Discussion in 'Technical Articles - Discussion' started by ADMIN, Jul 30, 2017.

X-Ray's Stick

How many times have you thought about which rifle you would keep if you could just keep one?
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  1. ADMIN

    ADMIN Administrator

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    X-Ray's Stick

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  2. Timnterra

    Timnterra Well-Known Member

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    I enjoyed this article! I like the idea of having a single go to rifle for all situations. I feel like I spend less time shooting and enjoying my builds than building riles and developing loads. I think rather than constantly chasing the new and better, all the while compromising on small things here and there, I should just build one ultimate rifle and burn the barrel up. I love the writers choice of components and only question one thing... What is the reasoning behind using 130gr instead of 140gr bullets? I am starting load development on a 6.5 SAUM right now and am planning on running 140s, i might reconsider if there is a solid case for the 130s.
     
  3. lesvoth

    lesvoth Member

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    Timnterra,
    Thanks for the compliments and questions. I wrote X-ray and asked him to send me his response to your question. This is what he sent me to answer your questions.

    les

    Timnterra,
    What is the reasoning behind using 130gr instead of 140gr bullets? I am starting load development on a 6.5 SAUM right now and am planning on running 140s, i might reconsider if there is a solid case for the 130s.

    Timnterra,

    It's a great question.

    There is no real good reason for choosing 130's over 140's other then personal preference. There are a couple of reasons why I personally chose the bullets that I did to shoot.
    1. It was what I had on hand.
    2. BC/Velocity ratio

    I'm currently shooting the 130 JLK which for the weight class has an exceptional BC of 0.620 G1. So with the combination of velocity and weight it just makes sense to be pushing the 130 class bullet. I've since gathered several more bullets to play with ranging from the 143grn ELD-X, to 127grn Barns LRX, 129grn Accubond LR, 130grn Swift Scirocco 2.

    Quickload data for my rifle and 130 JLK sits me at a node of 61.5grns H1000, Fed215M, Norma brass, and at 3034fps with the 24"barrel.

    Now, if i messed with the 143 ELD-x bullet which has the same suggested BC as the 130 JLK, being pushed at the same velocity, it's basically the same end game besides gaining a little bit of energy down range. I plugged in a 140grn Amax as a comparison and QL is giving me an estimate of 2983fps, it'll be pretty close to the same with the 143 ELD-X. The reason I'm not giving you the 143grn ELD-X load is because my ammo box with the 143's are all boxed up and in storage for the moment.

    Given the 140 amax numbers i'd be 1 MOA of elevation more, .2MOA more wind and about 30ft/lbs of energy more with them over the 130's. So that's my reasons, take them at face value as your numbers/ barrel/ components might differ, it's all personal preference in the end.

    X-Ray
     
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  4. Timnterra

    Timnterra Well-Known Member

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    I had no idea that the 130 JLK had such a spectacular BC! It makes no since to run a heavier bullet if there is no gain in BC! I just assumed that a 140 gr bullet of similar design would always have a higher BC. After looking at JLK's website it looks like the 140gr 6.5 and the 130gr 6.5 are dimensionally identical with the weight difference coming from the smaller lead core inside the 130gr. i will have to order some JLK's and give them a try. Thanks for the response!
     
  5. lesvoth

    lesvoth Member

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    You're welcome. Thanks for the questions. Glad to be able to help you.
     
  6. 7magcreedmoor

    7magcreedmoor Well-Known Member

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    Did you go with left twist to have spindrift and coriolis offset each other?
     
  7. lesvoth

    lesvoth Member

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    Sorry I didn't see your message sooner, 7magcreedmoor.

    I'll contact Xray and get him to send me his reasoning for his choice of a left twist. Just to give a beginning to his reply: The first part of his idea was shared with me as recoil-pulse mitigation. That was before he had the rifle built. I shot this rifle without that in mind and came away with the idea it was an easy recoiling round. The day I shot it we were shooting rocks together, me with my 6.5 Creedmoor and Xray with his 6.5 SAUM. Our rifles weighed about the same, our estimate was within a pound of each other, and the SAUM may have been the easier recoiling rifle - but he was using a suppressor and I was not using one that day.
     
  8. 7magcreedmoor

    7magcreedmoor Well-Known Member

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    I had not thought about the recoil aspect. I suppose having the rifle torque away from your cheek makes it seem more friendly (for a right-handed shooter). Is that how it works?
     
  9. bassrods

    bassrods Member

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    ONE RIFLE???
    lets see my 6.5X284 ??I have killed Elk out to 764 yards one shot, my wife same gun out to 981 yards one shot..
    But then my Moose same gun 656 yards one shot..
    Then my 7mm mag Deer out to 1069 yards Jack rabbet at 1316 yards..But pick only one?? How about only one rifle at a time (I like to give them all some love all 96) only one you must be NUTS..LOL...
     
  10. lesvoth

    lesvoth Member

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    Thanks for your patience 7magcreedmoor. I got ahold of Xray, and here is his reply written in his own words:
    7magcreedmoor
    Did you go with left twist to have spindrift and coriolis offset each other?

    So spin drift is basically the same if we're talking twist be it left or right. Left twists, left. Right twists right.

    Coriolis is a different issue all together. If you look at how the earth rotates here in the northern hemisphere, rotating east at approx 1,000 miles per hour. Shooting east the earth is traveling away from the target, making the bullet fall short. Facing West the bullet will land high because the earth is rotating into the target. Shooting north the bullet will fall behind the target because the target is actually moving east. And the opposit is true shooting South. This last case would be where the left twist would somewhat negate coriolis. This would only be at greater ranges.

    The main reason for doing the left twist in a mag caliber is what you guys have already discussed, the twist of the weapon. For a right handed shooter it pulls the stock into the shoulder pocket and against your cheek. So it's more managable and recoil management is much easier to attain.

    For cut rifle companies like bartlein, it's just a flip of a switch to make a left twist. I wanted to try one so I decided why not try it with a mag where it would be the most effective. So far I don't mind it. If you want to try one, by all means give it a try.

    Xray.

    PS: 7magcreedmoor, lesvoth here again. I'll just add a little about why recoil management is important to Xray. He hunts alone - without a spotter - so he needs to spot his own shots/hits/misses. He has to hit - it is his job. So whatever seemingly minute help he can give himself in that endeavor, in this case perhaps the barely perceptible "recoil pulse mitigation," - it all helps him do his job.

    Thanks again for your questions!
     
  11. lesvoth

    lesvoth Member

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    Bassrods,

    We all oughtta have at least a pair and a spare of each of our favorite, well chosen rifles! I'm on your side!
     
  12. 7magcreedmoor

    7magcreedmoor Well-Known Member

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    Thank you both for your explanations. As you say, every little bit helps.
     
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