Which 6mm???

[bailey1474]

I am wanting something w/long bbl life, no recoil and 1000 yd performance. Kirby has my rifle and a 5C Broughton 6mm bbl w/an 8 twist. I have laid to rest my dream of a 6BR due to my inability to find ANY Lapua brass in the lower 48 states and the fact that Kirby does not have a reamer.

Now what? Kirby has a 6-250 reamer and pretty much has me talked into that, but now I'm not sure. I'll have to buy dies and they don't give those darn things away ($200). I am also concerned about the case life on this round. How many firings can I expect and will case growth be excessive?

The way I see it, I only have two other options. Go w/the .243 win or the .243 AI. I have a Lee collet die for the .243 win and would only purchase a body die to bump the shoulder back w/out touching the neck. I would get near identical performance as the 6-250 but would be burning more powder. Would this greatly shorten my bbl life?

The AI is attractive to me b/c of the shoulder angle and it's lack of growth not the performance gains. I wouldn't have to trim it very often and would probably only load it to around 3000 fps w/the 105 Amax. There is no need to burn all that powder and toast the throat that much faster. Can I use my standard .243 collet die on the AI? I don't really like the idea of fireforming either as this will use up some bbl life.

 

[screech]

I havent shot a 243 at 1000 yards yet but I would imagine they would be able to with the right bullet. As for barrel life I would expect it to be long. I know people who shoot them and have put closing in on 2-2.5k rounds through them and they still shoot less than 1/2moa. I dont know if this is abnormal for this cartridge but I wouldn't shy away from a 243 or 243AI. Just my expierence.

 

[abinok]

If youre thinking about the 6-250, your 243 collet die will work, or you could have Kirby hold a standard 243 reamer short, and have a machinist chop off the needed amount and use any 243 die for FL sizing, or bumping the shoulder.

 

[bailey1474]

What brass would a guy use then?

 

[abinok]

For a 243 held short? 22-250 necked up to 6mm. Same idea as David Tubb's 6xc. /ubbthreads/images/graemlins/smile.gif

 

[bailey1474]

I see. What advantages does this have over the 6-250? What about a .243 AI reamer held short? Then I would get the best of both worlds.

 

[abinok]

Main advantage is cheap, and readily avalable dies. You can have the factory dies bought, and cut down for much less than a set of custom dies. Basically duplicates 243 performance, with 6 grains less powder... same as the 6-250

 

[EddieHarren]

According to Kaltron-Pettibone, the importer for Lapua brass, the 6BR brass is here. Should be in the supply houses by end of week. 220 Russian to follow in 2 weeks.

 

[budlight]

This is where my research led me. The 6mmXC. I bought a 243 Rem just to use the action to build this XC. In the mean time I'm having a good time with my 243 and it's 9 1/4 twist with 100 gr BT's

http://www.6mmbr.com/6XC.html

 

[LWolken]

I would give the thunbs up for a straight up 243 or the improved version. Reasons why? The 6BR looks really nice but is not really big enough to do anything but shoot varmints and this it will do very well. The standard 243 built for Lapua brass would be a sure winner. It will do everything the 6BR can and give you about 200 fps more which should make a better Antelope/Deer rig if you so desire. The improved version will give you even better velocities and less case stretch but you will need to fire form all your brass so right there atleast half of your shooting will be at standard 243 velocities. The 243 will also feed much better through the magazine than an improved version. The AI will feed but expect dented up brass. Remember you can always down load the larger cases which is a much better option than overloading the XC, BR or variant.

Lance

 

[Buffalobob]

As a reminder, you might ask Kirby to make you a shoulder bump checker dowhacky thing while he is at it.

 

[LB]

I think it depends, to some extent on the length of your action. You mentioned an advantage on trimming necks with the 243AI, but the same is true with the 6/250 and if you have a medium length action, you can really seat long bullets way out there and still fit them in the magazine. The performance level is probably adequate, but you really didn't state your application, targets or live animals?

I once had a 6/250, very sensible choice, if you have any consideration for barrel life, at all. Probably does not require as long of a barrel as the 243AI for optimum performance?

Good hunting. LB

edit: I am a big fan of the standard 6MM Remington, have had three. No flies on that puppy.

 

[bailey1474]

The application will primarily be varmints 1100 yd and in. I already have two hot rods in the 270 AM and the 300 RUM. I need something a little more economical to shoot w/less recoil.

I don't care if I can load from the mag. A single shot is ok by me.

BBl life is a major concern. As long as I hit 2800 fps w/the 105 Amax, I'll be smiling. I am just curious if the bbl life of the 6-250 will be that much more than the .243 or .243 AI loaded to sensable pressures? Also curious as to how ofter I'll have to trim the 6-250? It's not like trimming is that difficult, I just hate it!!!

I guess what it boils down to is the fact that the dies I want for the 6-250 are $200!! I guess maybe I should quit being such a lazy, tight wad and just order the dies.

 

[LB]

The 6/250 is an Ackley, which means no trimming to length, just like the 243AI. That 40º shoulder reduces forward brass flow to almost nothing.

I'd consider getting Wilson hand dies and buying an arbor press. I don't think that would run $200?

But, barrel life should be noticeably, to significantly better than the 243AI, depending on how hot you load it?

They are both good, but I am sure the 6/250 is more economical and the performance is close enough to a 243W that you wouldn't notice it. (edit: the reason being that you can usually load an Ackley to higher pressures than the 243)

Good hunting. LB