6mm slr & 243AI

[fredjake]

Just wondering how much difference between the two. I think the 243ai has a 40degree shoulder vs the 30 degree shoulder of the 6mm slr. I am thinking about one of these for a build & looking for imfo.

 

[rcw3]

243AI takes the existing 243 Win shoulder and blows it out to 40 degrees and blows out the body diameter in the front end a little too, but essentially retains the same short neck length of the 243 Win. 6mm Super LR reforms the 20 degree shoulder of 243 Win brass to give it a 30 degree shoulder and a nice long neck with a case capacity very close to a .243 Win. If you are looking for "max capacity" and don't mind a shorter neck, the 243AI has more capacity, but if you are looking for a case with 243 Win capacity but with a long neck and the accuracy proven 30 degree shoulder angle, the 6mm Super LR is just that. The long neck works well with not only the 115's but also the 105 - 108 gr bullets. If you take a 243 Win or 243 Win AI neck and throat it for the 115's, most 105-108 gr bullets will be just about falling out of the mouth of the case when they hit the lands, but if you throat it for the 105-108 gr bullets, then you have a whole lot of the 115's back in the case. The 6mm Super LR's long neck give one a lot of options and flexibility (in addition to some buffer from the throat torching that goes along with a short neck).

One is not necessarily better than the other, it's more a matter of what features you want in your 6mm.

There's more info on the 6mm Super LR here:

http://www.6mmar.com/Super_LR.html


Robert Whitley

 

[HPMike800]

The long neck of the 6SLR is a nice feature, I'm putting a 6SLR into service very soon. The 243 AI or 6CM allow the use of super slow powders like H1000. Idon't think there is any real performance diffrence.

For the 6SLR Robert has dies and reamers are easy to get.

Mike

 

[coyotehunter]

I have a 6 slr and it has turned out to be an excellent shooter. I am very satisifed and look forward to building another one day.

 

[Bigame1]

Coyotehunter;
Would you share your load info. as I'm sending my action and barrel back to have it made into the 6mmSLR. I'm planning on shooting it at 600 & 1000 yards and I'm hoping that the 115 grain bullets should shoot good as I know the 105,107 & 108's do.I'm going for the reamer that will set it up for the 115's and still shoot the 105-108 good also.

 

[coyotehunter]

Right now I am using Winchester brass with Sierra 107's For powder Im running 42 grains of reloader 17.
I will tell you that this powder seems to be temperature sensitive where as Im getting 3258 fps when temp is around 90 degrees and 3150 fps when temp is around 70 degrees. It seems to shoot well either way and my extreme spread is around 8fps. I have tried some H100 and settled on 41.8 grains and it shot well also but doesnt seem as consistant. My rifle seems to want to shoot from 3150 to 3250 fps. I hope to find a powder that is consistant like the Reloader 17 but not temp sensitive. I have tried the H4831sc but can't get the velosities without getting pressure signs first. Haven't tried H1000. My rifle is a remington 700 action with a Bartlien 1in8 twist in a choate varmint stock. The last time at the range I shot a 3/4 inch group at 500 yards and at 940 yards a 5 shot group around 4 inches with 3 of them being well under 3 inches.

 

[Bigame1]

Coyotehunter;

Thanks for your info and you might want to look into the Alliant 2000MR
powder? It is supposed to be for .223 & .308 heavy loads and since the 6mm SLR is based off that case .243 partly I think it should be a good performer. What about IMR 8208xbr or IMR 4064 have you tried any of these? I have a 1:7:5, 5 Groove S.S. Bartlein barrel that will finish off at 30" and it will be mated to a Savage action and I'm going to use the reamer for the 115 grain as it will be excellent for the 105-108 grain bullets also.

 

[rcw3]

Coyotehunter;

Thanks for your info and you might want to look into the Alliant 2000MR
powder? It is supposed to be for .223 & .308 heavy loads and since the 6mm SLR is based off that case .243 partly I think it should be a good performer. What about IMR 8208xbr or IMR 4064 have you tried any of these? I have a 1:7:5, 5 Groove S.S. Bartlein barrel that will finish off at 30" and it will be mated to a Savage action and I'm going to use the reamer for the 115 grain as it will be excellent for the 105-108 grain bullets also.

IMR 8208xbr or IMR 4064 are a little fast in burn rate to get the best out of 6mm Super LR with the heavier bullets - not that they won't shoot well - but their pressure curve is a little too quick for that application - for lighter bullets maybe. For 115's H4831SC works great (and N160, N560, RL19, etc.).

Robert Whitley

 

[Bigame1]

Thank you Robert. We need to talk about the project I presented you?
If you can please e-mail me at my ebco address .

Forrest