9mm leading and tumbling - help!

[Phred]

Howdy ‘all,

Just recently a bunch of us have run into some problems. We use commercially cast 9mm bullets for IPSC competition. Mostly minor power factor plus a small margin – 130pf for example 125gr bullet traveling at 1,040 fps or 135gr at 950. Up until recently both 125gr and 135gr loads were accurate, absolutely no, and I mean NO, leading in both conventional rifling as well as polygonal. Then our supplier of nearly 10 years went and died. I’m sure he is as unhappy about that as we are..

Switching to/trying _several_ (four) other sources of supposedly “hard lead”, coated bullets we’ve had nothing but problems. Using our exact same successful loads (same powder and weight, same OAL, same crimp) of nearly ten years with the new bullets:

. First, chronic leading. And I mean chronic – the kind of leading that requires a small to medium yield thermonuclear bomb to remove from the bore. Not just strips of lead, not just leading at the throat, but universal welded-on lead throughout the barrel. Thirty minutes of hard work to remove.

. Accuracy up the spout – tumbling at 5 yards, square holes in the targets.

The new bullets measure the same as the old, have _super_ coatings supposedly guaranteed to prevent any leading just like the old and are supposedly (we don’t have any way to actually measure hardness) “hard” lead like the old.

Now here’s the bit that has us rethinking everything. If we change our tried and tested loads to use a slower burning powder, producing the exact same muzzle velocity as the old faster burning powder loads, the problems with the new bullets largely disappear.

So, same muzzle velocity with fast burning powder = leading, tumbling
same muzzle velocity with slower burning powder – much less leading and improved accuracy.

The problem is that experiments over the last ten years, and indeed is the case now, show that slow(er) burning powders in 9mm have always been difficult to achieve really consistent velocities (small standard deviations). Old load old bullets fast(er) powder we consistently saw sd’s of 6. Now with new bullets, slow(er) powder it’s 50-60!

Any insights, help, pointers in any direction (we are basically lost) would be very much appreciated. What in the world is going on?

TIA for your time.

Phred

[44man]

Gets one to lose hair! I see only 2 things since everything else measures the same.
The "coating", whatever it is was put on for shipping and handling instead of shooting. Do you have any idea what it is?
Second would be a cheap alloy with the coating used to cover it up. The things might be dead soft with a hard coating on them.
Indications you give show extreme obturation, mangling of the boolit.

[Shepherd2]

I would measure the diameter of the cast bullets you are using and then slug the barrel of the gun you are using them in. You will probably find that the bullets are sized at .356 and the barrel is .357 or even .358. If that is the case you are shooting unsized bullets which would explain the keyholing and some of the leading.

When I first got a 9mm I cast some bullets and sized them at .356 and got poor results. I slugged the barrel and found my bullets were undersized fr my barrel. Increasing the diameter of the bullet solved the problem.

If you don't cast and resize your own you may have a problem finding the correct diameter bullets. A custom caster might be able to help you. I am also wondering what this "super coating" is. There is no substitute for a good bullet lube.

[bruce drake]

Lube!

Sounds like you need a good coating of Lee Liquid Alox rolled over those bullets or a dab of 50/50 Alox thrown into the grooves with a sizer.

Your special coating is obviously failing and your bullet velocity is easily handled by simple lubes.

You report the bullets are the same diameter so that leaves it to the hardness of the lead and lubricant. You speeds again are not so hot that a soft alloy should not be affected in shooting so that brings it back to lube failure in my opinion.

Lube them with a quality lube and leave that spray-on moly stuff the guy puts on them alone.

I've never seen a 9mm Bullet mold with a gascheck design so I believe you are left with the lube answer. I fire 230gr lead bullets in my 45ACP all the time without leading at 8-900fps without major issues using simple Lyman 50/50 and Lee Liquid Alox.

Bruce

[GabbyM]

Sounds like you all are stuck with a pile of bullets that won't shoot.

Question first. Do these bullets have a lube grove filled with lube?
Since it about sounds like you're shooting swagged bullets coated with wax.

If they are hard cast and lubed with some paraffin hard lube in a grease grove. You run into a limbo state with the 9mm at around 1,000 fps. Where you don't have enough pressure to push the hard lube out of the groves but enough to cause leading. The simple cure is to use a softer lube that will work at those pressure loads. You've changed your load with slower powder and found a spot where the bullets don't lead even without lube. You may be able to reduce velocity to 800fps with the fast powder and achieve the same results. Problem is of course your slides would not cycle and your steel plates may not fall.
Another rout would be to load them up to full pressure of the 9mm. With the hope of getting that hard lube to flow out from the groves. That will only work if your bullets are about BHN 13 or harder to withstand the velocity and the lube has any hope of working at all. If they are soft lead then low velocity or as you've found the low pressure load is what you're stuck with.
Yet another option. If your bullets are hard enough and it's just a lube problem. You may be able to cure them with a tumble lube like Lee Liquid Alox. (As stated in previouse post.)

Lastly you might call the vendor and explain his bullets don't shoot at the velocity you are loading. Hoping for an exchange. Politely avoiding telling them their bullets are no good.

[w30wcf]

Phred,
Sorry to hear of your troubles. Based on the fact that slower burning powder is giving good results with the new bullets, I'm thinking that the root cause is bullet hardness, with the old ones being of a lower bhn (possibly w.w) than the new (probably equal to Lyman NO. 2 or a bit more in hardness).

If you still have an older bullet, place it base down on the cement floor and hit it on the nose with a hammer from about 6" to 8" high. Do the same with a new bullet and see if there is a difference in the amount of upset.

Are the bullet bases on both bullets flat, or is there a difference (chamfer on the new bullet ?)

w30wcf

[Bass Ackward]

Yep. This is a lesson in how hardness and lube interact. In an ideal situation lead obturates out to seal, preventing lube from being blown off. Sounds like that is happening. The lube needs a film strength to lubricate and prevent the galling that you observe.

You haven't found the right combination yet. So the answer is to keep trying. We have several members here that provide this service that you can check.

[runfiverun]

i would hazard a guess that your "new boolits" are harder..
and your lube is failing.
i would tumble-lube some and try them.
that is where i would start [not really i cast my own] but if i were you that is where i would start.

[Ricochet]

If you still have an older bullet, place it base down on the cement floor and hit it on the nose with a hammer from about 6" to 8" high. Do the same with a new bullet and see if there is a difference in the amount of upset.Someone else who tests hardness as scientifically as I do!

[KYCaster]

Hi Phred, welcome to the cast boolit forum. I'm Jerry. I'm a commercial caster. You're probably wondering why I'm sitting here in this plexiglass booth. It's so that when these other die-hard booliteers start throwing sticks and stones and over-ripe fruit at me, I won't get hit. [smilie=1:

It's obvious from your post that you've already learned that one of the constants about cast boolits is that there are very few constants. The product you get from one source will most likely be different, in some way, from every other source. Most companys make a useable product or they wouldn't stay in business very long.
One of the most difficult things I do is try to convince my customers that their feed back is essential to my success. If the product isn't right, complain.

My first question...When you started buying boolits from your original supplier, did the first load you try work well, or did it take you a while to settle on a load that you eventually adopted? If the latter, then you should expect to go through a similar process with your new supplier. (I'm sure you understand that cause you said you worked up a load with a slower powder.)

An observation...You said," Old load old bullets fast(er) powder we consistently saw sd’s of 6. Now with new bullets, slow(er) powder it’s 50-60!"... It's been my experience that when you have little tiny, single didgit SD's, you're working at the very limit of the powder's useable pressure range, and any adverse change in conditions (higher ambient temp., boolit telescoping on feed ramp) could cause an over pressure situation. I always recommend useing the slowest powder that gives acceptable results. SD of 100 is not necessarily disasterous and I consider anything below 25 as great...I doubt that your 50-60 SD is causing any great problem. Tiny groups are great for braggin' rights, but for USPSA/IDPA, they're unneccessary. I strive for 2in. at 25yds., but if you can consistently make head shots (6"x6") at 25yds. off the bench, you really don't need any more than that. For stand-on-yer-hind-legs-and-shoot-like-a-man bullseye, then squeeze every last fraction of an inch out of your loads...but then, you wouldn't be shooting a 9mm for that, would you? For the action games, reliability trumps accuracy every time.

Second (and third) question....Have you talked to the "(four) other sources of supposedly “hard lead”, coated bullets..." about your problems? Have they suggested any solutions?

Another observation...There are commercial casters who will custom design boolits and alloys to satisfy almost any customer's needs. There are others who will tell you that their product will do everything and if you have problems, its your fault. Most of us are somewhere in between. When you say, "a bunch of us have run into some problems...", I assume that you're pooling your orders to get quantity discounts, so economy is a consideration in your purchase. If you deal with a "custom" caster, I doubt that you will get any quantity discounts, and delivery of large orders (10,000 or so) may be a problem. Those of us who deal in larger volumn depend on repeat customers for most of our sales, and for every design that we offer, we have dozens (if not hundreds) of shooters who are completely satisfied with our products. I know that I can't please everyone, but I (and most others I know of) will do everything I can to help you work up a suitable load using my product, but other than sizing to a different diameter, there is nothing I (or any other high volumn caster) can do to the product that will make it a better fit to your application.

Another observation...Lots of companies now offer some kind of "Wonder Coating" for their lead boolits. I have personally seen very few (actually only one) that provide any significant improvement over the conventionally lubed cast lead boolit.

Conclusion...As I see it, you have three options available...Three, find somebody who can duplicate your original supplier's product. Two, find somebody else's product that gives you acceptable results. Or....the No. ONE OPTION....Get your buddies together, start hangin' out here and learn to cast your own custom made boolits!!!! :drinks:

Hope I've been of some help.
Jerry

[HeavyMetal]

I'm thinkin this "wonder" lube that your suppliers are using is the cause of the leading. The fact that they suggested you go to a slower powder confirms you ain't the only one's that have said something!

If I was in your position I'd do two things: first I'd contact all the suppliers and tell them, again, what the issue is and I would firmly tell them it was the fault of the "wonder" lube. I would then ask for Boolits lubed in a conventional manner. One out of four should be able to see the fact that he will get repeat business, and maybe more, if he comply's with your request. Advise him you and your friends are not the only shooters with this issue and you'd be more than happy to add "Word of Mouth" advertising at your shoots!

The second thing? Find a supplier that would provide what I wanted or start doing it myself! I'd also get me a Lee hardness tester just to keep everyone "honest" about the quality of the product they sell!

[JIMinPHX]

Hi Phred & welcome to the board. I’d like to ask you a few questions before giving you my personal opinion on the possible causes of your trouble.

Do you have any of the original “good” bullets left as samples?

If not, do you remember what color the lube on the “good” bullets was?

Were the original bullets smooth on the outside or did they have a criss-cross pattern?

Are the new bullets the same general design as the old ones (flat base, bevel base, round nose, swc, same # of lube grooves, etc)?

Does the barrel lead up badly on the very first shot or does it take a while to get bad?

Does the whole length of the barrel lead up on the first shot or does it start in one area & then expand from there as you continue shooting?

How are you cleaning your barrel (solvent, bronze brushes, nylon brushes, lewis lead remover, DC-voltage & electrolyte, lead-away cloth)?

Are you pretty sure that you are getting down to a perfectly clean barrel before you start?

Do you have a soft backstop that you can shoot at so that you can recover a fired bullet in good condition & inspect it for signs of gas blow-by?