Hey All,
I've been attempting to develop a 9mm load but I think I'm having instabality (tumbling) issues. I searched this forum quite a bit before loading and found people claiming as low as 3.5 grains. Is this even possible? http://www.thehighroad.org/archive/index.php/t-102083.html
For fear for overloading I started really light. Probably way too light.
Sig P250 - 3.9" barrel
125 gr. LCN Midstates bullets
Bullseye Powder
cci primers.
1.15" OAL
no crimping
Varied the powder as follows:
3.8 gr. - definite tumbling
4.0 gr. - some tumbling
4.2 gr. - a couple of large holes in paper.
I'm trying 4.6 gr. next. The Alliant site say 4.9 is max so I should still be safe. Of course the give an OAL of 1.15 without bullet type so (it only say "L" so I assume it's lead").
If anyone can help, I have 3 questions.
1) Other than too light loads, can there be other causes of bullet instabilities? Perhaps if I over or under flare the case for bullet seating? Or something else?
2) Aren't bullets of different lengths for the same caliber? If so, what good is OAL if round nose is substituted for conical nose or vice versa?
3) Can people really load 25-30% less than max load and get any sort of stability let alone accuracy?
Thanks in advance for any advice.
mobiusnc
I've been attempting to develop a 9mm load but I think I'm having instabality (tumbling) issues. I searched this forum quite a bit before loading and found people claiming as low as 3.5 grains. Is this even possible? http://www.thehighroad.org/archive/index.php/t-102083.html
For fear for overloading I started really light. Probably way too light.
Sig P250 - 3.9" barrel
125 gr. LCN Midstates bullets
Bullseye Powder
cci primers.
1.15" OAL
no crimping
Varied the powder as follows:
3.8 gr. - definite tumbling
4.0 gr. - some tumbling
4.2 gr. - a couple of large holes in paper.
I'm trying 4.6 gr. next. The Alliant site say 4.9 is max so I should still be safe. Of course the give an OAL of 1.15 without bullet type so (it only say "L" so I assume it's lead").
If anyone can help, I have 3 questions.
1) Other than too light loads, can there be other causes of bullet instabilities? Perhaps if I over or under flare the case for bullet seating? Or something else?
2) Aren't bullets of different lengths for the same caliber? If so, what good is OAL if round nose is substituted for conical nose or vice versa?
3) Can people really load 25-30% less than max load and get any sort of stability let alone accuracy?
Thanks in advance for any advice.
mobiusnc