Cast boolit trouble shooting

[JCSC]

Hey y’all. First post on the forum and a brand new caster.

I have been working on some Lee 356 truncated cone tumble lube bullets and a Taurus 9mm G2C.

No issues getting nice looking projectiles from reclaimed range scrap and these were powder coated and sized to .356. 1/5 tumbled and I learned about slugging the bore.

Bore tested at .349 / .358 grooves, so I worked another batch of rounds as cast and powder coated and left unsized at .358/.359. These proved to be considerably more accurate, but out of 30 rounds I had 3 tumblers and about 3 yawing a bit. This was at roughly 20’, so I not great stability.

I have been running HP38 with these and charges up to 4.0 @ 1.06 coal.


What are the next steps for getting more stability?

I want to note that I had no leading issues from the first batch I fired. The second larger batch is still needs assessed.

[Dusty Bannister]

It is possible that your method of crimping is a bit too much and reducing the bullet diameter as you taper crimp. That is probably the most likely problem now that your bullets are close to the groove diameter. Most often the suggestion is to pull a bullet from a loaded round and measure with a micrometer to determine the actual diameter after seating and crimping.

[mnewcomb59]

With a bullet that low in hardness, that much oversized, I can pretty much guarantee the base driving band is getting swaged down to .353-.354 when you seat the bullet. 9mm cases are pretty thick and usually the bullet squeezes down in size before the case stretches to accept it. Pull a round and measure the bottom driving band on the bullet. You can get a 38 S&W expander for your powder die if you are using Lee dies. This expander will be about 2 thou fatter than the 9mm expander, and it will go deeper in the case.

[Rapier]

Powder Coat and then size, using case lube. Try sizing to .358 Then switch to a taper crimp die as a separate station, seat and then crimp, do not do both as one station, and just straighten the case with cast. Use the barrel for the "plunk" test. Use the accuracy load for 231, same, same as HP-38. Use a good, very hard, water dropped alloy.

If you can not get accuracy, fire lap, with valve grinding compound for lube, unsized, 5 rounds, then clean.

My Taurus 92 did not shoot like I wanted, out of the gate, so I converted it to a tapered bushing comp gun, with a re-cut slide to a full round hole. With competition sights and a single action set screw in the bar. It ran 1/4" groups with 160 grain RN cast. Yes, it was a major gun, when it was legal.

[JCSC]

Thank you all for the suggestions. I will do some more investigation in the seating and crimping side of things.

[gwpercle]

Tip - 9mm case needs to be expanded to take the soft cast boolit , if not the case sizes down the 9mm boolit when you seat it and you end up shooting an undersized boolit ... undersized = the erratic flight of some . I use a case expander from NOE along with the body of a Lee Universal Neck Flaring Tool .
Most regular die sets are made for loadinf hard jacketed bullets not soft cast so you have to buy an expanding tool . The only one used to be Lyman M-Die expander . The Lee Universal only flares the neck ... the NOE insert truely expands the neck in a two step profile for properly seating the cast boolit .
Tip #2 - after proper neck expanding ... seat your boolit in one step ... then taper crimp the boolit in a second step . This helps things a lot .

I solved my seating/sizing down problem with a NOE neck expanding plug and a NOE mould that cast a Gas Check truncated cone 124 gr. 9mm boolit ... that gas check fixed all the seating problems and I can drive them over 1200 fps with no leading . My alloy is soft also and I don't powder coat ...the gas check helped a lot .
The 9mm Luger is a stinker with cast ...not easy to over come it's particulars but work each detail out and soon you have it by the tail on a downhill drag !

Welcome to the addiction , always good to have a new member .

Gary

[ACC]

Hey y’all. First post on the forum and a brand new caster.

I have been working on some Lee 356 truncated cone tumble lube bullets and a Taurus 9mm G2C.

No issues getting nice looking projectiles from reclaimed range scrap and these were powder coated and sized to .356. 1/5 tumbled and I learned about slugging the bore.

Bore tested at .349 / .358 grooves, so I worked another batch of rounds as cast and powder coated and left unsized at .358/.359. These proved to be considerably more accurate, but out of 30 rounds I had 3 tumblers and about 3 yawing a bit. This was at roughly 20’, so I not great stability.

I have been running HP38 with these and charges up to 4.0 @ 1.06 coal.


What are the next steps for getting more stability?

I want to note that I had no leading issues from the first batch I fired. The second larger batch is still needs assessed.

I have the same gun and I HAD the same problem. The G2C has some pretty shallow rifling and although I don't have that exact bullet mold(I have the regular one with one grove) What I found out was that The bullet was being stripped because the mix of lead I was using was too soft. There are two ways to fix this. One, harden up your alloy, two reduce your load.

Your alloy is probably 10-11 in hardness so you may want to add a little antimony, or lower your load. What I did was lower my load a bit and it still operated the action but no more key holes. Hope this helps. I like my G2C.

ACC

[gwpercle]

You are going to get all kinds of conflicting advice ... what worked in one gun may not work for beans in another . The load must be hot/heavy enough to work the action .
Then there is a balancing act between enough velocity to stabilize the spin with enough hardness to hold the rifling .
The alloy I use is on the soft side , 50% soft lead (range scrap and lead sheathing) + 50% clip on wheel weights . Air cooled ... this hardness works ... I don't powder coat them but lube/size with Lithium-beeswax lube and use a gas check .
Maybe someone can tell you if powder coated range scrap is hard enough to use in your pistol .
No sense trying to get a boolit to shoot if it's just too soft to grip the rifling .
I had first thought sizing down when seating was "the" problem but it might be boolit hardness .

Anyone of you powder coaters got any input on powder coated range scrap with the Lee Tumble Lube design , he may be using TL356-124-TC (he didn't specify) , I don't have any Tumble Lube designs so I'm clueless on those . What do you think ... hard enough ?
Gary

[JCSC]

Tip - 9mm case needs to be expanded to take the soft cast boolit , if not the case sizes down the 9mm boolit when you seat it and you end up shooting an undersized boolit ... undersized = the erratic flight of some . I use a case expander from NOE along with the body of a Lee Universal Neck Flaring Tool .
Most regular die sets are made for loadinf hard jacketed bullets not soft cast so you have to buy an expanding tool . The only one used to be Lyman M-Die expander . The Lee Universal only flares the neck ... the NOE insert truely expands the neck in a two step profile for properly seating the cast boolit .
Tip #2 - after proper neck expanding ... seat your boolit in one step ... then taper crimp the boolit in a second step . This helps things a lot .

I solved my seating/sizing down problem with a NOE neck expanding plug and a NOE mould that cast a Gas Check truncated cone 124 gr. 9mm boolit ... that gas check fixed all the seating problems and I can drive them over 1200 fps with no leading . My alloy is soft also and I don't powder coat ...the gas check helped a lot .
The 9mm Luger is a stinker with cast ...not easy to over come it's particulars but work each detail out and soon you have it by the tail on a downhill drag !

Welcome to the addiction , always good to have a new member .

Gary


Thanks Gary! Great site and a brand new hobby for me.

I have reloaded for a few years but engrossed myself in the art and the next logical progression was to understand how, why, what makes a bullet tick.

Initial goal was to load my wife a bunch of cheap 9mm ammo (that was pink) and have it perform decent at the indoor range and tinging some outdoor steel.

Very cool hobby and hopefully I can start playing around with the 45 soon. I travel a lot and have found that wheel weights are tough to find, but it is fairly easy to gather 10-15# at the range and repurpose it.

I appreciate the advice. Thanks!

[JCSC]

I have the same gun and I HAD the same problem. The G2C has some pretty shallow rifling and although I don't have that exact bullet mold(I have the regular one with one grove) What I found out was that The bullet was being stripped because the mix of lead I was using was too soft. There are two ways to fix this. One, harden up your alloy, two reduce your load.

Your alloy is probably 10-11 in hardness so you may want to add a little antimony, or lower your load. What I did was lower my load a bit and it still operated the action but no more key holes. Hope this helps. I like my G2C.

ACC
Thanks ACC. I tried as low as 3.8, but similar results. This may boil down to getting some antimony to add for each 10# batch.

[JCSC]

Y’all were right on the money. I pull a seated and a seated / crimped bullet.

Both are sitting at .3552 / .3555.

I need to find a different expander at this point.

[super6]

Do not give up on hardening your range scrap! a bit of lino, mono type will work wonders! Both have tin and antimony.

[MT Gianni]

Long before powder coating I had tumbling results with the Lee 124 gr TC TL bullet. Switching to another design fixed my problems. No difference in load, alloy or weight, just a different type of mold.

[JCSC]

Thanks MT. I’m gonna stick this one out for a bit. I ordered a 6 round mold and 38 spl expander, so hoping CAn keep the driving band closer to .358. I haven’t had an leading issues, so can’t see that getting worse ( or would hope it doesn’t)

I kinda have a grudge now and I’m learning as I go.

[JCSC]

Quick update.

I ordered a 38 special die set. It’s too long to hit a 9mm case.

I called rcbs and they asked the barrel dims and what size stem I wanted. They are sending in free of charge.

Hopefully this works for the project and once again great service from rcbs.