9MM OAL question

[rawhide]

I was loading 3.2 tightgroup 147 jk bullet at 1.058 and blew my M&P up. I think the lyman book says the powder should be 2.1 at 1.058. From my personal exprence I would not load anything at 1.058 anymore

Data for Titegroup says starting grains 2.5 & 2.8 max load. I loaded Unique at suggested starting grains of 3.2.

 

[Twmaster]

Owie. Looks like you put too much powder in that load Ryan. 3.2 is the starting load for a 120 grain pill.

Badger, I hear ya. no worries.

 

[Mitch H.]

The Lyman data is a little bit misleading. Their load data is used for the molds they sell. Our 147gr. 9mm bullet works best at around 1.13" OAL.

When working up a load for a new bullet or powder, I always check multiple sources of load data to get a GENERAL idea of where to start. Work the load up SLOWLY, check for signs of over-pressure and chronograph to verify the needed result.

ETA: To answer the OP's question, don't worry about the vast difference in OAL unless you are loading to max velocities. You will see the variance due to using mixed brass. There is even a little bit of variance when using the same headstamp brass. For plinking purposes, I usually stay right around the starting load data.

 

[Brianatc]

I've shot over 1K of Mitch's 147's in my Glock 34 all loaded to 1.125 OAL. Using 3.5 of WST but always remember use load data at your own risk, these chrono right at 880fps.

 

[Twmaster]

Good info. Thanks Mitch.

 

[tul9033]

I've never gone below 1.10 on any of my 9mm loads and those would be FN or JHP's. I'd have to see several cited sources before going that low. My thought is going too long may cause feeding issues, but going too short can cause much more serious issues.

 

[Dr_Mitch]

My Lee book shows 1.095" as the general minimum OAL for 147gr 9mm loads. The recipe for Unique starts at 3.8gr, but that's for a large hollow-point that may take up extra case capacity, and the minimum OAL for it is 1.140". These things vary with bullet construction.