[Brad4]

I am interested in developing/testing 7m-08 loads for Honaday 139 gr GMX bullets. My understanding is the guilded metal bullets are relatively longer for weight than their lead alloy counterparts. I assume I should be using the same COAL for the finished GMX round as for lead alloy which will reduce space for powder capacity. Any suggestions for powders/loads to yield mid-range velocities in the 2600-2700 area would be appreciated. Any other techniquesuggestions for GMX or Nosler e-tip would be helpful too.

Brad

 

[Chief RID]

I am developing loads for this bullet now also. I had the same questions. I already had a load for one of the Hornady bullets of the same wt. It was far from a compressed load so I had no problem with the powder capacity. I did end up seating the rounds to the suggested COL of the Hornady manual for the SST of that weight. I plan to put a few down range tomorrow so I will post then.

My load is for 06 with the 165 gr GMX.

 

[Darkker]

I'd bet Hornady lists the COAL on the loading info on their website.
Otherwise if you reload anyway, you should be reloading per your guns throat. Just size a case, and just barely seat the bullet. Chamber the round, and extract. Measure the OAL, that is where the bullet contacts the rifling.
Seat the bullet deeper by about .03"; or 1/32" and you will have plenty of clearance.

As an example:
I have a 25-06 that has a VERY short throat, some reloading data would have the bullets jammed in the lands. But since I seat according to each of my rifles, it is a mute point what a book tells you.

 

[Chief RID]

I could find nothing on the web site for the GMX except what is in the adds. The big thing on this bullet is it is suppose to load just like the SST. If you shoot that bullet it is suppose to be an exact match. At least that is what is advertised and the internet chatter has been exactly that.