6mmBR or 6mmXC

[M700]

So, for a highpower rifle... Prone matches as well as cross-course stuff... Should I go with the 6mmBR or the 6mmXC???

My Model 70 .308 barrel is at about 5200+ rounds and although it's still shooting great, I'm not winning, but that's my fault...

Rifle is set up for both cross-course and prone matches.

Really don't know much about the little 6mm's for match use. Will the BR's feed slick enough or would the XC be a better choice???

Regards, Guy

 

[Wild_Bill]

If you want it to feed relaibly from a mag i would use the aaaaaaaaaaaaaaaaaXC as that was what it was designed if you were looking to single load the standard 6mmBR or the 6mm Dasher would be better options but in my opinion the XC would suit your purpose better regardless of ballistics or case quality arguments that could occor because your main concern is when you manipulate that bolt you MUST have a round rechambered without any problems. The seccondry issue it must be accurate enough to shoot the X ring on every range you shoot at we must remember you are not shooting benchrest.
Good Luck

Cheers Bill
Australia

 

[Webound]

M700,

I'm in much the same situation that you are. I'm shooting a 308 for tactical competitions, and just for fun. I have been looking for an able bodied replacement and the 6XC is really tempting. I have an AICS, and want to be able to use my mags. The XC just kills the 308, and 260 on paper. I'm dying to here from those who actually shoot this thing. I really want to know if anyone is running this round in a tactical rig. If you here anything please let me know.

 

[memilanuk]

Guy,

Try shooting Asa a PM or email... I talked to him about this some at Rattlesnake the other day...

HTH,

Monte

 

[M700]

Thanks Monte, I will!

 

[Asa_Yam]

XC advantages:
- Higher max velocity at similar maximum pressures;
- Factory 6XC brass has a thicker, stronger case head - less likely to blow out when using high pressure loads;
- Feeds more readily from double stack magazines,most good feeding mag fed 6BR rifles use single stack mags);
- Can push heavier bullets,i.e., 115 grain Sierras) to equal or higher velocities.

BR Advantages:
- Uses up to 5 grains less powder to achieve identical velocity,2700-2800 FPS);
- Less recoil at similar velocities due to smaller mass of powder,largely theoretical - actual reduction is quite small);
- Brass currently in mass production, and a proven quantity - third generation 6XC brass just being released at this time;
- Longer barrel life - up to 4000 rounds, versus 2500 or so for a 6XC.

 

[M700]

Thanks Asa! Food for thought while I work on wearing out my .308 barrels... Guy

 

[Forum Boss]

One other gun-handling factor to consider is that, for most people, a Dasher shooting a 107 is about as far as they can easily free recoil. The 6XC pushing a 115 can be free-recoiled, but it ain't so easy...

A 6BR with a 105 at 2850 fps has 28% less recoil than a 6XC moving a 115 at 3000.

Two good cartridges though, each with strengths and weaknesses.

 

[Changeling]

XC advantages:
- Higher max velocity at similar maximum pressures;
- Factory 6XC brass has a thicker, stronger case head - less likely to blow out when using high pressure loads;
- Feeds more readily from double stack magazines,most good feeding mag fed 6BR rifles use single stack mags);
- Can push heavier bullets,i.e., 115 grain Sierras) to equal or higher velocities.

BR Advantages:
- Uses up to 5 grains less powder to achieve identical velocity,2700-2800 FPS);
- Less recoil at similar velocities due to smaller mass of powder,largely theoretical - actual reduction is quite small);
- Brass currently in mass production, and a proven quantity - third generation 6XC brass just being released at this time;
- Longer barrel life - up to 4000 rounds, versus 2500 or so for a 6XC.

Asa_Yam, That is a pretty good comparison, but I would like to add because I have "Dug" deep into the situation.
6XC
1. Will reach higher velocities across the board with all bullet weights, up to and including the 115's, which the real train of thought is still "out" as to whether it is the answer!!
2. Definitely uses more powder, it's a bigger case! But I really haven't heard any hard facts about it's actual "round count" being in the 2000 ballpark, sort of a Little early to tell.
3. Brass quality and availability is definitely a variable.
4. Backing by the most "Premier" shooter in history, definitely worth a couple of points, don't you think?
____________

6BR
Everything you said, with exception of the 115's! Just not enough gas!
Changeling

Changeling

 

[reid308]

I use the 6XC in my T2K for XTC and LR. The original 25" barrel has over 1600 rounds down it and at that mark the throat was out .031". My Hawkeye bore scope showed some rounding of the lands and the beginnings of lake bed cracking but nothing serious and the thing hammers @ 600 / 107's. I do admit to using a milder load with the 70 gr sie @ 200 and the 85 Sie @ 300 and that may account for the mild erosion I'm seeing. I have used the 308 for 25+ years and really debated about going to a 6MM. Now,in my experience, the 6XC is the only way to go.
Milder recoil aside, it just shoots better and has less wind drift @ the longer ranges. The 308 is a great round and I use it in the Palma matches, but for XTC and LR, 6XC for me. I have a 30" Lilja chambered in 6XC for the LR matches using the 115
@ 3000 f/s. I had a 197 @ 1K using Irons this past Sunday @ Butner and my score keeper said it had the same trace as the 2 other guns had in 6.5X284 / 142 @ 2950. The 6BR is a fantastic round but you are really pushing the envelope trying to get the V for LR. Why run the ragged edge? You'll never see the susposedly better brass effects on paper @ 600 or 1K. You go ahead and chamber it in 6BR and we'll just see how it stands up @ 1000 yds down @ Butner in October. Conditions can get Ugly.