At what velocities dose accuracy (consifall off with cast bullets?

[Tripplebeards]

I haven't had a chance to try out my lee 310 PC and GC 44 mag loads out in my 77/44 yet and am working on PCing lee .452 300g for m Ruger American bushmaster. I have been weighing the bullets to match them within 1 grain before loading.

From some one of the posts I've read under 2000-2350fps?

If my rifle can shoot sub MOA to MOA with Jwords can I expect to do the same if I find the correct velocity? From what I've read pushing CB fast opens up grouping?

[JonB_in_Glencoe]

Tripplebeards,
welcome to the forum.

That is a good question, it has a complex answer.
the speed where groups start opening up depends on alloy hardness/toughness and the powder choice. The higher the pressure and longer the pressure curve, the more likely the boolit will deform and/or slump and wreck accuracy. So a harder alloy and a powder with a slower burn rate will typically allow a higher velocity.

The Lasc link at the bottom of the page has a lot of great info about boolit alloys. I refer to it often. If you scroll down that page til you see "Approximate "Maximum" Chamber Pressure For Lead Alloys (PSI)", it will show you what pressure a given alloy will take, if you keep your loads at or below those pressures, you'll be fine.

I really like the Lyman castbullet handbook #4, as most of the load data includes pressure.


http://www.lasc.us/CastBulletNotes.htm

[Tripplebeards]

I'm using 100% WW lead quenched in ice water immediately after casting and then quenching in ice water again after PC at 400 degrees for 20 min. They are older WW from the 80's brand new in the box. Really hard after first quench. You would rub your finger nail off and still not make a scratch in my lead.

[OS OK]

This is an interesting read...along the lines of what your asking...

RPM Threshold barrel twist/velocity chart (http://castboolits.gunloads.com/showthread.php?208186-RPM-Threshold-barrel-twist-velocity-chart)

[jcren]

Should be plenty hard for most purposes. With so many variables, rifling twist and barrel nodes even figure into max accurate velocity. Start low with light jacketed data and work up slowly on small increments until accuracy goes to heck. Remember to try a couple steps above that point to be sure it just isn't a bad node/vibe. While careful loading can get very respectable accuracy, cast bullets are inherently less accurate than swedged or swedged and jacketed due to slight density variations, but large/heavy bullets somewhat negate this (thing large bore black powder cartridges).

[Tripplebeards]

I don't care how fast or slow I push them...my goal is to be MOA or under at a 100 yards.

[NoAngel]

I don't care how fast or slow I push them...my goal is to be MOA or under at a 100 yards.


Exactly! The need for speed is nonsensical. It's either accurate for the range you are shooting or it's not.


To the OP, make sure your BS filter is in place. Find a load that is accurate and does not lead the barrel. Nothing else really matters.

There's no reason cast in your .44 shouldn't as good as any jacketed bullet. You might have to do a little leg work to get there.
That 300g PC'd .450 Bushmaster will kill anything that walks up there where you live. If you find accuracy around 1800-2000 fps with a 300g lead bullet you only need to place your shot correctly and watch your game fall to the ground. That's basically an auto loading 45/70. The 45/70 has never needed balls to the wall speed to drive any game into the ground.

[Reddirt62]

I guess this means I can't cast for my 223 wssm.....8)

Sent from my SM-N920V using Tapatalk

[fredj338]

I don't think there is a minimum vel for accuracy. It will be barrel specific. Plenty of good shooting has been done with lead bullets from old timers like the 45-70. my RBHBH will hold 3" at 100, 270gr bullet @1200fps. That is more me than the gun I am sure.

[Whitespider]

Not so sure there's typical answer... I shoot a GC boolit cast from air-cooled COWW metal in my .22 Hornet at 2300 FPS without problems.
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