Dillon 550 COL Question

[Luggo]

I am running a 9mm set up as follows

"once fired" brass, mixed head stamp

WSP Primer

115gr FMJ

4.4 grains Win 231

My target COL is 1.130

I am getting variations from 1.125 to 1.134 on COL.

The only variable that is obvious to me is the amount of bell that is being made at station 2. I notice most of the time at 3 when I place the bullet it sits in nicely prior to seating. Occasionally it is a little tight (not enough bell), but still seats. I did not and need to obviously mic the ones specifically that do this, but it didn't dawn on me til I typed this.

I am guessing this belling variation is due to the very mixed brass I'm using. I would like the vets opinions here please.

I am running practice ammo, no power factors etc... matter. I ran 50 and need to go to the range and see if they run in the 3 different 9's I have. Please let me know your thoughts, fixes or whether to worry about it at all.

Thanks

[Sarge]

My oal pretty much stays dead on. I am shooting for 1.14 and the most it has strayed is 1.141or2. Make sure you have the shell plate loaded full when you set it.

As for the belling. I guess mine floats just a tad as well but never enough to cause any problems. I chalk it up to case wall measurements? Besides the brass will last longer the less you bell it.

Like I posted just a minute ago, I had some minor issues priming etc but it seems to work itself out the more you get used to the machine.

The major things for me are, consistent powder drop, consistent oal, consistent gauge success and consistent reliability.

[benos]

I am running a 9mm set up as follows

"once fired" brass, mixed head stamp

WSP Primer

115gr FMJ

4.4 grains Win 231

My target COL is 1.130

I am getting variations from 1.125 to 1.134 on COL.

The only variable that is obvious to me is the amount of bell that is being made at station 2. I notice most of the time at 3 when I place the bullet it sits in nicely prior to seating. Occasionally it is a little tight (not enough bell), but still seats. I did not and need to obviously mic the ones specifically that do this, but it didn't dawn on me til I typed this.

I am guessing this belling variation is due to the very mixed brass I'm using. I would like the vets opinions here please.

I am running practice ammo, no power factors etc... matter. I ran 50 and need to go to the range and see if they run in the 3 different 9's I have. Please let me know your thoughts, fixes or whether to worry about it at all.

Thanks

A wide variety of mixed brass can definitely cause the AOL to vary. Also, inconsistent bullet ogive can also be a factor. But I wouldn't worry about it to much. It probably won't cause anything you can actually see on paper.

be

[h2osport]

Could check your seating die for the correct bullet profile. If the insert in the die is not hitting exactly on the tip of the bullet, you could get different col. As Brian stated this would be from inconsistent bullet ogive.

Does not really seem to me to be enough difference to matter. You seem to have 1.130 surrounded.

Randy