50 / 50 WW and Pure

[Bass Ackward]

This might be a bit premature because it will take me a year to answer my last question about this mix which is, how much will it soften in a year? I tend to mold a lot in the winter for use all year. I would like to HT in large batches for cost advantages. And if something should happen that ammo gets stored for a year, I want it to be accurate as well as safe.

My guess is that should be right around ACWW hardness of 12. But that is just a guess at this point.

I have been doing expansion testing with several hardnesses of bullets under a very unscientific methods and not for enough attempts to be statistically significant. My beliefs at this point are that there are benifits to using 50 / 50 mix.

I can't speak to obturation because I tried to eliminate it as much as possible as a variable by choking in rifles and sizing larger than my throats in handguns. But impact testing says that a bullet that has X amount of heat treated hardness expands like a bullet with that same hardness derived by chemical means. In other words, hardness is hardness. Now there is a qualifier here. That means right up until the point where the chemical produced hardness becomes brittle in the medium of interest.

The added benifit (to me) came from observation of bore conditions before and after. There strong advantage / disadvantage was in the lack of throat / barrel wear with the lower amount of antimony bullets that have been HTed comparred to antimony. IF you are wanting to break in a barrel go chemical. If you want to extend the life of your barrel, HT. After looking at my new 223 throat, I would say that shooting linotype is harder on a throat than jacketed at the same pressure. Besides being throat opening, it was eye opening as well. No wonder cast bullet bench rest rifles don't seem to last as long as jacketed bench rest barrels even when the jacketed are run at higher pressures. :shock:

[felix]

Very true, BA. Antimony will smooth a barrel quite quickly just as you say. It is more of a proportion of tin to antimony than anything else. To keep barrel wear to a minimum, make the tin component at least equal to the antimony component, like Lyman's 90-5-5 mixture. ... felix

[nighthunter]

I can't speak on this subject from a scientific stand point. I do know years ago when I could get cable sheathing from the phone company for free I shot tons of 50/50 WW to lead. I never had any leading or accuracy problems at handgun velocities. However ... I think WW were much harder back then than they are today. I still have a stash of the cable sheathing and I often add 10% lead to WW with no problems to nearly 2000 fps with gas checks. Just my 2 cents worth.
Nighthunter

[felix]

Nighthunter, it seems BA is talking wear versus accuracy here. Life is too short, really, to screw around with trying to save a barrel. When a barrel starts to shooting really good, however, then it is time to try to preserve its level of accuracy. Changing the alloy and boolit, and finding a cooler burning powder for a load is the way to go, with the hope of saving the velocity too. If not, so what. ... felix

[Bass Ackward]

Nighthunter, it seems BA is talking wear versus accuracy here. Life is too short, really, to screw around with trying to save a barrel. When a barrel starts to shooting really good, however, then it is time to try to preserve its level of accuracy. Changing the alloy and boolit, and finding a cooler burning powder for a load is the way to go, with the hope of saving the velocity too. If not, so what. ... felix


Felix,

Yes. I was talking wear. But I mean that not only did I lose the tool marks, but the throat lengthened what I would guess to be .020. I just finished setting the barrel back and cleaned it up again. Whoa.

Ya know that I "knew" this already. I myself am constantly telling everyone to balance tin and antimony. And my linotype was tin depleated. So why didn't I listen to my own advise? Well I will tell you why. I didn't think 40 shots would do that kind of .... smoothing. And I was too lazy and cheap to reconsitute the tin so I said I would just see. I chose the 22 caliber for expansion testing because it is the smalest diameter bullet I shoot so it is the weakest from a diameter standpoint and would show expansion the easiest as it can be much more difficult on larger bores to tell.

My next experiment is to take a junk barrel and cut a new chamber. Compare cast and jacketed at the same pressure levels. Then set it back again and use soft cast and different grades of fire lapping grit to see where I get close to that smoothing effect. (throat movement). If I had to guess right now, I would say that shooting lino is about like shooting ACWW with 800 grit on it.

And true, I have no qualms about screwing on a new barrel, but I'd prefer if it wasn't monthly. How many people are out there shooting lino that don't have this knowledge? And if they are choking, boy are they in for a surprise when they slug the next time. Whoa!

[9.3X62AL]

Interesting info. This might answer the questions I had about why the 25-20 started behaving itself after 650-700 castings went down its tube. The little rifle was a tackdriver with Speer 75 FN's from Day 1, but was reluctant to perform well with castings until SOMETHING occurred bore-wise, I'm guessing.

It's a little tough to get my head around the idea that antimony alloys might be harder or more abrasive than cupro-nickel jackets (all other variables being equal), but maybe so. Like BA, I'm not adverse to a re-barrel but would rather not require a fleet discount at the gunsmith.

[JohnH]

BA, It was good to hear someone say hardness is hardness. While I've done no testing of my own to satisfy my mind on this, it defies logic that a bullet of X hardness achieved by water dropping will still expand like a bullet of less hardness as some report. Sounds to good to be true, asks us to believe that WW is some sort of miracle metal.

As to barrel wear and antimony, just how much antimony content are we talking about here? I've got a bit over 1000 rounds of cast through my 375 JDJ and took a tight patch and 600 grit lapping compound to it Friday (The second time now) to finally get the barrel smooth enough to stop leading at the root of the lands. The chamber still chokes on a .377 diameter driving band, just as it did when it was new, and my seating length hasn't changed nor shown the need to be changed. My alloy is simple WW with 2% tin added. I can only assume that this alloy doesn't have a high enough antimony content to wear as you describe. What about those who shoot 50/50 WW and Lino? Do you think that alloy would be problematic?

[felix]

WW plus Lino is still top heavy on antimony, no matter the proportion. Add tin to stop wear beyond no more reason to wear. Using 600 grit took about 2000 rounds off of that barrel when the boolits are WW or Lino.

Cupro-nickle is probably the best jacket material to use for barrel conditioning after the barrel is fairly smooth to begin with. Why? Because the material is tough, and much tougher than guilding metal. Antimony is very brittle in comparision, and when a "parcel" of antimony breaks in half so-to-speak, it leaves very sharp edges. No sharp edges with cupro-nickle. More of a burnishing arrangement. ... felix

[9.3X62AL]

Wear is wear. OK, that tells me to enjoy the accuracy while it lasts. Look out, jackrabbits!

[Bass Ackward]

Well first let me say that I am NOT saying that lino causes more wear than jacketed. I only made visual observation and did not measure. Only that the amount shown by the lino was clearly more than I expected for the number of rounds fired. I would not expect jacketed to move a throat with those few of shots either no matter how deep the tool marks. And the polishing action was full throat. It could be that I have less tough steel than I suspected and I plan to investigate further. Or maybe I should have fired several jacketed first to smooth everything and sort of flame harden the steel in the throat area. This was not part of the origional experiment and I was unprepared for the results.

I normally use WW +2% tin for the wear qualities too and have few problems from it, although high pressure applications will cause more activity in a shorter period of time than low pressure stuff. That's because most throat wear is from powder and gases. I expect that as part of the game. There is no free lunch.

Tin does counter antimony effects. That is the purpose of trying the 50 / 50, WW / pure mix. Especially, if the answer for the long term softening question is positive. IF I can get by using 1/2 the antimoney of WW and still get bullets of ACWW hardness after one year, then why shoot more antimony I need to? 1/2 the antimony, then I only need 1/2 the tin too.


JohnH,

Bigger bore, wider rifling? Better steel? I don't have an answer.

[JDL]

Bass,
That's very intresting about the throat on your .223. This may apply to some of your thoughts.
I cast up a large lot of RCBS 35-200 in Oct. 1986 and still have a few. The alloy was 1 lino / 3 Pb, cast 9 on the thermostat of my Lee drip-o-matic and dropped into water. Should I have accidentally ciphered correctly, the alloy should be approximately 96%pb 3% sb 1% sn or slightly more sb & sn to the half and half you are experimenting with. I believe your alloy will be approx. 97.1%pb 2.12%sb .2%sn.
I got my hardness tester in 2003 and proceeded to check the hardness of everything I could find :-D, including this lot of boolits. They checked out at 23 BHN, which at first didn't seem reasonable as lino is supposed to be 22 but, the difference may be between air cooled and quinched.
Anyway, several years ago, I tested these against some 200 grain Sierra in wet media and could find very little difference in penetration and expansion, both were very uniformally expanded.
This probably doesn't do anything to help out but, I thought I might relate it to you. -JDL

[StarMetal]

Bass,

When I lived in Tulsa I had a mind boggling amount of lino type. So did my best friend. We shot it out of everything we had. I noticed absolutely nothing happening to my firearms...and believe me I looked and checked. I had read that most if not all the wear in a barrel come from powder abrasion especially when the barrel is really hot. You stated alot of times that when shooting full power cast loads equal to jacketed loads is when the wear was evident. Could it not be from the powder then?

Joe

[Bass Ackward]

You stated alot of times that when shooting full power cast loads equal to jacketed loads is when the wear was evident. Could it not be from the powder then?

Joe


Joe,

Oh sure. I said that. But there is still a problem with 40 rounds or so. The mix is right at 20 BHN. I assume that the loss of tin is the reason for the difference because my scale measures 22 as it should with "real" lino. This was the same hardness as my oven HT 50/50 mix with 22s. I could not get enough expansion out of 44s (17 BHN) into water from a wheeler to measure well enough. I would have needed much more velocity at that hardness. Which was why I went to the 223 in the first place. Saved on the amount of milk jugs too. :grin:

This is or was a short and tight match chamber. Maybe it would not have lengthened one whit more over the next 5000 rounds. Who knows. But I want this tight. Looking at it again shows no unnecessary markings other than what you would get with a circular cut cross grain. And maybe this is just one of those things where I won't be able to get what I want for very long too. This problem was described by several 223 owner shooting lead at moderate velocities and pressures. Nature of the beast?

[Bullshop]

short neck?
lube?
BIC/BS

[StarMetal]

John,

For curiousity who made the barrel?

Joe

[JohnH]

BA, Tis a puzzle indeed. I wasn't meaning to be contrary, just trying to relate your experience with mine. On the point of if 1/2 of antimony and tin will do, then it is surely a path to persue. I bought on of Buckshots testers over the winter and hardened up some 50/50 lead-WW using the oven method and each time got 28-30 BHN. I've not been able to prove satisfatorily that hardened bullets shoot any better from this barrel than does simple ACWW + 2% tin, but the latter alloy performs decidedly better than does 50/50 lead-WW.

[Bass Ackward]

Thanks JD.

Joe,

The barrel is a Walther that was mounted on a 220 Swift that was sold to a customer. It was not broken in and coppered badly which he would not clean. Clean it would shoot .250 groups if you shut your eyes and pulled the trigger. Coppered it was a 2" gun. He decided to change barrels and calibers. Since it was a 26" tube as a Swift, I put it on as a 24"er.

JohnH & Dan,

I don't know. I suspect shorter throat life from a short necked case, but come on. I am also wondering about the lino. Was this pure lino? Or was something else added? I fluxed the bajebers out of it as I always do and it .... seemed fine. I just didn't want to take the time / expense to go buy some tin to reconsititute the tin for expansion testing. It was the right BHN for apples to apples comparrisons after HT 50/50 22s. Strange thing to note, either my Lyman mold is vented very well or this mix molded better 22s than I expected. I wasn't real particular, but they didn't look bad.

After I have though about this some, both my and my dad's 35s were the same way. Both Shilean barrels purchased at the same time, cut by the same reamer on the same machine, etc, etc. And after 400 rounds, shooting the same bullets from the same mix my throat lengthened and his didn't. It walked until it stopped. He shot more jacketed than I did at first and he shoots jacketed every once in awhile during his rifles time was the only difference. Mine get's a steady diet of cast. Neither has shot any lino either.