Barrel Life

[Bart B.]

Now if we could just find someone to give us a 1.1 or 2.0 (Chris Long) OBT model we'd all be in shooter's heaven.

Having changed two barrels muzzle diameters a few ten-thousandths (measured) testing accuracy and saw no changes, I'm convinced that OBT theory and its muzzle flexing is figments of imaginations, not reality.

 

[Beau]

All those replies without a mention of the barrel life calculator right here on accurateshooter.com? For shame!
http://bulletin.accurateshooter.com...-barrel-die-spreadsheet-predicts-barrel-life/

 

[mike a]

All those replies without a mention of the barrel life calculator right here on accurateshooter.com? For shame!
http://bulletin.accurateshooter.com...-barrel-die-spreadsheet-predicts-barrel-life/

I can't seem to make it work on my iPhones 5

 

[mike a]

Amen.

A 30 M1 carbine barrel will last longer than a 300 Weatherby barrel.

22 long rifle match barrel lasts about 30,000 + rounds, 22 PPC about 3000.

How about this senecio. 6br light bullet, more powder vs 6br heavy bullet, less powder? Strikes me more powder more thrust errosion. OR heavy bullet more bearing surface? Or just splitting hairs here.

 

[Bart B.]

How about this senecio. 6br light bullet, more powder vs 6br heavy bullet, less powder? Strikes me more powder more thrust errosion. OR heavy bullet more bearing surface? Or just splitting hairs here.

Splitting hairs, in my opinion.

And I don't think bearing surface matters much. Bullets are fully engraved at one-fifth, or less, of peak pressure.

 

[Beau]

Bart, I believe it does matter. In 223, we get much better barrel life from light bullets than heavy, even using much more powder with the light bullets. I don't think it has so much to do with pressure as bullet dwell time in the throat. That is, heavies spend more time in the throat allowing more time for heat soak in the throat.

Kevin Thomas agrees with me. http://forum.accurateshooter.com/th...ing-heavy-bullets-reduce-barrel-life.3755009/

 

[Bart B.]

I don't think it has so much to do with pressure as bullet dwell time in the throat.

Have you measured the pressures? What's the round counts in your barrel life comparison?

I don't think bullets have dwell time after they start moving in case necks. Dwell is zero speed in firearms functions. They will accelerate less as they're first engraved but speed up fast as pressure is rising very fast the first 3/4 inch of bullet travel.

And higher pressures push more heat into metal than low ones, so thinks me. As do some barrel makers. Unless average peak pressures are the same across all bullet weights, the data is skewed.