Bullet base voids

Good morning guys,

I know that the base of bullet is as important or more important than the nose. My question is, if there are any small voids or low spots in the base center how critical is it? My base edges are sharp just some small voids where air got trapped and left a low spot around the middle. I will post a picture of later.

You just asked the question that was on my mind as well. I do know the cause, I added a little bit much bullet lube under the sprue plate since the bubbles were so tiny I didn't cull them guess I'll find out how they shoot soon enough. Still a great question just how much of a bullet or base defect can we get away with.

So I did shoot some over the weekend and had some results that made me happy and some that made me scratch my head. All shots felt good, so I believe they are all Valid. I had one out of every 3 shot group I did was a flyer. Sometimes it would be the second shot and sometimes the third. Sometimes it would go right and sometimes it would be low. Not crazy far off, but not what I would call acceptable to me. 2 of the shots would always be either touching or almost through the same hole. So, I wondered if this is what is causing it. The other variable is that I am not sizing them after dropping from the mold. I did order a Hankins sizer to handle this part. All bullets are with less then half a grain weight wise and all powder charges are by weight. Also no matter the charge load the result was the same. I shot from 60 grains to 80 grains of 2f swiss. The 70 and 75 grain load shot the best however. The bullet is 355 grains and .75 long. According to JB stability calculator I am at a 1.5 stability factor with a 48 twist. This is a stock TC Renegade.

Did you look at each bullet for defects before you shot them or were all bullets defective  to a degree

No and that was one of the head scratch parts. I honestly didn't even notice until afterwards. I was so focused on making sure the edges where crisp that I overlooked it. I know now for sure. When I came home from the range I was cleaning things up and noticed it. Then I started wondering if that was the issue I was having, or one of.

So, I shot some of the bullets that had the small imperfections today, followed by ones that didn't have them. I can say that the ones that didn't have any imperfections all shot much more consistent in my case.  I had no fliers at all. All shots were on the money. The ones that had the small imperfections shot just as before. Some did well and then there was a flyer in the group. Anything that is not perfect will go back in the pot for sure.

I found that happened to me when I use bullet lube under the sprue plate or on top of the plate. So I no longer use lube, I just get the mold to the right temperature and have my pure lead at 800 degrees. No more tiny holes in the base.

Ed, I have heard of guys doing that with bullet lube. I haven't tried that before. My case is simply a newbie error or still learning. I spent a few days playing with Temps of the mold as well as my alloy. I found what gives me the best result in my case anyway. I run my alloy at 750 and preheat my mold to 300 I also started leaving a larger build up on the sprue plate. After I drop a few it settles in around 275 and I haven't had the small voids since then. My first mold I started with worked perfectly, but its a smaller bullet as well. I am still learning and having a great time doing it. Looking forward to stretching its legs now that I have a confirmed zero.

Just curious as to how you heat your mold to 300 degrees? I insert one end into the melted lead for about 6 minutes with an iron mold. Scrape the excess lead off and start casting. I'm going to try Lew's method of using two butane torches for about two minutes to heat the mold up. Naturally, you have to move the mold back and forth to eliminate possible damage to the mold.

Ed, I use Lews method with 2 torches, then read it with a digital temp gun.

I have to get me one of them digital temp guns. How long using the two torches does it take to reach 300 degrees?

Its a great tool to have for sure. It takes about 2 to 3 minutes with a steady rotation of the mold. I check it on the inside of the bullet cavity.