Hornady GMX in .243 AI
Has anyone used the Hornady GMX in .243/6mm? I have a Tikka .243 that I ran an AI reamer into and it shoots 85 gr HPBT slightly sub-MOA. That was going to be my go to bullet but I'm now thinking of using a GMX as my standard load for the rifle but haven't tried them yet. Seems like it would make a great all around load for the .243 for deer and varmints. I think I can push them at or above 3600 fps.
Any experience out there with the GMX or even the Barnes copper bullets in the same weight range?
My only "experience" would be called inference or a wild guess. I can launch bullets at AI velocities from a 243 Ruger #1 with a 26" barrel and a very long throat. The throat is so long that I can seat the 105 grain Speer Spitzers all the way out with the base of the bullet at the base of the neck. We're talking a case FULL of slow powder with no allowance for deep-seating bullets. I also have a 240 Weatherby Mag and recently got rid of a 6mm-284.
None of those would top 3500 fps with any 85 grain bullet, though I was in the 3200 fps realm with some 100 grain loads. I kinda wonder about your pressures if you're getting 3600 from a 243 case, even an AI.
All that's for preliminary for saying I had expansion problems with 100 grain Nosler Partitions on deer much past 300 yards. They simply did not expand reliably out there, and I had several pencil-thin pass throughs that cost me long trailing jobs on deer. That's why I went to the 105 grain Speer spitzer in all those guns, since I was relying on them for 300+ yard shooting.
To the extent that a GMX might be tougher than the Nosler, you could experience similar expansion problems. If it's not as tough as the Nosler, I can guarantee you'll jello your deer inside 100 yards.
Thanks Brown Bear,
I was just looking at the data on the "6BR" web site: 3550 with a Berger 80 gr using H4350. 3400 would still make a pretty flat shooting round. If we can believe Hornady they say you can get adequate upset of the GMX at 2000 fps which should be easy at 400 yds, about my limit. I have had such good luck with the Sierra 85gr BTHP I should just stay with that but I'd like to try a GMX and see how it works for an all around load in the AI.
Give it a try. Seems like the GMX and Barnes TTSX are bullets with very similar constructions, but their ogive is definitely different. The GMX has a longer spear like point than the TTSX.
Just start with a box though. I couldn't get the GMX to shoot well in my 7mm-08, but I have gotten the TTSX to shoot well. I tried a lot of different combinations including varying powder types and charges plus varying the jump since the Barnes seems to like a longer jump. Never did get it to shoot well before I was able to get Accubonds and then two weights of the TTSX to shoot well. You might find that your rifle likes a regular diet of GMX. Only one way to know......
Too late...I just bought 5 boxes from Midway's blemished bullet sale so they were less than half price.
You are correct, only one way to find out. If they don't work in the Tikka I have other .243s I can try them in. I have my fingers crossed with the Tikka because it is such a nice rifle. My "hunting" .243 is a Rem 660 and while it has served me well since new in the late 60's I really like the Tikka better.
Barnes has quite a variety of copper bullets so if the GMX does not pan out I may give their 80 grain a try. I'm also interested in their 120 grain 7mm in my 700 280 Mtn rifle which has also been a steady producer of the years. It traveled with me to Kodiak and Afognak several times for deer...until a bear took a deer from me and I thought something a little heavier was appropriate so I went with an 06.
Thanks for the info!!!