Cast accuracy in 300 BLK

[reloader64]

Yes, mine is 1/8 twist.
I lubed first to keep the lube gooves from disapearing when I sized it down.
I had recovered some shot bullets from the berm and they didn't have very much engraved rifling on them.
I 'beagled' the mold and recovered some of those bullets and they had a longer section that was engraved.

I heated the lube until liquid, then painted the lube grooves.
Once sized,the excess lube stayed at the mouth of the sizing die, not on the base of the bullet.

[Gunnut 45/454]

reloader64
Sounds like your sizing a bullet too small. Correctly cast you should never remove the lube grooves during sizing. What mold /sizing die. I use lee molds and size die. Even sizing down the 155r made for the SKS .312" to .309" my lube groves are very much intact.

[popper]

Don't shoot subs but get a cast powder coated 145gr PB to 1800 with MOA @ 100 if I do my part. Above that needs a GC. 1:10 18" carbine. AR10 is feeling lonely.

[Gyrkin]

I get inch and a half groups at 100 yards with these: http://leatherheadbullets.com/30-cal-198-grn-fp-500-ct/

[destrux]

I cast the Lee 230 gr for BO
I was casting , Tumble lubing and shooting. No good accuracy.

I took some aluminum 'duct tape' and placed a piece on the mold halves to make bigger bullets, lubed them with speed green and sized down to .310

last week I worked up a load to cycle my AR (16", carbine gas,) of 10.5gr of RL7 cycles great and Locks open with best accuracy being .75"@50 yrds.

Adjusted dope on scope and sent 3 rounds down 200yrds for 3" group.

I did check weight and discarded any out of my Perimeters of 231.5gr +-.5gr (231-232gr)
Ended up discarding 15 of the 300 I cast for being lite or heavy.

My lee mold was casting the front driving band .306 progressing to .309 by the back band.
Now it cast them all over .310 and I size down.
I think the increased bearing surface for the lands to grab helped.

That's interesting. I wonder though if a portion of the accuracy gain was due to the bore riding section of the bullet being large enough with your widened bullets for the front of the bullet to engrave the rifling when chambered and cause pressure to go up and give more consistent burn. 10.5gr of RL7 was not a very consistent burner for me (among other powders) with the Lee bullet and I attribute that to the Lee having a low initiation pressure to get it into the rifling. The same load of RL7 was a consistent burner with jacketed Hornady 225gr for me.

My method for getting the Lee bullet up in diameter and to provide wider bands after sizing was to powder coat them thicker before sizing down to .309".

I can't claim stellar accuracy but I went from horrible useless groups when I started off casting these (so poor some were off the paper) to consistent 3" groups at 100yd. I'm not shooting for groups with this rifle though.

I find all of these long bullets need a hot plate to keep the mold up to temp, and require a slow pour to avoid air bubbles in the bullets. Air bubbles were a recurring problem I had with these and were absolutely killing my accuracy.

[afshirt]

I get inch and a half groups at 100 yards with these: http://leatherheadbullets.com/30-cal-198-grn-fp-500-ct/

How are you loading these? My leatherheads through my rem 700 blackout with 10x scope is lucky to hit a 6 inch gong at 100.

I am using 9.5g of IMR4227

[Gyrkin]

How are you loading these?

198 g Leatherhead bullets
11.5 g Norma 200
CCI 41 primers
COAL 1.80"
case necks belled and expanded with RCBS .311 Neck expander die
Moderate crimp (more than just taking the bell out)

My loads with their 240 g bullets don't group as well. Maybe with a little tweaking I will be able to get them tighter, but for now about 4 inches is the best I've gotten.

[afshirt]

How are you loading these?

198 g Leatherhead bullets
11.5 g Norma 200
CCI 41 primers
COAL 1.80"
case necks belled and expanded with RCBS .311 Neck expander die
Moderate crimp (more than just taking the bell out)

My loads with their 240 g bullets don't group as well. Maybe with a little tweaking I will be able to get them tighter, but for now about 4 inches is the best I've gotten.

The 240s are what I am using. Ok I dont feel as bad now that I am not the only one.

[popper]

Pushed the PB 145 to 2100 so far, No loss in accuracy.

['Borg]

If I single-shoot my 200 gr Lyman, PC'd, I get about 1-1/2 @ 100.
My barrel has a problem that it shaves the bullet and leaves a ring of lead in the throat So I have to remove after every shot.
I haven't done any testing since I discovered the ring by ejecting a live round that had chambered after the first shot,
it removed the ring.
I may have to try a different boolit to see if it occurs again, then I will contact Wilson and see if they can figure it out.
It really is a pain to have to eject every second rd to remove the ring in an AR.