In all honesty, how much better is a 6mm over a 243. win

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by matt_3479, Apr 22, 2010.

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  1. matt_3479

    matt_3479 Well-Known Member

    Jan 31, 2010
    If you have read my last 2 posts about either buying or making a rifle for long range hunting and shooting. I was strongly leaning towards the 243. win or 243. ackley improved. My neighbor and his best friend are huge into reloading, and told me they would be more then happy to reload for me as long as i supplied.

    My neighbor is a huge fan of the 243. win, and his buddy is a huge fan of the 243. ackley improved. I love the 243. win myself and im very interested in the Ackley Improved cartridges. Where i hunt around my house shots can be well past 1000 yards, but the majority of long shots around between 400-700 yards. When i go down south my buddy's place, he lives in Montana so shots can be extremely long. I would like to be capable of shooting and hunting out to 500-600 yards for varmints. Now i know loaded right, with the right equipment, the 243. win and AI are more then capable of doing it. Everyone keeps telling me to leave the 243. win and AI behind and go for a 6mm or 6.5 cartridge of some sort. Does the 6.5 really have that much advantage over the 243. Im not entering long range competitions, im not looking to break records, im interested in long range hunting and shooting and want to set my own records.
  2. texan79

    texan79 Well-Known Member

    Mar 28, 2010
    .243 is 6mm. Now my 6mm Remington, is about 200fps faster than the 243 win in factory loadings. I dont reload yet, so the tricks that the slightly larger case can deliver I cant comment on.

    As far as I know, the choice in bullets is the same, just depends on how fast you want to push them.
  3. Loner

    Loner Well-Known Member

    Apr 14, 2010
    The 6mm runs about 100 fps faster than the 243. I would think the AI in 243 is as
    fast or faster. A 6.5 is a lot more bullet, I don't put them in the same class. In either
    case it is barrel twist that is going to let you shoot the long heavy bullets needed for
    long range. After you decide on calibre, do your research on twist for it. Both 243/6mm
    and 6.5 bullets are doing well in 1000 yard events. 243 Has about 115 grain as max
    weight and 6.5 up to 160. Takes a 1:7 or 1:8 to shoot the heavies and mag length
    can become a problem for either. m2c
  4. B23

    B23 Well-Known Member

    Oct 30, 2008
    If you do decide on a 243 AI I have a brand new Redding Type S bushing 3pc die set for sale.
  5. royinidaho

    royinidaho Well-Known Member

    Jan 20, 2004
    If your question is about the difference between a 6mm Rem and a 243 Win 'my' answers is: "negligible"

    If your question is about a 6.5 something and a 243 Win 'my' answer is: There is a world of difference. If favor of the 6.5!

    I may be the odd man out here, but I've never been able to make any 243 Win I've ever had shoot even reasonably well.
  6. elkaholic

    elkaholic Well-Known Member

    Dec 4, 2008
    My personal preference would be a good 6.5 for what you want to do for a couple of reasons. There are a good selection of HIGH b.c. bullets which will buck the wind better and hit harder especially if you plan on hunting big game at all. This is especially true if you go to a little larger case like the .284 etc........Rich
  7. Booney

    Booney Well-Known Member

    Jul 18, 2008
    "The 6.5X284 is a good round I shot it for years. But when it come to varmit hunting the 6mm's at high velocity beats it to pieces. B.C. is important but there is a fine line between the 6mm 107 sierra bc of .53 and the 142smk at .59 so there really isnt that big of a spread betwen them. The 107 at 3400fps is way way flater shooting then the 142smk at 2950 to 3000 fps. The flatter shooting rounds make up for a lot in errors in ranging calculations and wind drift. So to answer your question with my real world expirence with both calibers going ground hog hunting. I would take the 6mm every time.

    Another real world expirence is bullet expansion on varmits. The 107 smk blows ground hogs to pieces. The 142 smk just punches holes in them. To each their own just my .02 cents worth" This was said in the thread i started a week ago there is a lot of good info check it
    Last edited: Apr 22, 2010
  8. Boss Hoss

    Boss Hoss Well-Known Member

    Nov 10, 2005
    Another advantage to either the 243 or the 6.5x284 is Lapua brass. The most accurate sporter I own and it is the lightest as well is a 6.5x284. The brass prep is the same as my competition rifles because the same reamer is used to chamber it.

    My 1K load is 48.5 to 49.2 gr of H4350 launching a 142 SMK between 2940 and 2980 depending on outside temps.
  9. theicon2u

    theicon2u Well-Known Member

    Dec 12, 2009
    I have a 6mm and I love it. I would go that route!