Got some range work to do with the 45-70

bpost

I was shooting some 405 grain cast loads with 35 grains of IMR4198 at 100 yards today.

After using one target to get it close to the black I started to shoot for group. One hit the 10 ring at 3 o'clock the next shot hit 4" high left, the next was 6 o'clock low 5" out the next hit the edge of the one in the 10 ring. Several other shots printed in a pattern not a group but 5 more went into the 10 ring in a nice cluster.

I need to figure out why the flyers are happening they are 50% of the shots. The barrel is the new MGM heavy contour with a 14 twist.

Got any ideas on where to start?

toad67

Commercial, or home cast boolits?

bpost

Home cast out of wheel weights

navc130

There was an interesting article in Muzzle Blasts a few years ago about voids in cast ROUND BALLS that caused flyers. The solution was to run the lead in the mold until it overflowed, i.e., "packing" the mold. The theory was that too rapid cooling caused the void. Not sure if it applied to conical bullets.

charliemeyer007

What lube and what are they sized to compared to your barrel.
I like the 50/50 Beeswax/Alox fill all the groves, the plastic stuff that needs heated to use like Rooster Red is crap.

Are you using a bottom drop pot or a ladle. Stir and flux the bottom drop pot often to keep the alloy mixed. Press the spru against the pot nipple so the weight of the pot full of lead is injecting the lead. Pour the whole ladle full - gives more molten time to let the voids out.

My Lyman book says the most accurate load for the 405gr. 457193 was their starting load of 40.0 of IMR-4198. Rem cases Rem 9 1/2 sized .458 in a .457 barrel.

Seat bullet about 1/2 way, lower the ram - rotate case 180 degrees, finish seating the bullet. Make sure the case is inside champher, belled enough to allow the bullet to enter without shaving. A long tapered stem is way nicer than a short steep angle for belling.

Clean it with a good solvent like Shooters Choice (works on coppar and lead), look for lead on the patches - new barrels can lead easily. Shoot a box of 50 jacketed bullets to help iron it in, JB Bore Paste. Compare the group size to your cast.

hillbille

as other said, weigh the bullets, you may be surprised by the difference in each.

perry shooter

when I first started casting I did not get mold blocks hot enough and had voids have you tried weighing bullets you have made also base is more important than nose once I got 4 cavity mold blocks never had any problems some times even had to let them cool between pours when the were too hot dull outside finish they still shot fine use a soft lube not hard lube and try to get bullet .002 larger than bore

bpost

I use alox beeswax. I have not tried weighing them and will do so. Since the rifle is a single shot I will load them a bit longer to see if the jump to the rifling is causing issues. The cases are belled properly the bullets lightly roll crimped in the crimping grove.

From your suggestions I think I will start by weighing them to sort out ones with voids under the surface.

Hawk Carse

Bullet diameter vs groove diameter?
Bullet diameter vs throat diameter?

Is this a pistol length or rifle length Encore barrel? (I had to look up MGM barrels to see that it was a TC.)

Are you flip-flopping between cast and jacketed bullets?
Does the gun shoot store-bought bullets well?

A little tin will improve the casting of wheelweights, especially the junk lead they are using now.

I do not crimp bullets for a single shot, in fact I leave a little flare to center the case in the chamber.