9MM Luger - Seating Depth - Need Your Help

[calvin_yung04]

Hi All

I used to reload my 9mm with the Round Nose 124gr (Left one).

The OAL I'd used is 1.13".

However, I'd purchased the Excel bullets today and found out the Round Nose had been slightly flated. It is not as flat as a wadcutter or hollowpoint.

My question is:

If I seat the new (Excel) bullet the same depth as my old bullet, then the over all length will be shorter. If I seat the new bullet not as deep as the old bullet, then I'll afraid it is not too secure to the brass.

Did anyone having this experience and can share with me about the Minimum OAL?? Maximum OAL?? BEST OAL??

The new bullets are only 115 Grain Jacketed Bullet.

On my Lee Reloading Data, it shows Minimum OAL is 1.125".
But when I seat the new bullet the same depth as the old one, the OAL become 1.1" or 1.095".

I am confuse and hope to seek for your professional advise.

 

[sunray]

A lighter bullet is shorter than the heavier one. If you measure a 124 grain bullet and a 115 grain bullet you'll see they're different lengths. It's normal.
The case length is the important part. The 9mm headspaces on the case mouth. Make sure your cases are all the same length and adjust the seating rod to give you the OAL you want. It is a trial and error thing though.
If you're worried about the lighter bullet moving, use a taper crimp die(and only a taper crimp) to keep it in place. Just enough taper crimp to hold the bullet in place.
The max OAL is 1.169". There is no 'best' OAL though. As long as your loaded ammo is between the 1.125" and 1.169" you'll be fine.

 

[waynesixgun]

I use 1.150 for all my 9mm...

 

[BCboy]

As long as your loaded ammo is between the 1.125" and 1.169" you'll be fine.

That all depends on what manual you look at, hodgdon lists 115's min OAL @ 1.100 ,the 125's @ 1.090 for min and 147's @ 1.100 for min . Most manuals list the OAL on what They tested it at ,the 1.169 is max sammi spec

 

[RT]

You may also find different manufactures of the same bullet type & weight will seat to different OALs due to the actual shape of the tip of the bullet ! Any time your changing bullet weight, type, manufactuer its best to measure the first rounds loaded to confirm the OAL then adjust the die if needed.

I also measure them at random as Im reloading just to confirm that nothing has changed...if your loading lead bullets the die may acumulate some lead in it if the bullets are soft and eventually the build up could affect how deep the bullet is seating, shouldnt be a problem really with a jacketed bullet but I still check on occasion just to confirm.