Barrel Wear Estimator

[Mystic Precision]

Interesting little program offered on 6mmBR.com right now to estimate barrel wear. Of course, it is not perfect but a nice little way to compare popular cartridges.

As suspected, I found many of the popular F class cases to offer similar life vs their performance potential. From 6mm to 7mm, all pretty much a wash.

The 6.5-284 based on the program was much longer barrel life then suggested by match shooters. Now what defines accurate too isn't explained.

The big unknown is guessing on the operating pressures. I don't have quickload so am just going the SWAG method. Pressures certainly have a big effect on barrel life.

As does coatings. Not sure what they are basing their data on but in all cases, moly shooting increases barrel life.

Also, interesting was the heat from the powder. It has been something discussed but now there is a quantifiable value to back up what we intuitively know.

Hotter powders burn out barrels faster. Burn rate does not determine powder heat!.

H4350 is notorious for this and the data backs that up. All those mid sized 6/6.5mm shooters might want to take note of this.

if it shoots, H4831SC is a much cooler powder.

Varget is the hottest of commonly used hodgdon powders. That is surprising indeed.

I have no clue how to post the actual program so have a visit and play with it.

The data agrees quite well with my 6.5 mystic with an estimated barrel life of up to 1800rds depending on how you muck with the inputs. My shooting shows 1500 to 1800rds and accuracy falls off hard. My loss of accuracy is above 1/2 min heading towards MOA with stringing.

All those 338 LM shooters might want to plug in their data and see the good news. Start saving for new pipes.

Jerry

 

[pilgrim]

nise one thanks a lot

 

[CyaN1de]

You’ll need an Excel viewer to open the file, but Mike has supplied three different versions. Hopefully one works with your version of Excel.

V.1 http://www.websitetoolbox.com/tool/view/mb/file?username=6mmbr&id=82551

V.2 http://www.websitetoolbox.com/tool/view/mb/file?username=6mmbr&id=82966

V.3http://www.websitetoolbox.com/tool/view/mb/file?username=6mmbr&id=82968

Looks like Moly helps with barrel life even having to add more powder to get same pressure/velocities. On paper anyhow.

 

[Mystic Precision]

I have used moly on a number of factory and surplus rifles. The effect of moly is obvious. However, no rifle was shot long enough to wear it out so I can't say if it would help with wear.

It is another step, can be messy and needs a different approach to load development and cleaning.

Now that I am shooting BR quality pipes, issues of accuracy loss due to fouling are small. And the velocities are right where they should be. might have to try some moly for S&G's and see if it can get the velocity up there.

Jerry

 

[Glock4ever]

Meh! Not to sound like an ass but does this matter? I like to shoot - re-barrelling is expected, I think performance is all that matters. If you want a barrel to last forever then just don't shoot. As well, does this program take into effect if you are shooting a lot in short periods of time? Heat can help accelerate wear.

 

[Obtunded]

There are so many variables NOT incorporated into this formula including barrel itself (the way it is rifled and to what depths) and its temperatures.

I guarantee an over-heated barrel will wear at an exponentially greater rate.

It is an interesting guideline, but it doesn't change the fact that the barrel can't read that formula and it will wear out when it wants to. (Usually mid-way through the shooting season)

 

[guntech]

There are so many variables NOT incorporated into this formula including barrel itself (the way it is rifled and to what depths) and its temperatures.

I guarantee an over-heated barrel will wear at an exponentially greater rate.

I agree... I saw a .257 Weatherby with the throat burned out in 100 rounds... one shot fired after the other until the 5 boxes of ammo were all spent.

The fellow did not know what he was doing and wanted to fire form the brass so he could reload it... brass was not available quick enough for him...

Hot barrels definitely wear quicker with each successive shot.

 

[Mystic Precision]

Glock, it does matter because it gives you a reference when to start considering looking for a new barrel/setting back or just parking it. Barrels tend to loose their accuracy very quickly once they go past a certain point.

I have had a barrel die over the span of 50rds in an afternoon. The last 20rds were pretty frustrating as a good shooting rifle suddenly sprayed all over the countryside.

For someone thinking about building a new super duper cannon, knowing that the barrel is going to burn out before he figures out his best load might save alot of dissappointment and $$$.

As a competitive shooter, this program gives me a general idea of my ideal lifespan. Knowing a barrel is likely to start fading around 1500rds, I would not use it for competition after rd 1400 no matter how well it shot.

If I thought the barrel 'might' last to 2000rds by the seat of the pants estimate, I would find out the hard way during a match. Been there....

As for wear due to heat, what if you just crossed 700rds with your 6.5-284 (1000rds best accuracy) heading into a summer event with 200rds needed. You know the weather is usually very hot so your barrel is going to get super toasty.

Is the barrel going to make it another 200rds in the heat? Do I want to take that risk?

With my 6.5 mystic, I know that there will be no issue at all because I can safely go to 1500rds without missing a beat. So even if those 200rds become 600rds of wear, I am still plenty safe.

Like all estimators, including ballistics programs, we use a few variables to try and define a highly complex system. No where near perfect but sure beats tea leaves and tarot cards.

YMMV

Jerry