I've loaded and shot around 5000 124 and 147 gr. poly coated bullets in the past year or so.  The majority of them have been shot through a couple of silencers.  

While I previously hadn't seen any leading in the barrels to speak of, I have found I get a pretty good buildup in the silencers.  Like as bad or worse than shooting bare lead.  Crimp is only enough to take out the flare in the case mouth.  And no, I haven't been shaving bullets as they seat.  

This was especially noticeable today.  I ran around 500 rounds through the Uzi & suppressor this morning.  Mostly short bursts and fast singles/doubles.  When I pulled the can and looked inside, I had a "cone" of crud built up on the blast baffle.  Noticeably more than when I'd started.


Also, I've got some heavy leading in the barrel.  



These are all commercially produced bullets using HiTek coating.  They are loaded with a mid-range book load of WSF.  

As noted, I'm not over-crimping.



Have other people experienced this?

Based on feedback I've gotten here and other forums, I might try a different brand of bullets and see if I get better results.

The rifling breaks the coating up.

While in the barrel it stays together.

Once in the suppressor it starts to break off.

If it's just coating being deposited, clean it out with acetone.

If it's lead you might have a bigger problem. I have not had issues beyond normal expected deposits with suppressors and coated bullets. Any leading in the bore to speak of?

If it is a steel suppressor, you might consider the dip method, but use proper safety procedures if you do.

Yes, the barrel has what appears to be lead in the bore as well. Or it did this morning, anyway. I got a great picture of it in the sunlight. Not so noticeable now. So now I'm not so sure. It's a surplus SMG barrel, so it's not like it had a mirror smooth bore to begin with.

I was running some drills, practicing for the Knob Creel match this weekend. There is enough buildup in the baffles I'm concerned the bullet won't pass throuh without rubbing. I'll just leave that can home and shoot with the .45 can and a different barrel.

It's an aluminum Bowers can, so I can just send it back to Tom to get cleaned.

Are the bottom of the bullets coated as well?

I'm not familiar with poly coating but powder coating solved my leading issue in my 500's muzzle brake.

There is no problem with bare exposed lead on a bullet base while it's in the bore it's when it exits the bore the hot high velocity gases tend to flame cut the edges a little.

This can "paint" a can or a brake with lead very easily.

Motor

Yep, the whole thing is coated, including the base.

Btw, it's a little hard to see, but here's what it looked like when it was new, before the first round had been fired through it.

Im curious as to just what the composition of those deposits are, lead, coating or powder residue. I shoot coated bullets from Palmetto Projectiles in my blackout and am not seeing any fouling other than powder residue but I don't do full auto or even rapid mag dumps. Are you going to scrape any of that fouling and see if you can identify the source or are you just satisfied that is lead with soot covering? I'm not busting on you, I'm just curious.

 

I can't really tell. The chunks that have broken off look the same as the buildup I get when I shoot a lot of lead-base JHP. I don't see any color from the coating, but it could be blackened or burned, or just mixed in with the other residue.

Don't know.

Switch to plated bullets.

Well the easy answer here is: fix the leading in the barrel. I know, obviously, but in all seriousness the lead in the bore is directly related to the lead in the can. The problem is most likely barrel to bore fit. Also, a lot of people experience this problem with 9mm, being a tapered case, when seating an oversized lead bullet into the tapered case, the base is swaged by a couple thousandths which will allow gas blow by and most definitely leading. The old timers used 38s&w(not special) dies to flare the case mouth to prevent this all to common issue.

1. First you need to slug your barrel, after you clean ALL the lead out(copper chore boy brand pot scourer around cleaning jag).
2. Slug it again for fun, compare results to step 1
3. Pull a couple of your loaded rounds and check the bases for swaging
4. DO NOT use Lee Factory Crimp Die, standard taper dies work perfectly
5. Check your bullets to make sure they are concentric and of desired diameter
6. Order correctly sized bullets
7. Switch to plated if problem persists

Leading in the bore and can isn't related to the coating, it's been proven many times over to date. Fit is king. I've shot a couple thousand or more powder coated bullets that I cast and coated through my suppressors , only time I had lead was my mistake and loading procedure was to blame.

I used about 5k coated bullets year back in my 40 before I gave up. They were from precision bullets. That coating does come off, no matter what they say. maybe it's dependent on the type of barrel or something, but it loaded up my SW99 barrel good. I had to use "the dip" to get it out. I can't imagine running that through a suppressor. If it's all stainless, go ahead and use the dip (Hydrogen peroxide, vinegar). It is hazardous waste when your done though.

Now I use Berrys plated. Similar price, much less problems.

BINGO!

Your gun is a UZI.  I'd place a sizeable wager that the bore is larger than US specs and/or something is haywire in the loading process.  Shooting coated bullets follows the same rules of shooting naked cast bullets.  You need to use bullets that are at least .001" larger than bore diameter to seal the powder gasses.  That means slugging the bore and finding the true bore size.

If using Lee dies, get a 38 S&W (not 38 spl) expander plug.  It bells the 9mm case large enough to properly accept cast bullets without ruining the 9mm case.  Then, take a punch and hammer and knock out the sizing ring in the factory crimp die.  I've "been there, done that" and can say that taking these steps will allow you to properly load 9mm with cast bullets without bullet shaving or swagging.

I'll have to try some of that. Need to slug the barrel. Only problem is that I have multiple barrels for the Uzi. And a dozen or so other guns chambered in 9mm. I don't really want to have a load that's specific to one gun. But I don't really want to be plugging up my cans either.

I only recently started using a Lee FCD. I'll try pulling some bullets and see if the base is getting swaged.

I had previously tried Blue Bullets as large as .358". They would chamber and fire fine in the Uzi, but were typically tight in the Dillon chamber gauge (no "plunk" in and out). I didn't like that the Blues only came in .355 and .358, and nothing in between.

I'll look into all of this when I get back home. Thanks for the suggestions.

Any chance you have access to a water trap and can recover a few shot bullets to look at as well?

I agree, slug those bores after a very spotless cleaning and see what the tells up front.

If you debris can be collected at all, try to see if the content is mostly carbon and lead, or bullet coating, by using the solvent tricks to see if it dissolves.

A specific scan would normally pick up some of both, but you really just want to determine what the bulk composition it to help with debugging.

Another point I would add, is not to expect too much in terms of cleaning intervals. Some designs just need shorter intervals.

Yes check some pulled bullets. The FCD is not a good choice when purposely using oversize bullets.

Another thing when using oversized bullets is ditch that gage. Use your chamber as the gage.

Motor

Do plated bullets have this issue? I am glad i read this thread as i was about to buy 1k of the coated bullets for running in a suppressed uzi.

never had this problem but I only use extremes and keep them way under 1500

I was interested in getting them to make subsonic loads using red dot powder.

Correct, I had problems with the coated bullets. Also the chemical smell I got from some of them seemed toxic as hell.

I just cleaned my Octane and won't be shooting anything but plated anymore. I wish I would have weighed it prior to cleaning.

UPDATE:

I pulled a couple of bullets from the loaded rounds and miked them. These had been loaded using a Lee FCD, so I was wondering about sizing them down too much when crimping. My mic read them as .3565", just like the new, never-loaded bullets. So that's not it.

I cleaned the barrel using the copper scouring pad trick. Or at least I thought it was clean.

I slugged the barrel with one of the coated bullets, and about half of the coating stayed behind in the barrel. So I cleaned it some more, and the next one was better, but still missing some coating.

It is a surplus SMG barrel, so maybe it's just got a bit of a rough bore. I'll have to check my other barrels, or maybe just break down find a "new" barrel.

Just for fun, I ran an Xtreme plated bullet through the barrel. I was wondering if the barrel was going to peel the copper off now. The resistance was noticeably less, running the copper plaited bullet through, and it came out completey intact.

The other interesting bit is the slugged bullets measured .3575" across the lands. Looks like I need a bigger bullet. I had previously loaded a trial pack of Blue Bullet .358" RN. They wouldn't plunk into the Dillon chamber gauge (had to push them in, and bump them out) but they shot fine through the Uzi. After the initial trial, I had loaded the rest in some .357 Mag cases.

Maybe I should try some more of them. But it won't do much good if the barrel continues to strip the coating. Maybe a new barrel is the answer.

 Iv been thinking this, as my YHM LT, sits in jail...

Iv been shooting some of the MBC 245, and Palmetto 203gr.
I noticed lead BAD on the flash hider, with the 245's Looked like I had been shooting anti-seize.
Last time out at 100yds the 245 was also shooting like crap, but the 203's shoot nice.
I was thinking of ordering more, being the Hornady ELD prices... Guess I will stick with the ELD's for the 300blk. They do shoot WONDERFUL.

Thanks OP for the post and bringing this up.

How would you even clean up lead in a aluminum can?
Melt it out?

GarrettJ. It looks like you found your problem. (Bullet diameter) My 9mm slugs .355" and I always shoot .358" cast bullets. I probably don't have to but it works great.

If you fallow the cast bullet forums there are many many people who do the same. Even on here when the subject comes up guys say the same. (.358" cast in the 9mm)

As I said above,  ditch the gage, use your chamber and get some bullets that are bigger than your bore.

I think powder coat is tougher than the poly, maybe the same, I don't know but I don't think even powder coat would withstand blow by which is what you are getting. It's basically flame cutting your bullets.

Be sure to do the pulled bullet diameter check if you use the FCD with the .358" bullets. If you are good at measuring you could just measure the inside diameter of the carbide ring in the FCD then take your brass wall thickness x2 plus .358" and see. What you don't want is your loaded round to be larger than the FCD.

If it is don't use the FCD.

Motor

You can try lapping the bore to help smooth it out.

At this point it can't hurt and might help.

Might be worth trying Tubb's Final Finish System

Check your leade (the funneling between the camber and the rifling).  Too sharp of a leade will never get cast bullets to work properly.  Its surprising how many gun makers take such little care about putting a proper leade in their handgun barrels anymore.  You see it most often with production 45acp guns but it can happen on any caliber.  Shooting thousands of jacketed bullets won't fix it.  The only fix is a few careful turns of chamber reamer.

Ok, more info:

I slugged most of the barrels that would see lots of suppressed use. All but one are used in full-auto as well, if that makes a difference.

It seems the surplus SMG barrel I've been using the most has by far the roughest internal surface, and also one of the biggest bore sizes. The Group Industries barrel that originally came with the gun has the tightest bore, and it's reasonably smooth. I thought I may just switch to using this one. But then I measured my other subgun barrels, and found the rest are all on the large side.

I've ordered a thousand .358" coated bullets to test. I don't really want to have multiple bullet diameters for different guns, but that may be what I end up needing to do. The nice thing about coated bullets is that I could at least use different colors for the different diameters.

Or maybe I'll decide it wasn't worth it and go back to plated & jacketed, and the higher costs.

Ok, I've been busy but slowly getting somewhere. I had seated and crimped a couple of the .358" bullets using the Lee FCD, then pulled and measured them. I was happy to see they still measured .3580".



However, once I started loading I pulled another and got a different result. The previous two had both been seated in FC brass. In Win brass I pulled a bullet and measured at .3565". Apparently the Win brass is thick enough to make a difference.

After this I replaced the Lee FCD with my Dillon crimp die and tried again. This time using Win brass I got a pulled bullet diameter of .3580" again. Good deal.  I'm going to load up a few hundred like this.

I also have a new Bowers muzzle brake. It uses the same mounts as the silencers, and should make a good approximation of a silencer blast baffle without being a regulated part. So replacement is quicker and less expensive, if it were to come to that.  The new muzzle brake end cap looks like this before starting.



Next up is to dump a few hundred rounds throuh it and see what I get. I'm thinking maybe 200 for starters. Or maybe I should run a few hundred of the known "bad" rounds first to get a baseline for leading. Then bead blast the brake and go again with the larger diameter bullets.

More to come...

I know a commercial reloader. He only uses  X-Treme 147 heavy plate FMJ for his clients running suppressors.

Welcome to the wonderful world of the 9mm. Add to the mix several bbl's, reloading equipment and a mix of bullets/brass & case gauge's.

Reloading:
As you can see your bbl's are all over the place. Using a .358" bullet is a good choice. Using factory 9mm dies and case gauges, not so much.

The issue with using factory dies is that they are designed for jacketed .355" bullets. They are designed to hold that .355" bullet in place with neck tension. When you look at a coated bullet and the trailing/back of the bullet is bare. That's telling you that that bullet was swaged down in your reloading process.

If you are using a .358" bullet you need a expander designed for a .358" bullet.

A lot of reloaders use a lyman m-die for this. A picture a a lyman m-die in a case. Note the step at the top of the expander ball. That is there to open the mouth of the case enough so the bullets sit straight, start straight & the sides of the bullet do not get scraped by the sharp edges of the mouth of the case.


A factory lee 9mm expander (left) and a custom expander (right) that I made for the reloading 9mm's with .358" bullets.


People that reload 9mm's with .358" lead/coated/plated bullets tend to use 38s&w/38spl expanders. I've used both along with custom expanders, they all work.

I typically seat a bullet in 1 stage and crimp it in another stage. Brass has different thicknesses and heights. Doing the seating & crimping in different stages levels the playing field.

Some different bullets recovered from the berm. They were shot in 38spl's/357's/44mag's/9mm's with pressures ranging from 16,000psi to 35,000+psi. Note the bases of every bullet, they are not only intact. They still have the coating on them.


A picture of what a 9mm bbl looks like after a 700 round range session.


I was shooting my favorite plinking load in that 700 round range session. It's nothing more than a 125gr coated bullet doing 1100fps+ from a 27,000+psi load. It took 1 wet patch and 1 dry patch to clean that bbl after that 700 round range session. No brushing/scrubbing/thothing/nada. Just a couple of patches.


I would also ditch the case gauge, they are worthless. You'd be better off finding out which bbl has the tightest chamber and if you plan of reloading a 1 ammo fits all. Then use the bbl with the tightest chamber as your case gauge.

Myself, I only reload for 3 different 9mm's. But I'm able to use the same reloads in all 3 9mm's.

Anyway the 1st step is to have the ability to make quality ammo without distorting/ruining the different components that make up that ammo.

Namely the correct expander for a .358" bullet and ditching the case gauge.

You want to get down to the brass tacks of it then get every bbl laid out and test 10 random cases in each bbl. Size and de-cap the 10 cases and then fit all 10 cases in every bbl. Note the differences in how far down the sized cases sit in the different bbl's. Use the correct expander & expand the cases and seat the bullets you plan on using in those 10 cases. Do not crimp them!!! Test them in the bbl's as they are, bullet seated and no crimp. Now pull those 10 bullets and check them for dammage such as scraping of the coating or being swaged down (base of the bullet is the most important thing!!!). Now redo those 10 cases and this time seat and crimp the bullet and test them in the bbl's. Myself, I put a 3/1000th's crimp on all my semi-auto ammo. 3/1000th's might sound like a lot but take into consideration the fact that the dies are 7/8-14. Typical 3/1000th's crimp takes a 1/2 turn on the crimp die which ='s it touching/affecting  less than 4/100th's of an inch of the case. Some 45acp's and 9mm's that I loaded. Both have a 3/1000th's crimp. You can see the crimp line when the light reflects off the brass, it's that shinny ring at the top of the brass. Note that there is no bullet bulge in the cases. The bullets are .452" & .358" respectively.

The wonderful world of 9mm bbl's:

The 9mm is 1 of those calibers that is all over the map. The saami specs have listed a .355" bll with a 4/1000th's + allowance. The end result is bbl's that should be .355" to .359" to be in saami specs. Add to that the fact that a lot of firearm mfg's are omittimg 1 little step in their bbl making process. Namely using a throating reamer.

Why the heck would a throating reamer or throating a bbl be sooooooo important???
Things like which bullet design, oal's & bullet diameter are all affected by this cost cutting measure.

What to look for.
A factory 9mm bbl (left) and a "match" grade 9mm bbl (right).


The real difference between the 2 is the "match" bbl has a tighter chamber. Both bbl's are not throated but the "match" bbl is designed to hold/align the bullet in the center of the bore better due to tighter tolerances. These types of bbl's tend to do better with jacketed fmj's.
A bbl that has not been throated at the factory. Note the short leade in front of the chamber and the steep angle on the lands. Using the same chamber reamer on a .355" bore and a .358" bore makes a huge difference in the amount of throat in a bbl.


Same bbl that has had a throating reamer used on it. Bbl's with throats will be able to shoot/handle a larger number of different bullets/ammo's/oal's.


"Match" grade bbl's are subjective at best. That match grade bbl in the 1st picture is designed to shoot fmj's. This "match" grade bbl is designed to shoot all bullet styles/shapes/metal's equally well. Note the llloooonnnnggggg highly polished throat and sloping angle on the lands. This style of match grade bbl is better designed for lead/coated/plated bullets along with the longer bodied bullets.


2 of my favorite bullets for that match grade throated bbl, a 150gr hollow based flat nosed bullet & a 125gr flat nosed hp. Both have long wide noes that engrave/held in those long tapered lands. The end result is a bullet that is centered in the bore and has no distortion/deformation.


The end result, a 10-shot 50yd group with that hb bullet.


A 10-shot group @ 50ft with that 125gr hp


The op is trying to take several bbl's with different bore diameters coupled with throated and un-throated chambers and use 1 ammo/load for everything. The only way to do that is to;
Take a good look in each bbl and see what throating your dealing with.
Find the bbl with the tightest chamber.
Find the bbl with the shortest throat.

The bbl with the tightest chamber will set the standard for the largest diameter bullet you can reload that will chamber in every firearm/bbl.
Setting the oal to the bbl with the shortest throat will allow the amo to function in every firearm/bbl.

I'm sure everyone has seen this picture before. This is what you want to do/use to find the largest bullet diameter for the tightest chamber and the longest oal for the bullet being used in the bbl with the shortest throat.


Do not load you ammo to the "best accuracy with lead bullets" BS. Give yourself at least 5/1000th's shorter oal. Do this for 2 reasons.
Load 100 rounds of ammo and measure the oal's on all 100 of them. Most reloaders are within 15/1000th's of their "target" oal. Good reloaders are within 10/1000th's of their oal and excellent reloaders are with 5/1000th's of their oal when reloading 9mm ammo.
Your using coated bullets. Any scraping of the coating will buildup in a non-throated bbl rather quickly. The buildup tends to take place where the step in the chamber is (step ='s the lip where the chamber meets the bore). You scrap off a bunch of coating and it builds up in that area. Bad things happen real quick.

3221, those are very helpful and informative posts.  Thank you.

Switch to plated.  I used to use a lot of lubed lead and moly coated bullets.  They really caked up on the FH of my 9mm, same as you show.  Since I started using Berrys and others, I no longer have any leading issues.

I load my plated stuff with FMJ load data, as the manufacturer recommends.

I tried the coated bullets and I had exactly ZERO luck with them in handgun or carbine.

I am not going to mess with them.  I have given up casting as well, just not worth the effort.

My time is worth more than the effort to cast and clean.

Did you slug with coated bullets?

A plain bare piece of pure lead is what you want.

With some Kroil in the barrel you can even feel variations in some barrels as you press the lead through.

I wouldn't worry about using different size bullets. All of my 9mms slug under .356" and all just simply love shooting .358" cast, powder coated bullets.

Cast bullets are very forgiving and slug down to bore size without fuss. If the .358s work use them in all of your barrels.

Motor

Why? Would that give different results?

This

That

 
is good stuff thank you for the post.  very informative.

So just for fun I used a Bowers FHB muzzle brake and put it on the Uzi.  It uses the same endcap as the Bowers lines of suppressors.  This was one of the barrels that slugged at .3570" which I'd had it chopped and threaded some time ago.

I ran 400 rounds of the same .3560" bullets, then I replaced the endcap, cleaned the barrel, and ran another 400 rounds, using some .3580" bullets.  Both sets were loaded on the Dillon 650 with 3.9 gr. WSF.  The only difference between the two was the bullet used.

Here is the brake im using.  



And 400 rounds loaded in mags, ready for testing.



Up first were the .3580" bullets.  Here is the endcap before and after:



You can see it picked up a little crud on the surface.  The endcap gained 16.1 gr weight.  

The barrel was cleaned and I went out again, this time with the .3560" bullets.  Here's the before and after on that endcap.



So in 400 rounds, this load picked up almost 3 times as much gunk on the end cap, totaling at 40.3 gr.  You can also see the ridge starting to build up around the apurature.  The silencer baffle I had posted a picture of at the beginning of this thread had had a few thousand of these rounds shot through it.  This type if buildup does not seem to get to a point where it breaks off, limiting its self.  

I am cautiosly optimistic about the .3580" bullets in the Uzi.  Same thing with the Lage uppers.  At this point I'll have to slug a few handguns and see how they check out.

Up next, I may try the same experiment with some plated and jacketed bullets.  I'm curious if the results from the .3580" bullets is the same as what I'd get with a copper jacketed or plated bullet.  Just depends on how many bullets I want to go through.  

Here's the two endcaps, for comparison.

I don't think I would run those through my can.

Plated bullets aren't that much more.

More testing. I scrubbed the barrel, cleaned up one of the end caps and did the same test using some Berry's 147 gr plated bullets. The bullets measured .3555" on my micrometer.

End result was almost no buildup, with the end cap gaining only 2.2 grains.

Before:



And after:


And here's a better look at the endcap when I finished shooting.




Also, while the coated .358" bullets gave much less buildup than the coated .356" bullets, it was still stuck on there pretty hard. It took quite a bit of scrubbing with a brass brush and some copper mesh.

I think I may stick with plates and jacketed bullets for suppressor use from here on out.

GarrettJ, did you buy the .356 plated from Berry's and they mic'd at .3555?
As soon as I'm done with my Acme plated 147s I'll be going back to Berry's myself.

Thanks for the awesome post with great informative replies everyone!

Correct. These are listed at .356"