Len - 7mm

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by BountyHunter, May 5, 2004.

  1. BountyHunter

    BountyHunter Writers Guild

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    The lack of quality bullets has been the reason, but that is changing rapidly. It was only Carteruccio and lately Berger and JLK that have good bullets.

    For competitive LR shooting, the bullet is rapidly becoming the most critical piece.

    Many mftrs make good barrels, basic match reloading techniques are readily learned.

    Many good 1K smiths can build good guns.

    Basically it comes down to who has good bullets and his loading technique and gun tuning are on for that match.

    BH
     
  2. Len Backus

    Len Backus Administrator Staff Member

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    I am far from an expert source of info on the use of the 7mm for long range. But from what I read, the current quality of bullets available is no longer a hindrance. Then if you consider the inherent ballistic coefficient advantage of the 7mm over anything else, there should be more use of this caliber in the future.

    As an example, my 7/338 Lapua should be done soon. I expect close to 3,500 fps with my 32 inch barrel and the 176 grain Cauterucio (.750 BC) match bullet. The ballistics with this combo, IMHO, beat anything else out there for an accurate, practical killing machine out well past my comfortable hunting range.

    It beats all the biggest 30 cal cartridges in stats for retained energy, wind bucking and flat shooting. Clicks to 1,000 yards will be 15 MOA vs 18 for the big 30/338 Lapua with the JLK 210 (.670 BC) bullet. Wind drift (10 mph)is 37 inches vs 46. Energy is 2,000 ft-lbs vs 1,850.

    Another important factor is recoil as it affects the ability to shoot well and to see the bullet's impact on game. 22 ft-lbs vs 27 (assuming an 18.5 pound rifle combo.

    [ 05-05-2004: Message edited by: Len Backus ]
     
  3. old fart

    old fart Well-Known Member

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    Len - would you give me the details of your 7/338 Lapua build ,I have owned a couple of 7 mags , have always been interested in a 7 STW , and still considering it , but like my 300 win mag - the seating depth has always bothered me , Magazine length ,I realize they say it doesn't mater but....thanks
     
  4. Len Backus

    Len Backus Administrator Staff Member

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    Nesika Bay action, 32 inch Krieger 9 twist fluted barrel. McMillan A-5 stock, NXS 5.5 to 22X scope. Custom reamer by Dave Kiff, smithing by Chris Matthews. Dies by Neil Jones.

    It should have, if I remember, 6 grains more capacity than the 7 RUM case but far better brass quality.
     
  5. Brent

    Brent Well-Known Member

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    Len,

    I'm gonna puke if you get 3500 fps with that thing! [​IMG]

    Thanks, my next Lapua Imp reamer will be ground for the 7mm too, you speed freak! [​IMG]
    I'll get the neck and throaters for the 30 and 338 too.

    I get 3500 with the 178 AMAX in the 30.5" 30-338 LI, but don't have anywhere near that BC.

    I think your 32" 7mm will hit 3400 pretty easy, and I hope you get 3500 or more! Should be quite a popular LRH round in the future reguardless.
     
  6. Len Backus

    Len Backus Administrator Staff Member

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    Can we get a picture posted here of you puking if I hit 3,500? [​IMG]
     
  7. Brent

    Brent Well-Known Member

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    [​IMG]

    With you trying to hit 3500 with the 7/338 LI and the 176gr, and Dave trying with his 338 SnipeTac and the 300gr, my 30/338 LI with the 210gr seems it's going the way of the 300 Savage real quick like! [​IMG]

    I'm looking forward to the results.

    I'm still building another 30/338 LI next. [​IMG]

    How's your 30/338 LI shooting? You've been too quiet about that thing, now come on, out with it. [​IMG]
     
  8. Len Backus

    Len Backus Administrator Staff Member

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    Brent

    I never once shot the 30/338. (In fact that barrel is also available, chambered by Wayne McDonald's reamer.)

    By the time it was done it was hunting season and I chose to go with the more familiar 7 Dakota barrel that was done for the Nesika action at the same time.

    I'm just a 7mm kind of guy. [​IMG]
     
  9. old fart

    old fart Well-Known Member

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    I need a little insight - I've watched and read , posted, from your site for awhile now and have really injoyed it , for this I thank you . But have found myself curious why the 7mm's are less popular for this long range stuff and bench rest - bullet selection can't be the whole story , people say it's hard to get them to shoot well - I am in the process of going threw the search engine -and theirs alot out there , been taking a while to get threw it all - good reading though . would you comment - thanks
     
  10. STL_Shooter

    STL_Shooter Well-Known Member

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    This is fun. I guess I'm a .223/.243/.308/.510 kind of guy...

    I am patiently waiting to see how fast Len's new one will go with a temp insensitive powder. I like to stick with Hodgdon - if 3500 happens with Retumbo or H50BMG, then I'm interested too.

    Although I have also been distracted with imagining how to push a bullet with a BC of around 1.0 to velocities around 3050-3150 fps...
     
  11. Brent

    Brent Well-Known Member

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    STL, you ARE nuts, but you've got a nice brake too. [​IMG] Do I see a 50 Fat Mac in your future too! [​IMG]
     
  12. STL_Shooter

    STL_Shooter Well-Known Member

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    Well, Brent, you never know!
     
  13. reed mosser

    reed mosser Well-Known Member

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    I think the 7-338 will be able to push the 176 3500 Fps. But the only problem I see you having is dusting bullets. I don't think those 180's of any sort will take the speed with those thin jackets. My gunsmith made a slightly shortened 7 338 lapua and his problem is blowing up the bullets. He know shoots sierra's. or BT hunting bullets because they will take the speed. Hope your gun shoots the 176's because that will unbeatable, flat shooting wind bucking abilities. Reed [​IMG]
     
  14. Brent

    Brent Well-Known Member

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    Bob Cuaterucio uses Sierra jackets.
    Which bullet was he blowing up?