6mm Super LR (.243 based wildcat)

[MalleeFarmer]

Hi guys another topic on my varmint build just thought I'd ask if anyone has experience with this cartridge if not what are your thoughts on it in very seriously considering it for a dual purpose varmint target round it appears to be from all accounts a lengthened 6xc case that can be made by simply full length sizing .243 cases which means I'll have no brass availability problems like the 6xc.its essentially a .243 with a 30• shoulder and long neck for more bullet and seating options It's also supposed to have better barrel life than the .243 with similar velocities.

What are your thoughts opinions?

[Chronos]

If you were looking for something for target only id say go for a 6BR or 6 Dasher instead but as a hunting round the SLR packs a bit more punch.

I'm having a 6XC built and I just bit the bullet and bought 200 Norma cases and Wilson inline dies. Performance with similar weight bullets is supposed to be equal to .243 but less powder and the sharper shoulder should mean longer brass and barrel life. I don't normally loose brass and I don't see the point in chambering a new barrel in .243 trying to save 40c a case then spending more because you occasionally buy factory ammo and burn the barrel out quicker.

I know Matt Peroz at OLRP has built a few 6mm SLR's as well as a few .243AI's. But he's probably built dozens of 6BR's and Dashers as well as 6X47Lap's. Might be worth having a chat to him.

Chronos

[MalleeFarmer]

I was set on the 6xc until I found brass availability was more of an issue than cost. I actually posted on your topic the other day. Where did you get your brass from?

[MalleeFarmer]

Also as it will be mostly a varmint rifle need it to mag feed I personally also have the potential to lose brass.

[Chronos]

I was set on the 6xc until I found brass availability was more of an issue than cost. I actually posted on your topic the other day. Where did you get your brass from?

Magnum Sports in Sydney carrys Norma. I got mine for $154/100 with free shipping before they went up another $20 or so.

I figure 200 cases will allow me to run through 100 say 10-12 times before the barrel gets too badly warn at which point I might rechamber it to 6mm-284 or 6mm Remington and finish it right off

I'll always have 100 spare I case I decide to do another barrel if not by then it'll be worth $200/100 and will help pay for the next project

Chronos

[MalleeFarmer]

Surely a 6xc barrel will last longer than 1200 rounds? Also cheers for the tip on magnum sports $170 today per 100. Ouch

[Hatter]

Performance with similar weight bullets is supposed to be equal to .243 but less powder and the sharper shoulder should mean longer brass and barrel life.

Are you saying the shoulder has an effect on barrel life as well? Or just the powder for the barrel, and the shoulder for the brass?

Wasn't sure which way to read that.

[Chronos]

Surely a 6xc barrel will last longer than 1200 rounds? Also cheers for the tip on magnum sports $170 today per 100. Ouch

I'm sure you're aware but the 6XC brass can be formed fairly easily from 22–250 brass if you're not worried about headstamp.

Chronos

[MalleeFarmer]

Surely a 6xc barrel will last longer than 1200 rounds? Also cheers for the tip on magnum sports $170 today per 100. Ouch

I'm sure you're aware but the 6XC brass can be formed fairly easily from 22–250 brass if you're not worried about headstamp.

Chronos

I was aware of this and also some of the associated problems with it so since I'm new to resizing and don't have the tools for neck turning I thought the 6xc brass would save some headaches or going for the 6slr
Which is a simple full length size of .243 brass in a 6slr die.

[Bourt]

It's also supposed to have better barrel life than the .243 with similar velocities.

Just regarding that, I'm never convinced about such claims. Always feels like they tack it on the end of the write up as a nice little cherry for whatever cartridge they are talking about.

Put the same bullet down the same barrel at the same speed.... How one thinks barrel life will be significantly different here because it left a different shaped case I cannot say.

[MalleeFarmer]

The sharper shoulder and longer neck supposedly keep the powder in the case better as it burns and helps to keep from torching the throat with burning powder exiting at full temp. Supposedly.

[Redwood]

The old 'supposedly' trick

[MalleeFarmer]

There are reports of 6mm SLRs with 3000+ rounds of F-class accuracy before seeing significant accuracy loss. But they'd probably do a couple thousand more before they're no longer hunt worthy.

[MalleeFarmer]

There are reports of 6mm SLRs with 3000+ rounds of F-class accuracy before seeing significant accuracy loss. But they'd probably do a couple thousand more before they're no longer hunt worthy.

[Tonit]

[quote="MalleeFarmer"Its essentially a .243 with a 30• shoulder and long neck for more bullet and seating options[/quote]

More bullet options? What goes in a 6mm super LR that wouldn't go in a .243?

[MalleeFarmer]

[quote="MalleeFarmer"Its essentially a .243 with a 30• shoulder and long neck for more bullet and seating options

More bullet options? What goes in a 6mm super LR that wouldn't go in a .243?[/quote]

The longer neck is supposed to be able hold heavy bullets at ideal seating depth but also allows to seat shorter bullets out further towards the lands without having a marginal neck hold on the bullet.