9mm leading

[Roundnoser]

Ran into a problem with some 9mm bullets I was casting. Looking for some suggestions...

I cast 9mm in Lee 125 gr. RN and Lee 125 Gr. conical with straight WWs. I cold quench both. I shoot both with 3.8 grains of Bullseye, and lube them with Jakes Purple Ceresin. Both are sized on a Star to .356" Dia. (I'm using a Glock 34).

The Roundnose bullets shoot with very little lead fouling. Only a little leading at the throat after hundreds of rounds. On the other hand, the conicals are leading pretty bad only after 25 rounds.

What could be causing such a difference? Could it be the depth I'm seating them in the casings?...The OAL of the cartridges?...Thanks.

[HeavyMetal]

you don't say which "conical" Lee mold your using but a quick look at my Lee catalog shows a Tumble lube 124 grain TC boolit.

I can only guess which RN your using but, sight unseen, I'll take a wild stab at this.

From what I can see in the picture the 124 tc has a lot longer bearing surface than any of the other 9 mm mold with one exception: the 356-120-TC. This looks to have the same amount of surface area as the tumble lube design but a much more usable lube groove.

So my thought is your RN boolit is on the border of not enough lube for bearing surface area and the Tumble lube 124 exceeds it.

I have no experience with Jakes lube but wonder if your tumble lubing or pan lubing or ????

So a little more info may help someone suggest a cure??

My thought is more lube on the boolit if possible.

[Roundnoser]

Thanks. After posting this question, I realized how many others had 9mm leading problems in other threads. I don't want to add to others frustrations with this same "leading" question with the 9mm and 40 S&W family of bullets. SORRY to those of you who have shown great fortitude with this learning curve!

After some searching on this site, I'm wondering if Im swaging the heel of the bullet when I seat it in the casing. The TC's apear to seat further into the casing than the RNs. Sooooo, as a trial, I have backed out the bullet seating depth to the top edge of the lube groove. The COL is increased from a 1.050" to a 1.085". This is as shallow as I can seat the bullet without exposing the lube groove.

Also, to clarify...in my last post I wrote "Conicals". Should have wrote "TCs". Both bullet designs have the tradtional lube grooves. Also, Jakes is a non-sticky, fairly low smoke, general purpose lube.

Like I said...all things between the two types of bullets are the same (diameter, hardness, lube...) Hopefully the problem of rigid 9mm casings / swaging the bullet heel upon seating is the problem. -- We'll find out tomorrow on the range!

[RobS]

With the 9mm you are pushing bullets at a higher pressure as you've probably noted and at pressures that are associated with the word "Magnum". Pressures can be greatly effected by seating depth with such a small case and I would look at how much free case volumn is left after seating the bullets as a comparison between the two. With that bullet fit is critical in the 9mm and I refer people to size a bullet to the largest diameter that will chamber freely. I've seen .357 work and .358 work even better in guns that will chamber them.

Also make sure the bullets that are sized are actually sized to what you think they are; just because they went through a sizing die doesn't mean they are at that specified diameter.

[Doby45]

I would say you need to bump the size up as well. I size my 9mm to .358 using a Storm Lake barrel.

[RobS]

Almost forgot.......the barrel. If it is the factory then I would shoot water quench as you are doing since it seems like they are more forgiving (less leading) with harder bullets. On the other hand, others have probably done fine with air cooled in a factory glock barrel too.

[finishman2000]

i ended up getting an after market barrel for my g34. no leading and fully suported case. win-win

[casterofboolits]

Back in the early 80's when the Glock 17 was just starting to be considered for law enforcement, the armorer for the Dayton, Ohio PD purchased one of the first 17's in the area for his personal use. He was a dyed in the wool boolit shooter and took umbrage at the "jacketed only" provision.

A friend, also was a Sgt. on the force, discussed the problem of finding good cast boolits with him to experiment with. My friend said "no problem" got just the guy for you and that I could supply a varity of cast 9mm boolits to experimement with. I was casting and selling boolits at the time to pay for my IPSC habit. I supplied him with several hundred 9mm boolits from H&G, Lyman and Saeco moulds. H&G #275 09-125-SWCBB, H&G #309 09-125-TCPB, Lyman 09-130-TCPB, 09-135-TCPB, 09-147-RFBB and a Saeco 09-125-RNBB (listed as a 122 grain, but drops 125 grains from my alloy) sized from .356 to .358.

After about three months he settled on the H&G # 309 09-125-TCPB sized .357 over 6.5 grains of Blue Dot as giving the best results. Another friend now has over 20,000 of this load thru his Glock 17 with stock barrel.

As others have stated, boolits sized to fit your barrel is the most important factor in improving accuracy and reduced leading coupled with correct taper crimping.

[Roundnoser]

Thanks for all the advice. As I said, I'm already shooting a .356" 125 grain RN bullet with very little leading at the throat...I'm happy with that. But the 356" TCs are leading. Same diameter as the RNs. -- FYI... I'm using a LW aftermarket barrel in my G-34 specifically for the lead / stock Glock barrel issue.

Gonna find out today if my latest test loads (with the longer OAL) makes a difference...will let you know.

Thanks again for lending your experience!

[HATCH]

try increasing the powder.

[MtGun44]

THE most common problem with 9mm is undersized boolits/oversized barrels.

It seems like most need at least .357 to stop leading.

Like Bret says "Fit is king" - size to .357 or .358 and make sure you are not reducing the boolits
when you are seating them into the case (pull one out after seating but BEFORE crimping
and measure). No need in any of my 9mms for anything harder than AC WWt with the
Lee 125 TC std lube groove at .357 diam. loaded to full power factory velocities.

Also - make sure you are using a micrometer for all this measuring. A caliper is not up
to the task - max accy is +/- 0.001" so if you measure .356" all that means is that it is
somewhere between .355 and .357.

Bill

[GabbyM]

I think you’re on the right track suspecting the bullet is being swaged down when seating in the case.

Not sure what round nose 9mm you were shooting with good luck. But the truncated cone bullets generally seat deeper into the case than round nose ball profile bullets. None of the expander balls I have in 9mm reach deep enough in the case to allow my Saeco 122 TC or Magma 147 FP to fit. Even the Lyman M die is a little short but it does seam to get the job done.

Do a little calculating to find how deep your bullet is being seated then measure your expander plug length. Also measure the diameter. Chances are you’ll find your case expansion isn’t working for that bullet

[chris in va]

Yup, my CZ leaded horribly with a .356 boolit, no matter the shape. Once I switched to a 38 Special mold sized to .358, much of my accuracy and leading problems went away.

[Roundnoser]

Thanks again for all the info. -- As I said, I loaded up 25 test rounds and went to the range today. I'm at a 1.085" COL which is as shallow as I can seat without exposing the grease groove. -- The leading problem got a little better. The leading is now limited to the first inch of the rifling. The rest of the rifling is fairly clean. -- On a positive note, the bullets feed nicely, and are accurate (2 - 3 inches at 15 yards shooting freehand).

My Roundnose .356" bullets don't lead up the barrel. Only two things sound obvious to me (as suggested)...the expander plug does not go down into the casing far enough (I'm using a Lee powder-thru die on a Loadmaster), AND/OR increase the powder charge from 3.8 to 4.? grains of Bullseye. (The data calls for 4.1 - 4.8 gr.).

Last call!!!!...anyone else with suggestions? Either way, thanks much for the advice.

[RobS]

Have you pulled a bullet after seating?

[noylj]

I have eight 9mms and they all shoot cast lead, including two P08s that love 115gn L-SWCs.
They all handle 0.358" bullet without any problem. I have two CZs in this group. One doesn't mind a 0.357" bullet and the other can handle down to 0.356" bullets. They all get 0.358" bullets.
I got rid of the last residual leading by tumble lubing all my cast bullets in LLA. I will try Recluse's formula next, but LLA has performed great for me for the past 3 years.
Also, leading isn't that big a deal if you are getting decent accuracy. Now, no leading and accuracy usually go together, but I have had guns that lead to a point, stabilize, and maintain accuracy from then on. Always look at the targets to see if there is a problem.
If leading is immediately at the lede (start of rifling), you could be seating too deep and you need a little longer COL or you are getting gas cutting from an undersized bullet or the alloy is too hard to obturate and seal the bore.
Too many people go right to a BHN alloy of 18-30, when a 12-14 BHN would be better. Except for magnums, my guns are all fine with 10-12 BHN.

[blikseme300]

I have eight 9mms and they all shoot cast lead, including two P08s that love 115gn L-SWCs.
They all handle 0.358" bullet without any problem. I have two CZs in this group. One doesn't mind a 0.357" bullet and the other can handle down to 0.356" bullets. They all get 0.358" bullets.
I got rid of the last residual leading by tumble lubing all my cast bullets in LLA. I will try Recluse's formula next, but LLA has performed great for me for the past 3 years.
Also, leading isn't that big a deal if you are getting decent accuracy. Now, no leading and accuracy usually go together, but I have had guns that lead to a point, stabilize, and maintain accuracy from then on. Always look at the targets to see if there is a problem.
If leading is immediately at the lede (start of rifling), you could be seating too deep and you need a little longer COL or you are getting gas cutting from an undersized bullet or the alloy is too hard to obturate and seal the bore.
Too many people go right to a BHN alloy of 18-30, when a 12-14 BHN would be better. Except for magnums, my guns are all fine with 10-12 BHN.

I second noylj's experiences. The best size in all my 9's is .358 and the alloy does not have to be as hard as people think.

My boolits are 120gr TC air cooled WW alloy and sized through a Star at .358 and lubed with LSSTUFF BAC/Carnauba lube. These are loaded on top of 4gr of HP-38. (This works for me, use at own risk.)

All of my 9's work well with these, but care had to be taken with the CZ's as these have a very short leade.

Enjoy,

Bliksem

[Roundnoser]

I pulled a bullet and found that the heal was slightly tapered. It clearly is a tight fit in the casing. Wen shooting, the bullets feed well, and are accurate. They just lead up the first 1 inch of the rifling ("Lede" as noylj states). Like I said before I shoot a RN lead bullet with a 356" diamater at approx 130 grain and they shoot great(!...almost no fouling.) It has the same bearing surface size as the TC bullet...the same diameter as the TC bullet...The same hardness as the TC bullet.

Differences: The TCs are lighter in wt. (5 + gr average), and seat a little deeper that the RNs. The longest COL I have tried is a 1.102". Any longer and the grease groove is exposed. And no crimp.

What about a small increase in powder, as was previously suggested? I currently use 3.7 grains of Bullseye with the 130 grain roundnose. Would increasing the charge to 4.0 gr. make a difference? The data call for 4.1 to 4.8?

[RobS]

The increase in powder charge more than likely won't help as you are shooting water quenched WW and is unlikely that it will obturate to fill the bore. In all this you'll take note to people suggesting a larger bullet diameter and it works for them because it is likely that the larger bullet does swage down in the case, but since it started out larger the swage down diameter is simply larger than your .356 swage down diameter.

The problem that I see with your .356 diameter molds it that they probably will not cast out a large enough bullet to size to .358. I have turned people to the Lee 358-125-RF for the 9mm and it has performed very well. By the way the Lee pic is not of the current production.

the post by springfield has the right photo of the mold that is being produced at the current time.

http://castboolits.gunloads.com/showthread.php?t=97095&highlight=358-125-RF

[Roundnoser]

Thanks RobS. I'll have to try that 358 mold.

[Tag]

but why no leading with the round nose bullet?

[Roundnoser]

but why no leading with the round nose bullet?

EXACTLY!!!! THATS WHAT I'M SAYING!!!! The RNs are the same except for the wieght and COL.

Maybe its a mystery that will never be solved....Like RobS suggested, maybe a .358" bullet sized to a 358 or 357 would solve the leading issue all together.

I'm gonna experiment with two more loads...1). increase the powder charge. 2). seat the bullet as shallow as possible to avoid swaging the heel.

After that, I've got nothing!

[Doby45]

Would you like me to send you a few of the Miha 126gr hollow point boolits sized to 358? It makes a SEXY 9mm boolit.

[RobS]

but why no leading with the round nose bullet?

The TC bullet is being seated further in the case vs the RN. Take a cross section of brass and you'll see the brass walls thicken toward the head of the brass and also the inside diameter becomes smaller. The TC bullet which is being seated deeper could very well be squeezed down to a smaller diameter (especially at the edge of the bullet's base) vs the RN. It doesn't take much to have gas blow by with a higher pressure round like a 9mm. Forget having a bullet the same diameter as your firearms groove diameter because there is simply too much pressure out of the gate with the powders used in the 9mm and not to mention the already small case volume.

The bullet diameter really needs to leave the case .001", often times .002" works better, larger than the groove diameter. Think about this one..........do many people have great success shooting upper 44 mag or 357 mag with undersized cast bullets???

for comparison:
44 mag SAAMI max pressures: 36,000 psi
or

357 mag SAAMI max pressures: 35,000 psi

and finally

9mm SAAMI max pressures: 35,000 psi