Boolit sized, lubed/coated etc properly- why am I still getting leading?

[mattri]

Rifle is a Marlin 336, originally a 30-30 that shot well. Unfortunately 30-30 is not kosher for hunting here so had it re-bored to 38-55 by JES. Barrel now slugs .377, have tried a number of different combinations- .379-.381, different lubes, gas checked and not- and most recently been using .380 Hi-Tek coated boolits @ 1300 fps and still seeing definite leading.

My understanding was that leading is caused by an improperly sized boolit, poor lube or excess speed. Having eliminated all of these issues I am still scrubbing lead out of the barrel after barely 50 rounds.

Thoughts?

[Thumbcocker]

Rough bore?

Sent from my SM-G960U using Tapatalk

[mattri]

Man I hope not. I had JES do the rebore mostly from recommendations on this site, everyone seems to love their work.

I don't have decades of experience like some folks here but I've been shooting cast for a few years in multiple caliber/cartridge/platform set ups and this is the worst I've ever seen.

[Iwsbull]

Before I cast my own and powdercoated them I bought some Hitek coated bullets and I had horrible leading, I figured out it was very hard slightly undersized bullet that was the culprit. When I jacked it up to max loads it got better but still leaded so I started casting and coating my own and the bore life got much easier.

[mattri]

Thanks for the reply! Hi-Teks are .380 which doesn't seem underbore for a .377 barrel

[AndyC]

How hard is your bullet?

[mattri]

Have tried everything from 12-20BHN nothing seems to help.

[Larry Gibson]

Try a traditional lube w/GC says the PC/HT.

[mattri]

Boolits have been lubed and gas checked, no help.

[jblee10]

Where is the leading? Toward the muzzle, or through the entire barrel?

[mehavey]

1. Are these your cast bullets, or store bought ?
2. Are you doing the PC-ing, or someone else?
3. What powder ?

As to hardness...at 1,300fps, you want soft -- 30-1/BHN 6 or so -- and a fairly fast powder.

[jim147]

What groove, twist was it rebored to?

[sigep1764]

Where are you located? A member here might be close and might be inclined to help in person.

[Larry Gibson]

Boolits have been lubed and gas checked, no help.

Lubed with what?

[DougGuy]

As to hardness...at 1,300fps, you want soft -- 30-1/BHN 6 or so.

I don't know about BHN6, that's near pure lead.

I would suggest soft enough to scratch with a thumbnail, which 20:1 is still too hard for that, and soft lube. 50/50+1% or 2% should be perfect and that will scratch with a thumbnail. I have good results with RandyRat's TAC1, I have excellent results with SPG! Felix is probably the best lube on the planet but you should be able to hit a working combo with several of the soft lubes.

Every cast boolit success story is a combination of factors. Miss one and you miss the combo. Too hard? Won't obturate.

Also, post some of your loads. What powder?

[ole_270]

My JES rebored Marlin runs a little under .376 groove dia. I size to .377 and run mostly 13 and 1400 fps loads. I've been up to 1700 with no leading. Bullet is the NOE 38-250B, I had the mold built for a plain flat based bullet, no gc. Alloy has been anywhere from 1Sn, 1.5Sb up to ww, all air cooled. Lubed with Winds Wonder Wax or powder coated, shoots great and no leading. One thing I would check is your neck size before seating bullets. If the neck is too small it can size the bullet down.

[waksupi]

For 1300 fps you need around 11 Bn.

[Rizzo]

Rifle is a Marlin 336, originally a 30-30 that shot well. Unfortunately 30-30 is not kosher for hunting here so had it re-bored to 38-55 by JES. Barrel now slugs .377, have tried a number of different combinations- .379-.381, different lubes, gas checked and not- and most recently been using .380 Hi-Tek coated boolits @ 1300 fps and still seeing definite leading.

My understanding was that leading is caused by an improperly sized boolit, poor lube or excess speed. Having eliminated all of these issues I am still scrubbing lead out of the barrel after barely 50 rounds.

Thoughts?

I've gotta ask since you did not specify your .377 slugging.
Was that groove diameter or bore diameter?

[DougGuy]

Had you even googled 38-55 you wouldn't have had to ask such a question. it is impossible for 38-55 caliber to have a .377" bore.

Don't be afraid to google, Wikipedia is stunningly accurate for almost any firearm related question (and is usually the first hit returned in a search). All of the specs are there, development history, everything you would want to know about any given caliber is right there at the click of a mouse or a verbal command on a phone.

[mehavey]

I don't know about BHN6, that's near pure lead
For 1300 fps you need around 11 Bn
1) I'm running 30-1 for a HiWall/38-55/plain base/ACC 38-320gr (standard 50-50 lube), 1310fps

2) Please note tested hardness of 30-1
https://castboolits.gunloads.com/showthread.php?366065-New-Lee-Hardness-Tester&p=4437398&viewfull=1#post4437398

Bottom line: With rare exception, lead alloy "mixes" "as reported on the internet" are much softer than advertised.
Think about it: Pure lead is 4.5- 5.0, and all you've done is add 3% tin.
Not much more effect that ease of fill-out has occurred.




Added thoughts on soft lead and PC
https://castboolits.gunloads.com/showthread.php?409893-Pure-Lead-amp-PC&p=5001471&viewfull=1#post5001471

[mattri]

For loads have been using Unique and more recently IMR4227 from 20-22grains.

Leading seems worse about 6-8" from muzzle.

[mehavey]

mattri: Are you doing the casting and PC, or someone else ?
(and if you, what is your PC process/temp, etc?)

[DougGuy]

I don't know if burn rate is part of the problem, Unique is 32 and 4227 is 65 on the burn rate chart, Hodgdon data suggests 4895 which is 94 which is much slower, I get my best out of 308 with H4895.

By comparison H110 is 63 and Lil Gun 62, AA#9 is 57 and 2400 is 54. These 4 I think are most associated with large bore straight wall heavy boolit pistol calibers, and the 38-55, just looking at the round, is a straight walled cartridge that makes me think it might respond well to any of these slower pistol powders. 4227 at 65 is right there with the infamous four, and it has been noted that 4227 can be temperature sensitive, so there is that.

If there is any logic to the burn rate in 38-55, and I had to strike out blindly I'd probably pick 2400, find some load data for it and see where that got me.

[mattri]

So far have been using commercial cast boolits. No reason to believe the BHN is off, the HI-Tek seems in tact and boolits measure appropriate diameter.

[mehavey]

There is no reason that a properly PC'd / 0.380" / 1300-1500fps bullet should even think about leading -- no matter how soft
In fact, soft is good. (Again see bottom of Post #20 (https://castboolits.gunloads.com/showthread.php?424854-Boolit-sized-lubed-coated-etc-properly-why-am-I-still-getting-leading&p=5185429&viewfull=1#post5185429))

I'm thinking PC-QC* is at the root of your problem.




* (Honest, I don't make these catchy phrases up. :veryconfu )

[mattri]

That certainly could be part of the issue but other boolits leaded badly too, not just these.

[DougGuy]

Ha! Commercial cast, unless you specifically order a softer alloy, is usually BHN22 and that hard crayon lube = guaranteed leading regardless of diameter or fitment.

[Larry Gibson]

...........Leading seems worse about 6-8" from muzzle.

That is a classic indicator the lube is failing or there's not enough of it.

What lube?

[jimb16]

Are you using actual measured .380 bullets or are you trying to use .380 bullets? .380 bullets are .355 dia.

[mattri]

Various, including Hi-Tek coating.

[Rizzo]

What groove, twist was it rebored to?


Where are you located? A member here might be close and might be inclined to help in person.


Lubed with what?


I've gotta ask since you did not specify your .377 slugging.
Was that groove diameter or bore diameter?


That is a classic indicator the lube is failing or there's not enough of it.

What lube?


Are you using actual measured .380 bullets or are you trying to use .380 bullets? .380 bullets are .355 dia.

OP,
Folks here are trying to help you but you seem to be ignoring their questions.
Just sayin'.

[W.R.Buchanan]

This is probably a bad gun. It should be sold or thrown away as there is no solution for this problem. You you could just let it lead and fire a Jacketed bullet thru it about every 5 shots that would clean it out for sure..

In fact since nobody said anything about breaking that barrel in, maybe fire a hundred or so j words thru it, clean all the copper fouling out of the barrel and try your boolits again.

I have never seen a PC'd Boolit transfer Lead to the bore of any gun. It is a Polymer coating .002-.003 thick and there is no Lead contact with the bore. Therefore it can't lead the bore.

Kind of wonder what's going on here? Unsolvable problems always seem to be knowledge related, and solved by increasing the understanding of the subject. Not some Miracle Fix.

Randy

[mattri]

To catch up-

Rebore is a 3 groove 1:16, using 245-265gr boolits.

I am in Iowa.

Multiple commercially cast/lubed boolits have been shot through this rifle, all with the same results, I do not know the exact lube composition of each. As noted coated boolits lead just as badly.

Barrel was slugged in the standard way, pure lead lubed and driven through barrel then mic'd.

As noted boolits used so far have been .379-.381, no 357 boolits were harmed in the making of this post :)

No copper has been down this bore, intention all along was to use cast boolits.

Originally I had planned to order a mold from Tom but wanted to send a little lead down range and experiment with a few different boolits to see how they fed, whether it seemed to like a particular weight etc- which is why I ended up with a selection of various "store bought" boolits. Was planning to use the info from these loadings to help select the mold I would order but would like to sort the leading out before I pull the trigger on a mold.

Not saying this couldn't be the first but have never heard of anyone having trouble with a JES rebore before, everyone seems to love them.

[Dusty Bannister]

Do you suppose that a pound cast of the neck and throat area would give you a better idea of the size of the bullet needed to correctly fit this firearm? If the neck area is too large, the ignition will blow the lube off the bullet before it seals the bore and this could be the problem with leading the last part of the barrel. Also with powder coated bullets, the hot gas may be cutting the coating and not protecting the sides of the bullet from contacting the barrel. What does the muzzle look like after firing PC bullets. Obviously, you more than likely have a silver star with lubed bullets. Have you checked to determine the cartridge OAL with the largest bullet you can cast? If the free bore is a little too long or your bullet is a little small or short, that might also be part of your problem. There is a very old and proven method used to verify that is not the problem.

If a tight patch does not pass smoothly down the bore, you might consider a bit of lapping might improve things.

[mattri]

Possible, but maybe not likely. An oversized boolit or more to the point a case with the "long" brass will not chamber so fit doesn't seem to be the main issue.
JES recommends short brass and say they cut to .376-.377 which seems to match actual field measurements.

Unfortunately it looks as though boolits sized correctly and with various types of lube/coating just leave a nasty amount of lead in the barrel.

[AndyC]

Are the lead streaks always in the same place?

[jonp]

Try a different powder.

[oley55]

IF a rough bore is suspected, the $46 Teslong bore scope will tell the story. Compatible with any laptop and most phones (but not an iPhone). Just do a search for Teslong and the Bezos outfit has them on their site.

[Mmacro]

It sounds like your still dealing with some unknowns (exact chamber dimensions, etc)... treat this like a science experiment and identify as many specifics as you can.
Shooting a box of J’d boolets will not ruin a gun you want to dedicate to cast... it will just speed up the process of smoothing out any microscopic burrs left in the barrel. Fire a box, swabbing the barrel really good every 3 rounds, letting the barrel cool between shot group.

Then, start collecting your data on a spreadsheet. (#1 to 3 are header/benchmark data and set the stage for 4 to 7, which is the test data)
1. Slugged bore
2. Chamber cast
3. Barrel/bore surface photos
4. Bullets of known alloy composition, hardness, and exact diameter
5. Lubes and PC of known mixture/hardness
6. Various powders and charge weights
7. Photos of the chamber and barrel and leading at: clean; 5 shots; 10 shots; 25 shots; 50 shots...

It is critical you only change one thing at a time so you can pinpoint the culprit. If you change lube and powder charge and a change occurs... what caused it - the new powder or the new lube mix?

Once you have a few hundred rounds through the barrel you can start to make decisions based on data and not guesses.

[Larry Gibson]

........Multiple commercially cast/lubed boolits have been shot through this rifle, all with the same results, I do not know the exact lube composition of each. As noted coated boolits lead just as badly. .

The leading with the commercial lubed bullets you are experiencing is typical. The hard wax used is not the best to prevent leading. If you have or can get some Lee's liquid alox then lightly coat the commercial cast bullets as per Lee's instructions letting dry thoroughly before loading. Or if you have some softer traditional alox based lube remove the hard wax lube from, say, 10 bullets then hand smear the lube into the grooves, load and shoot them. If no leading the there's nothing wrong with the rifle, barrel and Jes's usual excellent work. The solution, which it most often is, ito not getting leading s simply the to use a proper lube.

As to the PC'd bullets leading or leaving a PC fouling in my experience with such is some guns just foul with it and some don't. In my tests of the same bullet/load in multiple guns some foul, some don't. Its one of the reasons I haven't gone to the dark side....

[mehavey]

https://i.postimg.cc/6QYJTWMW/BACO-38-260-PB-Lead-PC-d.jpg

I cast these up this AM, pure lead
BACO 38-260 (262gr actual)
PC'd as you see in the picture.
Will size to 0.380" (PC'd they are .382")
RL-7 sufficient to approach 20,000psi (QuickLoad)
HiWall/38-55/32" barrel ought to hit high 1,650-1,680 fps

We'll see.....

[mattri]

Unique and 4227 are the only powders I have suitable for the 38-55. Would like to try some 4198 or 3031 but as yet haven't been able to find any.
Leading seems worst starting around 6" from the muzzle, it present as "streaks" of lead impressed into the rifling.

[mehavey]

Fired one round of the #42 above (just to get it one paper/calibrate the QuickLoad starting Burn Rate

BACO 38-26(2)gr - pure lead - sized 0.380 after PC (Eastwood Appliance White 2 parts/1 part Mirror Blue)
5744/20gr / OAL 2.515" / Burn_Start @Ba = 0.9
ReCalc'd Pressure 15,000psi/Actual muzzle velocity 1,421 fps (LABRADAR) (1,291@90 yds --> BC = 0.356)
Single dry patch down/out bore --> absolute Mirror. (like we expected something else after one round :kidding:)

Now that it's calibrated, I'll kick it up to 22.5gr / 19,300psi / 1,600fps for 10 rounds
Again pure lead.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

FWIW: 21.2gr / IMR4227 will produce almost exactly the same velocity/pressure (1,614/19,500)

[AndyC]

Leading seems worst starting around 6" from the muzzle, it present as "streaks" of lead impressed into the rifling.
Cut those 6" off - problem solved! :kidding:

I'm wondering whether there was "chatter" of some kind, at that section when the rifling was cut - I like the idea of a borescope so you can have a close look.

[mattri]

Probably be the next step, have a call into JES to see what he says.

[DonHowe]

Talking to the person who did the work is a good step. Before any conclusions are drawn regarding t he reborer readers of this thread should go to web pages of companies offering this service and do some reading.
When boring/rifling a new barrel, if it does not come out good it can be tossed. When reboring/rerifling an existing barrel there is risk of encountering conditions within the steel which can vary the outcome of the process. To my understanding this is rare in modern barrel steels but not unheard of, thus these risks are usually stated up front.
Even if there is an issue with the barrel in question I would not write it off prematurely. There are things to try but not before talking to the reborer.

[tmanbuckhunter]

I have a 38/55 rebore from JES that shoots laser beams, with no leading. Are you absolutely, positively SURE you're seeing leading? The bullets you are using are likely too hard which doesn't help. Sometimes antimony will streak and leave traces behind that scrubs out often times with just a dry patch.

[popper]

Crayon lube is terrible. Crayon lube depends on compressing the alloy into the lube grooves to 'leak' lube into the barrel. Hard alloy doesn't compress much. 2 coats BLL or something like it should work well. I push 170gr to 1600 in 300BO with BLL, no leading. Stick with the 4227 or something slower. I tried HiTek in 30/30/300BO and 308, didn't work well at HV.
As a test, try wiping/dipping the bullets with Mazzola oil, then seat. If rifling and alloy are good, you will NOT get leading.

[jonp]

I have a 38/55 rebore from JES that shoots laser beams, with no leading. Are you absolutely, positively SURE you're seeing leading? The bullets you are using are likely too hard which doesn't help. Sometimes antimony will streak and leave traces behind that scrubs out often times with just a dry patch.

Are you absolutely, positively SURE you're seeing leading? The bullets you are using are likely too hard which doesn't help. Sometimes antimony will streak and leave traces behind that scrubs out often times with just a dry patch.

Larry Gibson put me onto this with a Kahr barrel a few years ago. I tried everything to stop the leading but it seems this was what it was, at least I think it was as I eliminated about everything else.

As a test, try wiping/dipping the bullets with Mazzola oil, then seat. If rifling and alloy are good, you will NOT get leading.

I've not read that before. I now have a weekend project! It might be nit picky but is there a difference in corn oil, olive oil, cannola oil, peanut oil etc in this?

[mehavey]

Post#41 (https://castboolits.gunloads.com/showthread.php?424854-Boolit-sized-lubed-coated-etc-properly-why-am-I-still-getting-leading&p=5186595&viewfull=1#post5186595) Bullets today/3 Rnds at 50yds: 3/4"
Pure Lead again
IMR4227/21.5 gr/16,184psi/1,530fps

Having calibrated, tomorrow IMR4227/23.5gr ==>19,891/1,650fps
Soft is good.


Mirror Bore/Not even flakes

[mattri]

Just off the phone with JES.

Explained the situation, the different boolits, types of lube, coatings, gas checked and non, the velocities involved, that through multiple other firearms, calibers, chamberings, boolits etc have never had this issue before- and he replied:

"Huh, yeah, I don't know"

Any suggestions?

"No, not really"

At least he returned the call.

[tmanbuckhunter]

OP, before you potentially go down the rabbit hole of bad mouthing JES, have you at least tried some of the suggestions given to you here? Have you made a chamber cast and sized to the throat? Are you trying a softer alloy? Softer lubricant? Hell, take your commercially cast bullets, clean the crayon lube out of the grooves, and re-lube with NRA 50/50, SPG, or even just a Crisco/beeswax 50/50 mix and try that.

The bore on my 38/55 rebore is mirror bright and smooth. He hand laps these things. I'm not saying he couldn't have screwed up, but unless you have tried the suggestions given to you here, I don't know what to tell you. The man hand laps everything.

[centershot]

mattri,
As Dusty Bannister suggested, do a pound cast to determine your chamber/throat/bore dimensions. Until you nail down the numbers you don't know what you'll need for a proper bullet, COAL. Then, do as Larry suggested - re-lube a properly sized bullet with an Alox lube and go shoot them.

[DougGuy]

Re scanning the 3 pages of this thread, many suggestions have been made, I think of the ones repeated the most that I can see, suggest a boolit which is too hard. I suggested this too. Mehavey uses pure lead, I am not suggesting you follow his lead to the letter, but he has a combo that works for him.

I would once again suggest a softer alloy, one that can be scratched with a thumbnail, and no PC or HT, use a conventionally lubed cast boolit of soft alloy and soft lube. Get some samples from members here in the boolit exchange board, I believe you will finally have a clean bore with soft alloy and soft lube.

[mattri]

Thanks again for all who have replied and continue to chime in.

I can't imagine how anyone could possibly infer that I am badnmouthing JES, I have said nothing negative and simply repeated his replies.

A chamber cast is on the list of things to try, as are different lubes and borescoping.

The use of multiple alloys, lubes and coatings seem to preclude all of the above simultaneously being too hard and failing concurrently but nothing is impossible.

In all of the various pistols and rifles I have cast for or used commercially cast boolits for, with these and other lubes/coatings, also gas checked and non, also at these and higher speeds, with these and other powders, in new and old bores- never seen anything like it.

Can't be lucky forever:shock:

[tmanbuckhunter]

My only other suggestion is with these harder commercial bullets you are using, with the hard crayon lubes, you may be pushing them too slow. Step the heat up to 1500+ and see what happens.

[mehavey]

mattri: Let's chat Off-Line

https://i.postimg.cc/Wb88mHNN/38-55-BACO38-260-Pure-Ld-IMR4227-23.jpg

[Pavia]

My only other suggestion is with these harder commercial bullets you are using, with the hard crayon lubes, you may be pushing them too slow. Step the heat up to 1500+ and see what happens.

Agreed. Too slow of a velocity and you get gas cutting past the bullet, if it’s not fully into the rifling.

[mattri]

https://i.postimg.cc/p5YFxbNs/IMG-20210516-153642.jpg (https://postimg.cc/p5YFxbNs)

https://i.postimg.cc/jCXHGPst/IMG-20210516-153343.jpg (https://postimg.cc/jCXHGPst)

https://i.postimg.cc/v4pfWvvL/IMG-20210516-153338.jpg (https://postimg.cc/v4pfWvvL)

https://i.postimg.cc/9rk7hBs5/IMG-20210516-153315.jpg (https://postimg.cc/9rk7hBs5)

https://i.postimg.cc/7bsC3VHG/IMG-20210516-152409.jpg (https://postimg.cc/7bsC3VHG)

Sorry for the poor quality pics, guess I missed some lead too.

[mattri]

https://i.postimg.cc/gnNt7X2Q/IMG-20210517-190658.jpg (https://postimg.cc/gnNt7X2Q)
https://i.postimg.cc/NKnJg3Tx/IMG-20210517-190643.jpg (https://postimg.cc/NKnJg3Tx)

Shilen for comparison. Explains the leading anyway.

[PAndy]

Did anyone suggest fire-lapping the bore?

[oley55]

mattri,

if those pics are from/with a Teslong borescope you need to play with the focus to get clearer pics. There is a tiny lock ring screwed down against the mirror assembly, back it off and then rotate the entire mirror assembly to get in focus. The focus will change based on diameter of the barrel and location. i.e. in perfect focus in the barrel but as the borescope is pushed into the wider area of the throat and chamber it will go out of focus. Also try to avoid twisting the borescope in the barrel, but rather rotate the barrel. the focal point for clarity is pretty narrow and you have adjusted the mirror with the scope laying in the bottom of the barrel, if you twist the bore scope it's distance from the bore changes and things get blurry.

kind of a PIA, but for what they cost...just a matter of patience and practice. If it's not a Teslong all of this is probably useless information.

[mattri]

Thanks foe the tips on the scope, first time using it not a pro by any means. It certainly shows the condition of the bore though, I had obviously suspected it might be rough but was genuinely surprised at what I saw.

Firelapping is an option, have to think about where to go from here.

Thanks again to everyone who replied.

[oley55]

for what it's worth....that scope provides SIGNIFICANT magnification and the images you see can cause alarm when it's not really bad at all. There have been plenty of discussions critical of we dummies running around screaming the sky is falling after seeing our barrels under magnification. I'm no expert on barrels but even with your blurred photos, those button chatter marks don't look horrible.

I do note the near absence of chatter on the lands as opposed to those in the grooves. Makes wonder about the lapping process used. I only wonder because I am mostly ignorant of the processes.

A little fire lapping may help, but I'd wait n see what some of our forum experts have to say before heading there. Fire lapping is a loooong and laborious process. Especially, if you must do it a a public range.

[mattri]

Which is why I included the pictures of the other barrel for comparision. The difference in machining is obvious.

[oley55]

Which is why I included the pictures of the other barrel for comparision. The difference in machining is obvious.

my apologies if my post/s seemed arrogant or belittling. When I said, "we dummies..." I really meant "dummies like me..." from a been there, done that. I will continue to follow your progress with interest.

best regards, Oley

[mattri]

No offense taken, I agree a comparison is needed, hence examining the other barrel to show the striking differences.

[rockydoc]

When you have mentioned coating, I have seen only Hi-Tek mentioned. You don't mention powders or coating method. If you are powder coating commercial boolits You should completely remove the crayon lube before applying the powder.

[Larry Gibson]

A lubed cast bullet rides on a layer of lube. Properly lubed the alloy should not touch the bore, ergo, no leading. I have shot a lot of properly lubed cast bullets through rough, corroded and pitted milsurp barrels with no leading and good accuracy. Many original BP rifle barrels also are rough, corroded and pitted yet they also shoot quite well with no leading. Properly lubed cast bullets also shoot fine through inexpensive commercial barrels with a lot rougher machine marks than yours shows without any leading. It is your lube that is the problem. Before doing anything to the barrel try a better lube.

As to the PC bullets. I have tested quite a few and have found some leave a PC fouling in the bore which can be easily confused with leading. That is even in some very good barrels that do not otherwise foul.

Try a good lube such as Lars 2500+ or his NRA 50/50 lube. Even a light coat of LLA can solve the problem many times.

[tmanbuckhunter]

I've even been known to lube a PC bullet. Why not? :lovebooli