More COL schooling

[wlkjr]

Been reading with great interest the threads about the plunk test. All my pistols are Glocks and loading on a Dillon 650. I'm very new to reloading and still have questions about OAL for 9MM. The SAAMI spec of 1.169 is good in the Glock chambers. I've been loading 147 Berry RN plated bullets with Titegroup at 1.115 with good success and very good groups. Am I good anywhere between 1.115 and 1.169 as long as they fit the magazine. Is longer better? I've read where too short causes pressures to rise. 147's are longer than 124's and I'd assume the 124 needs to seat shorter to get enough bullet in the case. Most info I've seen in published by powder companies or in Lyman #49 shows most 124 plated bullets to be around 1.110. I've also been loading plated 124gr Xtreme HP at 1.110 or so and had no problems, so I'm good with that.
Guess one of my main questions: is there a minimum to maximum COL that I can use to try for accuracy? I understand different bullet shapes have a bearing on OAL I'm just wondering how much to experiment with this facet. I"m not interested in loading at the upper end, just low to mid levels. So far everything has been under 1000fps and functioned flawlessly.

 

[LiveLife]

Glock barrels have longer leade (slower start of rifling) that will accommodate longer OAL. Of course, closer the bullet nose is to the start of rifling, less high pressure leakage for more consistent chamber pressures but you want to have enough bullet base inside the case neck.

Many run 124/147 RN bullets out to 1.140"-1.150" OAL/COL for Glocks.

I load for multiple pistols so I typically use 1.135" OAL/COL for RN bullets to reliably feed/chamber in different pistols/barrels.

is there a minimum to maximum COL that I can use to try for accuracy?

I would test 124 gr RN at 1.125"/1.135"/1.140" and 147 gr RN at 1.135/1.140"/1.150" increments and see which produces best accuracy.


For HP/FP bullets, you will use shorter OAL/COL because of the shorter bullet nose at around 1.080" - 1.120".