6mm / 243 105 GR A-Max - What Cal?

[Lapua guy]

I'm getting 3300 with a .243 AI and 105 Bergers...can hit 3400 if I really want to push the limit...

You sure about that? I am a bit skeptical. Unless you are shooting a HEAVY bench gun with a 32 plus inch barrel, and even then.

As far as prairie dogs and paper, go with the 6 Dasher. Yotes, then I would choose the 6mm AI. If you want a repeater, go with long action. I don't see the draw to the 243 AI outside of maybe benchrest, and even then, the Dasher seems supreme.

 

[adam32]

You sure about that? I am a bit skeptical. Unless you are shooting a HEAVY bench gun with a 32 plus inch barrel, and even then.

As far as prairie dogs and paper, go with the 6 Dasher. Yotes, then I would choose the 6mm AI. If you want a repeater, go with long action. I don't see the draw to the 243 AI outside of maybe benchrest, and even then, the Dasher seems supreme.

Yup, I'm sure At 3400fps I was only getting two loads out of Lapua brass though. Now I'm down to 3250-3300 and getting excellent brass life...drop charts also match so I know my chrony isn't lying...

The reason I went with the .243 AI over the 6mm AI is because of Lapua brass, and being able to shoot regular .243 Win out of it which is cheaper and more available then the 6mm...

 

[Lapua guy]

Yup, I'm sure At 3400fps I was only getting two loads out of Lapua brass though. Now I'm down to 3250-3300 and getting excellent brass life...drop charts also match so I know my chrony isn't lying...

The reason I went with the .243 AI over the 6mm AI is because of Lapua brass, and being able to shoot regular .243 Win out of it which is cheaper and more available then the 6mm...

That is more like what I have experienced. I understand the draw to the Lapua brass. The increase in energy with the 6 AI was just too hard to pass up, and who knows, Lapua might start making 6mm Rem one can hope.

 

[adam32]

That is more like what I have experienced. I understand the draw to the Lapua brass. The increase in energy with the 6 AI was just too hard to pass up, and who knows, Lapua might start making 6mm Rem one can hope.

Now that I think about it, I was getting 3 loads out of them. Two full power and one fireform.

If I did it over I would probably do a 6x284 in a long action. But, my smith already had a short action, so I went with the .243 AI.

A 6mm STW might be something to look at for the big bullets too...horrible barrel life but oh well! Performance comes at a cost!!

 

[RockZ]

I have had awesome results with the 6-284.
I'm getting 3395fps with 107 smk's and very accurate. ES of 8fps.
I can highly recommend it as it is becoming one of my favorite cartridges.

 

[jrkotz]

Thanks for keeping the info coming guys.

I've narrowed it down to 6 BR, 6x47L and 243AI

I am building this on a short action Savage LRPV, with right bolt, left port.

Again, the goal is minimal brass prep, and hopefully reasonable barrel life for out to 400-600 yds at prairie dogs. I'll shoot our local groundhog match with it too.

I'd love to go 243 AI, but fireforming is NOT appealing. I'm really liking the 6x47L, seems like a good 'mid 6mm' cartridge - balancing MV with easy brass prep, lapua brass, and decent barrel life.

Any other thoughts before I 'pull the trigger' on a new barrel?

 

[Lapua guy]

6 Dasher.

 

[comen]

I have had awesome results with the 6-284.
I'm getting 3395fps with 107 smk's and very accurate. ES of 8fps.
I can highly recommend it as it is becoming one of my favorite cartridges.

I know this is an old post, but:
I recently acquired a 240 Gibbs, 26"BBL and 9.5 twist. I am shooting 105 A-Max loaded to 3.395" OAL. Accuracy node with Retumbo seems to be 61.0-61.5 grains at a little over 3400 FPS. 62.0 shows no pressure, but also almost no velocity gain over 61.5.
Am I on the right track here, or can I do better?