accuracy trouble

[XWrench3]

its been a while since i have been here, sorry, had things i was forced to do. but i am now in a place where i can play for a while. i have had decent results loading with "J" bullets, getting good, repeatable groups, in all of my rifles. but i am having trouble finding a good cast boolit load, that will repeat. i have found several that looked good, but i have been doing this long enough to know one set of holes in paper does not make a good verified, repeatable load. i am weighing all the cases, using the same components each time, hand weighing every charge, even started weight sorting the cast boolits as a last resort. i just can not find the magic. i never felt like l.l.a. was good rifle lubricant. but i now have a lyman lube/sizer, which was the best money i have spent in a long time. the one thing that i can not yet measure, well, now that i think of it, 2 things. the first one is lead hardness. i am using wheel weights, plus 1% tin, just to make them cast good. but i can not test the brinnel hardness in any way. the other thing that just popped into my brain was i can not measure run-out. i am sure the second one can and will have an effect. but what about hardness? f.w.i.w. i am having trouble in my 30-30 marlin 336, and my remington 700, 300 win mag. i am not trying to make these barn burners! if i need that, i have several good "J" loads i can fall back on. i am just trying to get less than 2" groups @ 100 yards, from a good solid rest. i have no trouble getting sub moa with all of them in "J" projectiles. i am just having a hard time figuring these out. i am thinking i need a fresh set of eyes on the project.

[runfiverun]

all that and you forgot the first rule of cast boolit shooting.

[RobS]

1. Boolit fit
2. Fill the throat the best you can
3. Seat to just touch the lands works best for me
4. Depending on the twist rate and velocity you may have to run a harder alloy (water quenched WW alloy)
5. I prefer to use slower burning powders to help fill the case more
6. I have also had better luck with softer lubes that are not so darn hard and/or tacky; I mix a lithibee/stp mix that works quite well for my rifle loads as well as others

1-10" twist rate barrels are tougher to get accuracy with when ringing velocity out especially when all your ducks aren't in a row.

[Pilgrim]

You don't mention a whole bunch of stuff needed to help you. Like; the boolit (s) being used. Some are more forgiving than others. The powders being tried, fillers (?), seating (are the boolits into the lands, or ?), what is your target velocity range, GC's (?), lubes, boolit size, bore size, and more items can all be important. Are your barrels squeaky clean and free of copper fouling. Starting with a clean bore for cast is usually critical. Weighing boolits at this time is a huge waste of time. Weighing cases fits in with weighing boolits. Don't bother. Boolit runout is another waste of time. Load them so the boolits are seated into the lands. Let the barrel correct any runout issues. Are you brutal in boolit examination prior to sizing and lubing? You seem to be approaching this as if you were developing loads for j*** rounds. Boolits aren't jacketed and seldom behave like them. I could go on, but I suspect I may have said too much already. Don't give up! A suggestion is to concentrate on the .30-30. Magnum cartridges are usually more difficult to work with re: accuracy due to case volume. When you do work with the .300, consider case fillers to hold the powder against the primer to reduce velocity variations due to ignition variations. FWIW Pilgrim

[RobS]

I don't use case fillers with the big ole 375 H&H. 58 grain of Varget behind a 265 grain HP cast boolit or a 270 grain solid cast boolit and a way we go MOA with single digit spreads. I shoot golf balls at 100 yards for the fun of it which becomes boring after a short while. Granted a case filler could be needed with some loads though.

[303Guy]

I knew it! The 375 H&H is made for cast.

From what I've seen/done and read/heard, I'd suggest you can't go wrong with Varget. I'd also suggest fillers can be of help when boolit fit isn't perfect and for plain base boolits (to protect against boolit base peening and seal the bore).

[RobS]

I knew it! The 375 H&H is made for cast.

It is!!! Very much like the 30-30

[44man]

I love Varget.
But run out is a huge problem with cast. Maybe the very worst because lead will not straighten in the bore. Start crooked, shoot crooked.
Since I started playing with bottle neck rifle cartridges again I have seen run out as much as .020" even with the best dies and loading I can do. It is driving me nuts.
I made my own run out measuring tool from scrap and a cheap dial indicator. I size and measure to find .001" or less on necks but after slowly seating with a die with a guide, I still get some. I have reduced it but not as much as I want. I made larger expanders and it helped.
I found a lube sizer sizes off center many times so went to Lee push through dies.
Anything you do to ruin a boolit will cost you whether slump or obturation. I do not believe in obturation, just fit to start. A crooked boolit in the brass has to be the worst.
Size a boolit off center and it will never seat straight.

[Doc Highwall]

What diameter are you sizing the bullets to, and are you expanding the case necks and if so what are you using?

[44man]

What diameter are you sizing the bullets to, and are you expanding the case necks and if so what are you using?

I don't know who you asked here but I size .311" for the Marlin and expand to .310".
It has helped but I need some tension in the tube magazine. Just enough crimp too.
I also used the .310" expander in the 30-06 Enfield with .309" boolits. They fit fine but I still got run out with some. I blame my lube sizer so I ordered a .309" lee. Everything is on back order.

[felix]

Finger tight seating, no machines, will perform the best every time. Looser the feel-fit in the case, the better the accuracy, but worse in terms of practicality. Talking about unsized cases for the most part. The assumption is that the boolit is sized right-on and the powder speed is appropriate for the next to zero boolit pull resistance. ... felix

It's danged hard to beat the accuracy of competition grade pellet guns. ... felix

[Doc Highwall]

Here is a thread I started a while back about what I have done/started on my quest for accuracy.

http://castboolits.gunloads.com/show...ullet-Shooting

I am in the process of making more expanders in .0005" steps to control neck tension. I also have a pressure trace system to use along with the chronograph.

[44man]

Here is a thread I started a while back about what I have done/started on my quest for accuracy.

http://castboolits.gunloads.com/show...ullet-Shooting

I am in the process of making more expanders in .0005" steps to control neck tension. I also have a pressure trace system to use along with the chronograph.

I admire what you do, a man after my own heart.
The perfect round is made at the bench, never in the gun.

[Tazman1602]

XMWrench,

FWIW ditch the 300 mag for now and concentrate on the 30-30, it's much more cast friendly. I personally will not cast for anything other than a 30-30 in the .30 cal range. *Most* of my efforts have been with .338 and up. I have especially good luck with the bigger bore, slower rifle cartridges.

First question man, is WHAT, EXACTLY is your bore size and what are you sizing the bullets too? This cured a plethora of issues with my cast shooting in rifles. Size .001 - .002 over bore size for proper fit.

In other words, before you cast a bullet, slug the bore to find out where you should start, that 30-30 should be an excellent cast shooter. Here's a pic of my .450 Marlin with cast loads:



So you know it can be done. My 45-70's shoot as well and thanks to my buddy Hardcast416Taylor I'm working on .338 WinMag right now.

...........of course, thanks to my buddy Hardcast416Taylor I am also looking at making a Mosin a big bore rifle too..........THANKS BOB! I really needed another project!

Keep at it man, sooner or later you'll get it figured out. I had cast bullets for handguns for 20 years and I started out with .30 cal rifles and *almost* gave it up as you just can't do that until I found this forum some years back. Lots of help here and if you need an answer google works better than the search function on the forum........it will point you right back here to the right thread.

Art

[cbrick]

But run out is a huge problem with cast. Maybe the very worst because lead will not straighten in the bore. Start crooked, shoot crooked.

I found a lube sizer sizes off center many times so went to Lee push through dies.
Anything you do to ruin a boolit will cost you whether slump or obturation. I do not believe in obturation, just fit to start. A crooked boolit in the brass has to be the worst.
Size a boolit off center and it will never seat straight.

44man brought up three very important things here that don't seem to get mentioned enough.

1> No, the bullet will not straighten itself in the throat or bore. Run-out needs to be minimal.

2> The in & out sizers do size off center. The better term is they do not size concentric. Best concentricity is sizing nose first with a flat punch & flat boolit base in a straight thru die such as the LEE or the Star.

3> 44man may not believe in obturation though he is 100% correct about fit. There is more to obturation than the base swelling to fit the groove diameter, also important is the boolit being able to back fill the trailing edge of the rifling, this too is obturation and it is here that too hard an alloy and/or too fast a powder can hurt and cause leading by gas cutting the edge of the boolit.

Rick

[Tazman1602]

Rick,

I recently (within the last year....) discovered with my flat nose cast bullets that Tom at Accurate Molds makes flat-nose punches to use with either Lyman or RCBS LAM II sizers that work VERY well to avoid the issue of off center sizing for me anyway. Just thought I'd mention that one...

Art

[cbrick]

Art, I think that is the problem, mostly with rifle boolits. A flat punch should help a great deal when sizing flat nose pistol boolits in the in & out sizers. Many handgun boolits have a flat nose but far fewer rifle boolits. However a poor fitting nose punch grabs the boolit is how it is going to push it into the die.

Rick

[Tazman1602]

You are absolutely right Rick, I didn't take "pointy" bullets into consideration since all of mine are flat point.

With the lack of ammo lately, I have taken to fixing and shooting my collection of Rossi rifles in handgun calibers -- those I *can* cast for and still afford to shoot.

FWIW my RCBS LAM II is in MUCH better alignment that the old Lyman is, thanks for reminding me that not everyone shoots exactly what I do...........DUH!

OH to be able to afford a Star.............<grin>

Art

Art, I think that is the problem, mostly with rifle boolits. A flat punch should help a great deal when sizing flat nose pistol boolits in the in & sizers. Many handgun boolits have a flat nose but far less rifle boolits. However a poor fitting nose punch grabs the boolit is how it is going to push it into the die.

Rick

[44man]

Rick, that is true. Obturation to bump up under size boolits is bad---(OOPS, BACKWARDS, bump up is first.) But some expansion to seal or maintain seal is different.
The term is used to say a small boolit should expand to fit. I don't like that. To keep the right size boolit sealed is where we should be.
It is only the two versions of obturation that is hard to explain. Since the word means SEAL and not to bump a boolit way up first, a boolit that fits first will sure obturate.
It is a definition of the word and how it is achieved.
Soft, undersize boolits need to expand to obturate. Fit needs no expansion. Hard undersize also needs to expand to obturate but fit needs no expansion.

[303Guy]

The problem with bump up is concentricity. Three things can happen; the boolit bumps up misaligned and/or bumps up unevenly and the nose can slump.

Something not mentioned is boolit weight and length. In a rifle, the longer the boolit the better the bore alignment is going to be if the fit is right. The high the sectional density the boolit the better the powder burn meaning that slower powders can be used to better effect. I consider a heavy for calibre cast boolit to make better use of the rifle's power with cast. Velocity attainable does not change (much) so energy, momentum and BC are better. They also use up more alloy which means you get to go out lead shopping for lead more and do more alloying - that's a good thing, right?