Opinions on Grouping

Discussion in 'Long Range Hunting & Shooting' started by 1984nitro, May 8, 2011.

  1. 1984nitro

    1984nitro Well-Known Member

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    I post this in reloading forums but thought it would better here


    So I went out yesterday to test some loads for my 220 swift ai and my 270 win.

    After testing many loads in each I got this results.

    The 270 win best groups were 54.7gn h4831 moly mag length 1.379" vertical and .375" wide at 200 yd with 30es and 9.5sd, avg fps 2872.

    Then I hit another node at 57.1gn grouping 2.5" vertical 3" wide at 350yd, 20es 8.4sd avg fps 2944.

    On the swift my best group was 1/2" vertical, 4" wide, shooting 80 amax moly, 44.4gn h4831. I couldn't get my chrono to ready on this load but it was most likely around 3400 fps guessing from the other loads speed.

    It was around 90 degrees all day and 15-20mph cross winds. Also all shooting was off a bipod and bag.

    So first what load is better for my 270 win from the two?

    Second is the load for the swift a good one considering the wind and great vertical?

    Thanks for any info
    Eric
     
  2. liltank

    liltank Well-Known Member

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    I'd say you need to take the first load out to 350yds and see what it does. Though with that much wind, I have a feeling you could pull the second group a little tighter. An ES of 8 is where you want to be.

    I'd say the Swift is right where you want it to be. The horizontal is more than likely the wind again. An 80grn bullet in 15-20mph crosswinds will definitely be difficult to keep together. I wouldn't go any further with the Swift unless you want for speed.

    Tank
     

  3. MrMajestic

    MrMajestic Well-Known Member

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    Did you mention the bullet weight on the .270? What's your twist on your .220 Swift AI? Yeh, load work with that kind of wind is tough and I agree those SD#'s look good.
     
  4. 1984nitro

    1984nitro Well-Known Member

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    sorry forgot some info. The 270 win is shooting 150gn sst. I have shot these many bullets many times before with great results. I start to work up a different load because I moly coat the bullets now. Before I was shooting same bullet with 54.7gn H4831 2880fps 26" barrel 1/4" at 100yd. ES 17 for 5 shoots.

    The swift is the first load work up. The barrel is a 28" 1-8" twist 80gn amax moly, 44.4gn H4831. I feel pretty good about this load and group because of the 1/2" vertical at 350yds.

    My problem comes that I have to drive 2hr to shoot my rifles, so I am tring to decide if I shoot continue load test or settle with these.
    Thanks for the help
    Eric
     
  5. long450

    long450 Well-Known Member

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    Eric, my experience is that if you go from non-moly with a good load to moly, you have to go up in the powder charge to get back to the node you were on with the non-moly. The amount of powder increase depends upon the particular barrel and powder used.
     
  6. budlight

    budlight Well-Known Member

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    I've had really good results with .277 Sierra SPBT 150 gr. home moly coated. I can get a matching your 2880 with: All rounds using cci 250 LR mag primers with 58.2 gr of 7828 or right at 3000 with 58 gr of R-22 or 60 grains of 7828. right at 3000 fps is the best grouping. Up around 3100 fps decreased case life without any better grouping.

    I'm using a .250 throated Mcgowen 26 inch 270 win
     
  7. MrMajestic

    MrMajestic Well-Known Member

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    "I also love my .458 mag for varmints and the biggest game in the world. "

    Ahh, I remember those days. 400 gr. Speer Flat Point at 2450 fps and chucks! It was a 1 MOA gun with that load however the 2 1/2X scope limited my distance. My Mother's arthritis and heavy flat bench pressing wiped out my shoulder and those days. It was a custom Spanish Mauser action with a Douglas barrel and a nice chunk of Walnut. That gun and a "like new" FN Mauser in .257 Roberts that wasn't even D&T'ed for scope mounts, and never fired by me, are on the list of guns I wished I wouldn't have sold!
    All apologies for the high-jack and reminiscing.
     
  8. budlight

    budlight Well-Known Member

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    In .458 I made some custom 275 grain hollow points out of a box of 510 grain round nose. I got them to go 3000 fps. They just tear apart coyotes and Marmots. Oh, it's a Ruger #1 with a 26 inch bull barrel.

    I had to think of something to do with it other than collect dust. Here in the lower 48 I've got a couple of mule deer with the Barnes X 405 grain
     
  9. 1984nitro

    1984nitro Well-Known Member

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    It is interesting that you say that. I have test teh 57.1gn load before without moly and it grouped around 2" @100yds. Now with moly 57.1gn is shooting good at 350yds. Where 54.7gn naked was shooting 1/4" @100. But that does seem like a big jump in powder to hit a node.

    I guess my best bet is load up the 54.7gn and 57.1gn about 10 per and shoot out at 600yds or so. And see what happens.