Thormold Pellet Swaging Die (early impressions)
- Thread starter dgeesaman
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I’ve worn out and replaced the parting face dowel pins already. I think they were 304ss and wore quickly. I lapped the parting face to reduce flashing and will probably lap it some more. The good news is that the main die halves do seem to be pretty well made.
I’m drawing up a different design and working with a local machine shop to get an idea of cost and machining accuracy (no idea if this can be done both accurately and affordably). A friend of mine really wants a swaging die and so this will be based on his preferences. Since best cost country machined parts are often 5x cheaper than domestic it simply may never work.
The 13.6gr pellet design is excellent at short range accuracy but so-so at 40 and 50y. It could be me introducing imperfections that make them unstable, my rifles, or it could be that the pellet design simply isn’t all that stable. So I might try a different finishing punch that drives deeper and improves the weight balance. I might also deploy a custom design I’ve worked up in the 12.x grain range.
I’m drawing up a different design and working with a local machine shop to get an idea of cost and machining accuracy (no idea if this can be done both accurately and affordably). A friend of mine really wants a swaging die and so this will be based on his preferences. Since best cost country machined parts are often 5x cheaper than domestic it simply may never work.
The 13.6gr pellet design is excellent at short range accuracy but so-so at 40 and 50y. It could be me introducing imperfections that make them unstable, my rifles, or it could be that the pellet design simply isn’t all that stable. So I might try a different finishing punch that drives deeper and improves the weight balance. I might also deploy a custom design I’ve worked up in the 12.x grain range.
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I’m curious how this die ‘bleeds’. A slug die has a bleed hole which allows excess to bleed off.
Obviously with swaging, to insure complete fill out, the core weighs a tad more than the intended finish weight of the projectile. That extra has to go somewhere. Where does it go in this setup?
Dave
Obviously with swaging, to insure complete fill out, the core weighs a tad more than the intended finish weight of the projectile. That extra has to go somewhere. Where does it go in this setup?
Dave
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It's not super clear from the photos I posted, but the photo of Rod scraping the top of the die is removing swarf lead that is squeezed out at the the skirt end of the pellets. When you press the core with the punch, the excess lead squeezes out around the punch like a raised donut. Then you scrape those off with a razor scraper blade.
The tiny bit of flashing I'm seeing now is much less that those photos showed. I'm hoping I can get the die faces even flatter to eliminate flashing completely.
The tiny bit of flashing I'm seeing now is much less that those photos showed. I'm hoping I can get the die faces even flatter to eliminate flashing completely.
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@degeesman I was hoping that accuracy was going to be there 50-75 yards at least. It seems like the machining cost differences will be a large determine factor coupled with the performance of the pellets produced that can make or break this product. Then incorporating your own elements of design to improve the product was something I wasn't expecting. You've done one helluva job testing this mold. Thank you for keeping us informed on your progress.
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Getting great accuracy at 50y+ is no small feat. So I’m not blaming the pellet production and I’m only half suspecting the pellet design. My rifles have a bit of a pellet stability problem shooting JSB 13.43s as past 40y.
As we all know, it’s academically ideal to only change one variable at a time so that differentiating factors are clear. The reality is that there are usually several important factors and when ultimate precision is the goal, all of them can matter.
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@dgeesaman This is precisely what I admire about your endeavor. I think this is the closest I've followed this type of testing and I'm learning a decent amount. I'm also not familiar with .177 and .20 caliber ballistics. So it sounds like an acceptable range for .177 pellets is around 40-50 yards before accuracy starts falling apart. Am I understanding this correctly? I hope I didn't come across like I was criticizing the pellet design here.
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As a field target shooter of sorts, I need my 177s to shoot reliably out to 55y. I don’t pinpoint accuracy at 55, though it would be nice, but I can’t tolerate flyers or spiraling.
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