Experienced Reloader w/ cast 9mm issues!

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3GunEric

3GunEric

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Over the last 15 years I have loaded thousands of 9mm fmj's (on Dillon 550b), under current shortage switched to Berry's plated - no problems. BUT am trying to figure out some MBC cast 9mm's.

The problem: Once complete the cast 9mm's and do not sit easily in my case gauge. They protrude (+-) a mm. Some have a small amount of excess lube, others have a small "ring" or shaving of lead where case and bullet meet.

What I have done: Tried to clean these obstructions by hand - it is slow, dirty, and still does not yield a "clean & easy" case gauge fit. These lead to misfires due to bullet not correctly seating - this is unacceptable.

Tried to "tumble" w/corncob - not good. Tried to tumble w/more abrasive walnut - still no good.

I know MBC is a quality product so what can I do differently to correct this situation. I have 3k MBC 9mm and want to shoot them.
 
1. Bell the case slightly more.

2. Chamfer the inside case mouth.

3. Seat & crimp in two different dies.

4. Most importantly?
Use your pistol barrel as the case gage instead of using a too small for lead bullet SAAMI spec case gage made for jacketed bullets that are .001" - .002" smaller diameter.

rc
 
I'll also add that you might benefit a great deal by using a Lyman M die. I use an M die for all my cast rifle calibers. I also would use an M die for 9mm, specifically, except I found a cheaper alternative, which is to use a 38SW expander plug in my 9mm expander die.

The stock 9mm expander plug (at least in a Lee die) is a great flaring die, but it totally sucks at expanding. Of all my pistol calibers, the 9mm expander is among shortest. On top of that, it barely goes in before the case is overflared. When seating an oversize cast bullet in such a poorly expanded case, the bullet is prone to seating crooked, throwing off lube or lead shavings on one side. Also, many cast bullets need to be seated deeper than jacketed/plated (I had to seat MCB to 1.05"). Unless your bullets are uber hard, it's quite possible that some of your thicker cases are swaging the cast bullet down too small when seating. (I measured the base of some of my pulled 9mm boolits at 0.353 inches!) So if you're using Lee dies, beware! If you're using another brand, it's something worth checking out.

Prior to this adjustment, I never got MBC bullets to shoot well in my 9mm's. I got mediocre accuracy at 20 yards, and poor accuracy beyond that. And there was the fouling. When I switched to a better expander, all the problems went away. I shoot cast in all my firearms, and 9mm is the only caliber that gave me these problems.
 
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Even the standard plug for the m die is too small in diameter for cast. You'll need to have a custom plug made .001-.0015 under your bullet diameter. Otherwise, unless you're using a really hard alloy, swaging of the bullet by the case will likely occur.
 
1. Bell the case slightly more.

2. Chamfer the inside case mouth.

3. Seat & crimp in two different dies.

4. Most importantly?
Use your pistol barrel as the case gage instead of using a too small for lead bullet SAAMI spec case gage made for jacketed bullets that are .001" - .002" smaller diameter.
Click to expand...

There you have it! Follow this advice and you will be good-to-go.
 
Shaving Lead when seating cast bullets

The seating die may remove the bell to soon, resulting in shaved lead. Test by over belling a case mouth & take measurement of the change. Run case into die a short distance at a time & measure. Open/enlarge the inside diameter of the seating die if needed. Do not go to deep and remove the taper crimp part of the die.
 
1. Bell the case slightly more.

...

3. Seat & crimp in two different dies.

4. Most importantly?
Use your pistol barrel as the case gage instead of using a too small for lead bullet SAAMI spec case gage made for jacketed bullets that are .001" - .002" smaller diameter.
Click to expand...

EXCATLY how I load MBC 9mms by the thousands. No problems at all!
 
Keep the ideas coming! Thanks
Click to expand...
Did you try the ideas we've already given?

Kind of silly to come up with MORE ideas if the ones you've been given will work perfectly...
 
rcmodel said:
1. Bell the case slightly more.

2. Chamfer the inside case mouth.

3. Seat & crimp in two different dies.

4. Most importantly?
Use your pistol barrel as the case gage instead of using a too small for lead bullet SAAMI spec case gage made for jacketed bullets that are .001" - .002" smaller diameter.

rc
Click to expand...
'Nuf said. I use these suggestions for all my semi-auto reloads...
 
Have not yet tried the above listed ideas because I am in the middle of another reloading project. Situation not silly because a number of good ideas were put forward. I am very thankful for all those who took the time to give me their advice.

Will update ASAP.

Thanks
 
I have reloaded many thousands of 9mm cast, over 20,000 in the last three years.

I bell the case enough to not shave any lead from the bullet when seating, taper crimp to get the bell out, I seat and crimp in one step, never a prob.

Use your barrel as a guage and set up a dummy round for each bullet profile.

It's so easy I have my pet monkey ( Clarence ) to help me:)
 
I cast the Lee 124 trucated cone and use the liquid alox (wheel weights quench in water). Then once loaded I run them through the Lee factory crimp die and like RCModel says I use the barrel of my Glock to check out the load.
 
I bell the case enough to not shave any lead from the bullet when seating, taper crimp to get the bell out, I seat and crimp in one step, never a prob.
Click to expand...
If you can get away with it, good. I do the same for MOST of my reloads. But there are some guns out there with tighter chambers, and they require a heavier crimp. Sometimes you have to suck it up and add a separate crimp step.
 
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GLOOB said:
floydster said:
I bell the case enough to not shave any lead from the bullet when seating, taper crimp to get the bell out, I seat and crimp in one step, never a prob.
Click to expand...
If you can get away with it, good. I do the same for MOST of my reloads. But there are some guns out there with tighter chambers, and they require a heavier crimp. Sometimes you have to suck it up and add a separate crimp step.
Click to expand...
I use KKM and Lone Wolf 9mm barrels and Lee dies. I seat and taper crimp in one step with MBC RN/CN/SWC bullets without issues.

For me, key to not shaving lead when seating and crimping in one step is to not use too much taper crimp. I add 0.021" to the diameter of the bullet so the flare will return flat on the bullet. So for .356" sized lead bullets, I use .377" taper crimp - any less and I will start to shave lead. Yes, they all pass the barrel drop tests in KKM/LW barrels with a "plonk".

9mm MBC CN/RN/SWC seated and taper crimped in one step with no lead shaving.
attachment.php
 
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The results are in!

Followed steps 1,3, & 4 as recommended by rcmodel.

Originally Posted by rcmodel View Post
1. Bell the case slightly more.

2. Chamfer the inside case mouth.

3. Seat & crimp in two different dies.

4. Most importantly?
Use your pistol barrel as the case gage instead of using a too small for lead bullet SAAMI spec case gage made for jacketed bullets that are .001" - .002" smaller diameter.


:)The results were good! No shaving, lube, or other obstruction issues. Finished rounds perfectly fit in my Sig barrel!

Thanks all for the advice and pictures! ;)
 
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