Why are my jacketed rounds so much more accurate than my hardcast loads?

I have been working up some plinker loads for my 30-30. I bought two different hardcast slugs (115 grain coated and 120 grain lubed). Using 11 grains of 700x, I could not get them to stay on a 6-inch target at 50 yards. They were literally all over the place - above, below, to the side. I would have done better with buckshot.

But when I loaded Hornady's jacketed 110-grain softpoints (same charge), the shots all clustered around the bullseye.

What am I missing? I have had good luck with hardcast in my .45LC rifle.

 

You are loading your lead bullets with too high a charge. The 115gr lead bullet Lyman data found in my 30-30 One Book list a suggested starting load of 7.0 gr to to a maximum of 8.9gr for 700X with the pressure at the maximum charge of 38,600 CUP and velocity of 1,643 fps.

A lead bullet driven at too much pressure will fail to engage the rifling properly and give poor accuracy. A copper jacketed bullet can take much more pressure.

Drop you charge to the Lyman start load for lead bullets and work up to 8.9 gr if you want max velocity to find the best accuracy.

 

Ah. Ok, thanks. I had started with 7 grains and worked up. The lighter loads weren't reaching the normal zero at 50 yards, so I just kept pushing it up.

I guess the hardcast loads will have to be for 25 yards or so, as I don't want to change the zero of the rifle. With normal Leverevolution ammo, it is zeroed at 150 yards and is very accurate.

 

Alloy hardness and sizing are two of they key the things that you have to experiment with when shooting cast in a rifle. You can get lucky every now and then but most often you'll have to put in the work to find what clicks with your barrel.

 

There's a lot (a whole lot!) more to cast bullet loads than seating them ilo jacketed. Rarely is the same powder appropriate, and almost never at full jacketed charge.

Start here: LASC Ingot to Target

 

Too fast, too hard and too small most likely. There are cast companies out there that claim you can push their cast bullets fast as jacketed - You can't.

 

This hard cast, gas checked bullet, sized to 309/.310" can be pushed almost to standard 30-30 , 170 gr. velocity with IMR 4895.
It was also a good bullet for the 1903 Springfield 30-06 rifle with same powder. But less velocity then a standard jacketed load. Accuracy 30-06 - 3" @100 yard groups with iron sights.


I did cast my own. Looks like some are for sale? http://www.westernbullet.com/ly3gr2.html

 

Velocity isn’t everything. Cast lead at lower velocity have been hitting targets at max ranges with great accuracy since the days of Ali Oop. It’s mostly up to the shooter and loader.

 

Agree on keeping them slow, I get great accuracy with 100-115 lead in 30-30 with just 7 grains of Trail Boss. POI is always low, unavoidable.

 

I agree with the lead may be too hard or undersized, or both.

Many commercial casters cast on the hard side, one reason is it keeps them looking better when they get to you.

Proper bore fit is imperative, did you shoot enough to see leading in the barrel? Undersized lead pushed on the fast side will often times leave a good bit of leading.

 

Roscoe,
I wanted to ask if your shooting Gas Checked bullets, I would think they should be but who knows. The gas checks are on there to keep the base from deforming and melting with hotter loads, like over 1300fps.
If they aren't gas checked you don't stand a chance with accuracy at higher velocities.
Check your barrel to see if it's leaded up to.

 

These slugs were definitely not gas checked. Just lubed/coated. I do need to invest in a chronometer, which would have cleared this up.

But thanks for the replies. I guess trying to keep the zero was just not going to work at 50 yards. I will try 25 . . .

 

My favorite 30-06 and 30-30 bullet. I use 4198, however.

 

"Hard cast" is always a trigger term to me. Too hard often means it is not sealing the bore due to the base not bumping up. I recycled 1500 hard cast 44 bullets as they couldn't be made to work in any of my handguns or rifles. Perhaps if they had been .431 they might have worked.

 

Check the following:

1. Slug your barrel and measure the bullets. Barrel groove diameter should be right at .308" and bullet diameter not less than .309".
2. Check your recovered bullets under a powerful magnifying glass -- look for gas cutting and skidding (grooves in bullet wider than lands in rifle.) Usually this means bullet too small.
3. Try a different powder. Accurate 5744 is THE powder to use with cast bullets in rifles.

 

Ok. Lessons learned: gas checks and 5744!

 

For rifles, gas checks are essential! If you're not using them now, you'll see a big difference when you start.

 

Size is the most critical. Some bullets are designed for gas checks and others not. If you have no desire to cast your own you may be able to order them without lube and powdercoat them and size them yourself. This puts you in the driver's seat for final size which is a big part of being successful if your bore and bullet are not a good match.

 

I think there are plenty of powders that will work. I would suggest reducing velocity, gas checks, and powder coating. I cast for lots of things and even in bigger cast loads (200 grain monster in 30-06 doing 1900 FPS), alloy/hardness seems to be of minor importance to accuracy. Lots of other things are more important. Fit is far more important than hardness.

 

1) Especially if your 30-30 rifle is a Marlin micro-groove, “hard cast” is a dirty word. At the speeds where cast bullets work well in Marlin micro-groove barrels (below 1800 FPS) BHN 10-12 is as hard as needed;

2) Sizing. Whether Marlin micro-groove or another makers regular cut rifling, .002” over groove depth is the rule of thumb for cast. If pushing them at 1200 FPS or more, gas checks are almost certainly needed.

3) 115 grs and 120 grs bullets are short. If you have a capacious chamber or long freebore in your rifle, you may be launching hard, ill-sized bullets crankwise into the lands. Ye Olde Thutty-Thutty likes 150 - 170 grs bullets seated long enough that they will cycle through the action but chamber not far off the lands.

Enjoy! With that nice long neck, the 30-30 caseis great for cast bullets.

 

First thing I learned after I messed up shooting lead bullets was to buy them at least .001 larger in diameter so that in can engage the lands and grooves better. Very high velocities and an undersized bullet could end up with you leading the barrel as the bullet may be shaved in tiny amounts as it is pushed through the rifling.

 

I have found that bullets cast from straight clip on wheel weights are hard enough for rifle and hand gun work. I have added tin in the past to "sweeten" the alloy, but see little reason to do this. I also am a gas check advocate. You can push a rifle bullet fairly fast if sized correctly and of the right alloy composition. I can shoot my rifle bullets with accuracy and no leading.

I do shoot some without gas checks in mild loadings, still with no leading. I have a nice little .314 SWC 115gr. mold that I shoot from my 2 groove Enfield over 8gr. Unique that has minimal recoil and great acccuracy. In the bolt action 30-30 it does well sized to .310 over 8gr. Unique.

 

There really is no reason to shoot light cast bullets in the .30-30. The idea behind light bullets is increased velocity -- velocity beyond what cast bullets will stand. A longer, heavier bullet, gas-checked and powder coated should solve all your problems.

 

Depends on your goals. I shoot light bullets in a 3006 because I want a minimal recoil load to practice with. Horses for courses.

 

I get accuracy equivalent to factory ammo with cast bullets in microgroove barrels. Lead hardness is irrelevant. Near pure to Linotype.
Secret is .311” bullets. Adequate lube, and gaschecks for greater than 1,500fps. .360” for .35rem.
(Spoiler: my .30Carbine adores a powder coated 93gr .312” at 2,100fps, no gc. Like new Underwood barrel.)
For decades, conventional wisdom (per Lyman) was bore diameter. Now we know it’s THROAT diameter. If a .30cal Cast bullet will Easily chamber, it’s not too big. Big is good!

A hard, undersized bullet is BAD, irregardless of rifling type Or how hard.
For advanced discussions on cast bullets, go over to gunloads.com/castboolits.