Barrel sizing/contour help

[limbic]

My fclass gun has a stiller viper action. Currently I'm shooting a 6BRX Broughton barrel and am in the market for a new tube. Kreiger or Broughton.
1)How do I know if the barrel contour I want can be threaded to fit my action. Specifically the "A" dimension varies so how do I know if I need a barrel that is 1.25 or 1.5 or ever 2.0.
2)Why does kreiger offer two different land diameters, .236 and .237. I currently shoot the 105 Lapuas. If that matters.


Thanks for your insight

 

[TRECustom]

Limbic, I can't help much, but I can tell you that if the Viper is a Remington clone, it's tenon diameter will be 1.062" for the thread major diameter and the recoil lug seat, so a 1.250" barrel is large enough. If you want a heavier barrel, there's just more room. If the Viper tenon is smaller, you'd just have more room with a 1.250". All barrel blanks will have a long enough shank on them for the tenon, plus a good shoulder to make up on.

I don't know the answer on the land diameters, but possibly a button rifled barrel might have about .004" tall lands, and a cut-rifled barrel might have .0045" tall lands. That assumes that the bore (groove) diameter is the same. I'll bet that Krieger will explain if you call or email them.

Good luck, Tom

 

[Eddie Harren]

I think that the Predator is the Rem clone. All of the Vipers, that I have barreled, were more like Pandas.

 

[alf]

Just get the contour you want starting with a 1.250" shank.

Rule of thumb for me is to get the .236 for long range shooting with the 105/107 boatail bullets, because they have no pressure ring and run a touch smaller in diameter.(except BIB 108 BT's)
.237's for close range 100/200 BR, using bullets that typically run a little fatter due to the pressure rings.

 

[Bob3700]

Limbic,

I order my bbl blanks with an extended breech end dimension. You will notice that most breech dimensions (diameters) run for about 2 inches. I order mine with 4-5" so that I can set the bbl back and rechamber it.

Once you have what you think is about half the bbl life, set the bbl back and rechamber it. That gets you into new throat material and the breech end is not excessively worn out.

That said, I chamber my own bbls and only have the inconvenience of removing the bbl and resetting my sights.

Agree with Alf on the bore diameters. I shoot NRA HP LR and always specify a .236 bore for all the boat tail bullets I shoot.

RGDS

Bob

 

[limbic]

Great advice as usually guys. Thanks.