Cast bullets in 45 AR / ACP

[Master Carper]

From left to right -

RCBS 45-300 FN GC / Red

Lee 452-255 RF / Red

Lee TL 452-230 TC / Green

Lee TL 452-230 TC / Red

All bullets were shot in 3-shot groups @ 50 yards from a solid shooting bench.

Bullet velocities were as follows:

Lee TL 452-230 TC -

750 fps.

800 fps.

850 fps.

900 fps.

950 fps.

Lee 452-255 RF -

700 fps.

800 fps.

900 fps.

1,000 fps

RCBS 45-300 FN

600 fps.

700 fps.

800 fps.

Now my question! Why will my gun shoot so accurately with jacketed bullets, but will NOT accurately shoot cast bullets?!?!

2 different jacketed bullets and weights shot like this at 125 yards:

The bore/groove diameter on my barrel is .4420/.4510 and the bore was lead lapped before the chamber or crown was cut, so there are no rough spots in the bore.

Best cast bullet accuracy was 3" @ 50 yards, with the average accuracy being 5" or more @ 50 yards!

Bullet diameters tested for the 3 bullets shown above was .450 .451 .452 and .453

With accuracy being so bad with the cast bullets, I thought something may have came loose on the gun, I decided to shoot my last three SLEDGE HAMMER loads before leaving the range, so everything was exactly the same as what it was when testing the cast bullets. 3-shots @ 50 yards were measured outside to outside, minus bullet diameter, for a group size of .110" which is just under an 1/8" at .125

I repeat my question - Why will my gun shoot so accurately with jacketed bullets, but will NOT accurately shoot cast bullets?!?!

 

[dlbleak]

Bunch of cast boolit gurus on here. I’m no where near as experienced as most but my first thought would to start playing around with crimp or even no crimp since it’s a single shot. Or maybe not enough twist for the heavy bullets? This from the Lyman 45th

 

[swampratt]

Agree DO NOT crimp cast bullets.
Bell the mouth slightly to start the bullet into the case and I run some of my cast loads through a Lee factory carbide crimp die.. but I do not crimp .. just run them through the carbide ring to remove the flare.

BUT some of my Carbide crimp dies the ring is too small of diameter for the case thickness and the bullet diameter.

Saying that IF I use the carbide ring it will swage the lead bullet down in size inside the case.
If I need .452" some thick wall cases will leave me with a bullet that is .449" inside the case.

Pull a loaded cast bullet and measure the diameter.
Too hard of an alloy will not bump up into the rifling grooves well and can shoot poorly.
Gasses blow past the bullet that is not seated in the lands well.
These gasses can strip the lead off the bullet..Yours are Powder Coated and should be a little higher heat tolerant.

I like to cast a bullet that is a bit soft if I powder coat them.. not pure lead soft just a tick above it.
Wheel weight clip on type is too hard.
Unless it is 357 mag gas checked in the 1300+ fps area or rifle loads 1400-2100fps gas checked and then it works well for me with hard wheel weight lead.

I mix 1/3 wheel weight to 2/3 soft lead for pistol stuff.
Slow 30 cal mouse fart rifle loads pure soft lead powder coated works very well.

Fast powders for pistols to get the soft lead to bump up quick. Red Dot for my slow rifle loads 600-1400 fps 30 cal.


Questions: Are those velocities posted above made with different amounts of powder?
Or is the velocity gaining as you shoot?
If it was mine I would also try the 200gr cast bullets if you have any.
I would also try 231 or HP38 powder and I would try Bullseye powder.

My 45 Colt did not like the heavies..I have that Lee 452-255 and the colt did not care for it.
It loved the 200gr TL lee best..Go figure.
My 45 acp pistols love that same bullet 200gr TL.

Pull a loaded bullet check diameter of pulled bullet.

Have you recovered a shot bullet..Are there rifling grooves in the sides?
If it is all scratched up and no grooves it is sliding and not engaging the grooves.
But that will be easily seen as the bullet will hit the target sideways.

2400 powder I would not use

 

[Master Carper]

dlbleak,

I appreciate you taking the time to post that - thank you!

I did try everything stated, but to no avail!

I also seated the bullets to jam the rifling, and seated them back away from from the rifling at .010 .020 and .030 and nothing I did made them accurate enough that I would hunt with them.

I have a 4 die set that works wonderfully for jacketed bullets, but trying to get cast bullets to shoot has been a nightmare!

 

[EKing]

Just spitballing here, but your velocities are much different for the two bullet types; your jacketed bullets are moving at 1200 fps and your cast bullets are much slower. With the powder coating, you can push those PC cast bullets faster than a regular cast bullet.

 

[Master Carper]

swampratt,

your information is much appreciated, thank you!

Trying to follow your post with what you do.

I do NOT crimp cast bullets. Those in the pictured had a light crimp but were dummy rounds for best seating depths, making it easier and faster to the bullet seating depth for every bullet that I shoot.

Dies are set to remove the case mouth flare and no more.

I pulled 3 bullets, and their diameter did NOT change from what they were before loading.

Bullets are harder than pure lead, but definitely softer than wheen weights.

I have not shot any of the faster burn rate powders because of the "noise level". Faster powders are definitely louder!

Velocities listed are different powder charges.

I do not want to go lighter in weight, but with a 1-16" twist rate barrel, it should handle the listed bullets without issue. My SLEDGE HAMMER load is loaded with Speer's 300 gr. Uni-Corp Soft Point and it is VERY accurate!

Since I am shooting a rifle, I am trying to stay away from the fast pistol powders.

There ARE rifling grooves in the sides of the bullets.

I pushed one of the Lee bullets through the bore after sizing and coating, and it shows the rifling from end to end, and uniformly around it's circumference. The top and bottom driving bands are .451 and after the bullet was pushed through the bore, the rifling marks opposite each other are .441 as shown in the pictures.

Before, loaded and pulled - all are the same exact diameter.

 

[Master Carper]

This post goes with the one above.

I may see if I can get a .452 diameter bullet through the bore without damage, and see if it contacts more than just the rifling.

Cast bullets - do you want them to be "bore riders" or not?

 

[OKCHunter]

This post goes with the one above.

I may see if I can get a .452 diameter bullet through the bore without damage, and see if it contacts more than just the rifling.

Cast bullets - do you want them to be "bore riders" or not?

I'd try .452 since your barrel measures .451. I'm no casting expert but have read you want the cast bullet to be .001 above the measurement. That's the measurement I attempt in my pistols. This was for cast and lubed bullets and not for powder coated, however.

 

[Master Carper]

Just spitballing here, but your velocities are much different for the two bullet types; your jacketed bullets are moving at 1200 fps and your cast bullets are much slower. With the powder coating, you can push those PC cast bullets faster than a regular cast bullet.

Very true, but I am loading more for accuracy than velocity. With the cast bullets, the faster I pushed them, the worse they shot!

 

[Master Carper]

I'd try .452 since your barrel measures .451. I'm no casting expert but have read you want the cast bullet to be .001 above the measurement. That's the measurement I attempt in my pistols. This was for cast and lubed bullets and not for powder coated, however.

I did. I tried .450 .451 .452 and .453 and all were disappointing!