Short barrel ballistics

Discussion in 'Long Range Hunting & Shooting' started by CLP308, Feb 25, 2011.

  1. CLP308

    CLP308 Active Member

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    Both of my rifles are carbines with 18 1/2" barrels. The first is a Rem 788 in .243 my father bought new in 1980 as a truck gun when we farmed. We went to Oklahoma that year(1980) prarie dog hunting. I know it will reach out there because he was shooting them out past 500 yds with it sporting an old Weaver 10X target scope.

    My other rifle is a Rem Model Seven in .308 Win. I bought it to be my mountain gun for white tails here in PA. I bought it tin 1997 new and love it because its so light and easy to carry.

    My question is how much velocity am I giving up compared to th 24" barrels? I have shot under two deer in the last couple of years that were out at 200-250 yards with my .308. I didn't think I would need any holdover looking at the ballistics charts, but evidently the short barrel is affecting the .308 more than the .243. I shoot 168gr Barnes XLCBT with 44gr of Accurate 2230, this is supposed to give 3090 fps out of a 24" barrel. I have also used H4895, but don't get as good of accuracy. My Data is right from Barnes and is the max load with no pressure signs.

    Thanks,
    Chris
     
  2. NomadPilot

    NomadPilot Well-Known Member

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    At least one guy on SH shoots his 18" 308 at 1000 yards, so there's no reason you can't kill a deer at 250.

    YouTube - 18" Barrel to 1000 yards

    Create an accurate ballistics table (with the real MV, not supposed) and you should have no problem.
     

  3. CLP308

    CLP308 Active Member

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    Does a faster burning powder have less difference since it will completely burn in the shorter barrel? I dont have a chrono or long distance range. Eventually I will get a chrono.
     
  4. NomadPilot

    NomadPilot Well-Known Member

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    A faster powder will certainly be better suited to your 18" barrel than a slower powder. However, with that said, Hodgdon lists some 308 pistol loads with Varget and 4895, both of which are slower than your 2230.

    I guess what I'm getting at is this: What you're using will probably work just fine. You just need to learn its trajectory, build an accurate dope card, validate the predicted drop, and go from there.
     
  5. Ernie

    Ernie SPONSOR

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    Since I do not have any rifles, all of my LR rigs are single-shot specialty handguns with barrels from 15 inches to just under 18 inches.
    I have chamberings from the 223 Rem. to the 338 Lapua Improved (338 AX).
    I routinely shoot out to 1200 yards on steel with these handguns, and sometimes further.
    I would would guesstimate about 40 fps per inch,but 35 fps per inch may be closer. I assume I will lose about 300 fps compared to typical rifle lengths.
    I do not use the faster powders.
    Example
    6-284 with 115 DTACs - H-4831sc
    6.5-284 H-4350 (140 VLD's) and sometimes Hybrid 100V
    284 Win (140 NBT) H-4831sc
    7mm Rem Mag Imp (180 JLK) H-1000
    6.5 WSM (130 Berger) H-1000
    7mm Dakota (200 gr. Wildcat) Retumbo
    338 AX Retumbo (300 grain SMK or Berger)
    7mm SAUM H-1000 (162 A-Max)

     
  6. CLP308

    CLP308 Active Member

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    I looked back through my load notes and I was mistaken. The load I shot under with was 42 gr of H4895for a published velocity of 2750. I'm new to this long range thing but am looking at buying an old BDL my local shop has in .264 Win Mag.$500 bucks and the ser # puts it in the mid '60s. Or would I be better off with a newer gun in 7 Mag? Im kinda drawn to old/differrent guns.
     
  7. liltank

    liltank Well-Known Member

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    I'm shooting 178 and 175 BTHP's right around 2500fps in my 18". Haven't really found a holy grail of powders to improve on that. I am currently using IMR4895. Seems to work pretty good.

    Tank
     
  8. CLP308

    CLP308 Active Member

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    Barnes no longer makes the XLC which achieved higher velocities than the TSX. But the Accurate 2520 and 2230 both show higher velocities than either 4895. And I get better accuracy. I will have to find a spot where I can set up targets every 50 out to 500 yards. What kind of targets are best to use? Whats the proper way to set up for checking trajectory?
     
  9. Hntbambi

    Hntbambi Well-Known Member

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    I too have a Rem 7 in 308 Win. I compared Southwest Ammo's 175 SMK load in it vs my 700PSS. The 700 PSS with 24" barrel is shooting 2650 fps and the Model 7 with 18.5" barrel is shooting 2495 fps. Which is about normal for each inch of barrel difference for a cartridge of that size. Mine is not accurate enough to consider it a 500 yards deer gun though.
     
  10. 1300meters

    1300meters Well-Known Member

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    Jan 23, 2011
    well i answered a similar question. I shoot two 7mags one with a 24 inch tube one with a 26 inch tube both top of the line same ammo handloads. only 25fps diff. forget published drop tables. suggest shooting @ 200 yd. zero then move on out to 300.If you shoot longrange move on out note temp,humidity wind. make your comeups for that weapon and load it will give you a baseline.checking all attachments for any loose or un-even torque. good shooting.gun)