Poor 9mm Cast bullet accuracy

Assuming you have slugged the bore and all that sizing jazz?

If yes,
look up pat marlins gas check maker. He sells a setup to make PLAIN base gas checks from pop cans.

Works wonders. 9mm is always a pain for me. This solved it.

9mm is a challenge. you can use the search function to find my saga of trying to get lead to work. (moderate success) About half the reloaders seem to have no problems with lead and 9, and about half seem to struggle. Maybe it is gun dependent, I don't know. Maybe 9's have shallower rifling. I know it is a high pressure round. Have yo slugged your bore yet? 9mm barrels seem to have a lot of variation to them.

But a couple things that helped me out: Fat bullets. Fat as will chamber. I use a 38 bullet sized down to .358. 2) Pull a loaded round apart and check to see if it is getting swagged down by the case when you seat the bullet. mine were, and either a lyman M die, or (if you're using lee) a 38sw long expander plug helps prevent that. Fast powders like red dot and tightwad didn't work as well for me as slower ones like WSF and hs6 do.

I can cover 10 rounds at 10 yds with a golf ball using factory ammo, and I can get 10 rounds in about 3" with my best lead load so far, so I'm not an expert. But at least I"m not leading like no tomorrow and all my rounds are on paper with no keyholing. So I'm improving! My current load is something like 4.4 grains of wsf (don't quote me on that, it's late) under a 125grn lee bullet cast from wheel weight and sized .358.

Good luck.

The common theme seems to be slugging your barrel, but the other thing mentioned in your post was "hard cast".

Your alloy or the hardness of it could be the culprit in of itself. I would wager though it is a combination of the two, size and hardness.

My friend just started casting for his Sig. I don't have a Sig, or even a 9mm, but we talked through what he was starting on, both did a little research on what most are using with success, and came up with the alloy should be somewhere in the Lyman #2 range, and he is sizing to .357", as his barrel slugged at .355".

I would start off with an alloy hitting somewhere in the 12-14 BHN range personally. I don't think quenching in water would help, but it might. You can get leading from an overly hard bullet just as quick and easy as with an overly soft one. I can tell you that pushing a 10 BHN alloy up to around 1200fps is a no no in a 41 magnum, even though it worked well in my 44 and 45 Colt. It only took 4 rounds to thoroughly lead plate my bore.

I would ask if it was leading the worst at the chamber end or the muzzle end, but you mentioned the recovered bullets not looking like they even took to the lands. If from the chamber it is usually size, and the muzzle usually lube that is the culprit. Sometimes tumbling in Alox will also solve the issue, even if you already have them lubed with something else.

Just throwing out ideas here, hope it helps.

While I still don't have a 9mm Lead load that I am 100% satisfied with, I am getting closer.

First, size cannot be stressed enough. Some 9mm barrels can be way oversize. I have a 92fs that is .3585. This sounds far fetched but I actually size my bullets to .359 ( i will be getting a .360 die when lee is taking orders again) and have even fired un-sized bullets as large as .363. I didn't think there was any way they would chamber and/or cycle properly... but they do.

Second is lube. If your lube is not up to the task, you will see leading even if you size properly. I no longer tumble lube 9mms. I powder coat them. I have yet to find a tumble lube that is sufficient for 9mm. Powder coating has increased my FPS and has eliminated leading 100%.

Third, In spite of all the talk about alloy that is "Too hard", I have found that my cast 9mm bullets are getting more accurate as I move up in hardness. That is actually my current project. I have some 30/70 antimony lead ingots on order to alloy into my softer lead to get it up around 18-20BHN.

Last, there are a lot of casters/loaders who successfully load accurate and reliable 9mms and there are even more who think that they do but don't really achieve what I consider to be accurate loads. Some of the guys I shoot with feel that a 3" group at 12 yards is acceptable... I think that is unacceptable. I know other casters/loaders who are not happy until they are putting multiple bullets through the same hole. In any case, you know what your standards are and what you are willing to live it. I personally have found it to be the most challenging handgun caliber to achieve precision accuracy but it sure is fun trying to get there.

The attached picture is my unsized bullets at 45 feet (20 rounds). As you can see, I still have some room to go but they are a far cry from the 4-6" groups I was getting when I started this endeavor. No comments about the sight being off... of this I am aware

Leading was always apparent, and after recapturing some slugs or it always looked like the rifling just washed and never took to the slug.

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I had major issues with leading in 9mm until I figured out that I wasn't flaring the case enough and it was swaging down the bullet to .355. That tapered case can do it in a heartbeat.
Most bell dies don't go deep enough to prevent this. If you're using Lee dies you can order the flare ring (I'm sure that's not what its really called) that's made for .38 S&W and it will fix the problem. Assuming that is your problem.

Arkansas Paul said:

I had major issues with leading in 9mm until I figured out that I wasn't flaring the case enough and it was swaging down the bullet to .355. That tapered case can do it in a heartbeat.
Most bell dies don't go deep enough to prevent this. If you're using Lee dies you can order the flare ring (I'm sure that's not what its really called) that's made for .38 S&W and it will fix the problem. Assuming that is your problem.

Click to expand...

Is this what you are talking about?

http://leeprecision.com/pm-expan-plg-38sp.html

If so, I am going to order one myself. I have my flare just about maxed out for those oversize bullets.

modwerdna said:

ruger p89 and a walther p38 ... Poor 9mm Cast bullet accuracy ... have always failed at 9mm ... So this weekend I attempted to try every combination I could think of or find online using a 124 rn 115 rn, 115 tc , 105 tl. minimum to maximum charges of Bullseye, bluedot, Red dot, AA 7 ,231, etc. ... ALL of the 9mm "type" slugs failed miserably

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As others already posted, I think slugging the barrel would be a good idea and using lead bullets sized .001"+ to better seal the high pressure gas. If your barrels are oversized (say .356"+) and your lead bullets are sized at .356", then you will probably experience leading with poor accuracy.

And as you posted, there's a limit to going .001"+ the groove diameter of the barrel as the rounds may not fit the chamber. Are you using commercial or hand cast bullets?

Also, pull the bullets from loaded rounds and measure the bullet diameter to see if you are swaging them down during bullet seating/taper crimping.

I was able to get halfway decent results using 158 swctl (357 mag slug) loaded at 2.7 grns of Bullseye, But no where near as good as a fmj, and the loads barely cycled the guns (sometimes not).

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That maybe because lead .357 bullets are sized .358" and the larger sized bullets are sealing with the barrel better. Also, if your loads barely cycled the slide, your charges are not high enough and chamber pressures may not be high/consistent enough to produce consistent muzzle velocities/accuracy.

Leading was always apparent, and after recapturing some slugs or it always looked like the rifling just washed and never took to the slug.

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If the barrels are oversized for the bullets, then the lead bullets are "skidding" down the barrel instead of rotating with the rifling to stabilize during flight which would result in poor accuracy, tumbling/keyholing and leading of the barrrel.

Also I tried some of those rainier lead safe plated bullets, and 115 fmj at 4.7 Bullseye was not as accurate as ww fmj.
Any Thoughts?

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Many years back we did comparison pistol shootouts for accuracy (one of the match shooters was looking to do bullseye type match shooting) and we all brought our pistols to compare. If I recall, P89 was one of the more accurate factory semi-autos tested using FMJ reloads.

For me, I never got better than FMJ accuracy with plated 115 gr RN bullets using Bullseye powder (which is capable of very accurate loads) or other powders like Red Dot/W231 etc. You could try loading the bullets longer that will still fit the magazine and reliably feed/chamber from the magazine to reduce gas leakage for more consistent chamber pressures.

Another option is using hollow base bullets that will expand better to seal with the barrel. Winchester makes hollow base 115 gr FMJ bullets and I got good accuracy with Berry's plated hollow base 115 gr RN bullets as range tested in this thread - www.thehighroad.org/showthread.php?t=745656

Schwing, I'm the guy you disagree with. Of course, I hand load and cast for fun, too, as a hobby, and groups like these,





That was chase the hole, IIRC...

But again, groups like this,



...are perfectly fine for me, especially fired two hand standing position.
I've been loading 9mm cast for a few minutes, and all I can say is I size mine to .355 with the Lee push through sizer. They work quite well in all my 9mm CZ pistols, thought some fatter bullets need to be seated deeper to avoid the notorious "CZ short chamber". The Lee 124gr tumble lube bullet seems to be the all around performer, with its narrow ogive. Cast from certified bullet metal from SeaFab metals in Casa Grande, I get what I consider decent accuracy with no leading and excellent functioning. Loaded with 6.8 grains of Accurate Arms #7 it gives me 1100 FPS in a full size pistol.
I'd have to say the biggest clue you gave was the lack of rifling, and I would hazard a guess your barrels might be far more comfortable with a .358 sized cast bullet, and ramped up to a decent speed. That is ONLY a casual observation from a guy who will always consider himself a novice reloader and hand caster.

Some guns won't allow you to chamber bullets bit enough for their barrels... Try to find thinner brass...

I use range lead in 9mm (mostly 22's and J's cores) and starting or lower loads.
Hard lead will work if it is a good fit, soft will seal better; as you found out, oversized is an asset.

About the water thing, don't do it in your bathtub... I would try a drum with some net/mesh at the bottom, if available. Allow for splashes, leaks, and shocks under the drum: no tiles or hardwood floor .

Your guns probably have oversize bores. The 9mm is not hard to make accurate with cast bullets if you have a nice 1911 with a .355" bore.

BHN 18 or higher for full power loads in 9mm. Oven heat treading works also. Using the correct diameter as always.

Is this what you are talking about?

http://leeprecision.com/pm-expan-plg-38sp.html

Click to expand...

No. The 38spl plug is reportedly too long (on the top part that doesn't do the flaring) to fit in the 9mm die. You want the 38SW plug to put into your existing 9mm flaring die body. This one: http://leeprecision.com/pm-expan-plg-38-s-w.html

I use this, too. It fixed leading and accuracy problems. Since I got this, I have absolutely no leading in my 9mm Glock barrels (I inspect them regularly, clean them never), and bullets that tumbled after 20 yards are now just about as accurate as anything I've shot out to as far as I have shot them... over 100 yards.

Since you have no problems with any of your many other calibers, I would bet this will fix your issue.

I load full power 9mm with BHN guesstimated around 11-15. Straight WW lead that is softer than MBC 18BHN bullets. You definitely don't need BHN of 20 for 9mm. To me "full power" is just regular fuddy duddy max book loads with medium burn rate powders, though. I don't know what other people are talking about by "full power." If I go beyond max loads with cast 9mm, I run into the same ceiling as I do with jacketed bullets... problems with extraction. Maybe if I was using different powders, I would have a different result, though.

I have three P38 barrels, and all 3 are just under .358". I use .358" and .359" bullets. I use mostly wheelweight scrap, with a bit of Tin added, and drop bullets from the mold into water, so my bullets are HARD!

Beware: I also have a Browning HiPower of my father's that has similarly large grooves, but the chamber will not accept a cartridge loaded with a bullet over .356".

My Walther and Beretta barrels all like the Lee 125gr Cowboy bullet, with a mild load of 231.

NuJudge. How are you flaring your cases for the 359's? I bet this is why you need to make those bullets so hard.

Scwing, ditto. You have maxed out your flare but passed the expansion limit a long time ago if your flare die is typical. The base of the bullet is where you get accuracy. You might be getting tighter groups with harder bullets because those bullets are not deforming as much in your shallowly flared cases. Flaring the case mouth doesn't cut it. Cast bullet shooters who like accuracy will eventually discover Lyman M die or equivalent that will set the entire bullet seating area of brass to a mic or two under bullet diameter.

You do not need 20 BHN bullets to have good results in 9mm if you have the proper size and proper lubrication.
I'm getting good results with straight wheel weights, which is a hell of a lot softer than 20. I haven't tested it but I'm guessing its between 10 and 12.

Arkansas Paul said:

You do not need 20 BHN bullets to have good results in 9mm if you have the proper size and proper lubrication.
I'm getting good results with straight wheel weights, which is a hell of a lot softer than 20. I haven't tested it but I'm guessing its between 10 and 12.

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paul, what are you using as lube? I"ve always just used lee alox, but I hear there are good home made formulas.

GLOOB said:

No. The 38spl plug is reportedly too long (on the top part that doesn't do the flaring) to fit in the 9mm die.

Click to expand...

Actually too short to work. Look at these parts as having a fixed height, plug + case, the expanding part being irrelevant .
In other words, plugs have to be able to reach their cases.

paul, what are you using as lube? I"ve always just used lee alox, but I hear there are good home made formulas.

Click to expand...

Lee Alox is fine for lower velocity stuff. I use it a lot in .38 Spcl, .40 S&W and even .45 Colt, but if you're going to load for 9mm, use something better.

True, there are a lot of recipes out there that are easy enough, but for me as cheap as you can buy NRA 50-50 lube, it just isn't worth it.

Go to this site for great prices on lube ready to go. They sell it in 1# blocks or in tubes for use in lubrisizers.

http://www.lsstuff.com/

GLOOB said:

Scwing, ditto. You have maxed out your flare but passed the expansion limit a long time ago if your flare die is typical. The base of the bullet is where you get accuracy. You might be getting tighter groups with harder bullets because those bullets are not deforming as much in your shallowly flared cases. Flaring the case mouth doesn't cut it. Cast bullet shooters who like accuracy will eventually discover Lyman M die or equivalent that will set the entire bullet seating area of brass to a mic or two under bullet diameter.

Click to expand...

So I did order a .38 s&w expander plug. I tested one of my bullets with the old 9mm plug and, after pulling them, they were getting squished down to .357. With the .38 S&W plug, they only get squished down to about .358 which is still a problem.

I am not familiar with the M die you are referring to. I currently use the lee powder through and expanding die. Will this M die work in the same capacity? It sounds like you have found the source of my problem. It does explain a lot about why the harder alloys are more accurate.

I'll betcha Gloob's suggestion about switching to a .38 S&W expander will work.

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Well, only two other people suggested it before me in this thread, alone. And I learned it from some some folks on Cast Boolits. But thanks for the acknowledgement!

Scwing, I believe Lyman will custom make M dies to specific diameters and seating depths to your specifications. I use stock M dies for all my rifle calibers, but I'm not using super fat bullets. For a bullet that much larger than normal, you will probably need something custom.

To get a .360" bullet to a reasonable depth, you might even need to sort your cases. I have some DAG stamped cases that will only take a short seated FMJ style bullet, cuz the brass gets so obscenely thick any deeper.

The M die for pistol is a non-powder thru die. Other than that, the main differences are that it expands deeper, and it doesn't put a conical flare on the mouth. It is machined to two discrete diameters. The part that expands does so to the same diameter, throughout. Then you set the expander to the right depth where the top, larger diameter (called the step?) opens up the case mouth to the same diameter throughout, just enough to easily start the bullet. Unlike a conical flare, it holds the bullet straight up/down, which virtually eliminates any possibility of the bullet tipping while seating. Together, these features ensure that the base of your bullet remains as perfect as possible by the time you seat the bullet - with no excess flare, no shaved lead, and as good and consistent neck tension as possible.

So basically, you would need to tell Lyman what two diameters you wanted for the expander part and the flaring part. And how deep you want the expanding part to extend beyond the step. If Lyman can't help you, you might want to check the Cast Boolit forums. There is a member there who has custom machined M die-style expander plugs upon request.

With my rifle brass, I no longer do any inside chamfer after trimming, and flat base bullets and short, stubby cast bullets still seat with ease, with no tipping or scraping. I had previously gone to competition seating dies with the drop-down bullet holder, but the Lyman M die expanders make those seaters completely redundant and ineffective in comparison, IMO. And the flare is so little that with jacketed rifle bullets I don't even do any crimp. Also, the M die doesn't stretch rifle necks, even with no lube!

Note, there is one annoying thing about M dies. The plug can screw itself out without you noticing, changing your expanding depth. Make sure it's torqued down before you start! Locktite isn't a bad idea.