look you are your own customer.
everything you do is affecting the next step in your process.
THIS is the key. No one can tell you how to get the results you want. Frustrating as it is, probably the best anyone can do is give you some guidance to eliminating variables, maybe make suggestions or share some experimental results, and give you some like-minded folks to bounce ideas off.
(That bolded quote from Fiver is sig-line worthy; someone ought to steal it.)
I went back to your first post with some questions, and pulled some stuff out:
I know for certain that it is NOT inadequate load selection and/or handloading technique shortfalls, as my SDs are reliably single digit.
This was my first question, what kind of SDs are you getting? Got that answered, so I'm going to drop it from consideration for now.
Why losing the ability to powder coat disappoints me:
Different shooters have different reasons for wanting and using powder coating versus conventional bullet lubricants. I personally value powder coating versus conventional bullet lubricants very highly because:
- I like the lack of sticky mess
- I like how clean powder coated bullets leave my rifle barrel after a range session
- I like being able to shoot at higher velocities without barrel leading
I wasn't sure if you had other reasons to want to use PC bullets (e.g. range requirements). You may have to accept that--for now, at least--the accuracy goal and the desire to use PC bullets are incompatible. Some of your later comments seem to indicate this is something you'll consider, so I'm dropping it for now too.
I need the higher velocity on the Pedersoli Sharps replica because:
- The normal 45-70 trajectory is a little much to manage for the 600 meter distance I want to be able to shoot
- The windage adjustments of the normal 45-70 1100 to 1300 fps velocities are a little much to calculate and manage in a timed session
- The normal 45-70 velocity range is right on top of the transonic velocity range, and transonic effects can be difficult to predict and manage
- It would be nice to have a lighter bullet traveling at a higher speed, as an alternate load for when I don’t want the heavy 500g bullet class 45-70 recoil
I'm an optimist--I think it is likely a load combination can be found to at least sometimes give you the desired accuracy (wind is an uncontrollable variable, and the big bullets get pushed around a LOT). I'm not sure how successful you will be finding two such loads, particularly with the bullets you have chosen. If the serious long-term competitors were getting results like that with these bullets, they wouldn't be getting custom moulds every time they turn around. (Heck, at one time I had over a dozen variations of the same Ideal/Lyman bullet, and only one of them would give me the results I wanted in my rifle.)
If I cannot find, or be given, reasonably workable solutions for the above powder coated bullet issues:
My next probable step will be to simply try the existing load (with its single digit SDs) with bullets lubricated by Lee’s Alex Bullet Lube, which I bought a bottle of recently as a Plan B to try. I am not looking forward to that.
I spent a bunch of time on the road today, and thought about this point. Then when I got home I dug through some notes on past experiments and ideas. You have some good objections listed. The ziplock bag method would work, but as you pointed out in your reply, there are still questions and variables.
I'm going to outline some stuff below, on this and on casting. I'll give measurements, numbers, etc, but these are just a starting point. You'll need to modify things based on availability of materials, your equipment, etc--and if, before you start you throw it in the dumpster and say "JustJim is a lunatic" . . . well you wouldn't be the first. Today.
Take an unopened bottle of Lee Liquid Alox. Mix equal parts Alox and mineral spirits (start with 10 mL of each) until the mineral spirits has thinned the Alox. Take a disposable blue shop towel (comes on rolls, basically an untextured heavy duty paper towel, get them at your auto parts store) and lay it down in a baking sheet or similar. Prop one side of the baking sheet about 5 cm higher than the other. Slowly pour the thinned Alox on the high side (you want to wind up with the thinned Alox saturating the blue towel). Let it sit for 5-10 minutes at room temp to allow the solvent to evaporate somewhat but not completely. One at a time, roll the bullets down the slope so they are covered with the thinned alox. Carefully pick them up by the nose, and stand them on their bases on a piece of ordinary kitchen waxed paper. Let them sit for a couple days so the Alox sets.
That gives about the thinnest, most-even coat of Alox I've managed to produce. (About '99, for some un-recalled reason I thought my Alox-lubed wadcutters had too much lube, and this was as close as I could get to the thin even lube applied to factory wadcutters.)
If Alox does not work well for me, and at high enough velocities, I think I’d rather simply switch to metal jacketed bullets, and at least be able to then shoot supersonically to even the 600 meter mark, which would enable me to use my about-to-be delivered Shotmarker electronic target system, which depends upon the projectile being supersonic to be able to detect it. That would certainly beat having to use a gong target in order to eliminate the need to walk 600x2 = 1200 meters = 1300 yards = 13 minutes each time I want to check or change my target.
This is an option, even if you only do it to prove the rifle is capable of this level of accuracy. I've had rifles where I did this, and some of them I gave up shooting cast in. I've had others where once I had the results I decided I didn't want to live with them.
I don't think a ghas check will help, Ian. There is already no "blowby" past the bullet shanks. I get NO leading. The problem I have uncovered is inconsistent and unpredictable distortion of the bullet's shape and the resulting BTO variances caused by that.
Jim G
Have you examined recovered bullets to see if you are getting skidding where the bands first engage the rifling? This can be a problem, in my experience particularly with heavy bullets.
I hjave fired these bullets at .458", .459", and .460" in a barrel whose groove diameter is .4563". That means I have covered .0017" to .0037" of bullet to groove interference. That is plenty of range to have tried don't you think? No way would I wnat to try more than .0037" of interference fit!
What is the land diameter? Have you slugged the throat of the rifle? How well does the bullet fit the chamber leade?
Your comments on mold temperature are so correct. I have been keeping the Lyman Mag25 relaibly at 720 degrees F. I have been able to get my casting to the point where the mold temperature stays reasonably constant as measudred by an infrared temperature gun, and the bullets are not wrinkled nor frosted, BUT I cannot seem to get the Lee 2-cavity "459 500 3R" mold to reliably drop both bullets when opened. The bullet from the cavity furthest from the handle almost always drops. The other cavity (closest to the handle) usually needs tapping on the handle hinge bolt, and sometimes a LOT of tapping. This is the same whether I pour the alloy first into the furthest cavity or the closest cavity. Slowing my cadence to let the mold operate at a colder temperature helped, but not enough. For some reason I have been unable to discern, that one cavity wants to hold onto its bullet. Suggestions?
Jim G
FWIW, for bullets the size of your 500 gr Lee, I cast at a measured ~750F (if the shop is room temp--if it is cold, I'll adjust that higher to get the results I want). I only fill the cavity farthest from me (using it as a single-cavity mould). I hold the mould so the lead hits the sprue plate about 7 o'clock and flows into the cavity. I'll pour it and build a good sprue, then hold it for one minute to cool. (just for example, on my 457132--roughly the same weight--I pour for about 8 seconds. After 1 minute cooling, the sprue is set and I get a clean cut.)
Cut the sprue, drop the bullet on the pad, and move it to what will soon be a row of bullets. For something like this--testing a mould for a serious goal--I'll keep the bullets in order cast (we'll come back to that). Immediately pour another, the same way. I usually keep this up until the lead level has dropped about 50% (my pot is marked--25 years ago!--but I think it was at the 50% level).
I take a permanent marker and number the bullets in the order cast. I weigh each one. Eventually, the weights start to cluster fairly tightly (plus-or-minus .5 gr). I regard the bullets before the cluster as rejects. I'll select one from the middle of the cluster and drop it in the rifle throat, and point the barrel down. Using a rod, I measure from the tip of the bullet nose to the muzzle. Bump the bullet out of the action, close the action, and measure from the muzzle to the breech. The difference is the max OAL for
this bullet in
this chamber. Loading with BP, I'll subtract .020" to give me a starting OAL.
From there, my loading tests are going to be different from yours due to my use of BP and you using smokeless. You can do a search and get some good ideas on test procedures for smokeless (I tend to pick a load and if the results are satisfactory, never change anything).
I'm most-emphatically-NOT saying this is the way to do things, just that this is how I do it. Depending on results, I may wind up changing temps, alloy, etc, but I always start from a known point--and I keep my notes for reference.
