338 Yogi OAL?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Nicholas, Feb 4, 2002.

  1. Nicholas

    Nicholas Well-Known Member

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    Steve or anyone who knows,

    What is the OAL of 338 Lapua IMP loads? And what powders are you using/ reccommend for this round?

    [ 02-04-2002: Message edited by: sr90 ]
     
  2. Steve Shelp

    Steve Shelp Well-Known Member

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    sr90,
    My OAL is 3.925". That is setup to where the pressure ring of the bullet is seated approx .020" above the junction of the neck and shoulder of the case with a 300gr Sierra.

    As for powders R25 and H1000 for all out accuracy has worked the best for me. I've never tried the real slow burners for speed though. I've gone over 3000fps with the above powders so it would be intresting to see what it would do with H870 or the surplus powders.
    Also beleive it or not I get better numbers on the target and across the chrono using H1000 and Fed210 primers and NOT the 215 magnum primers. ssshhhh. don't tell anyone. And I've used this combo in matches down into the 30-40F range and won with it.

    FYI: The truck was loaded and I went to my local range on Sunday but no go. Not only did it stay VERY windy, but it was a public range and everyone and their brother was burning rounds up. Didn't have room to really setup my portable bench and chrono among the "brass chuckers". The thought of hot 7.62 brass dinging off from my very expensive bench guns wasn't very appealing to me anyway.

    Have a good one,
    Steve
     

  3. Nicholas

    Nicholas Well-Known Member

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    I hate those brass chuckers! Seems like everytime they come sit right next to me. M14's seem to be the worste, HK91's are no problem because they chuck the brass so far forward that if you miss with the bullet you will likely hit with your brass. [​IMG]

    Does it cause problems if the pressure ring is inside the case? I didn't know Sierra used pressure rings. Reason for asking is that 3.625 is the max OAL that will fit in the TRGS magazine. Would loading rounds to 3.625 OAL in the Yogi be realistic?

    Thanks Steve

    [ 02-05-2002: Message edited by: sr90 ]
     
  4. Steve Shelp

    Steve Shelp Well-Known Member

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    sr90,
    The pressure ring I was refering isn't a driving band or something like that like you typically see in military sabot rounds and such. But most shooters who refer to a pressure ring on a standard jacketed bullet is refering to the junction of the boatail and the body of the bullet and that was my intention. Sorry for that confusion.

    That .030" deeper you would have to seat them isn't bad. So I would say yes it would be realistic. Just make sure your gunsmith is aware of this situation so he can get the throat depth properly set. If you go much deeper your taking away from case volume, possibly raising pressures and/or lowering potential velocity.

    As an example of how much bullets seated into the case make...

    In my 6.5-300 WWH when Sierra came out with the 155gr MK in the early '90s I tried some in my rifle that was throated for 140gr MKs. I forget how deep they went into the case but it was more than .030". Seems it was more like .100" or more. Well the best velocity I could get out of that combo was around 3050fps when I ran into pressure signs. I also own a 6.5-300 Winchester which has less case capacity than the 6.5-300 WWH case, but it was specifically throated for 155gr bullets and I could get 3200fps with that combo even with the less case capacity. Granted different barrels and such made some different I'm sure, but to get 3400-3500fps from 140gr bullets in my 6.5-300WWH down to 3050fps when the bullet only weights 15gr heavier didn't sound right to me.

    hope this helps,
    Steve
     
  5. Nicholas

    Nicholas Well-Known Member

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    I think you may be off a decimal point. 3.925-3.625=.3 difference.
    Do you think my rounds with a .3 shorter OAL than yours would have a lowered velocity than you are getting?

    [ 02-05-2002: Message edited by: sr90 ]
     
  6. Steve Shelp

    Steve Shelp Well-Known Member

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    sr90,
    I'll have my glasses checked tomorrow. sorry! you are correct in that it is .300 and not .030" That would be robbing a lot of case capacity in my book and out of the practical limit in my opinion.

    The other option is for true long range work I've always single loaded anyway. Then it's not an issue with seating the 300 out. And if your in a situation to where you need extra rounds to feed through the magazine, then load some 250gr MK. The 250gr MK aren't anything to sneeze at, but the 300's do rule the roost with that high 700 BC.

    I use the single loading technique as a check and balance to make sure I slow down and make the shot, instead of hurry up and feed another round to get it down range when hunting. Just my thoughts and reasons. Maybe you have other reasons or need to feed thorught the magazine.

    Steve
     
  7. Brent

    Brent Well-Known Member

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    Steve, what is your 338 Yogi, a blown out 338 Lapua? If so, what's the length to the body-shoulder juncture from the base and dia. at the juncture? Shoulder angle too.
     
  8. Steve Shelp

    Steve Shelp Well-Known Member

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    Brent,
    Yes it is a 338 Lapua Improved. It's Dave Tooley's (Tooley Custom Rifles) reamer design. So I don't have the exact numbers, but for a quick reference, the original 338 Lapua neck/shoulder junction is moved forward .050" with a 35 degree shoulder and minimum body taper but not real radical though to ensure ease of case extraction.

    Steve
     
  9. Nicholas

    Nicholas Well-Known Member

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    Thanks Steve

    I think I will be looking into single shot actions.