Lee 356-120-TC and the M&P 9c

[Jayhawkhuntclub]

I loaded some of these boolits sized at 0.358" at 1.105" OAL and tried to hand cycle them through my Smith 9c. That didn't go well. They had trouble chambering and they were a bear to get to get the action back open. It didn't take me too long to figure out that they were being driven into the 9c riflings. What's funny is I took the same length cartridge and hand cycled them through my STI Trojan with ease. I have discovered to things here (I think): 1) the chamber on the 9c is short (at least compared to the STI) 2) the bore is almost 2 thousands of an inch smaller in the 9c (0.356") vs the STI (0.3574") - both measured with a micrometer. I was told that I was probably wrong about the small bore of the 9c. But after slugging it 3 times, I know it's small. It was VERY obvious when I slugged it back to back with the STI. The same bullet was easily driven through the 5" STI and was a bear to get out of the 9c bore.

So anyway, I started seating the bullet deeper. When I got to about 1.055" I was able to cycle them through the 9c. This is where the cylindrical part of the bullet is completely encased in the brass up to where the taper begins. These loads are with 4.5 gr of Unique. I assume they are safe at this OAL? Thoughts?

I know this is kind of a ramble. I just wanted to process the information using a few more brains to make sure I wasn't missing any thing. ;) Thanks!

[Shiloh]

What is the start load for this powder with a similar bullet?? You could back off an additional 5%. I shooth a LEE 125 gr ,358 RNFP and seat it pretty deep. I could look at my data if yo would liike. I am at the gym currently. I use Unique in the 9mm's

Shiloh

[Jayhawkhuntclub]

Shiloh: I would like to hear about your data. Thanks. I think you are right about backing off. The 4.5 is a mid-tier load for my Lee 356-120-2R-TL. But the TC is going to be seated quite a bit deeper. I think I'll work up from 4.0 gr of Unique. Thanks!

[tacoma]

I use 2.9 gr of hodgdon clays with that mold, (lube groove), with boolits sized at .359". BHN #12. The recommended load is 2.9 minimum 3.3 maximum. My AOL is 1.040" , any larger and I have the same problems you mention in my S&W m&p 9mm compact. My boolits travel at 960 fps. I have been advised by many in this forum to be very care full going up on the load because the low AOL will bring pressures to the roof.

[JeffG]

Jayhawk,

I have a S&W SD9 VE and it's chamber and bore are .356 so that might be fairly standard for the SD's and M&P 9's. I called Alliant and they emailed me load data for the 9mm shooting cast bullets. For the TL356-124-TC from Lee I shoot the most, they recommended 4.0 - 4.5gn. I usually shoot those loaded with 4.2 of Unique or 5.9 of Blue Dot. My max possible OAL is 1.15 so I seat those to 1.145. I'm also using the Lee 356-120-TC with the same powder charges but loaded to 1.08 OAL. The TL round allows me to seater deeper in the chamber and seems to be a little more acurate. BTW, I'm running mine through a .357 Lee sizer and those mic at about .3565 out of the sizer die. You have a length on the bullet?

[Jayhawkhuntclub]

Jayhawk,

I have a S&W SD9 VE and it's chamber and bore are .356 so that might be fairly standard for the SD's and M&P 9's. I called Alliant and they emailed me load data for the 9mm shooting cast bullets. For the TL356-124-TC from Lee I shoot the most, they recommended 4.0 - 4.5gn. I usually shoot those loaded with 4.2 of Unique or 5.9 of Blue Dot. My max possible OAL is 1.15 so I seat those to 1.145. I'm also using the Lee 356-120-TC with the same powder charges but loaded to 1.08 OAL. The TL round allows me to seater deeper in the chamber and seems to be a little more acurate. BTW, I'm running mine through a .357 Lee sizer and those mic at about .3565 out of the sizer die. You have a length on the bullet?

Thanks Jeff & Tacoma! I just loaded up some 356-120-TCs at 4.1 gr and 4.3 gr of Unique at 1.055". Sounds like I'm in the ball park.