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  #1  
Old 01-01-2015, 11:47 PM
Troy G Troy G is offline
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Default 1/10 twist and .172 30gr Bullets Yes or No?

I have the opportunity to buy an unused 1/10 twist Krieger barrel in .172 for about half the cost of a new Shilen or Lilja.

Has anyone been able to shoot 30gr Golds and the older 30gr Berger HPBT match bullets with one in a bigger 17 case in winter. I am at about 2500ft above sea level on average.

The only other problem is that I believe the contour is a heavy varmint contour and I hope the seller did not mean the straight taper HV contour benchrest class.
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Old 01-02-2015, 01:10 AM
Chickenthief Chickenthief is offline
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Has to do with bullet length.

I have a 1:10 Tikka and it will not shoot 25gr V-MAX wich is .671" but the 25gr HP wich is .564" and the 25gr Berger wich is .556" both does ok.

What i know of the Berger 30gr then, it is @ .637" and that is not quite ok.

Yet some says that their Cooper rifles will shoot the longer bullets ok and i guess that they are a trifle steeper than 1:10. A famous barrel maker said that he could wary twist by as much as ½ either way by changing the speed the acorn is pulled through the barrel.

You can play with numbers yourself:
www.accurateshooter.net/Blog/millerformula.xls
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Old 01-02-2015, 01:46 AM
Troy G Troy G is offline
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When spending big money to buy a barrel and have it chambered I usually error on the side of caution and opt for recommended twist.

Hope to hear more anecdotal evidence.
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  #4  
Old 01-02-2015, 02:00 AM
trotterlg trotterlg is offline
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All the 30gr Berger boxes say 1 in 9 twist. Their 30gr BT is .660 long and there FB is shorter by about .030. It really all depends on how fast you make them go, and, a lot of people mistakenly think that their twist is too slow if the bullets don't shoot good because the rifle doesn't like them. If the bullets don't keyhole then they are stable. The other problems with the stability calculators is that they all assume the spin rate decays at the same rate as the velocity of the bullet. This is wildly untrue, the spin rate decays at a much slower rate than the velocity of the bullet does, so the calculated point where a bullet will go unstable is much higher than what happens in real life (the bullet stays stable at a much slower speed). If it is going to be something like a 17-204 or another hot 17, my guess is it will do fine with the FB 30's. Larry
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Old 01-02-2015, 02:12 AM
montdoug montdoug is offline
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I have a 1 in 10 that does well with the 25 grain V-Max's and when they first came out with that bullet many were surprised at that cause most 1 in 10's guys here had didn't seem able to make em work. I shoot at around a mile in altitude and was running them fairly quick so that might have something to do with it as well.
If I were to hazard a guess I'd say not likely on the 30's in my rifle but I've never tried em so I have no real experience to base that guess on. It's a crap shoot I wouldn't personally want to bet much money on.
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  #6  
Old 01-02-2015, 03:10 AM
Kdog Kdog is offline
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Gotta go with Troy G. Spend the extra $$ and get the 1 in 9 twist, then you can shoot any brand 30 grainer and not have to worry. I have had a 1 in 10 that would not stabilize a 30, and I won't do that again.

Ken
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Old 01-02-2015, 03:53 AM
17rimfire 17rimfire is offline
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Default 9 twist

I have 2 shilen 10 twist barrels, wish they were 9's. Neither will shoot a 25 grn vmax and one will stabilize a Berger 30grn FB at least at 100 yards. Havnt shot them past that yet. If you want to go through all the trouble of building a rifle, especially a big 17 specifically to shoot 30 grain projectiles don't cut yourself short with a 10 twist that "might", go with a 9 twist and know.
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  #8  
Old 01-02-2015, 08:45 AM
wally bennett wally bennett is offline
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1 in 10 Pacnpr 17A/H wont shoot 25 V/Max but shoots Hornady and Berger 25 HP,s ok at 3.600+ ft/sec but wont shoot any 25,s at just under 2.000ft/sec (looking for a slower quieter load )
Wally
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Old 01-02-2015, 01:49 PM
cmatera cmatera is offline
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If you absolutely want to shoot 30's, you NEED a 1-9" twist. I have a barrel that was supposed to be a 1-9", but was not. The bullets on my first rounds hit the target perfectly sideways (with 30gr Kindler Golds). My CZ 527 with a 1-9" Pac Nor barrel in .17 Fireball shoots them very well.
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  #10  
Old 01-02-2015, 02:14 PM
LT17 LT17 is offline
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Its a bit of a risk. I have a Pac-Nor 1:10 in 17 Rem and I have several boxes of Berger 30gr Match (small hollowpoint flat base) and 30gr MEF (large hollowpoint) my rifle will shoot these ok provided its a fast load. I also have a box of 30gr Berger target (boat tails) which are utterly hopeless. You might get away with some 30gr bullets, but 1:10 is not ideal for this weight. At the price of the barrel I would stick with 25gr hollowpoints or 20gr Vmax.
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