lyman cast bullet load data and jacketed bullets

[mattmillerrx]

I am pretty sure I have read about this on here but could not find it when searching + I had some other questions too.  This will be my first reduced loads with cast bullets I will be using laser cast 30 cal 170 gr rnfp bullets in an 03a3 ( 30-06).  I will be using sr-4759------before I was using jacketed bullets with h-4895

1.  With cast bullets and reduced loads do you still seat off the lands?---with jacketed I make a dummy round finding the max length and then back off .015-.02
         
2.  I have some left over 168 gr jacket bullets---I thought I might try the load data listed for cast with sr-4759 and 170 gr bullets.  Is this safe to do?  Anything else I need to know?

I am excited to try this out, it should give me a very light load to shoot in a military bolt action bench rest match.

[bilmac]

For target loads that won't be exposed to dirt, I don't see any reason not to get close to the lands. For loads that might see the inside of a pocket I try to get all the lube grooves inside the case.

Jacketed bullets run a little more pressure than cast, shouldn't be a problem to substitute a jacketed bullet for most of the light loads, just be cautious if you approach full power loads, like you could in a 30-30. I have never had much luck doing this, something to try for light or midrange jacketed loads is blue dot powder. I seem to get results as soon as I use Blue Dot. The Blue Dot experimenters say top end is 60% of case capacity and reduce that by 10% for safety. I often find accuracy at much smaller charges than that.

For Everyones safety lets stick with data from either the Bullet , Powder or other PROVEN companies !

stimpy

[stimpylu32]

I am pretty sure I have read about this on here but could not find it when searching + I had some other questions too.  This will be my first reduced loads with cast bullets I will be using laser cast 30 cal 170 gr rnfp bullets in an 03a3 ( 30-06).  I will be using sr-4759------before I was using jacketed bullets with h-4895

1.  With cast bullets and reduced loads do you still seat off the lands?---with jacketed I make a dummy round finding the max length and then back off .015-.02
         
2.  I have some left over 168 gr jacket bullets---I thought I might try the load data listed for cast with sr-4759 and 170 gr bullets.  Is this safe to do?  Anything else I need to know?

I am excited to try this out, it should give me a very light load to shoot in a military bolt action bench rest match.

Matt

A couple things here , one , its always a good idea to to start a new load off the lands , be it a Cast or Jacketed bullet as the pressure curve will change drastically with the bullet seated at a dead stop .

2nd , Cast bullets will produce less drag than a Jacketed bullet , therefore requiring less pressure to move down the barrel , that's why in MOST cases you can use jacketed data to load Cast bullets but not the other way around .

While in a lot , but not all cases you can substitute Jacketed data from one brand Jacketed bullet to another brand Jacketed bullet of the same weight and still stay in the safe range of pressures . And for that matter you can even substitute Cast bullets of the same weight into Jacketed data , yet even that must be looked at in a diffrent light as the speed the bullet will be traveling and the fact of weather it has a Gas Check or not comes into play .

Another thing to think about is that a light load that will move a Cast bullet down the barrel with no problems may very well stick a Jacketed bullet in the barrel or even worse stick the jacket and allow the core to move on out the barrel leaving a partial blockage for the next round to slam into . VERY BAD !!!!!!! 

Basicly what I'm trying to say is that you can not just swap data around without something bad happening . 

stimpy

[mattmillerrx]

Thanks for the help guys.  stimpylu32, you reminded me of the jackets coming off.  I was under the impression that SR 4759 was ok to use with jacketed bullets (but apparently not with the same data listed for lead bullets).  I had read this before but was reminded of it when reading the article on the .32 special in the jan 09 guns and ammo, this is also what gave me the idea to finish off the left over jacketed bullets.  I am not sure but think the first place I saw it was in the old Speer manual dad has.  I can't use it since it is so old but would pick up a new Speer manual if it is still in it.  The cast stuff is new to me and  I want to be cautious