Need advice on 'Casting' a chamber on a M1A.....
I am in need to cast a chamber on my own personal M1A. I am primarily casting the chamber for reloading purposes.
I am having a little issue with creating an accurate load, I am trying to seat the bullets COAL out a little further to help minimize bullet jump, and case dimensions and whatnot. Basically wanting to exactly know what my chambers dimensions are to the 'T'.
I have looked and found Cerrosafe on Brownells, as it looks the easiest to apply and work with. Also I can remelt the material I previously used and use it again.
My questions are......
How was your experience with Cerrosafe?
Is there other materials that can cast chambers as easily as Cerrosafe?
My only concern with using Cerrosafe is that after letting it sit in the chamber for around 10 minutes or so, you must remove it, because even though it cools down enough push it out of the chamber, it will continue to grow (swell) for at least 24 hours. Cerrosafe states that the maximum it will grow is 0.025 overall over the entire body, I would like to use that casting later for comparison and the dimensions would have changed by then (after 24 hours). Basically using the casting as a tool for later reference.
Is there another material that does castings that does not swell after pushing it out of the chamber? Maybe a wax or resin based material that works well?
I read about this in the Tennessee Gun Works catalog many years ago.
They suggest using molten sulphur.
Cerrosafe is the standard because the expansion and contraction are known factors. Other materials have unknown or varying expansion and contraction so there's no way to know for sure at any step what you have.
All materials will expand or contract, but there's usually no way of knowing what those rates are at any time.
With Cerrosafe you have a known quantity.
I believe that after a period of time, 24 hours??, Cerrosafe stabilizes, so you can just allow the next cast to stabilize too.
Another option is to just measure all demensions of the casting at a specific time after removal from the chamber and record those demensions. For the next casting, wait the same time and measure it.
If you can make a measurement, you can record it.
There's really no benefit of having the actual casting available since there are no other measurements you can practically make.
You can try casting the chamber with paraffin wax.
But the whole exercise is a waste of time for what you're trying to accomplish. You'll have a very hard time taking lengthwise measurements of any accuracy, and when you're done, you still won't know the relationship between the bullet ogive and the rifling origin.
Size just the end of the case neck so it will hold a bullet, seat a bullet out long, then gently chamber the cartridge and ease the bolt down. Carefully extract the dummy cartridge and hope the bullet doesn't stick in the rifling pulling it back out of the case.
Don't ignore maximum length for magazine loading unless you're planning to shoot this ammo single loaded.