reloading, got cold feet
 

have you ever wondered why all the warnings about reloading danger from the bullet and powder company's?
Are you one of those reloaders who looks at the book and picks the load one grain below max and loads it. well, i have a brother that does just that as well as a good friend.
the good friend was in search of an early sako extractor just for that reason, it was a 149.00 lesson. his rifles max load is book starting loads, he is one of the guys that's the smartest guy in the room and so is my brother.
For safety reasons i have told both to at least 1 shell with the lowest load listed up to the load they are convinced will be the right load. Chronograph each load up to their chosen load.
here is why, i loaded some 7.62x39 loads for my Cz 527, all the forums were saying they were using 31.0 of cfe bk with a 123 gr sst bullet at 2573 fps.

i loaded 27.5-31.0 and here is the chro results.
27.5 2449
28.0 2473
28.5 2553
29.0 2563
29.5 2593
30.0 pulled
30.5 pulled
31.0 pulled
it should be noted the 29.5 gr load and 27.5 showed the same primer signs (nice round edges) and it took both hands on the priming tool to seat the primer.
Thoughts?

Thank you for the reminder.

Very good explanation.

Thats about the way I "develop a load"

Load 3 of each charge starting a couple grains less than I know is too low.
and load .5gr or whatever until 2 over than I know is too much.

Fire and inspect each case as it comes out of the gun.
I learned a nasty lesson with that NEF build of .17 VR.

Just because one fires fine don't mean all three will.

I shot ten times with the same 10,0 gr, same case.

upped it to 10.1, just fine 3 times. upped it to 10.2
and blew the gun up. All with the very same case.

I used the same case to make sure there wasn't any
case difference to bite me.

That time I got mighty lucky as only a few small parts were broken
and just a few tiny spots of blood on trigger hand from
the plastic trigger guard coming apart.

Parts broken were: firing pin, extractor lever and trigger guard.

It's mighty handy having a bullet trap in my shop. Much closer than
the 13 miles to the range. OF course I live alone too.

Like most reloader, I am loading to maximize cartridge performance in a safe manner (not trying to redline).

My initial load development / rifle introduction usually starts at or below the minimum charge weight (3 shots) and goes up in 0.3gr increments until I get close to where rifle and target groups come together. I do this to just get to know the rifle and see how it behaves with a specific bullet and powder. When I get it near the ballpark then I start doing a real load workup in 0.2 gr increments starting at least a grain or more below the charge weight I am focusing on. Then it shifts to 0.1gr for final powder weight selection. There is plenty of redundancy and some might say wasted time and reloading components. However, I get a good feel for how the rifle performs and what the cases look like as pressure increases.

Another item that can change a safe proven load to a questionable load is the variations from powder lot to powder lot. In recent years I have begun paying much more attention to changing to this as results of using CFEBlack, which has some noticeable differences in combustion from lot to lot. This is just one more item to consider during reloading process / thought matrix of what risks to mitigate.

...and yer CZ likely has a fairly long barrel too, close to one used in load data.

All I can say is that I have been very very lucky. I do not ever remember starting at a book minimum load (except when deviating from the book recipe, changing certain components). Many times I had no book to look at and just used what little bit I have to develop a load. Can’t express how lucky I’ve been.

"upped it to 10.1, just fine 3 times. upped it to 10.2
and blew the gun up. All with the very same case."
George that is one cartridge i move in .2 of a grain especially with faster powders i.e h110, ww296 and 300-mp.
WW680, aa1680 and n110 are much more forgiving.

Gary: Yep, some of the things I've pulled it's amazing I've been let live
this long. How you doing pard???

Bob: As you should recall this was a couple years before you decided
to part with that Cooper.
My first try at playing with these tiny cases. At the time all I had was H110.

IF I had increased by .2, I'd bet there would have been more blood loss
and broken parts.

As it was, the primer pocket was a full 1/4" dia and head of case was
split. Break open type rifle blew open.
Mighty lucky I didn't eat any of it, or get the safety glassed busted.

I started loading at 14 in 1958 without the first clue with Herter's crap and a Lyman book of the era and an old 1917 Enfield '06. Scrap yard brass for a nickel or dime a pound. IF there were mistakes to be made, I made 'em~! At that time there wasn't a sole we knew that reloaded anything.

Those OLD Enfields were fool proof, I'm proof of that in never blowing one up.

just glad you didn't get hurt, the whole point of this thread and yes we have all done less than smart things.

Thanks. One thing I've always done starting about age 2

has been a steady blood and tissue donor.