COAL for 9mm 124 gr RN

[hawk in ct]

I seem to hae found the sweet spot in my Sig P-226 with 124 gr. Rainier plated round nose over 4.4 gr. W-231. Function is 100%. Chronos around 1050. What I'm finding, however, is the groups tighten as I increase bullet length. 1.16 shoots much smaller groups than the manual recommendation of 1.125. I haven't gone beyond 1.16. Does anyone have any experience in the 1.16 to 1.169 range. Is there any reason I shouldn't go into full production with a bullet so much longer than what's recommended?

Thank you for the help.

Edited January 27, 2009 by hawk in ct

[19852]

I used to run COAL as long as the magazine would allow. The only problem I had was sometimes the next cartridge would slide forward and not allow the mag to drop. I now load my 124/125's to 1.085 COAL. This works in my CZ75.

[robertbank]

hawk in ct - There is a wide variation in chamber length in guns chambered for the 9MM as you likely know. Load you cartridges as long as the mag, chamber and smooth function will allow. Chrono the loads once you reach your maximum length to see if you are still achieving your desired velocity. If you play IDPA/USPSA you might want to try 4.7 gr of 231 with that bullet to meet PF requirements. That is my go to load when shooting plated or jacketed bullets. Very accurate in my nines.

Take Care

Bob

[revchuck]

I seem to hae found the sweet spot in my Sig P-226 with 124 gr. Rainier plated round nose over 4.4 gr. W-231. Function is 100%. Chronos around 1050. What I'm finding, however, is the groups tighten as I increase bullet length. 1.16 shoots much smaller groups than the manual recommendation of 1.125. I haven't gone beyond 1.16. Does anyone have any experience in the 1.16 to 1.169 range. Is there any reason I shouldn't go into full production with a bullet so much longer than what's recommended?

Thank you for the help.

Sounds like you're trying to fix something that ain't broke. If you're getting that velocity at that OAL, tighten everything down and start pumping out ammo!

The only reason I would change anything is if you were in my situation where I load for five different 9x19s. I load to the longest length that functions 100% and makes the PF in all five guns and then keep it there.

[hawk in ct]

Many thanks. I'm loading and shooting 500 before the full 2,000 I need to make sure I've got what I want.

Sorry about the error in the title. Now fixed. I meant to say 124 gr in the title. The 147's are next which I plan to test 3.2 to 3.5 gr. W-231 with COAL of 1.14 to 1.16 based on the success of the longer rounds in my pistol.

[WestWorld]

I run my 9mm in 4 different guns. 1.160 works great in my SP-01 but that length is a little cramped in my XDm mags. I don't want to build separate bullets for all my guns so 124 RN gets loaded at 1.145-1.150 and feed reliably in all my 9's.