Attempting 9mm 125 gr LCN reloading with Bullseye

[mobiusnc]

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

 

[Chief-7700]

From what I read "No crimping" I always taper crimp my .45ACP and 9mm since that is the only way that I know of to remove the bell from the case mouth.
Chief-7700

 

[rcmodel]

Yes, with lead bullets you should be belling the case mouth quite a bit to keep from shaving lead off the sides of the bullets when you seat them.

Then, you have to taper crimp at least enough to remove the bell and make the case straight again.

But if you overdo a taper crimp, and the Lee FCD is the worst, it will squeeze the bullet down too small for the bore, and accuracy will suffer greatly.

It could be you have hard bullets, and the light loads are not bumping it up to fit the rifling like it should.

This will allow gas to leak by the bullet, melt the sides, and cause heavy leading of the bore.

Once that happens, accuracy goes out the window, and bullets may very well tumble.

I'd make sure the barrel isn't leaded, and increase the power level somewhat and see what happens.

rcmodel

 

[mobiusnc]

Hmm, I'll definitely look at the crimping then. I had read that some other people do not crimp. The cartridge looked OK to my eye, but I'm very new to this so I'm not too sure. I have the Hornady 3 die set, so I can apparently crimp with the seating die. Hopefully I won't over do it.

Thanks for the suggestions. mobiusnc

 

[IdahoLT1]

your barrel length might also be a factor in your loads. Most reload guides use 4.5" or 5" barrels for their tests. So using 4.0gr. of powder will give them more velocity than what you are getting with your shorter barrel.

I would have figured you would run into FTE's or FTF's before the accuracy suffered with your lighter loads.

 

[243winxb]

http://www.carrollsweb.com/gunshop/html/midstates_cast_bullets.htmlI would look at the bullet first. Is the diameter correct? Is the bullet deformed on loading? Is the 9mm 125gr. "Conicle Point" .356” dia. bullet to long for the rifling twist? The COL OR OAL is just a guide line. The round must fit the magazine length wise. When choosing a bullet for a certain twist rate, it is not always the weight of the bullet that is important , but the length of the bullet. A longer bullet will take a faster twist to stabilize it.

 

[243winxb]

http://www.varminthunters.com/tech/barreltwist.html "My 9mm M&P has been flawless in function. If I get lazy and don't clean it, after 3 matches and about 500 rounds it will keyhole with 147gr berry bullets and accuracy past 5 yards suffers. No problems when it's clean. Someone suggested I use 115gr bullets. I haven't put a lot of 115 through it but it seems to have solved the problem. (I had a Sig that didn't like 115s, figure I can live with a M&P that doesn't like 147s.)"

 

[sturmgewehr]

Here's the problem, any crimp below .380" will cause the bullet to tumble. Crimp to anything above .380 and it should work fine.

 

[Galil5.56]

What pistol are you using? Many have groove diameters well in excess of what .356" cast bullets like best. My Beretta for example has a .3572" groove diameter, and I shoot cast bullets I make sized .358", and unsized @ .359".

The sharp internal taper of the 9mm case can actually swage soft bullets down to the point they will tumble. I have personally seen this happen when I tried to get the softest alloy possible for my plinker loads using long full diameter shank bullets. I too am no fan of Lee FCD unless the sizer is over-sized. If the 125 grain cast bullet is properly sized/hardness, I have had good luck with 4 grains of Bullseye which gets a measured 1090 fps from my Beretta. IMO, 4.6 grains is too much, and more velocity won't fix the true problem.

 

[Eb1]

I don't know what dies you mentioned or if you did.

But if you follow the RCBS taper crimp/bullet seater info. You will be okay.

I use a the exact bullet you mentioned with 5.0 grains of Unique. It shoots like no bodies business. It is by far the most accurate load I have shot with my Springfield XD 9mm.

It is also the bullet I carry when I go into the woods. I think a hard cast 9mm bullet would be good medicine for a wild pig that wants to take a chance. Keep in mind I do not hunt them with this, but if I am working on the lease it is what I carry.

I am trying to get the wife a hint to buy me a .45 Colt convertible.

 

[wankerjake]

Where does the site say 4.9 gr max load for a 125 gr lead bullet? The max load for 124 gr jhp is 4.4 gr, and lead data isn't even listed. I emailed alliant and they said to load 3.5 to 4.0 gr bullseye for 125gr lead bullet. I've been shooting 3.5 and 3.8gr without any problems. I haven't shot a bunch of them but at 3.5 gr bullseye at 15' free hand 6 of 8 were touching and the other two were right there. I would say try the 3.5gr and see what happens. I get great accuracy with it, and I haven't yet noticed any keyholes. I admit I've only fired 50 rounds of that load so far.

 

[Galil5.56]

Where does the site say 4.9 gr max load for a 125 gr lead bullet? The max load for 124 gr jhp is 4.4 gr, and lead data isn't even listed.

Not so long ago, Alliant had 4.9 grains of Bullseye listed as max for a 125 lead and jacketed bullet in their prior online and printed manual.

 

[Marlin 45 carbine]

I use Bullseye with cast bullets in 9mm and .45acp with good results (.32acp and .380acp also). light LFCD as a last step. seems it's fairly dirty but it shoots better with light target loads than Power Pistol the other pistol powder I load with.