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

[jrkotz]

Hey guys -

Looking for a new barrel for my LRPV.

I've decided that the 105 gr A max bullet is the one I'd like to base the build around, main purpose is 600 yd bench shoot and prairie dog shooting from 400-700 yards.

The question I have floating around in the ol' knoggin is - what brass should I put ehind the bullet?

Looking for MINIMAL brass work with MAXIMUM speed and accuracy. Goal is to have a few hundred rounds to shoot the long distance dogs that my 223 and 204 can't reach.

I'd like to scream the thing out at 4000 fps ;D

But seriously, what do you have in mind? Thanks!

[358Hammer]

I have been going over this pretty heavy the past four days with a friend who also wants a 6mm laser. SInce he can't make up his mind he is going to do both the 6mm AI and the 6 X 284. Both are barrel burners so he is going to send the barrels in with my next shipment and have them Nitrided.

53.0 RELOADER 22 Accurate reloader ( 6X284)
3223
0.402
HORNADY 75 VMAX

54.0
3277
0.311

55.0
3382
0.402

56.0
3415
0.623

57.0
3510
0.357

58.0
3600
0.493

59.0
3705
0.300
Reloader 19 is 100fps faster. Try a 55 grain ballistic tip and I have been well past 4000fps.

Found a smith who has a bunch of Savage takeoff barrels and he sells them for $45. each. I just purchased a Unfired takeoff 300 Rum barrel for that price.

Neal

[jrkotz]

I wonder if the MAGICAL RL 17 would get it any quicker with a heaver bullet?

That's QUICK!!

[tammons]

At anything close to those speeds shooting dogs, you will burn out a barrel a week.

Get a 6mmBR or if you can deal with some brass reforming build a 6x47 lapua or a BRX.
If on the cheap just build a 243 win.

If it was me I would build a 6mmBR. Definitely the most accurate round I have ever shot.

[82boy]

WOW, your not asking for much.
4000 FPS with a 105 A-max.
I would say it would have to be a 6-284 or a 6x300 RUM.
Don't expect that barrel to live a long life.

[desertcj]

I have been dreaming about a 6mm screamer for a while now. A 6mm-06 Ackley Improved is what I want to build some day. 28"-30" barrel to wring out max velocity and it would mostly be for long shots on deer/antelope/pigs. A 6mm based on the 7mm Remington Magnum might do it for you if you don't mind wildcats.

[GaCop]

I vote for the 6mm BR too. I get good results with the 105 gr A-Max in mine.

[Apache]

+1 on the 6x284 Winny like Neal suggested.....For the least amount of brass work and the best performance for it.

I shoot a 6mmSAUM that is a screamer. Kills deer like lightening. Everything I've shot with it so far has been DRT. But "least amount of brass work" it isn't. Necking 7mm or 300 SAUM brass down that far takes several steps. The thing about brass work for a wildcat is.....once it's done, it's done. One other aspect is, if the brass has to be fireformed, it adds that much more barrel wear to the barrel unless you have a fireform barrel.

These types of cartridges are barrel burners and require special care also. Don't get them hot and keep them clean or barrel life will be VERY short, and it's pretty short even WITH all the precautions. Neal can tell you more about Nitriding that will extend the barrel life as well as velocity if you willing to go that direction.

Just some things to consider.

[Armed in Utah]

Quick twist 6XC or 6BR

[jrkotz]

As expected, lots of love for the ol' tried and true 6 BR. I was just not happy with the amount of wind drift that I'd see with the speeds out of it.

Why 6 XC vs 6 dasher?

6-284 seems to be getting a lot of attention - what would it take to prep the brass? How would that compare to 6x47L?

Thanks for all the input so far fellas!

[358Hammer]

Brass prep is nill. 6X284 is about as good as it gets.
It outruns the 240 Weatherby but like Apache said. Any of the real hot 6mm's the barrel life isn't worth it. Until I found the barrel hardening process I would not have made the things I am playing with right now. The 6.5WSM will eat up a barrel long before one gets it dialed in for long range competition unless one loads down.

Neal

[jrkotz]

What a conundrum!

Law of diminishing returns, hotter that load, shorter BBL life. I want something quicker than regular 6 BR or 243, so seems like wildcat is the way to go.

What kind of velocities are you guys getting with the 6x284? What twist BBL for the 100-115 GR range. Is it possible to get a twist that will stabilize 107's and not rip apart 87 gr vmax?

Thanks!

[DGD6MM]

6CM....

[jrkotz]

Thanks the info 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 def like the fall back option of the 75 and 87 Gr V-Max's.

I'd love to go 243 AI, but fire forming 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?

[okie2]

6-06 85 gr at 3925 fps

[kslefty]

I have a 6-06 improved with a 28" barrel. It is a 1 in 10 twist, never tried a bullet over 95gr but I am betting it would shoot 105gr a-max fine. I haven't shot it enough to get much data from the chronograph but I use 240 weatherby data to start out with and have worked well past this with the 75-95gr bullets. Also have a 27" 6mmAI from SSS that is an 8 twist either one will do what you want and to be honest I am drifting towards handguns more now so they are both for sale.

[keeki]

the only 6mm thats gonna hit those velocities is the 240 incinerator that I know of

[okie2]

6-06 AI
58 GRAIN VMAX
VARGET 60.0 GR.
4320 FPS

[snowgetter1]

I have a 243 wssm in a 28" shillen and it will do about 3150 with 100 grain. I have not chrono'd my 105 Amax yet but it shoots better than anything I have ever owned. Overall it seems to be the same velocities as others have reported with 243AI and 6mmAI.

[CJ in WY]

I'm getting 2885fps out of the 6 BR and 2952fps out of the 243 and 3350fps out of the 6-284 with 105 grainers. The 6-284 is one sweet shootin rifle that doesnt get brought out often and then only shot a couple of times, the 243 prefers the 55 Nos @ 4000fps and the 6BR is haveing technicle problems and waiting for funsds to fix :-[

I'd love to go 243 AI, but fire forming is NOT appealing.
Fireforming ai cases is as easy as loading any other round and most of the time the fireform load is just as accurate as the final case.......just not as fast or cool lookin ;) Loaded hot it will eat a barrel within 1000 rounds though.