6mm/220 swift?

Discussion in 'Long Range Hunting & Shooting' started by huntokanogan, Mar 22, 2011.

  1. huntokanogan

    huntokanogan Well-Known Member

    Mar 7, 2011
    Just wondering if anyone has ever wildcated a 6mm bullet on a 220 swift cartridge? Is that even possible?
    I am looking for a project rifle. I want to build a 6mm caliber gun. Maybe I should just buy a .243 or 6mm rem and save the trouble. But rounds I'm considering are: 6mm/284, 6mm-06, .243 AI. Any other 6mm's I should be looking at?
  2. scenarshooter

    scenarshooter Active Member

    Mar 13, 2011
    The swift case is based on the old 6MM Lee Navy case. It is semi rimmed and the web is very strong.

    Tkae a little of the body taper out and sharpen the shoulder a bit and you'll have a nice little round there...

  3. eddybo

    eddybo Well-Known Member

    Jan 5, 2007
    If you are not going to improve the case you may as well go with a 6x47 lapua. I have worked backwards from your idea making a 22x47lapua. The 22x47 has identicle case capacity and I use 220 swift load data interchangably for starting loads. Both have 47grs powder capacity.

    I am fond of the 243AI in a short action if it is throated properly for whatever magazine you go with. A 6x284 is a little crowded in a short action.
  4. Outlaw6.0

    Outlaw6.0 Well-Known Member

    Feb 18, 2010
    I am fond of the 243AI in a short action if it is throated properly for whatever magazine you go with. A 6x284 is a little crowded in a short action.[/QUOTE]

    I do agree, my first AI cartridge was the 243AI, what a great round, when I shot out that bbl I rebarreled & rechambered to 6mmAI & I'm lovin it as well.

    IMHO the 6mm-284 is not the best cartridge for a SA platform, a cartrigde of that capacity is better suited to long heavy for caliber bullets (think DTAC, SMK, VLD). These bullet weights are where that particular cartridge really starts to shine; similar performance to it's ballistic twins the 6-06 & the 240 WBY.

    For a short action, i'd stick with the 243AI throated to your mag length & save yourself some frusteration..... unless you can deal with a single shooter :D
  5. ubettcha13

    ubettcha13 Well-Known Member

    Aug 22, 2010
  6. budlight

    budlight Well-Known Member

    Sep 30, 2004
    What are you trying to do? the 6mm XC is the best for the barrel. I enjoy the 243 and the 243AI has some good points. the 243 wssm Is something I would really like
  7. mike33

    mike33 Well-Known Member

    Dec 19, 2008
    6 x 284 own having the third one put togeather. Stick with the 85 and 100 grainer s/a works fine.
  8. SBruce

    SBruce Well-Known Member

    Oct 31, 2009
    I shot a 220 Swift for many many years. For a long time, it was my only rifle.

    A little crowded in a Ruger short action. Couldn't get bullets out to the lands and still mag feed.

    Easily the most accurate factory barrel rifle I've ever owned though. Unbelievable shooter. Only thing I didn't care for was quite a bit of case stretching.

    If I was going to do a long 6mm now, it would be a 6mm Improved.

    Short action, 6X47 Lapua (actually doing a variation of that currently) or 243 Improved. There's plenty of room in the short action for the 6X47 Lap.
  9. B23

    B23 Well-Known Member

    Oct 30, 2008
    My 6-284 is on a M700 short action too and I think one of the most important factors to keep in mind when using a SA w/6-284 is using a smith that knows how to build a 6-284 on a SA. If you want to load to, or close to, the lands and still use it as a repeater with no feeding issue you have to obviously seat the bullet deeper and if it wasn't setup correctly to do that you will either not have your bullets touching or close to touching or if you do have them close then they will be to long to feed thru the mag. My dad has a 22-6mm on a short action and the guy that built it didn't keep those things in mind because when my dad loads for his 22-6mm it shoots really well at 20thou off but at 20thou off the lands using a Berger 75VLD it is way to long to feed thru the mag. I'm pretty sure they make a longer box for the SA M700 which would certainly help this issue but I'm not sure how much extra length you gain but I'm sure there is somebody here that could answer that.
  10. Barstooler

    Barstooler Member

    Jun 14, 2005
    I own and shoot an original 6mm Lee Navy. But of course with that straight pull action and pressure limits it not a barn burner.

    If you are looking to making a 6mm-220 Swift Improved, you may think about building a 6mm Lee Navy Improved. The Lee Navy has a very long neck compared to the 220 Swift. You can buy 6mm Lee Navy brass from Buffalo Arms. Pricey, but it can be bought. It is made from 25-06 brass sized down and the head trimmed to Lee Navy specifications.

    That would be the case to base an improved version on. You could put a false shoulder on the neck and gain a quarter inch of case capacity blowing it out. Would be a hell a lot of trouble however compared to other options...but it would be unique.


    KNHOTROD Well-Known Member

    Dec 28, 2009
    I had a 6mm CJ which is necked down to .224, back 20 years ago bullet selection was junk and it did take some extra reloading steps neck trimming etc.. once you get up to 4000 fps it would key hole bullets all day, she was fun to shoot and I shoot a heck of a alot of fox, coyote, etc... back when they where worth $100 to $150. I was always into hotrod guns thats my log in. I set the barrel back 3 times than sold it. It was a ruger varmit heavy barrel and shoot 1/2 moa all day long. Have never seen barrel since like that one and all I own are barrel burning guns. With bullets now it would be fun to have again.