Casting from one cavity vs two

[newton]

I am wanting to eliminate as many variables as possible for some loads I am working with in the .223. I have an RCBS 22-55-SP mold and have been using the boolits from both cavities. I am curious if just casting from one of the two cavities would eliminate a variable, or if both cavities are cut from the same cherry?

I don't know if there is an difference in the two per say, they both throw very good looking boolits. I may be thinking I can get better results when in fact the difference, if any, is so small it would not matter. I don't cast for super fast production, just shooting them in a bolt gun. Thought about trying to separate the two after casting, but they drop out real easy and I like to keep a cadence going which wouldn't allow me to take a lot of time separating them.

Also thought about having one cavity hollow pointed, then they would be easy to separate. Guess I am just looking for opinions on the topic. I cant find much talk about it anywhere. Seems a lot of guys are of the more cavities the better type thought. And when it comes to precision shooting a lot of guys like the single cavity molds.

[country gent]

Put a light prick punch mark in the nose of one cavity, just enough to show in the casting as close to center of the nose as possible. This allows you to cast both cavites and sort them after as to cavity shooting each segregated. A dimple 0 or X works well to mark cavites. Make a punch up that just slips into the cavity clamp blocks together in vise and slip punch in and lightly tap to form the mark check and see if it is enough.

[newton]

Put a light prick punch mark in the nose of one cavity, just enough to show in the casting as close to center of the nose as possible. This allows you to cast both cavites and sort them after as to cavity shooting each segregated. A dimple 0 or X works well to mark cavites. Make a punch up that just slips into the cavity clamp blocks together in vise and slip punch in and lightly tap to form the mark check and see if it is enough.

I thought about this, but couldn't decide how to do it. That sounds doable though. The nose on these suckers are really small.

[Geezer in NH]

Buy a 1 cavity mould??

[gwpercle]

I don't think you are going to see a difference between the cavities of a modern mould, RCBS makes fine moulds.
The only way to tell is cast some from one cavity and see if there is an improvement.
I know serious black powder cartridge silhouette shooters that cast from one cavity and one that even marks the boolit so he can position it in the rifle in the same exact way each time. But these guy's are shooting long range and take it serious !
Gary

[reddog81]

Try to drop them from the mold right above whatever surface using are using and try to keep the bullets in seperate areas (top section vs bottom section). I've done it before win 4 cavity molds to try and measure any variance from cavity to cavity

[Le Loup Solitaire]

With one cavity molds there is no issue, but the prevalent belief over time has always been that two cavity or more do not throw the same bullets. Marking the mold in some way was the usual practice to indicate what came from where. For those concerned with this, the probable way to tell the difference is to measure and/or weigh to be sure. It is, a slow and for some, a tedious process unless there is a way to have the bullets drop separately....reasonably possible with a 2 cav, but difficult to do with a 4 or 6 holer. LLS

[newton]

I tried casting from just one of the cavities last night. It worked fine, guess the mass of the mold in comparison to the small boolit didn't need to have both cavities full to keep temp.

But, when I went to weigh them there was the same variance that I always get. So, I guess I cannot see the benefit now.

I still think I will have one hollow pointed at some time. Trying to get some prices on doing such now. If it was a cheap Lee mold, or even a larger cavity mold, then I might attempt to do it myself.

[44man]

Means nothing, just use both.
I use my old beam scale and went through the work of sorting many times and always shot worse groups anyway. I would need the gun and ability to shoot one hole at 100 to see a difference.

[Don Purcell]

Maybe with benchrest target shooting but in the overall scheme of things nothing makes up for quality trigger time.

[Spector]

Newton, do you use a a PID on your pot when you cast boolits? Just curious if a PID will make weight and diameter variances much smaller. It seems to me like it would especially if just casting from one cavity.

If it turns out it doesn't then I may stop concerning myself with that aspect of quality control when casting for 45 ACP and 45 Colt. Or even the 44's for my Swiss Vetterli. Or the 38 S&W.

I used to shoot well with my Glock 21 and never really worried about pot or mold temp or even about adding tin to my straight WW alloy. And I could hit things at 100 yards....most of the time.

Life seemed simpler back then and I spent more time shooting than reading about magic in the casting or reloading rooms.

I'm betting with all the smart people here someone has already thoroughly researched this with pistol ammo. At 69 I don't want to waste any more time worrying about things that simply don't matter significantly to pistol accuracy at 25 and 50 yards. Shooting at 100 yards is just for fun and bragging rights.............Mike

[newton]

No PID, but one day I will get around to it just to eliminate variables although I cast with the pot temp control knob set at the same place each time. However, this will only be when I am going for absolute accuracy, with known accurate rifles.

When casting for pistols I do not even worry about what alloy I use. I've never had an issue getting a good load for 25 yard groups.

I am working with my .223 and I can see it has potential for some really small groups. Right now I am hovering around the 3/4" to 1" mark at 100. Just trying to examine all the variables to try and see what works and what doesn't.