What Practice Bullets to Mimic Non-Lead Bullets in 30-06?

[falldowngoboom]

Hi all,

I'm just getting into reloading and would love some sage advice from anyone who cares to share. I've decided to use non-lead for all my hunting (deer, pig, possibly bear). I'm leaning strongly towards Hornady GMX in 150 or 165 grains.

My dilemma is I'd like to find a practice bullet that I can use the same load recipe for and have it be ballistically the same as the non-lead bullet. Would this just be a matter of matching ballistic coefficient, sectional density, and grain weight of the two bullets or is there more to it than that?

My goal is to be able to practice with the cheap bullet and not have to worry about re-sighting or remembering a different trajectory for the non-lead load.

Any bullet suggestions?

 

[dmazur]

From Hornady's 2009 catalog -

"Additionally, GMX bullets share the same ballistic coefficient as their SST and InterBond counterparts, so hand loaders can use the three interchangeably and maintain the same exterior ballistics."

There is also mention of tasking Hornady's engineers with making sure the GMX bullets would work with standard published reloading data. (i.e. "lead")

"It will not foul or increase pressure the way solid copper bullets do."

So, choose either Hornady's SST or InterBond for practice...

 

[falldowngoboom]

Thanks dmazur! I didn't see that on their website and there's no ballistics data for the GMX bullets on there either.

At least SST is quite a bit cheaper than the GMX stuff. Am I right in assuming that the same BC (and grain weight) makes it okay to swap bullets while still using the same load? Could an FMJ bullet with the same characteristics just be substituted in there? Hornady's 150g FMJ has got a BC (.398) that's pretty close to the 150g SST (.415).

 

[dmazur]

The best thing to do is either email or call Hornady for a definite answer.

I'm going in the same direction as you are, anticipating "no-lead" areas in Washington State. I have 150gr GMX's on order, and quite a few 150gr SST's on hand. I hope to prove Hornady's engineers correct, and have nearly identical 200 yd targets without scope adjustment.

My understanding is that Hornady designed the GMX to be interchangeable with the other two mentioned, the SST and InterBond. I would assume that would include COL.

Hornady's 150gr FMJBT isn't the same profile as the SST, so the COL will differ slightly. And, as you noted, the BC isn't the same either.

I suppose it depends on what you want to achieve. If you're working up accuracy loads for 300-400yd shots, you probably want "equivalent", which means the SST or Interbond, in the same bullet weight. If you're not taking shots past 200 yds, the difference between a 150gr SST and a 150gr FMJBT may not be significant.

 

[falldowngoboom]

Just spoke with someone at Hornady. He verified that the BC is exactly the same between SST and GMX of the same grain. Load data is the same as well, and he said he found from his personal shooting experience that they print the same under the same loads.

FWIW he also said that the 150g FMJ round wouldn't be very different except out to longer ranges. He said barrel harmonics would play more of a role in discrepancies more so than BC.

Realistically, I'm not really planning on shooting out to more than 300-350 yards. So for practice, I'm gonna stick with the FMJ and save the 25%, even though the SSTs aren't all that pricey.

Also, FYI here is the load data he quoted me for IMR 4350:

150g (GMX/SST) 50.4g 2500fps to 59.9g 3000fps
165g (GMX/SST) 48.1g 2400fps to 57.0g 2900fps

Let me know how the GMXs treat you. Cheers!