Confirming 9mm OAL

[scole]

Hey all,

I am new to reloading 9mm and recently got a bunch of Dardas 124gr LRN bullets. I made up a bunch of dummy rounds at different OALs to check for feeding/seating issues. The best OAL seemed to be around 1.075 which i gather from reading is a somewhat common length.

Now my question is about the charge. I will probably be using W231 because i have it on hand. I've read charges ranging from 3-4.1gr on the site for similar OAL and bullet weights. Would I be best starting at the lower end of that spectrum or starting at 10% off the 4.1gr figure?

Other question is, how much does bullet diameter matter between .356 and .357?

Thanks in advance,
scole

[l98ster]

First, you should definitly start at the low end and work your way up.

As far as the OAL, I would get a good reloading manual and check. the deeper you seat the bullet, the more pressure will be created.

What kind of pistol are you using. The way I check is that I will load up a magazine of a certainOAL, and rapidly empty the mag with my fingers (NOT shooting the gun!!) if it seems to eject all the rounds smooth, its a good starting point.

I am currently loading 147gr JHP with 3.1gr of titegroup with an oveall length of 1.155. These are pretty long, but work perfectly in my XD.

BTW, that load makes 125 power factor for USPSA, its soft and accurate!!

-Good Luck!!!!
George

[chris in va]

I didn't start getting accuracy out of my two 9mm's until I sized my boolits to .003 over slug (bore) diameter.

And yes, start at the beginning charge grains. My CZ won't chamber my boolit profile until 1.01oal (not a typo) and I put the minimum grains of Unique in there. Works fine.

[wncchester]

"Other question is, how much does bullet diameter matter between .356 and .357? "

Neither you nor your pistol will ever see a difference.

[aerod1]

I've been loading 115 gr fmj @ 1.158 OAL.

[scole]

FWIW, I started at 3.2 and worked up in .2 grain increments. I ended up with 3.8 grains cycling reliably at a OAL of 1.078.

[Mike-Mat]

My books say max OAL for 9mm Luger of 1.169. I usually set them to 1.155-1.165. Anything deeper will effect your internal pressure. 1.075 seems like a big difference to me.

[jepp2]

As others have mentioned, the 9mm can be very sensitive to differences in seating depth. Also don't forget that unless you are using the same manufacturers bullet, the OAL may result in a different seating depth. Seating depth is what actually impacts the pressure.

Winchester White Box is normally loaded to 1.169" which is the SAAMI max.

Just something to consider as you decide on your starting point for a load.

Depending upon the hardness of your lead bullets, you need to select the proper velocity range to minimize leading.

[scole]

In the 40 or so rounds I shot testing out those loads there was zero leading.