Finding the right load data for lead casted bullets....

I'm casting with a Lee mold that is in theory making 125gr RN bullets. After checking the weight I'm getting on average 127.5-128.5 Grain weights. Now back to my questions, I'm stuck at deciding if I should use the 125gr load data from my book and be around 2.5-3 grains over or go with 130gr data and be 2.5-3 under? Not sure what's better/safer to go with? I did have other weight options like 126 and 127gr, but I do not own any of those powders and would rather use the massive amount of accurate powder I have now, if this is safe of course. Let me know what to do guys....thanks

i would use the data for the heaver bullet and gradually in .5 gr increments work up to the max for the lighter bullet. That way you know you are safe and some where you should hit a sweet spot where you are very accurate.

use the 130gr data! You should be able to go up to the max charge without any problems.

Once you find a load that works...accurate and non-leading. I bet it will be at or slightly over the starting load for 125gr.

hawcer wrote:use the 130gr data! You should be able to go up to the max charge without any problems.

Once you find a load that works...accurate and non-leading. I bet it will be at or slightly over the starting load for 125gr.

So use my 130gr starting load and slowly progress upwards until I find a perfect match I'm happy with?

Reload3006 wrote:i would use the data for the heaver bullet and gradually in .5 gr increments work up to the max for the lighter bullet. That way you know you are safe and some where you should hit a sweet spot where you are very accurate.

So separate all my bullets by weight?

I get the general understanding of "leading", but how does one calculate the accuracy factor? Basically I'm asking, how do you figure out if your bullets are accruate enough or not?

you'll probably be ok starting in the middle of the 130gr load data since you are between 125gr and 130gr.

But if you have the extra time and components it might be worth your while to begin with the 130gr starting load. If you take good notes...you will have a broader spectrum of data and that will equal more knowledge for the future.

you never know...that gun/bullet combination might like slower speeds.

victor8881 wrote:I get the general understanding of "leading", but how does one calculate the accuracy factor? Basically I'm asking, how do you figure out if your bullets are accruate enough or not?

don't try to shoot 1" groups at 25 yards or anything that drastic. For a 9mm, I'd consider a 3" group shot off hand at 10-15 yards acceptable. You'll know when it isn't right, your probably won't have any bullets hit near each other... a whole group of flyers is the best I can describe it.

It is always good to have something to compare your results with. 115gr Winchester white box is my goto 9mm ammo for comparisons. It seems to work really well in all the 9mm's I have fired it in.

hawcer wrote:you'll probably be ok starting in the middle of the 130gr load data since you are between 125gr and 130gr.

But if you have the extra time and components it might be worth your while to begin with the 130gr starting load. If you take good notes...you will have a broader spectrum of data and that will equal more knowledge for the future.

you never know...that gun/bullet combination might like slower speeds.

Confused here, start in the middle of my min to max charge load data for lead 130gr bullets? If this is correct, why would I start in the middle not from the starting charge?

Because you have 125gr bullets dropping out at 127-128gr...that is in between the 125 and 130gr loads.....so a load midway between the min and max of the 130gr data should be real close to a starting data for a 127gr bullet. This is in theory... so to be on the safe side, start at the minimum of the 130gr loads.

sorry for any confusion I may have added. I tend to over think the problem sometimes

victor8881 wrote:

Reload3006 wrote:i would use the data for the heaver bullet and gradually in .5 gr increments work up to the max for the lighter bullet. That way you know you are safe and some where you should hit a sweet spot where you are very accurate.

So separate all my bullets by weight?

Some people would tell you to do that. It really depends on how anal you want to get with it and how accurate you want to be. For safety reasons i suggest finding the heaviest bullets your mold drops and work from there. If you use the same charge for a 130 grain bullet with a 125 gran bullet. you would be safe and really probably wouldn't see that much difference in the way they shoot. but if you were to go the other way it could be an over pressure situation. and as everyone else has said your gun may just like slower stuff maybe it wont its just one of those things you have to experiment around with and find what works for your gun.

victor8881 wrote:

Reload3006 wrote:i would use the data for the heaver bullet and gradually in .5 gr increments work up to the max for the lighter bullet. That way you know you are safe and some where you should hit a sweet spot where you are very accurate.

So separate all my bullets by weight?

I do, and it shows. i line up the bullets by wt from heavy to light and seat them in that order, that way when shooting them out of the plastic box, if i shoot in the same order i load them(or backwards), they group much better than if i shoot a couple randoms from the box...

that being said... some guns don't care, and some purposes don't call for it... reload30-06 is right... it's kinda anal, and feels like a pain in the ass when you're sitting there getting a crick in your neck weighing them all out and lining them up...
one of my rifles wont shoot worth a shit if i don't do it, luckily the others don't care

Reload3006 wrote:

victor8881 wrote:

Reload3006 wrote:i would use the data for the heaver bullet and gradually in .5 gr increments work up to the max for the lighter bullet. That way you know you are safe and some where you should hit a sweet spot where you are very accurate.

So separate all my bullets by weight?

Some people would tell you to do that. It really depends on how anal you want to get with it and how accurate you want to be. For safety reasons i suggest finding the heaviest bullets your mold drops and work from there. If you use the same charge for a 130 grain bullet with a 125 gran bullet. you would be safe and really probably wouldn't see that much difference in the way they shoot. but if you were to go the other way it could be an over pressure situation. and as everyone else has said your gun may just like slower stuff maybe it wont its just one of those things you have to experiment around with and find what works for your gun.

Damn I'm stuck like unsolved mystery!

I don't know why I'm so confused right now! So your saying charging a (127.5-128.5) with a 130gr data is ok,but charging at 125gr for a (127.5-130) could cause over pressure issues? I'm so sorry that it's not registering.....rather fully understand and ask too many questions than guess and have a missing body parts!

lol, hey you can't hate on extra effort. I'm lazy and if I spent all my free time in the reload spot my wife would soon be my ex! I just pull a random hand grab sample weigh those and if there not all over the board I'm good with that as my "average". I was past down a good casting method, so I stick strictly to that and I'm seeing good steady weights thus far.

victor8881 wrote:

Reload3006 wrote:

victor8881 wrote:

Reload3006 wrote:i would use the data for the heaver bullet and gradually in .5 gr increments work up to the max for the lighter bullet. That way you know you are safe and some where you should hit a sweet spot where you are very accurate.

So separate all my bullets by weight?

Some people would tell you to do that. It really depends on how anal you want to get with it and how accurate you want to be. For safety reasons i suggest finding the heaviest bullets your mold drops and work from there. If you use the same charge for a 130 grain bullet with a 125 gran bullet. you would be safe and really probably wouldn't see that much difference in the way they shoot. but if you were to go the other way it could be an over pressure situation. and as everyone else has said your gun may just like slower stuff maybe it wont its just one of those things you have to experiment around with and find what works for your gun.

Damn I'm stuck like unsolved mystery!

I don't know why I'm so confused right now! So your saying charging a (127.5-128.5) with a 130gr data is ok,but charging at 125gr for a (127.5-130) could cause over pressure issues? I'm so sorry that it's not registering.....rather fully understand and ask too many questions than guess and have a missing body parts!

yea i think we all agree using the heavier boolit wt's data is safer. i'd start there and work up your load like you normally would; checking for pressure signs starting at the minimum load listed for the "130gr Lead boolit" data

Its a matter of physics. It takes more pressure to move a heavier object. Newtons Law. an object at rest tends to stay at rest an object in motion tends to stay in motion. It is like lifting weights it take more effort to pick up a fifty pound barbell than it does to pick up a twenty five. So that is why we are suggesting using published data for the heaviest bullet your mold drops and work up form there. If you show no signs of leading or over pressure you can work up to the max load for the listed weight of the mold but always think safety its your life your gun etc type of thing. You can get into the math if you like you can calculate your anticipated pressures but the formula is long and complicated. So its easier to just trust published reloading manuals and work from there. The exact weight you have may not be listed in manuals so always use the data listed for the heavier bullet. that way you know you will be safe when you pull the trigger.

The exact weight you have may not be listed in manuals so always use the data listed for the heavier bullet. that way you know you will be safe when you pull the trigger..

+1 with 3006

I cast the same Lee 125gr bullets and they are usually over a grain or two from the mold. Lube and size them and then a light final lube (if using alox type lube. Let them sit for 48 hours) and then put them on the scale. I have had "fat bullets" that were much closer to 125gr after they were sized and dried.

Once the bullets are ready to load use that weight to pick load data. I just grabbed a few bullets that I have here ready to load and the range on my digital scale was 124.8gr to 126.6 gr with the majority being in the mid 125gr range.

For this, I would use an upper mid range Bullseye load of 3.8 to 4 as dropped from my Lee powder measure set for 3.8 but we all know that means drops could be from aprox 3.7 to 4.1gr with the majority being 3.8gr. I also have my COL a little longer than the book suggests around 1.142-1.145 as that is what my guns seem to like best and there is no chance of a compressed load.

I know Lee says that you can load the bullets as dropped but I have a couple Norinco 9s and one of them runs them fine as dropped, the other, a Tokarev clone has a tight bore and the bullets must be sized for that gun. As a general rule I size all of my cast pistol bullets for ease of use in either gun.

In short, the same thing applies that was said above stay wwithin the listed load data and find out what your gun likes best.

Cactus

I'm a little late in adding my two cents to this post. But what confused me a lot in the beginning of loading cast bullets was that, many bullets of equal weight had different configurations. Lets say...a 45 cal. 200 grain SWC. A cast Lee was shorter than a Lyman, because the cone of the Lyman was narrower and steeper than the Lee. And a Lee 45 cal. 200 gr RFN shorter still. Thus the distance from the base of the bullet to the crimp grooves would be different with the same C.O.A.L. So with a given powder and charge weight the case volumes would vary under the seated bullet. Bullets in a cartridge case are a bit like a piston in an engine cylinder, in that the smaller space you compress the gas/air mixture the more power you got. Reloading data is conservative to keep it safe. What I do when I can, is load a bullet of similar weight to put the base of the bullets at the same depth or a little higher. Lee loading data in particular is hard to interpret sometimes because it is based on weight only and not bullet style, adding to my confusion.