new member first time posting please dont flog me. At the range first round it happened. Have been reloading round 25 years got the basics down.never had this problem before. Rifle used Belgium fnfal had the gas all the way open so i can single shoot and save my brass. Cases used LC 19 got them new with crimped primers this would be the 2nd loading primers cci no.34 with 43.5 grs varget lab radar sait it went 2550. Used rcbs precision mic to check my sizing. Two things that stick i had to trim cases becouse they grew to 2.025 in length and gas open all way both pieces landed on the bench any thoughts.
Case head seperation
- Thread starter Cr1775
- Start date
How are you using your precision mic? Sizing to saami specs, or to your chamber size based upon fired brass?
Take 3 measurements with the precision mic and post them.
1)new unfired LC case.
2)fired case from your rifles chamber.
3)case you resized.
1)new unfired LC case.
2)fired case from your rifles chamber.
3)case you resized.
New LC .001 .002 under. Fired cases .004 and .005 under yes they were smaller case's i resized .001 under on the mic
If I am understanding correctly this is only the 2nd firing? I do not think bumping shoulders back as far as the die would allow would cause a case head separation that soon. Brass should have lasted much longer then that. Brass that shitty of a quality?
Ok also put rounds through my M1A with resized cases there +005 and+006 on the mic
Brass strength is no match for 65k psi. Give any case enough room and it will separate.
I all but ignore measurements given as it varies too much from person to person and comparator to comparator.
Easier to just say it’s either too much bump or shitty brass. If he’s sure of his sizing, it’s shitty brass. If he’s not, he needs to tweak his methods.
That’s the best we can do without being there in person to check it.
I guess after thinking about it with the FAL having probably a machine gun style chamber if that makes sense lol I bet the brass is expanding a lot. Do the FAL's have a chamber like the HK with the grooves?
I know my numbers dont make sense after i had the separation with the 2nd loading i stopped shooting them but i did have some 1st loadings that i shoot out ou my M1A and FN and i just checked again im +.005 on the M1A and -..004on my FN
I sold all of my rifle case gauges a longggg time ago. Reload for your rifles chamber, not a case guage.
Numbers make sense now. Loaded 3 rounds that were seated at the 0 on my mic let the bolt slam forward seating them in chamber they are now -003 and -004 on mic so thats how my cases are getting smaller i got a tight chamber
When you say "loaded 3 rounds that were seated at the 0" do you mean you loaded rounds with bullets, and the overall length from base to bullet was at zero?
Yes not seated that was wrong loaded 3 rounds that were headspaced at the 0 on my mic then loaded them letting the bolt slam forward into the chamber that was sizing the cases another .003 .004 further
Thanks for all the replies .i know what happened, when i got the brass for shits and giggles i loaded up 10 to shoot cast bullets i made up not knowing how the tar or bullet seal crap would do for accuracy well nothing good i then did not keep them sorted good enuff only found 9 of them together now i seen for myself what happens when you shoot a full charge after.
