Originally Posted by
Doc Highwall
cstrickland, welcome to the forum! The first three rules of cast bullets are ,BULLET FIT, BULLET FIT, BULLET FIT!
Bullets need to be .001” to .002” larger then your groove diameter in order to seal the powder gasses behind the bullet.
A 5.56 NATO chamber is different then a 223 Remington chamber, not in where the actual chamber is but forward of the case mouth sometimes called the throat/lead/ball seat.
This is the area of concern with a NATO chamber in both 5.56 and 7.62 and how the bullet will fit to seal the powder gases and align the bullet.
As bullet caliber goes down defects are magnified, and in the case of a 22 caliber they are greatly magnified. With a 500 grain 45 caliber bullet a 1% variation = 5 grains, with a 50 grain 22 caliber bullet 1% = .5 grains so sorting and culling has to be more ruthless in order to get accuracy.
One of the problems with casting 22 caliber bullets is keeping the mould hot enough. First a hot plate to pre-heat your mould and additional alloy to replenish your casting pot will go a long way of starting out. Next you will have to maintain a good cadence in your casting speed to keep the mould at a good operating temperature along with your alloy.
Two things I have started to do thanks to CastBoolits members here is, I now have a PID controller I bought from Frozone a member here at CastBoolits, and Al from N.O.E. started to drill his moulds for a temperature probe that he also sells, I have been drilling and tapping all my moulds as I use them. Now I agree that you don’t really need both of these to cast good bullets, but it will sure make things a lot easier and repeatable casting good bullets.
Not bragging but with cast bullets in my Remington 40X chambered in 7.62 NATO, my record 5 shot group at 100 yards is .305” and at 300 yards is 1.610”
The more effort in controlling every step you take with documentation, the more satisfying the results you will receive.
So my question is how much accuracy do you want to get out of your guns?