bullet weight influence on .243 barrel life?

[MadCountyDep]

So, while I'm learning this shooting game, I'm happy to shoot out my factory barrel (.243)... But, at some point I'm going to want to rebarrel...I'm debating going with a fast twist to stabilize the 105-115 gr vld offerings, but I'm wondering,

will there be any discernable increase in barrel life by having a faster twist rate for heavier bullets vs slower twist for lighter 90-100 gr bullets?

ideally I'd like to be shooting the heavier.243, but I'm not sure about barrel life with heavier.243 roundss

Option #2 is go with .260 with an 8 twist.....

 

[ToddKS]

Re: bullet weight influence on .243 barrel life?

I do not believe bullet weight plays much of a role in barrel erosion.

My understanding of barrel erosion is that is primarily a function of pounds of powder burned vs. the surface area of the barrel. That is why smaller calibers with heavier powder charges burn barrels up faster than larger calibers with relatively smaller powder charges (.243 vs. .308 for example).

Higher velocity rounds may also erode the throat faster due to the higher velocity at which unburnt powder particles hit the throat (think sand blasting).

The hotter you run your loads, the faster erosion will occur (more powder, higher velocity). I have read that a faster twist rate can also increase the erosion rate slightly, but that effect is far less significant than the other factors.

The .260 will have a longer barrel life than the .243 all else equal due to the factors above.

 

[MadCountyDep]

Re: bullet weight influence on .243 barrel life?

just what i needed to know, thank you sir!

 

[Deadshot2]

Re: bullet weight influence on .243 barrel life?

If there was an "Angie's List" for powder/primer suppliers, Powder Valley would be right at the top.

Place your order and just be patient. There's a good chance that they will be able to fill your order before anyone else fills backorders. Not only that, the order will be right.

 

[1lnbrdg]

Re: bullet weight influence on .243 barrel life?

JoseR (I think) on the National Match forum shoots H-1000 in his .243. Claiming over 4,000 rounds without a barrel set-back. He placed well in the Nationals at Camp Perry with that barrel. He's done a lot of work to see what would work and what wouldn't with the .243.
I think he gives up just a little velocity over what other powders would shoot in the .243 but gains over other 6mm chamberings are impressive enough to take a look along with the increased barrel life.

 

[30SMK]

Re: bullet weight influence on .243 barrel life?

If I was serious about getting into long range shooting with a 6mm and was concerned with barrel life I would probably get my next barrel chambered in 6XC. You can shoot those heavy weights with similar ballistics to a 243 with less recoil and longer barrel life. Take a look at this info page from 6BR.com http://www.6mmbr.com/6XC.html

 

[1lnbrdg]

Re: bullet weight influence on .243 barrel life?

Joe Hendrickson's words:

Barrel life with the 243 Winchester is all about powder choice.

Yes, some barrels last for less than 1000 rounds, but that is 75% due to powder choice and 25% due to barrel choice.

I finished this year's National Championships with over 2800 rounds through my barrel. I shoot the same rifle both XTC and Long Range. It is chambered in 6CM, which is simply a 243 Winchester with a 31 degree shoulder (243 Winchester has a 20 degree shoulder). My scores at 600 this year were 199-12x, 200-14x and 200-13x. By the X counts you can tell the tube is still shooting very well. I will shoot this barrel for about another 1000 rounds. I shoot naked bullets with the 115’s at around 3200 fps from this barrel. The load is 49.0 grains of H1000 with the bullets jumping .040”

I don't believe the shoulder angel has much to do with barrel life.

What does affect barrel life, is the burning speed of the powder and the makeup of the powder. I shoot only very slow burning, single based powder. My choice is Hodgdon's H1000. H1000 is in Hodgdon's extreme family of powder and thusly is not sensitive to temperature changes over a huge range of temperatures.

H1000 has proved to be very accurate with good velocity. N165 is a very good choice also.

It is important to note that I’m getting 3500 to 4000 rounds out of every barrel WITHOUT rechambering. And when I say I’m getting 3500 to 4000 rounds that is without any signs of accuracy falling off. I replace the barrels at the end of the year just so I don’t start a new year with an “old” barrel. I don’t know how long these barrels actually last.

I have been doing shooting this recipe for over 10 years. I’m getting this barrel life, first with the 243 Win, and now with the 6CM. Barrel life is similar between the two cartridges.

I am shooting only cut rifled barrels, Bartlein is my current choice, but Kreiger barrels are just a good. To get a little more technical, I shoot only .237” dia bores and only straight 4 groves. I have found that the 5 grove shaped rifling is problematic at the velocities I shoot, furthermore the .236” diameter bores create pressure issues over time. (I don’t know why)

This is a little insight into how I load for and shoot the 243 with great barrel life and good success. I’ve been doing this long enough to know that it works consistently barrel to barrel.

Many shooters don’t believe my results. I’ve stopped trying to convince shooters it works. I just shoot it and enjoy it. I don’t sell anything, or do I benefit in any way from sharing my experiences or results.

My feeling is that with a 243 Win sized cartridge a shooter can obtain more velocity AND longer barrel life than a 6XC, 6BR or similar cartridges with the same or better accuracy. Just burn more powder of the right type.

Joe

By the way, velocity is important. 80% of the time my additional velocity means nothing, but 20% of the time it is the difference between winning and not.

 

[Frank Green]

Re: bullet weight influence on .243 barrel life?

The longer bearing surface of the longer bullets will add wear to the barrel and shorten barrel life.

You also should list what you consider accurate barrel life. Is your accuracy requirement 3 shot, 5 shot or 10 shot groups and in that equation is your group size required to be .250moa, .3moa, .5moa or 1mos?

Yes as mentioned before I as well only use single base powders. Teh double based powders will wear the barrel faster.

If we do any testing on steels and barrel life we use .243win. Why because it shows wear so fast.

Ammunition makers when they load for it from the feed back I've gotten from them they don't like the round because it is so hard on the test barrels. By the time they start hitting around 800-1000 rounds they start to get erratic readings on pressure etc....

Later, Frank
Bartlein Barrels

 

[Hawk45]

Re: bullet weight influence on .243 barrel life?

If you are just shooting for fun and let your barrel cool between shots or short strings (1-5) you will get better life than if you are using as a match rifle shoot 10-40 rd strings w/o giving the barrel much time to cool. Velocity and heat are the killer of barrels.