9mm with 147g. Missouri Bullet getting heavy leading

[oldreloader]

After my measuring and finding that the FCD did size my lead bullets, I use the Lee bullet seat / crimp die with the seatiing stem removed. I use a Hornady seat die.

 

[LiveLife]

So if the Lee FCD is the issue, what do you use to crimp then? I have been using the Lee FCD for my 45 with no leading issues and planned on using the same for 40 and 9mm as well. Does the leading issue have to do with the lighter weight bullets as compared to the 45 or am I off track as well?

How did reloaders load their pistol rounds before Lee Factory Crimp Dies were sold?

The leading issue has to do with bullet-to-barrel fit and post sizing will reduce the diameter of the lead bullet, especially for some oversized factory barrels.

For semi-auto calibers, it is my opinion that FCD was really meant for jacketed bullets to produce comparable "factory ammunition" taper crimp. For larger diameter lead bullets, FCD will post size the bullet, reducing the bullet-to-barrel fit. Another problem is reduced neck tension as the lead bullet will stay post sized but some case neck will spring back out (depending on the make/lot #/condition of the brass). Leading problem will be further increased for some factory barrels that are oversized as more high pressure gas will leak around the bullet and cause gas cutting/bullet base erosion while blowing liquefied lube off the bullet surface and out the barrel leaving the bullet "naked".

I do not use or recommend FCD for lead semi-auto caliber bullets. When I help setup new reloaders, I have them use just the 3 dies to fit the tight chambers of Lone Wolf barrels. Even using almost no taper crimp of .020" over the diameter of the lead bullets (i.e. .376" taper crimp for .356" diameter lead 9mm bullet and .421" for .401" 40S&W bullet, etc.), they fall into the tight LW chambers freely (for newer LW barrels in semi-auto calibers, you may need to very slightly widen the chamber for lead bullets). When they ask when should they use the FCD, I ask them, "If your rounds work with just the 3 dies, why would you need to use the FCD (4th die)?" I tell them to leave the FCD in the die box.

Some will argue that they use FCD to seat and taper crimp separately (Lee semi-auto caliber bullet seating die will seat and taper crimp at the same time). You can do this by knocking out the carbide sizing ring from the FCD so the bullet seat/taper crimp die will seat only and FCD will taper crimp without post sizing the bullet.

Many reloaders (including myself) have used die sets without FCD and do not have leading problem. If you are using FCD and having leading problem, my recommendation is to leave the FCD out and readjust your dies to maintain the lead bullet diameter for proper bullet-to-barrel fit.

 

[918v]

Sammy needs to figure out his chamber dimensions and match his bullet diameter to fit. KKM barrels mike .355" I had one in .357 Sig. SAAMI chambers have .358" throats. A .356" barrel therefore leaves a .002" gap for the gas to escape. A bullet will not obturate by .002" at 9mm pressures. People need to understand that gas travels at 7000 FPS instantly. The bullet has to accelerate to 900 FPS in 4-5" of barrel. Therefore, the gas will overtake the bullet before it even begins to move. This is why the bullet to throat fit is important.

 

[Notoast]

After I started crimping with my seating die and quit using the FCD my leading problem went away too. To use the seating die, first seat a bullet to the desired seating depth with the entire seating die screwed out far enough that it does not apply a crimp. Then, back the seating plug out a few turns away from the bullet and set the desired crimp by screwing the die in and raising the ram. Once you get the desired crimp, tighten the locking nut. Then, with the cartridge in the shell holder and the ram held in the fully up position, reset the seating depth by screwing the seating plug down until it stops against the bullet.

 

[mknpwr]

OK, the last three posts clear up some questions I had concerning the 9mm cast bullets. I have been loading .45 cast lead bullets for about a year using the Lee FCD and have had no issues with leading in my 1911. Looking at the pressures developed by the 9mm and the 45 I now have a better understanding why people were having issues with the smaller caliber. My Lymans should be here Mon-Tues this week which will be very helpful in working up loads for my 9mm. Thanks for the input guys, you have been very helpful to me. I hope the OP has had his questions cleared up as well.