More Leading

[Johnw...ski]

Last week I started a thread under "Leading?", below is a copy.

This week after returning from the range I am still having the same problem.
Upon getting home I proceded to clean my rifle and the first few patches produced some lead, sort of like little shards stuck together on the patches after being run through the barrel.

The only changes today from last week are 1 gr. less powder and a change in boolit lube to Carnuba Red from White Label.

I would think that the 1700 FPS range should be doable with a gas checked boolit at 15.4 BHN.

The lead is super easy to clean out and I would think dropping the charge another grain or two would cure this problem. Am I missing something?

Thanks,

John


(from 7-3-09)
Just got back from the range. Today I loaded some of the boolits from the 462560
mould I got on a recent group buy. The lead I used is an unknown mix as most of my lead is but the cast boolits are 545 gr. which is the correct weight and are
15.4 BHN. That is how I always determine my lead mix, by weight in a known mould and hardness. The boolits were sized to .460 and the lube was BAC from White Label. My barrel slugs at .4582. The load in a .458 Win Mag with CCI 250 primers, 59.0 gr. IMR 4064 which should give a velocity of around 1730 FPS."

I sighted in on an SR-1 target at 100 yds. offhand, after a minor sight adjustment,
I was shooting 6" groups offhand which is about right for my ability.

When I got home and started cleaning the rifle, the first several patches came out with quite a lot of lead on them. The funny thing is I was able to get almost all the lead out with wet patches, one swipe with my Lewis lead remover did the rest. It's not like the barrel was really leaded, it came out so easily, but there was certainly lead there.

I have been having a similar problem with my .35 Whelen, I can shoot Glenhills Cast Boolits (245 gr. sized to .359) with great accuracy at around 2000 FPS but my 245 gr. boolits from a similar mould sized to .359 with BAC lube and a BHN about 2.0 harder leads whenever I get near that velocity.

Does anyone on here know how White Label Red Carnuba would compare to the Glenhills green lube? I think I could cure this leading with a better lube.

I look forward to hearing any comments about this.

[243winxb]

When the velocity is over 900fps, you must have 2 to 4% tin in the alloy. From Lyman-
While antimony is used to harden the bullet, the mixture of tin is critical, for while antimony mixes with lead in its molten state, it will not remain mixed when it solidifies. If tin were not added, we would have pure antimony crystals surrounded by pure lead. A bullet of this type , while it feels hard , would certainly lead the bore and eliminate all potential for accuracy. In a lead-tin-antimony mixture, the antimony crystals will be present just the same, but they will be imbedded in a lead-tin mixutre. As the bullet cools the tin will form around the antimony-lead keeping your bullets from leading the bore.

[Gohon]

Maybe LLA to cover that long bore riding nose hanging out front??

[Johnw...ski]

Is there a chart out there listing the relationship between hardness and velocity possibly with some mention of gas checks?

Thanks,

John

[WHITETAIL]

:Fire:Ski, have you tried coating your boolets with JPW?

[Johnw...ski]

:Fire:Ski, have you tried coating your boolets with JPW?

No I haven't

[WHITETAIL]

The process is easy.
Just put them in a jar and add
some JPW.
Then heat the jar in the sun,
or on low on a hot plate.
Then roll them around in the jar.
Take tweesers and stand them on
wax paper.
Let them dry over night, and then
size them and load them.:cbpour:

[243winxb]

The funny thing is I was able to get almost all the lead out with wet patches, one swipe with my Lewis lead remover did the rest. It's not like the barrel was really leaded, it came out so easily, but there was certainly lead there. Sounds like you have normal foulling. Leading to me is when accurace goes away. Pure copper is 40 BHN good to 56,900 PSI. A GC is 90% copper, 10% zinc, harder then pure copper, i would guess?? Got the 40BHN info here, not sure if its correct. http:///en.wikipedia.org/wiki/Obturate Here is a lead alloy chart. Lyman #2 has 5% Tin. Click for larger View. http://i338.photobucket.com/albums/n420/joe1944usa/th_Alloy_20090610_1.jpg (http://i338.photobucket.com/albums/n420/joe1944usa/Alloy_20090610_1.jpg)

[Johnw...ski]

Yah, the accuracy is still reasonable, for offhand anyway, I don't really want to bench this thing. As I said it seems to be a lot of lead coming out with the first few patches. I guess I can either back off on the powder some more or try a harder lead. Being a .458 I would like to keep a little snap to it, going much lower on the powder charge I may as well shoot my 45-70.

I have a batch of lead that is 17.9, I'll have to cast some boolits and try again.

[243winxb]

I have a batch of lead that is 17.9, I'll have to cast some boolits and try again. You must have Tin in the alloy as said in post #2. I never know what is in my alloy % wise. I do add 1 ingot of linotype to 7 of misc indoor range scrap or WW's. Using 50/50 bees wax and alox has worked well for years. Shooting 30 caliber GC to 2200 fps has always worked using IMR 4895. Pistol PB to 1300fps. All with normal fouling.

[Johnw...ski]

I seem to have a lot of unknown ally that has a lot of tin but no antimony.
I say this because this alloy is much less dense than pure lead and hardly age hardens. Last year I got some foundry type, so my antimony shortage is over, my boolits age harden nicely now.

I have a mold I use for testing alloys, it's over 500 gr. and I mix an alloy until I get the weight in the mold I am looking for then test for hardness and adjust the alloy as needed. I know its not the most accurate way to mix lead, but with all the unknown stuff I have around it seems to work.

John

[Bret4207]

Are your boolits truly coming out of the sizer at .460 or is that what it's marked? It can be marked .460 and sizing them to .458 or 9, just something to check. You might try a .461 if you have access. Dropping the powder may work and upping might work, strangely enough, too. Is it possible it's a rough spot in the barrel?

On the 35, you're using a similar boolit made by someone else as I understand. "Similar" isn't the same, your alloys are different and the moulds are different as are the lubes. In essence you're starting from zero all over again with a different boolit.

[Johnw...ski]

Are your boolits truly coming out of the sizer at .460 or is that what it's marked? It can be marked .460 and sizing them to .458 or 9, just something to check. You might try a .461 if you have access. Dropping the powder may work and upping might work, strangely enough, too. Is it possible it's a rough spot in the barrel?

On the 35, you're using a similar boolit made by someone else as I understand. "Similar" isn't the same, your alloys are different and the moulds are different as are the lubes. In essence you're starting from zero all over again with a different boolit.

Actually closer to .4605.

Both of these barrels are older McGowen barrels, older being they were new when installed 22 years ago and not shot since last year. The barrels are not the smoothest inside and do not compare to the quality of McGowens latest barrels.
I agree it would be better if the were smoother but I don't think that is the problem.

On the .35 the boolit is from the same Saeco mold lapped to .359 and then sized and lubed in a .359 sizer. They mike at .359. The alloy from the commercial boolit is 14.3, I checked it yesterday, and mine are 15.4. The commercial lube is a very hard green lube and must be extremly effective.

John

[Bret4207]

A rough barrel can do some bad things. It could be part of the problem. BA would tell you to put 500 jacketed through it and then try cast.

You are using the same mould the other guy used? Or are you using the same design? His alloy may be softer, but it may also have other characteristics different than yours. I'm not trying to talk you into another idea, just trying to get you to see it's not as simple as "same mould design, harder alloy". The difference may be something you never quite identify.

It could be the lube. Or it could be a tiny difference in diameter or another characteristic that makes the diff.

[44man]

Leading is a funny issue. You have to know what you have. If you shoot 5 rounds and get a few strands of loose lead out on a patch and then shoot 100 rounds and get the exact same amount of lead on a patch, it is something you can ignore because each boolit is cleaning out the lead from the previous shot. You MIGHT improve accuracy by not getting any lead at all. I have done it, I mean I have had zero lead out of the bore many times, but I can't say I shot better because of it.
As long as the lead is loose and wipes out, the lube is working.
The time to worry is when lead keeps packing up in the bore, getting thicker and thicker. If you need brass scrubbers to remove lead, then you have leading.

[HeavyMetal]

I'm thinking your load is generating about 28,000 PSI.

Your 15.4 BHN alloy is "fading" out at about 21,000 PSI. THe 17 BHN alloy will go to about 25,000 PSI and that may be all you need to lose the leading with the Carnuba Red.

However I woulds also try an alloy that was about 19 BHN This should hold up to about 27,000 PSI loadings .

I think you've got the sizing right and also the lube.

I might also suggest a return to basic's here and ask if you've pulled a seated boolit to make sure the case neck isn't sizing your boolit a little more for you?

This is one of those trust but verifiy things I always do when I have a problem I need to solve.

Bear in mind I have never loaded for a 458! But the same basic alloy "principles" must remain the same, no?

Looking forward to your next post on this subject.

[Johnw...ski]

I'm thinking your load is generating about 28,000 PSI.

Your 15.4 BHN alloy is "fading" out at about 21,000 PSI. THe 17 BHN alloy will go to about 25,000 PSI and that may be all you need to lose the leading with the Carnuba Red.

However I woulds also try an alloy that was about 19 BHN This should hold up to about 27,000 PSI loadings .

I think you've got the sizing right and also the lube.

I might also suggest a return to basic's here and ask if you've pulled a seated boolit to make sure the case neck isn't sizing your boolit a little more for you?

This is one of those trust but verifiy things I always do when I have a problem I need to solve.

Bear in mind I have never loaded for a 458! But the same basic alloy "principles" must remain the same, no?

Looking forward to your next post on this subject.

Good point, I just seated and pulled a boolit and it was .001 smaller (.4595).

Do you have a list or chart of those hardness/velocity numbers?

Thanks,

John

[Freightman]

Had a barrel that was rough and leaded somewhat, a friend at the range suggested I paste wax my barrel for awhile before I came to the range. Well I thought nothing to lose so did it and the leading quit, I now just run a patch with some JPW down it every once in awhile. Does it work? haven't a clue but doesn't waist anything.

[243winxb]

Do you have a list or chart of those hardness/velocity numbers?Bullet's BHN x 1422 = Pounds per square inch. This would be the Maximum PSI for a flat base bullet. It has little to do about FPS. Its the pressure working on the base of the bullet. If over this pressure the base of the bullet is deformed. Its good to stay 10% under the maximum pressure. The Chart is with the Lee hardness test. I do not own one. Another problem is guessing at what the pressure might be of your loaded ammo.

[runfiverun]

that 1422 works for a good start if you stay at the 90% margin and work up.
it really isn't the endall though, as i have pushed 16 bhn well over 2200fps. with super accuracy. with a g/c without a g'c iv'e gotten over 1600 with a plain base.
i totally agree with 44 man on his post if it isn't causing any problema why sweat it.
i'd try the wet bore condition before your next range session.
if your are cleaning it every time out our bbl may just like to be seasoned for the best long term results.