6mm STW

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Hicks, Apr 2, 2008.

  1. Hicks

    Hicks Well-Known Member

    Messages:
    281
    Joined:
    Sep 19, 2007
    I've got a long action Remington action and I'm in need of a good varmint round. I was thinking about a 6 or 6.5 STW. Does anybody have any experience with either of these rounds?

    Hicks
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

    Messages:
    6,848
    Joined:
    Jun 12, 2004
    The 6.5mm would be a much better choice then the 6mm. The 6.5mm STW is actually a very impressive performer. Its best loaded with bullets of 140 gr or more for best consistancy at long range.

    The 6mm bore is, in my opinion, to small for the STW class of case capacity. In fact the standard 2.5" long belted magnum is about all the 6mm bore can support and even then a 6mm-284, 6-06, 240 Wby or 6-06 AI will nearly match the larger belted magnum case.

    Another problem is getting a 6mm bullet that could handle the launch speed of a 6 STW. That is if your wanting to use a long range match type bullet.

    Another very real concern is powder bridging. With stick powders, the 257 STW will on occasion have this problem which is when the powder locks up in the shoulder area of the case as its trying to flow through the neck when burning in the case.

    This situation would be dramatically worse with the case necked down to a 6mm neck. If you used only the very slowest ball powder, it could work if you used the very heaviest bullets out there with the very slowest powders available. The problem there is carbon fouling, it would be SEVERE. I would suspect you would need to clean the powder fouling out of the bore every 10-15 rounds to maintain any accuracy at all.

    In the end, your 6.5mm STW is a MUCH better idea for a high performance, long range varmint round that is relatively user friendly. Even with this chambering, throat life will be limited.

    Kirby Allen(50)
     

  3. britz

    britz Well-Known Member

    Messages:
    1,217
    Joined:
    Mar 11, 2007
    I just thought I'd remind you of the barrel life since you said you wanted a varmint rifle. I can't imagine that the 6.5 stw would last too terribly long. Possibly not much worse than a 6-284 though. If this is a consern, perhaps a 260 rem, or a 6.5-284 if you want capability to take larger game.

    But, Man I know how velocity can be real cool LOL ;)
     
  4. malcarjeb

    malcarjeb Well-Known Member

    Messages:
    224
    Joined:
    Mar 12, 2006
    I have a 6mm STW and It shoots great. Mine has a Shilen 29" 10 twist barrel on a Remington PSS action.

    I am shooting the 85gr. Barnes XLC at 4150, Swift Scirocco 90gr. at 4000 and the SMK 95gr. at 3850. All with excellent accuracy. The 95 SMK is VERY accurate all the way out to 500 yards. I haven't had a chance to try it any futher yet. All of these loads are very safe with no pressure problems at all. I am using the slowest ball powders as Kirby mentioned. Load development went very fast as everything I put through her shoot very well. I don't think I got any groups over an inch and most were 1/2" or less. So far I have not seen any more carbon build up than any of my other large overbore mags.

    I don't think I would want to use this as a varmint round because of barrel life, mine will be for deer hunting and should last a long time with only a few shots per year. This is if I can control myself and not shoot it alot, It is a blast to shoot!!
     
  5. Hicks

    Hicks Well-Known Member

    Messages:
    281
    Joined:
    Sep 19, 2007
    Guys,

    Thanks for the replies. I really appreciate the expertise here. Let me elaborate a little further on my issue with this action. It's attached to an 8mm RM barrel with a break, a crappy McMillian stock and a crappy Bushnell scope. But, I'm getting it for a screaming deal at $400. I already have another 8mm, which is presently getting a 29" Lilja barrel, and a 7mm RUM which shoots really well. I really don't need another "big" gun, so I thought I'd try to justify the purchase by telling myself that "the action is worth the $400 by itself, and I can sell the other stuff on ebay. So what should I build?" Since I've got some nice "big" guns, I'm thinking that I need something smaller.

    Some ideas:

    1. I go ahead and build the 6mm STW and never try to load it really hot. I'm guessing at nominal pressures it would launch heavy 6mm bullets at fantastic velocities but yet keep a reasonable barrel life.

    Or

    2. I build a .458 Lott. I've always seen myself in Africa with a double but who can afford those?

    Any other ideas?

    Thanks,

    Hicks
     
  6. Varminator 911

    Varminator 911 Well-Known Member

    Messages:
    337
    Joined:
    Dec 7, 2007
    Impressive speeds but...

    That 6mm STW sure gives impressive speeds. 80-90 gr bullets at 220 Swift speeds!! But when you get on JPM and look at the long range ballistics, neither the 6mm nor 6.5 STW can compete with the good old 7mm STW. Not as a long range round for deer size game. Past 500 yds those little high speed bullets cann't compete with the 168 or 180 gr Bergers. But you guys already know this. It's just everytime I read about a 6mm super douper etc and I check it out on a ballistics program, I end up with the same conclusion; the small bullets cann't compete at long range.

    So what do you have; a real barrel burner that's no good for high volume varmit shooting and a deer round that cann't compete at long range.

    Just my 2c
     
  7. Hicks

    Hicks Well-Known Member

    Messages:
    281
    Joined:
    Sep 19, 2007
    Hi Kirby,

    What I'd really like is a rifle I can use to waste prairie dogs out at long range so I can impress my friends.:cool:

    In any case I see that you have a .257 built on a .338 RUM case? How is the barrel life in something like that?

    Thanks,

    Hicks
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

    Messages:
    6,848
    Joined:
    Jun 12, 2004
    My wildcats are designed specifically for big game hunting where shooting volume is limited. In a varmint rifle role, you would burn through the barrel life pretty quickly on my 257 AM. But for big game hunting where the number of shots taken a year is very limited, they work very well.

    Remember that if you take a chambering using large charges of slow burning ball powder, and only load it to moderate pressures, you will have a powder fouling issue like you have never seen before.

    In best cases, the ball powders are dirtier then stick powders and thats when you load them to their top pressures where they burn the cleanest and they are still dirty.

    Drop the pressure and powder fouling increases dramatically. If your going to run ball powder, run her to top pressures for best results most of the time.

    Kirby Allen(50)