I'm going to order one of the above from VV and wanted some input. I have shot 6x47
several years ago in BR, I have had one 6TCU from TC Custom shop and haven't had or
shot a 6x45. The plus side I see with 6TCU is no trimming and the 40 degree shoulder.
Any experience to be shared will be appreciated

All 3 are similar enough that you won't notice any difference in the field, and all are capable of tack-driving accuracy.

My vote goes for the 6x45 (6mm-.223). It forms with a simple run through the size die, and brass is widely available. .222 Rem Mag brass is a bit iffy on availability.

All three cartridges are basically the same so it really boils down to your personal opinion. The obvious points are that the 6x47 will give the best velocities as it has just a bit more case capacity, but I really don't think it is enough to quibble over. I'm partial to the TCU rounds as I have the 6 the 6.5 and the 7.

My suggestion is to pick one at random and never look back. Just shoot away!!

I will be shooting my 6X47 Improved, that Virgin Valley made for me, real soon. I wanted to try to get a little more velocity than the TCU had to offer as I will be using this barrel on small deer (hopefully not too small <grin> ) and maybe antelope. Bob Milek used to take antelope with the 6X223 which is basically a 6x45.

If you are planning to shoot varmints and/or small game, go with the TCU. If you go with anything larger make sure you go to at least the 6X47 Improved cuz as the other guys have said, you do not pick up that much velocity. Heck, if I can not achieve enough with the 6X47 Improved, I may switch to the 6X50R.

I have had absolutely no problem buying 222 Mag brass. But you sure can't beat .223 brass for availability and price.

Hi Jules was there a reason for the link to 222 brass on this thread? I had considered a 222x6mm.

My bud, Howard, in MO called last night. He shoots 18" barrels almost exclusively and has several of my 6mms based on .225 Win brass similar to the JDJ type, but shorter in the body, longer neck than the JDJ.

He is now shooting the 6mmx47 Imp. extensively and finds that it is about 100 to 150 fps slower than is possible with the .225 Win case. So far, the powder of choice seems to be AA2460; whereas, in the .225 Win based case, AA2520 has worked best.

The 6mmx47 Imp. case holds almost as much powder as my .225 based case and runs higher permissible pressures, but just does not quite come up to what the .225 Win case permits, which came as a little bit of a surprise. I had hoped to equal it.

I think he is on the right track shooting lighter bullets, and that most shooters use bullets heavier than needed or even adviseable.

He is driving 55 gr. bullets from the 6mmx47 Imp. case at 3500 fps, but gets to 3600 fps (+) with the .225 Win based case.

Later when he is not hunting groundhogs and coyotes, we are going to extend the chamber body on the 6mmx47 Imp. to give it a couple more grains capacity and shorten the neck in the process of course. He feels the couple extra grains will put the two rounds on par with each other without having to go to 5.6x50 R brass to do it.

Two points in regard to the 6mmx47 Imp.:
1) You do NOT have to have dies marked 6mmx47 Imp. and pay a high price for them. Use plain Jane 6mmTCU dies. They work just fine and dandy and are more readily available at better prices than the less common 6mmx47 Imp. If per chance your particular size die has enough radius in the mouth that it will not size the case webs of the slightly longer .222 Mag case, then get a .357 Mag. pistol size die that sizes small enough at the base and run the cases through it as needed.

The Lee carbide .357 Mag. size dies are cheap, usually size small enough, but may need to have the tops bored out to clear the longer cases. I have had to do this to Lee dies used for sizing webs on 5.6x50 R based wildcats.

2) When having a 6mm barrel made, especially for the Contender, opt for all the speed you can get to help make up for the Contender's pressure limitations. Focus on lighter bullets, and to get the maximum velocity, go with the longest twist rate that will stabilize the heaviest bullet you will actually use. My recommendation is either a 1-12" or 1-13" twist as being about optimum, and if you intend to shoot only bullets 60 gr. and under, go with a 1-14" twist.

Compared to a 1-10" twist, I think Howard said he is getting difference of about 200 fps between the same chamber with one barrel being a 1-12" twist and the others 1-10" twist. The 1-12" twist barrel is apparently a Wilson and has a somewhat large groove diameter, which is very characteristic of Wilson blanks. This may account for some of the velocity difference, but the faster the twist rate, the more energy is expended spinning the bullet. Use a longer twist rate and pick up some speed. This will do you much more good than zipping a heavier bullet through a critter with little expansion due to a low velocity.

If you are hunting something large enough to need more expansion, imho you need not a heavier small diameter bullet, but a larger bore size to begin with.

The smaller the bore size, the lower the velocity potential will be for a given bullet weight.

Said another way, if you intend to shoot for example an 80-85 gr. bullet, do it in a .25 rather than a 6mm. And while doing it in a .25, go with the longer 1-12" twist rate.

Mike

Mike I agree about the bullet weight. I'm looking at a 12 or 14 twist. I would more or less stick to bullets 70gr or under. Probably a 62 or 65 gr BR bullet. Does Howard live around Cassville? I live in Neosho Mo. I had sent you an im about neck od on 221 cases. I'm getting a 221 barrel and wanted to stick with a .250 neck and didn't want to neck turn. Thanks for any info.

Mike,

As usual, interesting info. As it is, my 6x47 Improved barrel is made up on a 1 in 10" Shilen blank and is 12" long. I will post my velocities here to compare. I am hoping that the Wilson blank's bore had more to do with it than the twist. I do agree, as you seem to insinuate, that the cartridge may be marginal for deer. In fact, I started to obtain a 6mm TCU, then decided a 6x47, but ended up with a 6X47Imp, for exactly that reason. I am planning on using 80 grain bullets to start. I really can't imagine using a lighter bullet for my purpose. I chose the 10" twist on purpose. My plan is to rechamber if I need to, and I wanted to have a little too much twist than too little. In the end I may end up with a .25 bore, but I am sure to have fun on the way.

I must reiterate that I am stalking Eastern Whitetail as I live in the South.

[ 07-25-2002, 06:25: Message edited by: Cokdnloded ]

Thanks for the reply Mike as I do know Howard. We agree to disagree on most things contenders are and do. Alans gun store is a very interesting place. All kinds camp there in the mornings. Some different and I include myself in that group shoot the bull. First liar doesn't have a chance.