Seating depth

[Jack Stanley]

For you fellas that know the ins and outs of the .223 cartridge and cast bullets help me out will ya . In the past I've used a pretty light bullet in the cartridge and never had to seat the gas check below the neck . My supply of lightweight bullets is gone so now I'm left using bullets from my Lyman 225462 mold .

In looking at Lyman data they said to give an overal length of 2.090" with this bullet . My experience has always been seating the gas check deep , at least in my thirty caliber stuff , didn't work real well .

So , I seated some at 2.080" and some at 2.175" with the same powder charge and shot them today at thirty yards . I really couldn't believe how well the deeper seated bullets worked .... at least todays shooting . I will load some more and see if it does it again .

Question is , why did it work so well ? Is it because rifles are individuals or somethiung else I'm missing ?

Thanks , Jack

[felix]

The acceleration curve of the load is correct for the gun. The boolit is into the barrel by the time the case fully expanded. This is one of the reasons why a tight neck is problematic for boolit shooting. Getting the whole kitten and caboodle correct takes patience and sometimes a whole lot of it. ... felix

[303Guy]

Felix, may I ask you to elaborate? What you've said is what I have been wondering about. I started abandoning 'case neck tension' when I had no hornet sizer dies (mine went walk-about while still unused and I refused to buy another set). I ended up with a heavy for hornet bullet and a slow to ignite for hornet powder - 55gr and Lil' Gun. It was a perfect combo. I had to seat the bullets in a soft paper cup to hold them in the middle of the neck. Now I'm pretty much trying to do the same thing with cast. I do attempt to seat my boolits right into the throat and leade and the neck fit is to hold the boolit secure during loading and unloading and that's all. But I paper patch so paper compression and friction make it easy.

[felix]

There's not much to elaborate on because the combination required to make things perfect depends on just too many factors. The rule using the slowest powers and the softest primer for the case size and powder along with the boolit and its resistance at startup is a good one to start with. Then work towards faster ignition with the combinations to find the best spot to play around, and that includes the boolit's resistance. A chrono can help to hone velocities such that they are divisible by three, i.e., 600, 900, 1200, 1500, 1800, etc. These velocities have shown to be the best areas to seek a sweet spot with todays stuff, guns and all. Always keep in mind that EVERYTHING expands, including the projectile, when the gun is fired starting with the primer itself. BR guns are made exceptionally solid to help control this expansion by restricting the resulting contrary forces that play havoc with accuracy. ... felix

[Jack Stanley]

So I lucked onto a good load right off yahoo !! Now I'm guessing I'll need to see if raising or lowering the charge makes it better or worse .


This acceleration curve is something that can be found on most all rifles then ?

Thanks Felix , I apprieciate the help .

Jack

[felix]

Not just rifles, but all propulsion systems. ... felix

[Jack Stanley]

Thank you !

Jack