Interesting "gas cut"!

[JWFilips]

Hi Guys,
I was out this morning with my new .358 Win rebore by JES.
Since I was the only one on the range I got to probe the berms for my shot bullets.
I was shooting a plain Base version of the RCBS 35 200 with a new alloy ( 3 parts Jacketed range scrap / to one part Commercial Cast range scrap. Water dropped and aged 3 weeks for a bhn of about 17.)
I had a pretty good success rate of recovery ...but this one bullet really jumped out at me! There is a hole from the base to the lower part of the lube groove! Anybody ever seen this before? I can stick a straight pin right through the hole!
Here are some annotated photos:

 

[quicksylver]

Jim ...you weight sort your bullets right..?

I can create voids like that by pouring too fast and or with less than good venting....also with insufficient sprue material.....I imagine if a plain base bull had one hidden just below the surface or just skined over the gas could cut through ...

 

[Ian]

Oh yeah, casting void. Seen a few when cleaning out my own bullet traps. An eye opener for sure. I've caught a few coming out of the luber sizer after wiping the bases and inspecting them, sometimes the air pressure will make a tiny dimple where there's a hidden void just under the surface. A pinprick will determine if it gets recycled or loaded and shot.

 

[quicksylver]

Gota raise heck with accuracy....

 

[quicksylver]

I wasn't through....there was a guy who cut bullets down the middle to expose stuff like this...very interesting ..when I get back I will try and find the thread

 

[358156 hp]

There was an article in an old issue of "The Fouling Shot" about cast bullet voids. It was suggested that tumbling "as cast" bullets in walnut media could show you all sorts of interesting things about cast bullet voids. I've always meant to try it, but never have.

 

[quicksylver]

HP....the thread I was mentioning also showed the crystalline structures like those found in rocks...
that could be found inside bullets ....

 

[JWFilips]

Well the first one I had since 2012 ...at least that I know of! I figured it as such! You guys are top notch!
Yes I bet that one "screwed the pooch" but I have no Idea which "pooch"

 

[fiver]

I have got a couple of lino pigs that had hidden voids in them.
a 5 pound hole right in the middle [of a 25 lb pig] surrounded by 1/4" of alloy on 2 sides.
never could figure that one out, there for sure is enough venting with a 2 sided triangle shaped mold.

 

[Ian]

Eutectic alloy + splash when pouring = void frozen in place in an instant.

 

[Rick]

Seems pretty obvious, Jim has a serious termite problem.

 

[KHornet]

Have over the years seen a few similar to that void, and agree with all of the comments above. Most of us small bullet shooters weigh and segregate our bullets just as a matter of expediency. However, we tend not to be so expedient with big heavy ones, and pistol and revolver bullets, due to time constraints, etc. If I was a betting man, would put money on the fact that that bullet Jim, probably weighed from at least 3 to possibly closer to 5 grains from the mean. Have cut thru 45-70 400-500gr bullets that weighed 5 or more grains from the mean and found voids near the base. At the time I attributed that to be an inadequate sprew puddle, and still think that is the most probably cause. I cast the vast majority of my bullets from an RCBS bottom pour, but, if when I cast big (4-500 gr) bullets, I have gone to ladle pour with runover, and believe that to be the best way for me to do it. There are some I am sure that will pressure pour to eliminate that problem with heavy bullets, but have never done that with heavy ones. And then sometimes, just sometimes crap just happens!

 

[James W. Miner]

I ladle cast and hold the ladle tight to the plate for enough time the boolit takes what lead it needs without depending on the sprue. To try and take lead from a sprue that has set before the boolit is full will lead to that.

 

[Missionary]

Greetings
That is the best picture of a cast void I have ever seen ! Thank you for posting this. Never have seen one so extreme as to blow out the side. But then I have never recovered one blown through.
Sure is a super incentive to keep the little electronic scale handy. Thank you !
Mike in Peru

 

[JWFilips]

Well guys, I do weigh all my cast bullets most times they are put in baggies of .1 gr increments for my my sub .30 calibers For my 8mm + calibers I may go as "carefree an reckless" as .3gr .
I'm thinking that since this was one of hundreds I had thrown down range in the past 4 weeks ( into the same part of the berm) It may have been one of my many culls that instead of remelting , I used to blow out my reformed .358 Win brass. I fire formed about 250 pieces in that time. Much of that I just shot into the berm ( selecting clumps of dirt as targets of opportunity!) I would imagine If I had shot that one at a target I would have known!

I have been pretty lucky recently in that every range trip I can usually recover bout 1/3 or more of my bullets without any real digging
I will be saving that one , for sure!

 

[KHornet]

It will make a good addition to your collection box.