My bullet is growing

[Tomme boy]

I gave some bullets to my old lady to load in her magazine to put in her lower receiver. But it had grown to big since it was sized.

Anyway, I went to load some 183gr NOE bullets for my 350 tonite. I loaded a couple and grabbed the gun to check that they would function.

NOPE!

They were very hard to close the bolt. I knew I would not be able to get it to close so I had to use a cleaning rod in from the muzzle to give a slight tap to get the bolt moving. I checked the length that was fine. but the brass had a little bit more bulge where the bullet is seated.

So I grabbed a few bullets to measure them. 0.357" I sized these to 0.3555" So they grew 0.0015" in a month. I sized and gas checked these right out of the water after powdercoat. They were right at 0.3555" This Ruger has a lot tighter everything compared to the AR barrel. I could get a 0.3565 in that and no problem. Not this one.

Anyway, This is some of the lead I mixed up from the lead I got at the scrap yard. I still have not made it down to get it scanned yet. It was mainly bullets that were already cast that I melted down. They were shiny and extremely hard. My guess is linotype. I have close to 40 lbs of whatever it is. Once I get it scanned then I can add the lead from the sheet lead I have to make it more usable. Heck, Hard lead is what I have a lot of. Over 40 of the linotype pigs I got from my old ladies father when he past. The DNR came into our public range a couple years ago and took off the top 2' of dirt from the flats and dug into the berms about 3 '. Ever since they mined it out softer lead has been more difficult to find. This range has been running since the early 60's and has never been cleaned before. I was told they made over $125K off the lead and copper. And they did not even get half of the trap field before they had to quit.

Sorry for the long >>>>>>>>> I do that. Anyway, what makes the bullets grown? I have not run into this in a long time and forgot what it was that did this.

 

[JamieHazel]

Not saying it is the case for sure here, because of Murphy and all. But, normally when that happens your tin to antimony balance is way off track in favor of too much tin. Have used that trait to my advantage to intentionally make bullets grow on purpose in order to make things fit the past. Throw a little copper into them tin rich out of balance with the antimony equations and things can really get fat and/or simply out of control fast. Since powdercoat has entered my arsenal of tricks, I use mostly pure clip on ww for most target and steel blasting ammo. For what this is worth: Powder coating simply made all them sometimes unpredictable alloy witchcraft and wizardry tricks needed for super HV much less important. I do not talk about my HV with powdercoat experience much. No one would believe me anyway. Talking about FPS readings that are north of 3K with near M.O.A, M.O.A, or less than M.O.A accuracy seems to bring out the worst teenage drama in people for some reason. Not all of us are built to deal with such petty internet arguments.

 

[Ian]

Tommy, if that's your first time you haven't been doing this enough! Bullets grow as they age, some an immeasurable amount and some a LOT. I don't know what exactly causes the growth but it seems to be a combination of things with Antimony, I suspect calcium could be an issue.


I believe you, Jamie. This board isn't like that.





100 yard test load using pc .22s and nothing special for brass prep. No tuning, dumped the same powder charge behind several different bullets with no special prep and let it rip. Need to cast and liad some more of these, they worked pretty well.

 

[JamieHazel]

Ian

That growth can be induced with certified alloys containing no calcium. I too thought contamination of some sort at one point. Spent a bunch of money only to prove myself wrong on that one. Too much tin in relation to the lead+antimony matrix will cause it all by itself. Waterdropping and/or heat treating can really let things get crazy on out of balanced alloys. If you get too tin rich with Lead+antimony AND copper it really goes haywire fast. Copper even in tiny amounts really amplifies the effect for some reason. Not a scientist, so not sure why, just keep pretty good notes. Not even sure about what the balance of the alloy needs to be, always knew when I went too far with the tin though. Luckily PC and a simple CoolWhip bowl made all that painful thinking and grey matter abuse go away. Now I just toss a tiny ingot of them super mixes into each pot of melted wheelweight and ladle my old troubles away 2-55 grainers at a time. If I live long enough the proof of all that crazy alloy nonsense will be scattered though the hills and valleys at some point.

FWIW, I was not really asking anyone to believe me. I am just a bit gun shy because I got in a fight with some ornery dude on another site that told me what I was repeatedly doing, group after group day in and day out, could not be done. He basically called me a liar then started spouting off about theories and the spin of Venus and the rpm of Mars and I simply lost it. I pushed back with proof/pictures and chrony results that others had witnessed. In the end I got banned and the thread got deleted, end of story there. He obviously has friends in the right places.

I am perfectly happy with my two loads made with an over the counter mold that anyone can buy. One load is 3022FPS (H4198) on average. The other is 3042FPS (BenchMark) on average. Both will shoot m.o.a or near m.o.a on a bad day and sub m.o.a on a good day. I am the limiting factor most days unfortunately and cannot blame the load or the gun. Whether folks believe me or not no longer affects which direction the hair in my crack lays. Heck I cannot even take credit for the loads. I stole them from another and just replicated his results. I am not too proud to steal another's effort.

 

[popper]

Tin grows into large blobs, excess makes it worse. Blobs take up more space. Cu/Sb molecules are larger (blob) than individual atom space so the alloy 'grows'. Lots of 'empty 'space between atoms.

 

[fiver]

the copper lays down a boundary layer around the antimony anyway.

it just takes time for all the migration to happen especially when you water drop freezing the alloy traps the antimony away from forming bonding chains and it then affects more alloy, of course the copper is hanging with the antimony and the whole thing keeps working until it's finished.
[that's why you see the BHN numbers creep up over 4-6 weeks time after quench cooling, and then it still takes another couple of months for it all to settle down]

Tin really retards the BHN magnification when it's in equal to or above the antimony when the alloy is quenched, that doesn't mean it isn't happening, you just don't see it because the tin has [like Popper said] blobbed up on the surface blocking you reading anything else.

 

[Ian]

interesting analysis. I don't keep very specific alloy notes because I use mostly scrap stuff and don't have a clue about the trace contaminant amounts in the first place. I do know for certain that growth long after sizing (and loading) has happened to me with straight wheelweight alloy before. I make a point to never get close to overtinning the alloy because free Sn forms nodules on the last phase of crystallization and that causes abrasion leading.

For the last several years (especially since converting almost exclusively to powder coating) I find myself making my ammunition more "universal" and giving the bullets more wiggle room. Bullet growth months after casting is much less of a concern now.

 

[fiver]

it becomes a concern when it sneaks up on you out in the field.
I can still see that 4 point slowly trotting through the sagebrush into the pines while I decide whether to squeeze the lever harder or try to jack it back open.

 

[JamieHazel]

If you can get ahead of yourself enough to only shoot 1 or 2 year old bullets, life gets much better IMO/IME. Once I figured that out I started buying my gas checks 15K -20K+ at a time and making large casting runs. My bullet storage jars for important stuff are like them beer bottles with the "born on date" now.

 

[Joshua]

So, what is the “magic age” where the majority of growth has already happened? Two weeks, two months, or two years?
Josh

 

[JamieHazel]

Personally I do not even try for semi serious groups until two months of age. I am sure others would pick differently. I can only account for what my results tell me.

 

[JWFilips]

Wish my wife could say the same for me

 

[JamieHazel]

Wish my wife could say the same for me

Have you tried poison ivy? It was temporary and very uncomfortable, but it worked.

 

[fiver]

a month has everything mostly settled down.
6 months is really super close to the max you should see.

a recommendation made to me by Felix once when we were discussing this very thing was to shoot old bullets freshly sized.

 

[Tomme boy]

I have had them grow, but not this much. This rifle must be on the tighter side in the chamber. All the other guns I have had it did not matter if they grew or not. They all shot well and had no problems until this one.

This whole 350 Legend thing has been a real pain in the rear end. If it keeps up I am going to pull the barrel and put a 223 barrel on it.

 

[fiver]

reamer a throat in it like most do for their 45-70's.