Best 6mm wildcat?

[billy_56081]

   My freind called me from Iraq today. He is an avid coyote and deer hunter. He was talking about having a rifle built in a 6mm wildcat. To him speed is important, as is die availability, and feeding as this will be a bolt action repeater.What are some good ones? 6mm-06, 6mm-06 ackley, 6mm-284 or what are the other hotrod 6MMs?

[Reed1911]

The 6mm-284 is likely going to be his best bet. It is redily available as far as dies and data, it is not an overly hot barrel burnner, but it will eat up the throat pretty quick (apx 1500 shots at max load;and depending on how accurate he is to see the difference). While speed may be important to him, he should shoot a bit and he'll see that once you get to the top tier of speed (4000'ish) you are really not doing much but burning the barrel, your wallet, and brass. Most folks cannot shoot accuratly enough at very long range to actually get the benifit of a slightly flatter shot. If he is interested in a long range flat shot, the 6mm-284 with a ULD/VLD design bullet will do everything he wants (I think; since I don't know him; but he's prob. like most folks)

Now, please, please do not take offense. He very well may be an extremly accurate shooter, but most people try to get the best equipment and hottest "new" round and think they will be bench rest accurate. The rifle certainly may be, but most people cannot really get to the level that the rifle is.

[iiranger]

6mm/'06 = .240 Weatherby magnum. Yes, the Weatherby has a belt on the case and Weatherby chambers usually call for more than average free bore, but the similarities are too close to ignore.
This round require a "long" action. (Interestingly, many factories make on length action and "block" the magazine for shorter rounds... I.E. no weight savings on a "short action...")

6mm/.284 has a long, great rep. Reflects more recent thinking...only 30-50 years old, commercially. Short fat powder column like the .308. Sharp Shoulder. Not too many like that but more in the newer rounds. And it will work in a real short action that might save 2 or 3 or 5 ounces of weight. You do give up one round in the magazine. Same powder capacity, approx. as the '06/ .270.

One of the oldest, most respected but not "hottest" is the 6mm/.250 Savage. (Yes, neck up .22/250 cases too.) Target cartridge for a long time. I think Rem still chambers it in 40X. And barrel life should be better than most.

.243 Rockchucker and .244 Remington are necked down .257 Roberts or 7x57 Mauser cases. Well thought of for "hot" and long barrel life. .243 and .243 AI are on the .308 case and work at a bit higher pressures from the start. Good barrel life.

Rediculous extreme that just "hangs on," .6mm Gibbs. Mr. Gibbs "blew forward" the shoulder on the '06 case. I think he insisted on a one caliber length neck. Wolf Publishing had a book on Mr. Gibbs and his cartridges. Not alot more than .240 Weatherby velocity, but glamorous.

His bucks, his call. HAPPY HOLIDAYS. luck. Happy Trails.

[Reed1911]

largest I show (other than idea cartridges like the 6mm RUM) is the 242 Belted Rimless H&H, Capacity of 89.83g the 240WBY comes in at 63.08g; the .240 Super Varmiter at 70.90g; .240 Mashburn Falcon at 72.26g; .240 Souper Pooper at 61.49g; the 6mm-284 at 47.75g; I don;t have the capacity for the 6.17 Spitfire, but I believe it may take the cake.

[billy_56081]

   My friend is probably one of the best shots I know.( I told him when he left for Iraq that any body who gets shot at by him is dead) He's really leaning toward a 6x284. I think your right about the VLD Bullets being a winner in these guns for long shots. Are the Berger VLD's frangible? That is pretty important here in the open plaines of MN. The 6mm rem ackly looks like it might be a good choice too. Or maybe a 6mm-06 ackley.All of your help is appreciated.

[Reed1911]

Frangible? No. They will expand to some degree, but they are not really meant for it. VLD/ULD designs are really made for paper, although there are some meant for bodies. What distance are your shots running at (min to max)?

[992]

6mm-tcu is a very good round,as it uses the .223 brass necked up to 6mm.
Not a real barn burner in speed but deadly accurate,less powder,plenty of cheap brass,and long barrel life.
Just an all around winner on all counts as everthing to load it is already cheap and plentyful,even the dies.
Also the 6x47 is very accurate and somewhat faster but the brass is a lot higher in price with limited availabilty.it is the 222 Rem.Mag brass.
Ithink I am right on the cases,but it has been a while since I had them to use.

992

[Doesniper]

I've had the .243 AI, and if you want a hot rod 6mm, this one is hot. I could get over 4300 fps with the 55g Nos. BT. but the throat was gone in less than 700 rounds. None of the big wildcats are going to have long life barrels with the 6mm if you push them to the max. The 6mm-250 is a good "wildcat" if you want something that is going to give long barrel life, but it's not much different from the .243 Win. as far as speed. After my dissapointment with the 243 AI, I rebarreled to a .260 AI with a fast twist. This is what I was looking for. Good luck with your buddies project. Tell him thanks for his service from all of us.

[roper]

When you get to shooting the 6mm VLD 105/107gr they shoot better at a certain velocity so cases like the 284 doesn't have any real advantage over a 243,6br type case.  Speed cost in 6mm cost around $500. for a new barrel and chamber if  using a Kreiger  or others.  I mush prefer the 284 case over a 06/06AI as the 284 it's just almost an ackley case the way it is and with Nosler now making 280AI brass you could just neck that case down have a 6mm chambered for that round be a nice 6mm wilcat.  Wyatt make extented magazine for rem and win action that are set up for the 284 case so you shouldn't consider feeding problems when looking at that case.  I've always figure the 6mmremAI is a better balance round when looking at the bullets now avaiable but you give up alittle velocity when compaing to the 6x284 but it's not much.  I'm shooting a shorten 6br case,6x284,6mmremAI,6x250 and might do a 6x250AI.  I much prefer the 243 as is and that what I shoot.  Don't ask me to pick one over the other.  Well good luck

[IOWA DON]

I have a 6mm-06 barrel for a Thompson-Center TCR (hammerless breakover singleshot). The barrel is 29 inches long but I probably keep pressure lower than in a bolt action and get 2,930 fps with a 70-grain balistic tip. I think one could get the same velocity in a bolt action with a 26-inch barrel with a little more pressure. That is a trajectory flat enough for a 300 yard zero with a maximum rise of about 2.7 inches (dead on holds for coyotes to 350 yards). Cases can be made by just necking down .25-06 cases in the full length resizing dies and a full length model 700 action or model 70 action would feed perfectly. If you want a 600 yard 14-pound prarie dog gun, a 6mm/284 may be better, but is you want a coyote deer rifle light enough to carry around all day a 6mm-06 has a lot going for it. A 6mm-06 may burn barrels faster but for a deer/coyite rifle the barrel would likely last many years. Also, I've read at least 3 articles where some of the gun writters say the 6mm-06 and .240 Weatherby kill deer a lot better than a .243 Win or 6mm Rem. I've only shot 3 deer with mine they were does and all shot with the 70-grain Balistic tips. They work fine on lung shots but a 90 or 100 grain bonded bullet would probably be better for a big buck on a shoulder shot. - DON

[RaySendero]

How about a 6mm/270WSM?

[Lone Star]

Tests by the American Rifleman showed a barrel life of around 150 rounds with the .244 H&H Magnum and maximum pressure loads - useless.  As others have recommended, the 6mm-284 is probably the best choice for a number of reasons.  It has a higher accuracy potential than other cartridges of similar capacity due to case shape, and a proven track record at extreme ranges. 

I would not recommend VLD bullets at all!  For a varmint gun they are too tough to be safe downrange, and they will not reliably open on varmints so that kills may not be humane.  Strange as it may seem, the "best" 6mm varmint bullet is arguably the 55-grain Nosler.  Launched at 4200 fps, it compares with two other varmint bullets:

Bullet......MV..... 500 yd V...500 yd drop
55 BTip..4200......2328..........-23.6"
70 BTip..3800......2231..........-27.6"
80 BTip..3600......2173..........-30.1"

I don't have the wind drift values for the 55BTip, but it will not be substantially different between all three at 500 yards.  The 55 Ballistic Tip carries higher velocity to 500 yards for better expansion and killing power, drops less, and kicks less.  All are advantages for long range shooting in the field as opposed to shooting at a range.  Barrelling the rifle with a slower twist for the lighter bullets will aid accuracy too.  But any higher velocity 6mm will have a shorter barrel life than milder cartridges.  The way the rifle is used matters a lot to barrel life.  I burned out the throat of a 6mm Remington in one afternoon's shooting on a hot day.  One of my .257 Weatherbys is still giving sub-moa accuracy after over 1200 rounds because I have been very careful not to get the barrel too hot.....

.

[roper]

Lone Star,  I don't think case capacity has anything to do with small groups when your looking at having a rifle build in a 6mm Wildcat.  I don't know where you are getting your velocity or what loads your are using in your 6x284 but mine is alittle over 4100fps with a 68/70gr bullet, I can down load it to alittle over 3800fps and then groups start to open up.

 I've never shot a 55gr bullet so I cann't say if 's the best but the Berger 68gr and Gentners  6mm work pretty good in my 6mm rifles.  I'm just starting to work with some Berger 95gr VLD bullet in a 6mmremAI for varmit shooting.  My 6mmremAI is pretty close to 240 Wby velocity.

Only problem I've ever had with the 6x284 it's not a high volumn shooter barrel heat pretty quick so it's not a caliber you want to take out for a day varmit shooting like you would a 223 and   I always take along another rifle.  You can always have the barrel set back on the 6x284 get you alittle more barrel life.  I've been shooting the 6x284 one form or another for over 20yrs and since I've been shooting the 6.5x284 I may not do another when that barrel is gone.

[Lone Star]

Lone Star,  I don't think case capacity has anything to do with small groups when your looking at having a rifle build in a 6mm Wildcat. 

I'm not certain that I said anything about case capacity related to accuracy, but I did state that case shape was important.  Same reason that on targets the 6PPC outshoots the 6x47 and the .308 outshoots the .30-06....case shape.

...iin your 6x284 but mine is alittle over 4100fps with a 68/70gr bullet, I can down load it to alittle over 3800fps and then groups start to open up....

I really don't care how high a velocity a wildcatter claims to get - without pressure equipment the loads are not proven safe.  Hodgdon shows a maximum with a 70-grain bullet of 3731 fps at 52,200 CUP in a 26" barrel.  For you to get almost 400 fps more means you are operating at extremely high pressures.  Be careful.

My 6mremAI is pretty close to 240 Wby velocity.

Sierra lists a maximum of 3600 fps with a 70-grain in a 6AI (26" barrel) - and they show 3700 fps for the .240 Weatherby - a 100 fps difference.   What you are seeing with your 6AI makes sense and is right in line with pressure-tested published data. That's how it is supposed to be.


.

[Ironworker]

My vote is 6x284 I've been shooting one since 2000. Hart 26" BBL 1in 10 twist. I shoot 87gr V-maxs at about 3,625. Its also "Bad to the Bone" Hey tell that brave well respected soldier to give one of them rag heads a bullet for us.

[crawlnshoot]

All of the hotrod 6mm's are barrel burners, "BUT", this can be overcome by using a slower burning powder, such as H1000, or 4831SC and the proper cleaning technique. I am having a barrel chambered in 6CM (Competive Match), it's basicly a 243 that has had the shoulder pushed forward while still retaining the factory taper for enhanced magazine feeding. The case neck has been left long to allow the longer seating of the VLD's. The shooter who designed this round is an"over the course" shooter, he's pushing the 115DTAC's at 3200-3250 fps, and so far has over 3200 rounds through the barrel and still shooting 200-20X's from the sling. He believes that the slow burning powders will enhance barrel life on other 6mm's such as the 243AI, 6mm Rem,AI, 6-284, 6-06, etc. I know some shooters will not give up their 4350, or Varget powders, or even try the slow powders but I for one don't enjoy burning my barrels up after 1000 to 1200 rounds. Hope this was helpful.
Jim

[roper]

All of the hotrod 6mm's are barrel burners, "BUT", this can be overcome by using a slower burning powder, such as H1000, or 4831SC and the proper cleaning technique. I am having a barrel chambered in 6CM (Competive Match), it's basicly a 243 that has had the shoulder pushed forward while still retaining the factory taper for enhanced magazine feeding. The case neck has been left long to allow the longer seating of the VLD's. The shooter who designed this round is an"over the course" shooter, he's pushing the 115DTAC's at 3200-3250 fps, and so far has over 3200 rounds through the barrel and still shooting 200-20X's from the sling. He believes that the slow burning powders will enhance barrel life on other 6mm's such as the 243AI, 6mm Rem,AI, 6-284, 6-06, etc. I know some shooters will not give up their 4350, or Varget powders, or even try the slow powders but I for one don't enjoy burning my barrels up after 1000 to 1200 rounds. Hope this was helpful.
Jim
[/quot

I've been reading about the 6CM on another site and Joe Hendricks has spend alot of time developing it.  From my understanding and please correct me if I'm wrong but doesn't the 6CM shoot only single base slow powders etc and 3200/3250fps are at the very high end velocity range and I mean high end?  You are very limited to bullet/powder selection with the 6CM.  There is no question that the 6CM,6XC and 6.5x284 plus others are great over the course calibers and how many will make the change over to a varmit caliber?  I'm getting ready to build a 243AI and I did look at the 6CM but I'm not going to shoot 115gr bullets.  I happen to shoot H-4831 in my 6x284,6.5x284 and IMR-4350 in a 6x250 and 6RemAI.  It's very interesting when comparing single or double base slow burning powders and after reading Joe Hendrick theory on powder and barrel wear but for some reason I burn barrels out when using H-4831 must have something to do with velocity is my theory.