Bushman Pete Posted October 9, 2011 Report Share Posted October 9, 2011 Hello, Well I am now underway but I had a question regarding data. When various pressures are given what do you go for? Eg I have been loading these:- Lead Shot 12 1 3/8 oz. Longshot Win. 209 Fed. 12S4 26 8300 PSI 1185 Lead Shot 12 1 3/8 oz. Longshot Win. 209 Fed. 12S4 27.5 9300 PSI 1240 Lead Shot 12 1 3/8 oz. Longshot Win. 209 Fed. 12S4 29 10,400 PSI 1295 I have made a few 26gn, a couple of 27.5gn and around 10 29gn, with shot-sizes 3 & BB Does it matter which one I go for? I just assumed the best idea was the fastest. I thought I would make a few of the slower ones to try first in case there was a problem. What is the best way to test new loads? Is there a procedure I should follow? What is the pattern checking procedure I should follow? Thank you. Peter Quote Link to comment Share on other sites More sharing options...
sitsinhedges Posted October 9, 2011 Report Share Posted October 9, 2011 I just use as little powder as poss to get a reasonable speed and clean bores which means the powder is burning well and at enough pressure to be consistent. As an example I am using 20gn of Vectan A0 in a 28gram 20gauge load for 1250fps but the Nobelsport site suggests up to 23grains. If the speeds had been erratic I would have upped it until the burn was consistent and clean. It's OK to use less powder than a recipe states for shotgun shells. If you haven't a chrono, with some exceptions, clean bores are a good way of knowing that you are getting decent pressures. Poor pressures often leave a lot of unburnt powder residue. Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted October 10, 2011 Report Share Posted October 10, 2011 I just use as little powder as poss to get a reasonable speed and clean bores which means the powder is burning well and at enough pressure to be consistent. As an example I am using 20gn of Vectan A0 in a 28gram 20gauge load for 1250fps but the Nobelsport site suggests up to 23grains. If the speeds had been erratic I would have upped it until the burn was consistent and clean. It's OK to use less powder than a recipe states for shotgun shells. If you haven't a chrono, with some exceptions, clean bores are a good way of knowing that you are getting decent pressures. Poor pressures often leave a lot of unburnt powder residue. i often use as little powder for a given cartridge. if you read the pressure data, some loads really dont respond well to less powder. one cartridge comes to mind, 12gauge, 28grams lead, A1 powder. that is a seriously anaemic load, the published recipe is 5000psi. that is seriouly a bad cartridge, its safe, but the performance is real poor. just chopping a few grains from this load would make it bloop. it is publishable because the pressure is safe. but doesnt mean the load is any good. spotting a good / bad load is easy when you understand the fundamentals. sits is quite right, you can use less powder than a given recipe. his cartridge, with the reduction of 3 grains isnt going to make that much difference. depending on the load efficiency, will show how it responds. i dont have a chrono, but my criteria for selecting a load to manufacture, speed is the last thing i look at, i believe speed isnt that important, but load efficiency is. i certainly like my loads at 1200fps or below. most powders can achieve that and efficiently too. Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted October 10, 2011 Report Share Posted October 10, 2011 so, when i look for data, look for the shot weight first, then look at the pressure data. thats most important. if the efficiency is good, the pressure above 9000-10000psi, then the load can be reduced alittle. if the load is 11,500psi, thats a hot load. that "can" have a powder reduction, and not really alter the pressure profile too much. but if it takes 30 grains or so powder to get to that figure, then that suggests its a slow burning powder. however you`ll end up finding the data that suggests less powder anyway. removing a grain from this load isnt going to do nothing, i grain is under 5%, 5% is acceptable variance. you`ll find with large loads, that have conventional powder, are slow and higher in pressure. knocking down the payload, will increase the speed, drop the pressure, and could make the load inefficient. however faster burning powders perform better under this application, because the minimal pressure needed for these fast powders to burn. some real slow powders need atleast 10000 just to barely work. 12000psi being the pressure limit. 11.500 i would safely load up to. Quote Link to comment Share on other sites More sharing options...
Bushman Pete Posted October 10, 2011 Author Report Share Posted October 10, 2011 Thank you for the good explanation. So looking at the data I have the middle load of:- Lead Shot 12 1 3/8 oz. Longshot Win. 209 Fed. 12S4 27.5 9300 PSI 1240 Would be good without much benefit from using 29gn. I have made them all so I will try to get a pattern and see what they look like. What are the acceptable variations in power and shot weight? I am lucky in the fact that I just got my hands on a very nice electronic scale that weights to .001 of a gram and .01 gn so I am using that. However I was hoping to make a number of pigeon loads up and I would like to use the charge bar. Pete Quote Link to comment Share on other sites More sharing options...
motty Posted October 10, 2011 Report Share Posted October 10, 2011 I have loaded some steel loads recently at 12700 psi. Quote Link to comment Share on other sites More sharing options...
Bushman Pete Posted October 10, 2011 Author Report Share Posted October 10, 2011 I have loaded some steel loads recently at 12700 psi. Well I have to say I am going to be holding my breath when I pull the trigger while testing what I have been making. Pete Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted October 11, 2011 Report Share Posted October 11, 2011 I have loaded some steel loads recently at 12700 psi. 3.5" loads have a maximum psi of 14000. but thats foe 12gauge. at that pressure should burn clean and get the most out of the "slower" burning powders. good ! Quote Link to comment Share on other sites More sharing options...
Bushman Pete Posted October 13, 2011 Author Report Share Posted October 13, 2011 3.5" loads have a maximum psi of 14000. but thats foe 12gauge. at that pressure should burn clean and get the most out of the "slower" burning powders. good ! That is a lot of pressure! Pete Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted October 14, 2011 Report Share Posted October 14, 2011 That is a lot of pressure! Pete probly at that pressure, the psi and speed variation would be quite consistent, shot for shot. i think the manufacturers try and hit 500psi below the maximum. Quote Link to comment Share on other sites More sharing options...
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