.284 base to ogive measurement 180 hybrids

Discussion in 'Big Stuff -- 6.5mm, 7mm, 30 Cal' started by jefo65, Feb 11, 2018.

  1. jefo65

    jefo65

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    Just looking for some feedback from you .284 folks. Just got mine back from the smith and being my first 284 I don't want to jump on the guy if mine measures okay. Using the Hornady lock n load col body with the 7mm insert and the anvil base mine finds the ogive at 2.561" bto and an approx col of 3.275". Freebore was supposed to be .188
    Mine seems to long...maybe? I know there can easily be a .010 difference from bushing to bushing..an approx average of a few other rifles would sure be appreciated
     
  2. Cowtownup

    Cowtownup Silver $$ Contributor

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    I was at 2.503 BTO and 3.232 OAL with the 180’s on a .225 freebore..
     
  3. ShootDots

    ShootDots Gold $$ Contributor

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    I think it is long.. My freebore on my .284 WAS (not now due to some erosion) .235. I just measured some 180 VLDs and their base to ogive to JUST touching the lands is 2.530. There is "about" (differs from lot-to-lot) 30 thousandths difference (VLDs have a LONGER bearing surface) in bearing length surface... My best "guesstimate" of your freebore is more on the order of .250...
     
  4. Keith Glasscock

    Keith Glasscock True believer - Straight 284 Gold $$ Contributor

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    For 180 hybrids I start at .220" freebore. The barrel gets worn out before I move out .030" (leaving a lot of bullet in the case), so I wouldn't sweat it.

    Think of it this way: You WILL have donuts. With a longer freebore, you WON'T have to worry about them.
     
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  5. jefo65

    jefo65

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    Thanks for the help so far guys,..much appreciated! Got word back from "my smith" and it very much looks like it'll become a pi$$ing match. Said the freebore is set at .222,..so much for the .188 requested,..why would you listen to a customers initial request? Even at .222 freebore it sure seems long, confirmed by what you folks shared. Thinking it may be time for a new smith.
     
  6. dskogman

    dskogman Gold $$ Contributor

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    It’s closer to .250 free bore I’d guess. You can shoot 195’s if you want ;)
     
  7. ShootDots

    ShootDots Gold $$ Contributor

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    Don't be so hasty about wanting a new 'smith.. Yes, you wanted a .188 freebore, yes he gave you something you did not pay for>>BUT in MY humble opinion, whether it's .222 or up around .250 he did you a favor. A .188 freebore will put the Berger 180 Hybrids RIGHT AT the neck shoulder junction. And like Keith stated, you WILL develop doughnuts! At a .188 freebore there is the REAL possibility, that the end of the boattail closest to the bearing surface will run right into the doughnut! I have had this happen with freebores that are supposedly designed to keep the bullet above the neck shoulder junction. If you are shooting Hybrids, that .222 freebore is an excellent place to have it at. If you are going to shoot 180 VLD's, in my opinion a .235-.250 is better yet! So do not fret. But I would voice my opinion about what you ordered and what you got>>>then if he "fights back due to his inability to admit error", then look for a new 'smith..
     
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  8. jefo65

    jefo65

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    Great advise man,..as far as the smith's inability to admit error,....sounds like you've met him! LOL,....when questions like this are asked,..I'd have been happy with "let me take another look at it" instead of telling me what I asked was "bullsh1t" and after explaining how I went about gathering my measurements,..replying "still bullsh!t" ultimately is gonna be bad for business and be a valid reason why my business may be better off elsewhere.
     
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  9. accuracyman

    accuracyman Silver $$ Contributor

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    My 284 has a 220 Freebore. When seating a 180g Berger VLD in Norma brass the bearing surface of the bullet is .050-.060" away from the donut. The Norma brass has a very distinctive donut. After finding my touch point I loaded a dummy round where the bullet just kisses, but does not jamb, the rifling. I write down this loaded round dimension using a tool that measures off the ogive. Using a once fired case I slide a 180g Berger VLD bullet into the neck until it bottoms out on the donut and using the same ogive tool I write that number down. The difference between the two was .050"-.060". The reason for this range is I measured several fired cases and this represents the two extremes. All of this just to say I consider a 220 Freebore to be the shortest freebore I would use if you plan to shoot Berger VLD's and want to stay off the donut. It gives you at least a .050" jump and still be off the donut if your rifle needs that much. 180g Hybrids do not seat as deep so the 220 freebore is perfect for the Hybrids. This is using Norma brass and the chamber was cut with a JGS reamer designed for Norma/Lapua brass with 1-30 degree lead, 220 Freebore, and 316 neck. This is my opinion and I'm sure others might chime in and have a different view but this is how my numbers came out. I hope this helps.

    Kris
     

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