Originally Posted by
HighUintas
IJ, did your modification of that Lee mold make it a solid base?
yes I just turned the little tit off it but also milled the roundish nose off - maybe I am overcautious but that nose fit neatly inside the primer cup as it was - never seen a magazine ignition but seen pictures - my hand (only got two) and a $2000 rifle better safe than sorry I say-- the shorter boolit I made up a dummy base plug for the mold thats longer than standard so it eliminates the base driver band and lube groove
I measured my Lyman M expander mandrel. The main portion before the mouth flare is 0.456. The mouth flaring portion is 0.460 and I did have it adjusted to use the entire length of the flaring bit.
So, yes there's a bit of neck tension there.
I'm using a cereal box was I cut with BACOs .462 hammer punch. It makes a nice tight fit in the case. You think I ought to try an hdpe wad cut from a milk jug? Not sure why the wad type would promote or prevent it
wad diameter sounds good - I was doing juice box - but tried the poly because of all the long range bods were touting it - groups shrank with it so I didnt go back - I use HDPE cuz its easy to find - could not get the LDPE without a major effort and $$$'s -- my take here - we need a sturdy wad in these bigger rounds (yours more than mine) cereal box maybe not enough tough? juice box tougher, tablet backing tougher again, poly wad much more tougher again, auto gasket material tough as poly ? heavy card too ? those gurus of the 1000yard were using 60 thou LDPE - that is a stout wad !!! -- mine is 45 thou HDPE = a stout wad, it comes out of that 45/75 unscathed even with an 80 grain charge and a 500 grain boolit (yep pointy boolit loaded long and single loaded) juice box and cereal box runs about 20-25 thou - me ? I would try juice box as I think its a bit tougher and stack em - two at least maybe three - that might work better if you punch the three layers at once - might make a difference (or not) -- all theories that will come unravelled real quick if you dont get enough lube happening - have a good look at the pic of that LEE boolit and if yours is not like it - there might be your problem ----so boolit diameter 459 - 460, + good solid wad 45 thou of decent material, + lube enough you get that little lube star at the muzzle
Looking in the barrel with my borescope, I can't imagine anything I'm seeing in there would cause the leading I'm getting.