Continental Shooter]

Couldn't the imprints be as a result of thermal energy rather than kinetic? Just a thought.

I think that is very possible, and would be my first guess TBH.

 

The wad will heat up as a result of the explosion as well as the friction of the polymer travelling through the barrel at high speed and the pellets will push sideways marking the softened plastic.

 

As i said; i don't think the wad will expand more than the barrel and the math is there to show it (but by certain parameters in this forum i might be wrong).

 

Would also be interested to see if the marks are there (even slightly) when opening one factory shell.

 

Anyway, my gut feeling is that if you have a steel proofed gun, I don't think you ever need a protective wad to start of with... so, even 3 rows of pellets out of the wad should never mark the bore

Edited April 12, 2017 by Continental Shooter

[motty]

I think that is very possible, and would be my first guess TBH.

 

The wad will heat up as a result of the explosion as well as the friction of the polymer travelling through the barrel at high speed and the pellets will push sideways marking the softened plastic.

 

As i said; i don't think the wad will expand more than the barrel and the math is there to show it (but by certain parameters in this forum i might be wrong).

 

Would also be interested to see if the marks are there (even slightly) when opening one factory shell.

 

Anyway, my gut feeling is that if you have a steel proofed gun, I don't think you ever need a protective wad to start of with... so, even 3 rows of pellets out of the wad should never mark the bore

I think you're way off the mark with this one. Steel can/will mark the bore if it gets into contact with it. Steel proofing is just a test that the gun has had, not anything special that has been done to protect a barrel.

[Guest cookoff013]

steel proof is just a level of proof as said, thats the 1050bar test, which actually is HP or high performance proof as apposed to "steel proof".

the industry and slang had attached itself to the terms steel proof as HP.

 

while i agree HP shells are a doozy.

 

the HP criteria was set up to accommodate the many new shot types, tungsten being one of them, (T18) which is even harder but oddly no "tungsten proof guns were ever made..." odd that.