175 SMK loadout for 20'' barrel

Samuel23

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May 18, 2014
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I have a howa 1500 308 with a 20'' barrel and I want to shoot 175 SMK's through it so I can get 1000+ yards out of it. Has anyone had this similar situation? It has a 1 in 10 twist, and im working with varget powder and Winchester primers.
 

ChrisGarrett

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  • Feb 2, 2007
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    I have a howa 1500 308 with a 20'' barrel and I want to shoot 175 SMK's through it so I can get 1000+ yards out of it. Has anyone had this similar situation? It has a 1 in 10 twist, and im working with varget powder and Winchester primers.

    Do you own, or have access to, a chronograph?

    What...43-44grs of Varget, looking for pressure signs?

    Unless you're just going to go out to the 1k line and wing it, you'll need to see what you can get the 175s up to, firing them out of your barrel.

    There is no magic load to give you, hence you need to start low and work up a bit, if you haven't already done so.

    I don't know if you can get them up to 2600 fps, but if so, you would need ~11.27 mils according to my Palm program, to get to 1k.

    You need to go to JBM and crunch the numbers, seeing what you need and then get to the range and chrono your loads.

    Chris
     

    berms03

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    Dec 11, 2013
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    I have a howa 1500 308 with a 20'' barrel and I want to shoot 175 SMK's through it so I can get 1000+ yards out of it. Has anyone had this similar situation? It has a 1 in 10 twist, and im working with varget powder and Winchester primers.

    I run my Remy 700 with Varget 43.3grs behind a 175 SMK with Lapua brass at around 2630fps from a 24" barrel, its deadly accurate at. You'll lose about 50fps per inch. A lot of people find around 44gr of Varget for their 308s. The military shoots their 175 at around 2550 I believe. Be safe and start lower and work your way up, find an accurate load at 100, 200, 300 and check your velocity, shouldn't be a problem to get a 20" out to a 1000 yards
     

    ChemE1975

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    Dec 6, 2012
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    not sure you are losing 50fps/inch. every rifle is different, and thus the need to chrono the load.

    you are just going to need to do load development. watch for pressure, find a load your rifle likes, and run it.
     

    dauntedfuture

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    Aug 19, 2014
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    Your going to need a chronograph. You need to be supersonic at 1000 yds and a little more to compensate for SD and ES. 20" is too short for an effective 1K .308 load, it will be marginal at best. I have observed far too many guys that are new to 1K shooting that have ammo and rifles that just will not cut it at 1000 to know better. You also need an ES of 25 FPS or less. This is assuming you want a 1MOA or better load and your not just attempting to bang big steel plates.