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6XC


Elwood

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Does anyone here have any experience of the 6XC? http://www.6mmbr.com/6XC.html

 

I have spent a lot of time researching and from what I can gather the 6XC was made to compete with the 6BR Dasher but without any case forming, it also gives you the opportunity to shoot 115 grain 6mm heads.

 

The Dasher takes over where the 6BR finishes all be it with case forming and allows you to shoot 105-107 6mm heads to 3000-3100 fps, does the extra velocity give any significant gain over the standard 6BR ? which is hard pushed to get to 2900 fps. Now I know most people are going to say no, not if you can't read the wind so for arguments sake lets say I can (had my fingers crossed when I typed that)

 

This now brings me back to the 6XC, it's supposed to have the accuracy (well nearly) of the Dasher without the hassle of case forming, but barrel life is compromised when using quick powders and the 115 grain bullets (DTacs and Berger VLD) Someone then made the 6 Competition match that had more case capacity and a longer neck than the 6XC which allowed you to use a slower powder and shoot the 115 gr heads up to 3100fps easily and have a longer barrel life.

http://6mmbr.websitetoolbox.com/post?id=61...mpetition+match

 

Next we have the 6 SuperX very similar to the 6 CM.

http://6mmbr.websitetoolbox.com/post?id=14...highlight=super

 

Both the 6 SuperX and 6CM are appealing but they haven't actually caught on as a wildcat round, although the people using them have nothing but good words to say about them (but then isn't that always the case!)

 

And lets not forget the 6x47, but I can't see what this would gain over the XC other than the ease of using Lapua brass and perhaps a bit more case capacity, barrel life would still be the same as the 6XC, 2000 rounds?

 

I should add that this is for 300/500/600 F class, I'm currently using a gob smackingly accurate 6BR which I still have another 2000 rounds of barrel life left, but I like to explore other avenues for a future build.

 

Thanks for reading this far, I hope you still have the will to live, any comments are welcome (well most ;) )

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Guest varmartin

You already have the most accurate 600 yard 6mm round in history, if you are

looking for the Holy grail F class rifle i think it may be built

around a 7mm round.....IMHO...

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Like you know Ian I run a 6x47 Lapua. As you say pretty similar to the 6XC but with Lapua brass and the small primer.

6XC formed from .22-250 brass so still have to fireform where as 6x47 just load and shoot (case forming is as simple as run a 6.5x47 through a 6x47 FL die).

Good news is they're as acccurate as the BR but with another 250 fps which makes a difference in the wind.

Dave Tubb did make brass for the 6XC, made by Norma I think, but at what cost and availability.

Cheers

Dave

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Elwood,

 

the 6XC was designed by David Tubb the top US competition shooter as an accurate 600yd cartridge that would feed faultlessly from his Tubb 2000 'across the course' straight-line bolt-action magazine rifle, or T2K as it's known as across the pond. The 'across the course' (hence cartridge name XC) refers to US Service Rifle and its more expensive / higher spec 'Match Rifle' competition brother that sees rapid fire, compulsory magazine changes, and three position shooting at 200yd (standing slowfire and sitting rapid-fire); 300yd (prone rapid); 600yd (prone, slowfire). 6XC rifles are used in Match Rifle and that's what the T2K was designed for.

 

These diciplines need good accuracy, ability to buck the wind, light recoil. The 6XC gave / gives all these, and also turned out to be an excellent 1,000yd prone rifle cartridge. Several US NRA long-range prone shooters (like our Target Rifle off the elbows with iron match sights, but any calibre / cartridge allowed) have chosen the 6CX - quite a tribute when you think that the alternatives include cartridges like the thirty magnums and 6.5-284, .284Win with heavy bullets etc. The lighter recoil is seen as a big plus and offsets the slightly poorer long-range ballistics.

 

Like several similar cartridges before it, it is based on the .22-250 case, necked up and given a much sharper shoulder, and with the shoulder pushed back a little to reduce the powder capacity / lengthen the neck. Conversion of .22-250 brass is said to be easy - open up the neck with a mandrel, resize in a 6XC die, fireform. Tubb had brass made specially which was / is very expensive, the first two generations of which were not well received by users. Gen 3 is said to be much better. Norma makes 6XC brass, regarded as the best going. The Tubb stuff is expensive and pretty well unobtainable here, the Norma is also (but a bit less) expensive and is also difficult to find. You can probably find it somewhere or have it supplied if you try - HPS Target Rifle in Gloucester and Norman Clark are the best bets. Dies are readily obtained, Forster and Redding Comp types the best bet.

 

Tubb specifies a 7.5" rifling twist as optimal for 6XC with 115 DTACs, although 8" is usually regarded as fine unless you shoot in minus 10 degrees C or colder air at sea level.

 

Tubb also devised a 115gn bullet for the cartridge, made for him by Sierra - the DTAC. Norman Clark and HPS had these bullets, although I think I got the last of Norman's stocks - they didn't sell that well over here and he supplies the competing Berger 115 VLD. Bryan Litz has calculated the G1 BC is .540 for the DTAC, .545 for the Berger (compared to .558 for the 142gn 6.5 SMK and .612 for the 140gn Berger 6.5 VLD). Ballistically, it will therefore be slightly behind the 6.5-284 with 139-142gn bullets, but not a lot as sensible 6.5 users keep loads down to provide MVs of 2,950-3,000 fps.

 

H4350 and H4831sc are widely used in the USA in the 6XC, but the new wonder-powder Alliant Reloder 17 is taking over as it gives a huge MV increase in this cartridge. Users are now getting up to 3,300 from 105-108s and 3,200 from the 115s (in long barrels). Knock 150 fps off from those figures for other powders. Accuracy is said to be excellent at these top velocities and pressures (the cartridge is rated at over 60,000 psi). Barrel life is said to be around 2,000 rounds, more if loads are kept down a bit, under 3,000 fps with the 115s, and just over 3K with 105-108s.

 

Similar cartridges are the 6mm Swiss Match, 6X47 Lapua, 6X47 Lapua Improved (6mm Long Dasher), 6 Dasher and other such improved sixes. One difference from the Swiss, BR and 6.5X47L based jobs is that it keeps the .22-250's large rifle primer. Some see this as a disadvantage, but it seems to work OK and there is a big plus - you can load the damn thing up to 60,000 psi + and get away with a Remy 700 or whatever action without having primers blow back / pierce. Big plus if you want to use a factory action.

 

In summary, it's an excellent mid to long-range cartridge, but 6BR is regarded as better for 600yd precision shooting even if the bullets move a bit more in the wind. A lot depends on what you want to use it for. It won't be competitive in F-Open against 7WSMs etc, but will give 6.5-284 a run for its money with longer barrel life and less recoil. I'm having a 6XC built as a 1,000yd BR 'light gun 'throated for 107gn Sierra MKs, and will see how it works out.

 

6XC performance against 6.5-284 Norma and 7WSM is as follows using Bryan Litz's G7 data and ballistics program

 

6XC: 115 Berger VLD at 3,050 fps MV: 1,000yd = 1,549 fps / 70" wind drift

 

6.5-284N 140 Berger VLD at 3,000 fps MV: 1,000yd = 1,767 fps / 63" drift

 

7mm WSM 180gn Berger VLD at 3,100 fps MV: 1,000yd = 1,810 fps / 53" drift

 

The wind drift is for a 10mph 90-degree crosswind.

 

 

Laurie

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Laurie, I was hoping you might reply :wacko:

 

I have a 7 WSM for 1000 yards, this will be a 300-600 yard rifle, although I expect I would take it out to 1000 just for the hell of it. I have been told several times that the 6BR is the most accurate,( to which I agree ) but how many days at Bisley do you get without a wind, and even when there isn't a wind there still is!

 

I did read that getting 6XC brass could be problematic, I'm shooting with someone at the end of the month who uses a 6XC so I will ask him.

 

Will you be using Moly, Boron or going naked with your XC? and did you get a chance to read the threads on the 6CM and 6 SuperX, if so what's your take on them.

 

I still think the 6x47 Lapua is the safe option.

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Ian,

 

If you're restricting yourself to 600yd, even a relatively large change in ballistic efficiency doesn't have that much of an effect on the target.

 

Running Bryan Litz's G7 experimentally derived BC data for the two bullets at lilkely MVs for these cartridges gives the following deflection in the 'standard' 10mph 90-degree crosswind at 600yd:

 

 

6BR 105gn Berger VLD

2,800 fps MV - 25.7"

2,900 fps MV - 24.3"

 

6XC 115gn Berger VLD

2,950 fps MV - 23.0"

3,050 fps MV - 21.7"

 

So a typical 6XC load v a typical 6BR load sees a reduction of only a couple of inches, maybe three, that is a third to half MOA at 600. And that is in a 10mph wind, but wind changes between shots don't run at on/off 10mph at 90-degrees (even at Diggle, even if it sometimes feels like that!). In practice, typical wind strength / direction changes might equate to a third or at most half of that amount - an inch difference on the target that might or might not gain you an extra point - and that assumes you hadn't noticed the wind shift at all (as can happen when its switches as you squeeze the trigger) and tried to read it / correct for it. Yes, in really rough conditions, the 6CX is going to have an edge over 6BR even at this range.

 

1,000 is a different matter - the 6XC has a real advantage here, but loses out to the WSMs badly as noted in my last post in F-Class. BR is different (he hopes!) in that low recoil / little disturbance on the rest / rear bag / rapid recovery and firing a string of five shots is important, and you hope the wind doesn't change much in the 30 seconds it takes to get them off. Unlike F etc where you start from scratch with the wind on every shot, in practice.

 

On the face of it, 6X47L looks the safer / easier option - virtually 6XC performance, very good brass that is avilable now. Reloder 17 is expected here soon, and though I haven't seen any mention of it in 6X47L, if it gives stunning performance in the XC it should do the same here.

 

The only caveat I have about 6X47L (apart from the small primer / big factory action firing pin issue) is that it's all gone very quiet here. When the parent cartridge appeared, there was a flurry of ordering dies, commisioning rebarreling etc by 6mm enthusiasts, but I'm told interest has dropped off to very little now, while 6.5X47L rifles are popping up everywhere like mushrooms. Is there a reason for the loss of interest in the 6mm version? I've not heard anything bad said about it, rather very little at all.

 

I'll run with 'naked' bullets in the XC at least initially.

 

I've read a bit about the 6CM, and don't think I've come across the Super X. However, I've always fancied the 6XC, and a chap I shoot with had some Norma cases going for a reasonable price. He still shoots XC but reforms .308 WIN brass instead now for some reason. He has some more cases he'll part with if you're interested - send me a PM and I'll pass your email address onto him the next time I see him (next weekend at the national F-Class round at Diggle now that I think of it).

 

Laurie

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Laurie, once again thank you for a most comprehensive answer. I will pass on the 6XC brass for the time being and decide which way I want to go, I do have the matter of a 6BR barrel to shot out first.

 

There really isn't much in it over 600 yards, which surprised me. I do know one frequent user of this forum will be reading this with a I told you so smirk on his face, no names mentioned of course :rolleyes:

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Er,,,,,,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

told you so :rolleyes::D:lol::lol::lol::lol::P

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We've got 4 guys in our club running T2K's in 6XC (7 T2K's in the club in total). We shoot Highpower regularly at Bisley and the one thing the 6XC shooters have in common is a good supply of spare barrels.

 

Most shoot DTAC's but only at the 600yd line, for shorter range, 200 & 300yds, they use 107's

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Bradders

 

 

We've got 4 guys in our club running T2K's in 6XC (7 T2K's in the club in total). We shoot Highpower regularly at Bisley and the one thing the 6XC shooters have in common is a good supply of spare barrels.

 

 

That's a surprising number of T2Ks for this country - most impressive! When you say 'Highpower', that's a service rifle type discipline?

 

The Americans quote around 2,000 round barrel life for 6XC, so presumably the round counts are pretty high in these competitions if there is a good supply of spare barrels held?

 

How well does the T2K perform? I've always thought it looks impressive design-wise, but looking good isn't always the same thing as doing the business on the day. How do they stack up against the straight-pull ARs in rapids?

 

Laurie

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Bradders

 

 

 

 

 

That's a surprising number of T2Ks for this country - most impressive! When you say 'Highpower', that's a service rifle type discipline?

 

The Americans quote around 2,000 round barrel life for 6XC, so presumably the round counts are pretty high in these competitions if there is a good supply of spare barrels held?

 

How well does the T2K perform? I've always thought it looks impressive design-wise, but looking good isn't always the same thing as doing the business on the day. How do they stack up against the straight-pull ARs in rapids?

 

Laurie

 

Highpower as we shoot it is identical to the US version in that we run two classes, Service and Match.

Service means you must use a designated service rifle (which through limited choices exclusively means an AR15) and this must be identical to an as issued rifle. It must retain the exact external silhouette but we do allow the concession of a modification to the charging system. This is, as would be expected, a side charging handle.

All other NM upgrades are also permitted such as DCM style float tubes, weights, after market triggers (although these have a minimum weight limit of 4.5lbs) and upgraded sights which normally consist of a custom sized front post and hooded rear sight with interchangeable apertures. It must also only be chambered in the as issued calibre.

The beauty of Service Rifle class is that there is only a finite amount of money you can spend on your rifle. You can't buy points. Barrels is barrels and triggers is triggers.

It also helps that the AR15 is an excellent design and lends itself very well to being a competiton grade target rifle.

 

In Match Rifle class anything goes. Calibre's, sights, triggers, adjustable handguards, hand stops and adjustable butts.

These rifles do make a difference when it comes to scores, but only when they are in the right hands and even then, a good Service Rifle is hard to beat.

As I said, there are 7 or so T2K's in the club and in 6XC the 2000rd barrel life is right on the money because at 2000, they just die.

We have had a few Rem 700's with detachable mag systems as this is a must. In Match, the gun in rapid fire must be loaded 5&5 where as in Service it is loaded 2&8. AR15 space guns are also popular in Match too.

 

In rapid fire, the timings are 60secs and this is ample time to get off 10rds including a mag change. You must realise that the original timings were 50 secs for semi's but a concession was made for bolt guns, therefore allowing them 60 secs. In the interests of conformity, all timings were eventually changed to 60 secs for all rifle types.

 

The T2K is an excellent design, especially being as it was purpose designed for rapid fire. The Detachable mag system works very well, bolt throw is both short and light enough to operate with one finger and as it was styled similarly to the straight line configuration and ergonomics of the AR, is just about perfect as a shooting machine.

 

As to Highpower, well the club has been running for 9 years with an average of 11 matches per year. We have a membership of approx 45 and attendances are usually 18-20 shooters.

 

We have some excellent scores put in as well with a current UK record of 779 ex 800.

My personal best with a Service Rifle is 760 with a straight pull and I have achieved 200-9x in 200yd sitting, 199-12X 300 rapid and 194-10x with a Service rifle at 600 prone and 198-12x with a 6BR AR15 as well as the same score with a similar rifle in 6mmAR.

 

For more info www.highpowerrifle.co.uk

 

Mark Bradley

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Mark,

 

thank you for your detailed explanation and other information on 'Highpower' - very interesting. I'll have a look at the website.

 

I've read a fair bit about the parent US disciplines and their rifles, but hadn't realised it was as popular here.

 

Laurie

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Well Gents,

What a fantastic read!!!!!!!

 

Elwood, I think that you have got to much money :lol:;)

 

All the best Darrel

 

Darrel as Theo whateverhisnameis would say, I'm spending my children's inheritance, but not to worry I don't have any children.

 

Laurie, many thanks for information.

As far as I can work this all out it goes something like this......The 6 Dasher was created to take over where the 6BR left off, being able to push a 105 grain head at over 3000 fps and with the correct twist able to shoot the 115 grain Berger's and Dtacs.

 

The 6XC was created to be able to compete or better the Dasher without having the hassle of creating false shoulders and fire forming. The 6XC is now the choice of the high power shooters but was it created for them or did they adopt it?

 

Barrel life became a bit of an issue with the XC ( I don't consider 2000 rounds barrel life that bad)and although it could manage the 3000 fps mark it wasn't without compromise. This then moves us on to the SuperX and the 6CM using 243 brass and singles base powders to shoot the 115 grain bullets with ease. We have now moved away from the gentle recoil of the 6BR/Dasher and of course there's still Baldies option of the 243 AI, it just seems that we are moving away from the benefits of the 6BR all the time.

 

Perhaps I should consider the Dasher, I don't mind forming cases running then through dies but I don't like the idea of fire forming, never have.

 

I will keep reading up on whats happening around the world ( USA ) as I have no rush as I still have a 6BR barrel to enjoy.

 

Oh and one more to throw into the mix, the 6mm Crusader.

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Ian,

 

As I read it, the 6XC was created for the American High-Power Match rifle shooters as Bradders correctly advised - it was partly extra performance wanted, but the key thing was a thin, tapered case that would feed reliably from a box magazine. The US long-range prone shooters then decided it was a good thing too for their discipline, no doubt encouraged by David Tubb taking his T2K rapid-fire magazine rifle and wiping the floor with everybody else and their specialised single-shot rifles in the prone deliberate 1,000yd National Matches at Camp Perry three or four years ago.

 

Many High-Power Match Rifle competitors fancied 6mm BR Norma for its accuracy and light recoil - after all it had become the cartridge of choice for 3P 300 metre UIT shooting which has some things in common with Service / Match Rifle. But there is one crucial difference - slowfire / single-shot v rapids / magazine use. The BR just doesn't feed!

 

However, we now have Gary Eliseo at CSS in California producing the CSS R5 6BR repeater tube-gun kit for Remy 700 actions and with a custom designed and built BR magazine set-up that apparently works faultlessly, so the Tubb rifle and 6XC have a High-Power Match Rifle competitor.

 

Like you, I regard 2,000 round barrel life as reasonable, but I think the SR / MR guys go through a lot of rounds both in competition, and in the essential practice to hone the standing and kneeling position skills. I'm pretty sure the Tubb T2K rifle is a quick DIY barrel swap job, so it only involves the barrel supply / cost, no gunsmith charge and waiting list to get the rebarreling done.

 

When I eventually wear the 6BR barrel out on my Remy, like you I'll no doubt consider the 6 Dasher. To be honest though, with what I use the rifle for I doubt if I could do much better than with the straight 6BR, and suspect I'll end up keeping it as such. Why make life complicated with fireforming etc unless you absolutely have to?

 

I'll Google the 6 Crusader - hadn't heard of that one.

 

Laurie

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are the police aware of a 6mm dasher, or would they need ballistics reports and all that to get one on to your liscence

 

 

as i have a spare slot for a 6mmbr at the moment and looking for a project for next year

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However, we now have Gary Eliseo at CSS in California producing the CSS R5 6BR repeater tube-gun kit for Remy 700 actions and with a custom designed and built BR magazine set-up that apparently works faultlessly, so the Tubb rifle and 6XC have a High-Power Match Rifle competitor.

Laurie

 

 

We have one of those in the club too....I built it :-)

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are the police aware of a 6mm dasher, or would they need ballistics reports and all that to get one on to your liscence

 

Probably not Spud - my lot in North Yorks had never heard of the 6XC. They're apparently hogtied by the national licensing computer, and can't add these sorts of things locally any more!

 

Anyway, we agreed that the variation just got listed as "6MM", so I can have any 6mm cartridge that I wanted. I think most forces will do this, but I bet there's the odd awkward buggers who insist on seeing proof there is such and such a cartridge. (I was told recently of one team that refused a variation for 6.5-284 Norma only a year or two back because they hadn't heard of it, and when they approached the head of the firearms response unit, he said there was no such cartridge in existence!)

 

 

Laurie, SnipersHide in the rifles section, created by George Gardner of GA Precision.

 

Thanks Ian - I'll look it up.

 

Laurie

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Bradders,

 

I wondered if any had got here. I have the single-shot Model P version for the Barnard action as my F/TR rifle. I love it!

 

It seems that there are no more coming through though unless an exporter / importer with a US export licence can be found to do the necessary. gary Eliseo just sent me mine in the mail a year ago, but he won't do that anymore.

 

Laurie

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I had sent a large cheque to Gary, Laurie, just as he sent yours out. he promised me faithfully that there wouldn,t be a problem.....then renaiged on the deal. he did send me my money back, but i lost about £50 due to the exchange rate, and bank charges on the cheque.

We were all set to become the importer for them, but this episode soured the deal somewhat.

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Sherri Gallagher has just set a new record of 800-53X using a T2k.

Calibre was .260Rem and she shot 142MK's all the way back.

She has broken 6 national records this year and out of 3000pts competed for, has only dropped six.

 

So you see, it's not the calibre, it's the shooter.

 

There's plenty of good calibres out there, it's just what you do with them

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