9mm C.O.L. Question

dlmmist · December 4, 2017, 07:45 PM

Hello, Have a quick question for you. I have for about six months trying to reload 9mm for a Glock 34 and Glock 17. I have tried all Lee bullet molds for 9mm and settled on the TL356-124-2R 124gr. seems to feed the best in my barrels. I use range lead and mix brass with CCI primers and CFE Pistol powder. I also powder coat my bullets and use a mix of hornady and lee dies. I'm not having problems with any of that. My problem is OAL Most load data recommends 1.140 to 1.150 OAL for lead 124gr. and other types of bullets but that does not feed well. My bullets hang up going into the barrels chamber on the feed ramp. I found that 1.155 to 1.160 OAL works flawlessly. So I would like to see if anyone out there sees a problem with my reloading data that I have come up with. Tested last weekend with longer OAL and seems to shot good accuracy also seems good. Shot 200 round with longer OAL.

Lee 124gr. powder coated (Bullet weight really between 124gr. to 127gr.)
Bullet Diameter= .356
OAL= 1.155 to 1.157 (Seating depth varying do to press but within 1.153 to 1.157)
Crimp= Between .373 to .375
Mix brass with CCI Small Pistol Primers #500
Powder= CFE Pistol 5.2gr. to 5.3gr.
Not sure on velocity or pressure

Thank you

**Unclenick** · December 4, 2017, 09:08 PM

No general COL exists. It is bullet-specific. The numbers commonly given are SAMMI Max, which is not to be exceeded if you need the ammo to fit in all magazines made for all 9mm guns, but which is not necessarily good for any particular bullet or gun. If you find what works in your gun, you found what is right for you.

5whiskey · December 4, 2017, 11:10 PM

1/100th longer usually errs on the side of caution in the realm of pressure. As for proper chambering, maybe or maybe not. If it passes the plunk test roll with it.

kmw1954 · December 6, 2017, 12:24 AM

dlmmist I have used a length of 1.160 with a plated bullet that the suggested length was 1.150 with no problem other than having to bump the powder charge up a little because of the extra length. At the starting load charge it would not lock the slide back on the last shot. Once I was up .2gr then it worked just fine.

hdwhit · December 6, 2017, 12:11 PM

In general, going slightly LONGER than published OAL will not cause a pressure problem. It is seating a bullet deeper (i.e. resulting in SHORTER OAL) that has the potential to cause problems.

For many years (I don't have the latest edition, so I don't know if it is still in there) the Speer Manual included a caution regarding 9mm Luger regarding bullets getting set back as a consequence of recoil that when the OAL was reduced by 0.030 inch (thirty one-thousandths) the pressure of one load nearly doubled. That is, no doubt, an extreme case cited as a caution to the reader, but it does illustrate that published OALs are important.

December 4, 2017, 07:45 PM	#1
dlmmist Junior Member Join Date: March 28, 2016 Posts: 6	9mm C.O.L. Question Hello, Have a quick question for you. I have for about six months trying to reload 9mm for a Glock 34 and Glock 17. I have tried all Lee bullet molds for 9mm and settled on the TL356-124-2R 124gr. seems to feed the best in my barrels. I use range lead and mix brass with CCI primers and CFE Pistol powder. I also powder coat my bullets and use a mix of hornady and lee dies. I'm not having problems with any of that. My problem is OAL Most load data recommends 1.140 to 1.150 OAL for lead 124gr. and other types of bullets but that does not feed well. My bullets hang up going into the barrels chamber on the feed ramp. I found that 1.155 to 1.160 OAL works flawlessly. So I would like to see if anyone out there sees a problem with my reloading data that I have come up with. Tested last weekend with longer OAL and seems to shot good accuracy also seems good. Shot 200 round with longer OAL. Lee 124gr. powder coated (Bullet weight really between 124gr. to 127gr.) Bullet Diameter= .356 OAL= 1.155 to 1.157 (Seating depth varying do to press but within 1.153 to 1.157) Crimp= Between .373 to .375 Mix brass with CCI Small Pistol Primers #500 Powder= CFE Pistol 5.2gr. to 5.3gr. Not sure on velocity or pressure Thank you

December 4, 2017, 09:08 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	No general COL exists. It is bullet-specific. The numbers commonly given are SAMMI Max, which is not to be exceeded if you need the ammo to fit in all magazines made for all 9mm guns, but which is not necessarily good for any particular bullet or gun. If you find what works in your gun, you found what is right for you. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 4, 2017, 11:10 PM	#3
5whiskey Senior Member Join Date: October 23, 2005 Location: US Posts: 3,657	1/100th longer usually errs on the side of caution in the realm of pressure. As for proper chambering, maybe or maybe not. If it passes the plunk test roll with it.

December 6, 2017, 12:24 AM	#4
kmw1954 Senior Member Join Date: June 11, 2016 Location: SE Wisconsin Posts: 1,524	dlmmist I have used a length of 1.160 with a plated bullet that the suggested length was 1.150 with no problem other than having to bump the powder charge up a little because of the extra length. At the starting load charge it would not lock the slide back on the last shot. Once I was up .2gr then it worked just fine.

December 6, 2017, 12:11 PM	#5
hdwhit Senior Member Join Date: June 22, 2017 Posts: 1,011	In general, going slightly LONGER than published OAL will not cause a pressure problem. It is seating a bullet deeper (i.e. resulting in SHORTER OAL) that has the potential to cause problems. For many years (I don't have the latest edition, so I don't know if it is still in there) the Speer Manual included a caution regarding 9mm Luger regarding bullets getting set back as a consequence of recoil that when the OAL was reduced by 0.030 inch (thirty one-thousandths) the pressure of one load nearly doubled. That is, no doubt, an extreme case cited as a caution to the reader, but it does illustrate that published OALs are important.