Another 9 mm question

[Rayc384]

I am attempting to load the Lee 124 gr. .356 TC bullet in 9 mm. I finally figured out the FCD was resizing my bullets down to .355, they are now .358. The question I now have, is what should the OAL of the round be with this bullet?

I have been using a Lyman gauge to check my rounds and they are shorter than what I am reading in the manual. I have found if they do not fit the gauge, they do not fit the barrel.

[gefiltephish]

Just use the barrel as your gauge, then work up the loads from there.

[SlowSmokeN]

Just use the barrel as your gauge, then work up the loads from there.

+1, works every time. I am using 4g Unique with the same boolit.

[Case Stuffer]

One really needs to use a taper crimp for the 9MM . The case should be tape crimped down to .376-.378 right at the mouth. With most semi autos the straight section of a cast bullet can not extend more than about 0.020 pas the end of the case's mouth or the bullet will jam against the rifling in the barrel. You can load a dummy round no powder or primer and chamber this round and check to see if the lead is being deformed,shaved due to being seated out to far.

[Le Loup Solitaire]

It is strongly advised to use a taper crimp die on 9mm. If not, then when the round is picked up and hits the ramp, there is the probability or at least the possibility that the bullet will be pushed/set back into the case to some degree. This decreases the air space/loading density and in the 9mm this is critical as even the slightest amount can send the pressure way up. Not only does that effect accuracy, but it pounds the gun and eventually leads to other problems that you don't need or want. LLS

[ku4hx]

The question I now have, is what should the OAL of the round be with this bullet?

I use 1.075" overall length and they feed flawlessly in all my 9mm guns. I do not use the Lee FCD; I've used a taper crimp for decades and never had a problem.

[mdi]

My $.02. Forget the term "crimping" when you are reloading semi-auto handgun ammo. Neck tension will be enough to hold a bullet in place during recoil and feeding and a crimp can actually be bad for the finished round. Case buldging and loose bullets can result from taper crimping too much (case buldges; pushing brass down on bullet and buckling the case below the bullet. Loose bullets ; taper crimp swages bullets and brass springs back, lead don't). A taper crimp die is used to straighten out the case mouth for reliable feeding only. Just enough to remove any flare. I've been reloading 45 ACP (17 years) and 9mm (5 years) this way w/no problems.

Start with a few dummy rounds with the OAL of a similar bullet in your reloading manual. Use the "plunk test" to varify chambering, and run some through the gun to determine feeding. If necessary you can shorten the OAL to feed/chamber better, but ferget the "crimp"...

[Case Stuffer]

According to my data the case mouth of a 9MM should be a max. of .380 " thus in my opinion taper crimping this are to .376-.376 does not reduce the dia. of the bullet. I have pulled lead and jacketed pullets and they were not reduced in dia.. My experience shows that using an undersized expander with lead bullets is the second worse mistake made and the very worse mistake made is using a roll crimp which ofcourse should never be used on any straight wall semi auto round as the case mouth provided head spacing.

Perhaps we are both saying the same thing and perhaps the term crimping needs to be replaced with removing the flare.

[Shiloh]

+1, works every time. I am using 4g Unique with the same boolit.

I like the 3.8-4.0 of unique with that range of boolits myself. Been seating the LEE 125 RF sized at .358. Because it is a little deeper in the case Ibacked off a bit.

Shiloh

[MtGun44]

LOL! Another person discovers the "benefits" of the pistol type FCD.

9mm is not as critical as .45 ACP due to the tapered case on 9mm, but IME about 85% of
the feeding problems with .45 ACP were due to missing or inadequate taper crimp.

Do not skip the taper crimp and do it in a separate die, but NOT the darned FCD!

Bill

[williamwaco]

Then AOL should be the longest that will feed through the magazine reliably, and chamber whey you apply the "thunk" test.