9mm COL problem.

[joshb]

I’ve been reloading 9mm for a couple years. When I started, I loaded some test rounds and took all of my pistols to the range and shot each gun with the reloads. I recorded the load that worked in every gun and started on a large lot of brass.
One day, I took my son in law to the range with his new Glock 34. It worked fine with factory rounds but had problems with my reloads. The gun kept jamming while feeding a new round.
The only difference between the rounds was the COL. I’ve been using the Hornady book and thier COL for a 115HP is 1.07 and the 124HP is 1.06. I measured the factory Speer Gold Dot 124 HP at 1.12.
I’m wondering why and how there is such a difference in specifications. I would think the COL would be standard across the industry.
What COL is everybody else out there using?

 

[GotRDid]

The ogive profile could be the issue. While I have not experienced any feeding issues with the Glocks I have fired related to COL, I have had issues with velocities affecting the cycling of the slide.
What is your propellant, and charge weight (and velocity if chronographed)?

 

[stavey]

I load 115 Hornady HAP to 1.125”. I will usually make a dummy round and chamber it in whatever pistols I plan on shooting it in. Just to make sure it’s good to go.

 

[SKWERLZ]

Col depends on magazine restrictions and bullet profile.

 

[joshb]

The ogive profile could be the issue. While I have not experienced any feeding issues with the Glocks I have fired related to COL, I have had issues with velocities affecting the cycling of the slide.
What is your propellant, and charge weight (and velocity if chronographed)?

I’m thinking you nailed it. I’m using CFEPISTOL. My load is 3 tenths below Max. Although it works fine in all my 9’s, maybe this new Glock has a stronger spring. We do notice the Speer ammo is a bit snappy.
I still wonder how the COL is so different between book and factory loads.

 

[joshb]

I load 115 Hornady HAP to 1.125”. I will usually make a dummy round and chamber it in whatever pistols I plan on shooting it in. Just to make sure it’s good to go.

Yup. I tested all of my pistols with the loads before I started reloading in quantity. It was quite an effort!

 

[DRK]

When I load 115 & 124 gr RN, I load them at 1.16" OAL. Runs fine in my pistols & SMGs.

 

[Hoser]

For the most part, all of the bullets I load in 9x19 work fine and pass a plunk check when loaded to 1.130-1.140.

 

[MikeT124]

In 9mm I load only 124gr bullets, for practice it's Missouri coated LRN and loaded to 1.145 COL. My defense loads are Federal and are at 1.103 COL. Have no problem in 4 different S&W Equalizers.

Mike

 

[GuitarmanNick]

I load 124 grain FMJ to 1.15", and 124 JHP to 1.06". These work well in all of my toys.

 

[Coyotefurharvester]

Sounds like the SIL pistol was short stoking with your reloads, not a fitment issue? Easy to pull the barrel and do a drop in fit check(plunk check). Different spring rates? Or old well broken in pistol vs new pistol.

 

[markm87]

Factory ammo varies greatly in COL and ogive shape. I honestly don't even measure my COL beyond eyeballing it against a similar round and then dropping a round into one of my chambers for the plunk test.

 

[Doug Casner]

Loads for my Sigs wouldnt all feed in my kids Springfield. Shortened the oal a little. Doug

 

[Idaho-Lefty]

Try 5.0 to 5.2 grains ( Max ) of Win 231, Fed Pr., with, a Hornady 124 gr. JHP at, a COAL of,1.055 to 1.060, gets me 1,075 to 1,100 fps from, my New, 5 inch Glock, model 34, w/ a 17 lb Spring.
NO Feed "issues",.. EVER and Shoots,.. "Small" group's !
Found SHORTER COAL's and LOTS of Powder ( Near Max ),.. to Be,.. Better !
Watch, your Spring "Poundage", also ( AND,.. Keep Rails, CLEAN and Lubed ! )

 

[Doom]

I’m wondering why and how there is such a difference in specifications. I would think the COL would be standard across the industry.

Welcome to joys of pistol reloading. First there is no uniformity in bullet profiles so a 9mm 115 grain FMJ (or any other type) bullet from one manufacture may have a different ogive shape and hence length than another manufacturer. If seated to the same length there will be different volumes for powder under the bullet and with the same powder load the pressures will be different. The 9mm Lugar is very sensitive to this.

The pistols are also different. In 9mm you may have three inch barrel in one pistol and a five inch barrel in another. There is a huge difference in weight for the slide and spring rate for the recoil spring.

Without knowing the actual recoil energy of the round you will not know if it will work in different pistols other than the one that the load was developed for.

The gun kept jamming while feeding a new round.

It sounds like the Glock is short stroking. The slide travel is sufficient to eject a spent casing but is not compressing the recoil spring enough to have sufficient energy to chamber a new round.

 

[kenhwind]

You're trying to compare two different proprietary bullets and the COAL of these bullets.

Hollow point bullets are not necessarily considered "standard" and if you were to look up the SAAMI specifications for the 9mm you will find the data for a 124 grain FMJ.

Speer Data list the 1.120 for the GDHP, the Hornady bullets have an entirely different profile, and I'd have to go look that up.