Barrel Heat vs Contour vs POI shift

[Cactus Kid]

I know that a shooting several shot strings from sported weight barrels causes the POI to change as the barrel gets hotter.

When I shoot my .308 that has a heavy varmint contour barrel, measuring .875" at the muzzle, the poi does not shift, no matter how many rounds I send down range.

I know that any heavier countlur iaides in recoil management,

But how much lighter can a barrel be and still not change it's POI when shooting several shots in rapid succession?

Can the rem varmint contour (.820 at muzzle) do it?

 

[biffj]

Re: Barrel Heat vs Contour vs POI shift

What you will find is that there isn't a consistent amount of shift with temp. It varies considerably from barrel to barrel and depends on a number of factors. Some heavy barrels will shift a lot and some light barrels not at all. Cut rifled barrels tend to have less shift (sometimes) when compared to button or hammer forged barrels. It all depends on residual stresses left in the steel from the forming work and whether or not they were removed during the stress relieving. A barrel with no internal stress won't move which is what makes the cut rifled barrels so good. Some button rifled barrels may show some very odd drift due to internal stress that wasn't removed through the stress relieving heat treat.
Not a very clear answer but its what you get.

Frank

 

[The Punisher]

Re: Barrel Heat vs Contour vs POI shift

now my old sps tactical would shift after a few shots but it was the pos hogue rubber stock. put on a B&C stock problem solved.

 

[Neil Allen]

Re: Barrel Heat vs Contour vs POI shift

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Cactus Kid</div><div class="ubbcode-body">I know that a shooting several shot strings from sported weight barrels causes the POI to change as the barrel gets hotter.

When I shoot my .308 that has a heavy varmint contour barrel, measuring .875" at the muzzle, the poi does not shift, no matter how many rounds I send down range.

I know that any heavier countlur iaides in recoil management,

But how much lighter can a barrel be and still not change it's POI when shooting several shots in rapid succession?

Can the rem varmint contour (.820 at muzzle) do it?




</div></div> Have a Rem Sendero in .264 WM. Used it at Thunder Ranch for the Medium Range class.
Uh, yep, got her HOT! More than once. End of the third day after a, if memory serves, shot string of about 35 rounds in less than 45 min Hedi put up a playing card at 100yards for each shooter. Card had a 3/4" red dot on it. I missed the red by 1/2 a bullet.

So, it was still shooting <MOA at the end of day. A HOT frickin day!

As a side note I did have to buy Clint a 8" plate. Poked a hole in one at 100 yards.

 

[cummins cowboy]

Re: Barrel Heat vs Contour vs POI shift

I used to have a 270 factory barrel that once it got hot the groups really started to tighten