9mm reloading - inconsistent OAL

[HDS]

I set up my XL650 for the first time this weekend to reload 9mm, at the moment I am using uncalibrated and tumble lubed 147gr cast bullets that I've made using Mihecs 147gr BB bullet design, they drop at .359 from the block. It's pretty fat but they drop into my glock factory barrels chamber without any problems.

The problem I do have is that I am getting inconsistent OAL, it's not the seating die either, the OAL is all within spec (1.145") after being seated. It's after crimping that the OAL problems turn up, they get longer after they are crimped. To me it feels like the crimp die is catching on the bullet itself and pulling it out as the cartridge is pulled back out of the die.

I tried recrimping one round multiple times and it got progressively longer each time, when I got to 1.165" I stopped trying. I don't really know what todo here to address this issue. Have I set up the die wrong somehow? Or do I need another type of die more friendly to cast bullets?







Also as an aside....

Some people have talked about expanders and M-dies and whatnot in response to my problem, and while those seems like potential problems for cast bullet reloading, for completely different reasons though, I don't see how it has any link to OAL issues like mine?

A question on the M-die which seems to come up so often in any 9mm search on this forum, can it be used with the dillon measure, or would it require a dedicated station? I got the impression the latter is true, which would rule it out for me.


I am thinking maybe a custom sized version of the dillon expander might be the better solution if I wanted to address the expander issue. It doesn't have any bearing on my OAL problems AFAIK but it might be nice to have for its own set of reasons.

[Alvarez Kelly]

Goodsteel, on this forum, can MAKE you an "M die" like powder funnel for your Dillon.

Ask him about them.

[LUBEDUDE]

HDS - I believe two things may part of your problem.

One, running .359 bullets in 9mm (.356) dies. This is "squeezing " your bullet, causing the bullet to be pulled a bit by resistence as you mentioned.

Also, since you are not sizing your bullets they are not always perfectly round. So, sometimes being out of round will cause the same thing as mentioned above.

I would bet if you sized your bullets to .356 your problem will go away. Some guys here size their nines to .357 with success, but .356 is the norm.

Good Luck

[HDS]

Yeah I am hoping the issue will go away after I start sizing them conventionally, the plan is to get a die for my star sizer once I get my aftermarket barrel for my glock and I have slugged it to see what it likes. For now I am just tumbling and using fat bullets since I hear that's one way of having better performance with glock factory barrels.

And thanks for the tip about custom M-die style funnels Alvarez Kelly!

[HDS]

I have another question on this, what size do you want for the plug? I mean if I got a bullet that's say .357" - Will I then want that size for the plug, or do I want it slightly smaller or larger? If so by how much?

EDIT: I think I found it out, should be .001 to .002" less than bullet diameter. It does lead me to wonder, what would happen if the expander was the same size as the bullet? Would that be bad?

[MBTcustom]

You better get a good crimp on your boolits if you are expanding to the same size as finished diameter. Its just not enough to hold the boolit in place during the effects of recoil. You got it right, .0015-.002 less than boolit diameter. There will be a slight amount of spring back in the brass, but I find that as long as I make the expander.0015-.002 less than the boolit diameter, then I don't get any undersized boolits.