I've been messing around with some different slug designs for a bit now and figured I'd share and ask for some help.
Here's my latest attempt at making a .51 mold that shoots straight.
This is a 300gr .510 design that represents the culmination of my (novice level) understanding of what makes a decent air gun slug. I made it specifically for my challenger elite 51, so one of the main requirements is that it fit in the magazine. I just made these and haven't tested them yet, but this is a V2 of a previous design that did reasonably well. Hoping this is an improvement.
I've been on a mission to find a decent mold for my 51, and boy has that let me down a rabbit hole. I did the "buy and try" method with a bunch of 357 molds... that got expensive... so instead of spending a fortune on noe and accurate molds it kinda made more sense to make my own molds from scratch. In the pics above is my first completely-from-scratch mold, aside from the lee 2cav handle.
I started making molds from the lee 2 cavity blanks. Having used a bunch of them I quickly learned their shortcomings. One of my biggest gripes about them is the sprue plate. They have a tendency to lift up on the cavity farthest from the screw causing one slug to be longer. Doesn't seem to be a problem on molds that have a second screw to hold down the sprue plate, so I integrated that concept. I also discovered that having a very flat and smoothly machined sprue plate will help the mold operate smoothly, with less lubrication and less galling of the aluminum. Another gripe about the lee 2cav blanks is that they are not, flat, square, true, plumb, centered, even or consistent. All the things that would help make a precise mold... they don't have it. This made machining a pain... so just another reason to make em from scratch.
As far as the shape of the projectile... I have very few answers and many, many questions. Some of the first slugs I made were very simple shapes. Straight sides with a modestly rounded nose. These shot horribly. Maybe even keyholing, which was quite confusing. I only fired them a few times... just enough to know that they were wild then moved on. Here's an example of that.
I started making some attempts at a slug with higher BC than a typical hollow point or wadcutter. Simple G1 style, tangent ogive, and some simple grooves on the OD. I've had some interesting results that raise a lot of questions. Here's an example that shot wildly.
I had high hopes for that one... it looked cool at least! Here's a couple that shot pretty well.
The two above... both molds had some chatter so I endes up remaking them with a few tweaks. Results are pretty decent... need more testing time at the bench.
‐‐---------
That's some of what I've done so far... too tired to write more... will continue soon.
Also, I am actively seeking any books, docs or comments that would help design better slugs. Please let me know!
Here's my latest attempt at making a .51 mold that shoots straight.
This is a 300gr .510 design that represents the culmination of my (novice level) understanding of what makes a decent air gun slug. I made it specifically for my challenger elite 51, so one of the main requirements is that it fit in the magazine. I just made these and haven't tested them yet, but this is a V2 of a previous design that did reasonably well. Hoping this is an improvement.
I've been on a mission to find a decent mold for my 51, and boy has that let me down a rabbit hole. I did the "buy and try" method with a bunch of 357 molds... that got expensive... so instead of spending a fortune on noe and accurate molds it kinda made more sense to make my own molds from scratch. In the pics above is my first completely-from-scratch mold, aside from the lee 2cav handle.
I started making molds from the lee 2 cavity blanks. Having used a bunch of them I quickly learned their shortcomings. One of my biggest gripes about them is the sprue plate. They have a tendency to lift up on the cavity farthest from the screw causing one slug to be longer. Doesn't seem to be a problem on molds that have a second screw to hold down the sprue plate, so I integrated that concept. I also discovered that having a very flat and smoothly machined sprue plate will help the mold operate smoothly, with less lubrication and less galling of the aluminum. Another gripe about the lee 2cav blanks is that they are not, flat, square, true, plumb, centered, even or consistent. All the things that would help make a precise mold... they don't have it. This made machining a pain... so just another reason to make em from scratch.
As far as the shape of the projectile... I have very few answers and many, many questions. Some of the first slugs I made were very simple shapes. Straight sides with a modestly rounded nose. These shot horribly. Maybe even keyholing, which was quite confusing. I only fired them a few times... just enough to know that they were wild then moved on. Here's an example of that.
I started making some attempts at a slug with higher BC than a typical hollow point or wadcutter. Simple G1 style, tangent ogive, and some simple grooves on the OD. I've had some interesting results that raise a lot of questions. Here's an example that shot wildly.
I had high hopes for that one... it looked cool at least! Here's a couple that shot pretty well.
The two above... both molds had some chatter so I endes up remaking them with a few tweaks. Results are pretty decent... need more testing time at the bench.
‐‐---------
That's some of what I've done so far... too tired to write more... will continue soon.
Also, I am actively seeking any books, docs or comments that would help design better slugs. Please let me know!
).
