Barrel life
- Thread starter traper
- Start date
I agree with Dennis on this one! I have actually burned up a half dozen barrels over the years, and it is my belief that you cannot stop erosion by any known means. However, one of the primary factors in barrel life is how "hot" you let your barrel get while shooting. If you allow cooling down time between shots. (particularly not shooting long, rapid fire strings) you can extend barrel life expectancy somewhat. Burning large quantities of powder in smaller bore sizes simply makes a hotter fire, and erosion becomes an ever increasing problem. That being said, I am a 220 Swift user. This chambering has long had the standing accusation of being particularly tough on barrels. I washed one up in 2400 rounds, but another, which I was much more careful with as to heat, I managed to get 3500 before it would no longer keep inside an inch at 100. At one time it was believed that boat-tail bullets contributed to shorter barrel life, but I think that there is no empirical evidence to actually support that assertion. If you are really concerned, keep in mind that a good barrel is relatively inexpensive over the long haul, and can easily be replaced by Guntech (or other good smith of your choice!)
Regards, Eagleye.
Regards, Eagleye.
How many rounds before barrel starts to washup say on a big boomer like 338RUM shooting 300GR, bullets, later, Traper.I agree with Dennis on this one! I have actually burned up a half dozen barrels over the years, and it is my belief that you cannot stop erosion by any known means. However, one of the primary factors in barrel life is how "hot" you let your barrel get while shooting. If you allow cooling down time between shots. (particularly not shooting long, rapid fire strings) you can extend barrel life expectancy somewhat. Burning large quantities of powder in smaller bore sizes simply makes a hotter fire, and erosion becomes an ever increasing problem. That being said, I am a 220 Swift user. This chambering has long had the standing accusation of being particularly tough on barrels. I washed one up in 2400 rounds, but another, which I was much more careful with as to heat, I managed to get 3500 before it would no longer keep inside an inch at 100. At one time it was believed that boat-tail bullets contributed to shorter barrel life, but I think that there is no empirical evidence to actually support that assertion. If you are really concerned, keep in mind that a good barrel is relatively inexpensive over the long haul, and can easily be replaced by Guntech (or other good smith of your choice!)
Regards, Eagleye.
- Location
- Edmonton, Alberta.
I have read that barrels chambered for the .308 win should have a life of around 10,000 rds where magnums will have a life expectancy of about half that.
That depends on what kind of accuracy you are looking for. At 10,000 rounds I doubt a .308 would still give you MOA (I have never had one last that long).
While it may no longer be a MOA barrel, it might still be a Minute of Deer/Moose accurate.
And I've seen barrels that were toast with under one thousand rounds through them (prairie dog shooting in Utah). There are a lot of variables at play, pressure, temperature, hardness of the barrel, etc. I think if you shoot slowly, you can get a few thousand rounds out of MOST barrels without much in the way of problems, even with magnums. And keep in mind that you arent trying to keep BR accuracy on most of these guns either. - dan
We can at least begin to approach this mathematically, as well.
If we consider that a throat erosion of (let's say) .2" no longer allows you to seat long enough for max accuracy, then we can find the surface area at .224" is pi*r*r*l, or 3.142*.112*.112 is 0.00788 in2, while the area at .338 is 0.0179.
Now we can find the ratio of powder capacity to surface area (the amount of burning powder vs the amount of are it will work on), and we find that your 338 with a powder capacity of around 120 grains results in about 6704 grains of sandblasting per square inch of throat.
A little cross-multiplication, and we can see that a .224 with a similar volume of powder working on the same surface area would have to start our with around 53 grains of capacity.
So, all else being equal (which it probably isn't), would 338 RUM would erode similarily to a 220 Swift Improved, or a 22-243 middlestead.
I don't think that muzzle velocity has a lot to do with it, unless you're using different powders which may have different burning heats (4350, for example, tends to burn hotter than 4831, and there is anecdotal evidence that it erodes throats faster)
If we consider that a throat erosion of (let's say) .2" no longer allows you to seat long enough for max accuracy, then we can find the surface area at .224" is pi*r*r*l, or 3.142*.112*.112 is 0.00788 in2, while the area at .338 is 0.0179.
Now we can find the ratio of powder capacity to surface area (the amount of burning powder vs the amount of are it will work on), and we find that your 338 with a powder capacity of around 120 grains results in about 6704 grains of sandblasting per square inch of throat.
A little cross-multiplication, and we can see that a .224 with a similar volume of powder working on the same surface area would have to start our with around 53 grains of capacity.
So, all else being equal (which it probably isn't), would 338 RUM would erode similarily to a 220 Swift Improved, or a 22-243 middlestead.
I don't think that muzzle velocity has a lot to do with it, unless you're using different powders which may have different burning heats (4350, for example, tends to burn hotter than 4831, and there is anecdotal evidence that it erodes throats faster)
Now you're scaring me Prosper - dan
- dan
