Minerat
04-21-2014, 01:02 AM
I have a new 412640 Mehi mould and appear to be having some problem with getting a gas check for it. Then I send the shank measurements to Blammer he kindly pointed out that the diameter of the GC shank was large for the caliber of the bullet.
That got me to looking in to what else might be a problem. Let me say up front this is my first try at casting so it may be a operator error and not a technical problem so be sure to point out my weaknesses as appropriate.
The case bullets coming out of the mould are sweet but too big. Then problem is, that the diameter of the casting from all 4 cavities at the drive bands are 0.415 and the GC shanks are 0.398-0.399. Blammer said the 0.398 is too large for a 0.410 bullet.
The first step was to measure the GC shank dia on the mold and it was 0.390. I don’t have the tools to measure the drive band diameters. I think this is in spec but am not sure. So the following are the measurement and paraphrased responses to Blammer questions.
The GC Shank appears to be a straight. I took the measurements between the bullet base and the first band and it seems to be pretty uniform at the bottom, middle and near the first drive ban at a uniform 0.398.
The cast bullet diameter is 0.415 and it is round. The dia from seam to seam is the same as the dia from mid seam to mid seam on the GC shank across the front drive band seam to seam is the same at 0.415 and rotated 90 deg they are the same. Across both drive bands along the long side of bullet it's the same. The bullets appear to be round not oblong or flattened.
The mould is completely together and there are no flags at the seam. All of the hollow point pins are seated flush on both sides of the mould.
Could it be I am not keeping a firm hold on the handles and letting the alloy slump as it cools? I’m not choking it to death but just keeping the handles together.
I am not dropping the bullets until then spure had solidified for the count of 5 and the bullets just drop from the mould.
I wonder if the lead mix I have is the problem and is something different then what I was told it was. I got it from a friend who's dad passed and was a caster and he said he thought it was a WW + 1% tin. But it is throwing solid bullets at 206.5 instead of the 220 gr estimated. It is a little strange too that the diameter is 0.415 not the 0.412 that the mould is designed for, but the swelling on the drive bands is less then the swelling on the GC shank (0.002 vs 0.008).
Is it possible that the alloy swells after leaving the mould? But if so how is it so uniform from cavity to cavity and pour to pour?
Sorry for being so long winded and I appreciate your help.
Attached are 5 photos of a bullet from each cavity. I tried to get some contrast on the GC shank and the first drive band. It's a 4 cavity mould and I have been casting one of each HP and a solid until I get the hang of it.
102842102843102844102845102846
That got me to looking in to what else might be a problem. Let me say up front this is my first try at casting so it may be a operator error and not a technical problem so be sure to point out my weaknesses as appropriate.
The case bullets coming out of the mould are sweet but too big. Then problem is, that the diameter of the casting from all 4 cavities at the drive bands are 0.415 and the GC shanks are 0.398-0.399. Blammer said the 0.398 is too large for a 0.410 bullet.
The first step was to measure the GC shank dia on the mold and it was 0.390. I don’t have the tools to measure the drive band diameters. I think this is in spec but am not sure. So the following are the measurement and paraphrased responses to Blammer questions.
The GC Shank appears to be a straight. I took the measurements between the bullet base and the first band and it seems to be pretty uniform at the bottom, middle and near the first drive ban at a uniform 0.398.
The cast bullet diameter is 0.415 and it is round. The dia from seam to seam is the same as the dia from mid seam to mid seam on the GC shank across the front drive band seam to seam is the same at 0.415 and rotated 90 deg they are the same. Across both drive bands along the long side of bullet it's the same. The bullets appear to be round not oblong or flattened.
The mould is completely together and there are no flags at the seam. All of the hollow point pins are seated flush on both sides of the mould.
Could it be I am not keeping a firm hold on the handles and letting the alloy slump as it cools? I’m not choking it to death but just keeping the handles together.
I am not dropping the bullets until then spure had solidified for the count of 5 and the bullets just drop from the mould.
I wonder if the lead mix I have is the problem and is something different then what I was told it was. I got it from a friend who's dad passed and was a caster and he said he thought it was a WW + 1% tin. But it is throwing solid bullets at 206.5 instead of the 220 gr estimated. It is a little strange too that the diameter is 0.415 not the 0.412 that the mould is designed for, but the swelling on the drive bands is less then the swelling on the GC shank (0.002 vs 0.008).
Is it possible that the alloy swells after leaving the mould? But if so how is it so uniform from cavity to cavity and pour to pour?
Sorry for being so long winded and I appreciate your help.
Attached are 5 photos of a bullet from each cavity. I tried to get some contrast on the GC shank and the first drive band. It's a 4 cavity mould and I have been casting one of each HP and a solid until I get the hang of it.
102842102843102844102845102846