243 8 twist barrel life with heavy bullets?

[ttfreestyle]

Hey guys, was curious what real world numbers yall were getting out of the 243. Looking to shoot the 105 to 115 grain bullets. Thanks

 

[abishai]

I got 2800 before I retired mine . Load was 49 grains of retumbo , 115 naked dtacs win LR primer . To be fair , the last 800 rounds , I had to clean (scrub) every 30 - 40 rounds before accuracy fell off. I had a hard time letting it go even after the bore scope revealed it had almost no riffling left for the first foot and a half . It still shot in the 145s on a 15 shot string . Slow powders are your friend with a 243 ....... So are inside neck turners . Every one will tell you they are toast after 1200 .

 

[ttfreestyle]

Thanks for the reply, I was looking at a used 243 bbl but think I will pass due to the short life as compared to some other calibers.

 

[KevinThomas]

I'll agree with Abishai . . . about the 1200 round figure. Even then, I'd say that's optimistic. It really depends on the shooter, and what the barrel is being used for. If we're talking about a competitive gun, with a High Master or even Master class shooter, figure 1000 rounds, or somewhere in the neighborhood. For a prairie dogger, yeah, you'll get more, but the last half of those rounds will be giving the prairie dogs a very sporting chance.

 

[abishai]

I love the 243 , but I did switch to the 6 xc ........ I guess I like shooting cleans better

 

[chuckles]

Kevin Thomas, i was wondering if you would reply to the issue of whether slow-burning single base powders (such as H1000 or N-165) could extend the barrel life of the 243 Winchester (or similar variations,e.g., 6CM). It seems counter-intuitive that burning a larger powder charge (as in H1000) could extend the barrel life.

thanks, Chuck

 

[KevinThomas]

Chuck,

No, it won't. It's primarily (in my experience, anyway) the heavier bullets that are the bad guys here. More dwell time, longer time frames to overcome inertia and get them moving on down the bore, and that translates to all that heat and pressure doing it's damage right there in the throat. Section a shot out barrel that's been used mostly with heavy bullets and that's what you see; a pristine barrel a short distance ahead of the chamber, but a small scale model of the Grand Canyon right there ahead of the chamber mouth. Really does them in, very badly. Lighter bullets tend to show lighter wear, but extending further up and into the bore than this.

To be more concise with your question, no, I've never done any testing specifically to determine barrel life with single base vs. double base powders, or compared case capacity issues per se. I have made the comment that within a given boresize, it takes X lbs of powder to wash out a barrel. Whether that's X spread out over a much larger number of smaller cased rounds, or the same X lbs in a smaller number of larger cased rounds, it's still X lbs in each case. I started to do an article on this many years back, and never wrapped it up. At the time, I had two identical M700s; same twists, same brand of barrel, etc.. One was chambered for a 6x45mm, while the other was in 240 Gibbs. The Gibbs used almost exactly twice the powder charge for a given bullet that the 6x45mm did, and has long since been shot out and rebarrelled. The 6x45mm still sits in the safe, and has plenty of mileage left in it. Don't know if that helps ort answers your question exactly . . . but I would like to restart that article.

 

[mikegaiz]

I have to agree with 1200 rounds being the optimum high for a 243 barrel. Having said that,
I have one 243 prairie dog gun with around 2500 rounds of all molly bullets and ball powder H380, that still shoots 1 in. groups at 100 yds. I think it is the combo of molly and cooler burning powders. I think that is some kind of a record for a 243 for barrel.

 

[chuckles]

Thanks Mr. Thomas, for your prompt reply. An article on this topic would be great to read.
Chuck

 

[Raptor]

I have a barrel that started life as a 6XC at 1800rds I decided to re chamber it to the 6SLR. I put close to another 1000rds through it as a SLR then pulled that barrel and tried the BRX but it didn't feed well so I decided to go back to the 6SLR. I had left the old barrel with my smith and one day I had him bore scope it and he said, "Hell, it doesn't look that bad. If you cut and inch off the rear it will still be a pretty good barrel". So I had him cut and re chamber it again. Its shooting 1" to 1 3/8" 5 shot groups at 300yds and close to 3000rds through it now.

I honestly think that the H1000, 30 degree shoulder and the longer neck helps with barrel life. I used H4350 with the 6XC but then went to H1000 with the 6SLR. I am sure I will easily get another 1000+ rounds out of it. In all fairness I really only shot it in competition once so I guess it hasn't been abused all that bad which may help with the good barrel life too.

 

[IA_shooter]

It's primarily (in my experience, anyway) the heavier bullets that are the bad guys here. More dwell time, longer time frames to overcome inertia and get them moving on down the bore, and that translates to all that heat and pressure doing it's damage right there in the throat. Section a shot out barrel that's been used mostly with heavy bullets and that's what you see; a pristine barrel a short distance ahead of the chamber, but a small scale model of the Grand Canyon right there ahead of the chamber mouth. Really does them in, very badly. Lighter bullets tend to show lighter wear, but extending further up and into the bore than this.

I always wondered if the lighter bullets would increase the barrel life. It just seems to make sense the way you describe it. I have a .243 28" Criterion bull barrel that had 550-560 rounds through it of ONLY 107gr MOLY MK's that I then had reamed out to Ackley Improved and when my smith reamed it he said the bore looked really, really good other than just a very tad bit right at the start of the rifling. I didn't have the barrel shortened this time but I'm now going to shoot 80gr-95gr naked bullets out of her for at least another 500 rounds before I may have it shortened to a 26" and try and hopefully squeeze out another 500 or more rounds before it starts to show any decrease in accuracy. As it is now this barrel gives me between 1/2 and 1/4 MOA consistently and it's a keeper. I have only used IMR 4350 in it so far but I do have some H1000 that I want to try to use for the 87-95gr bullets I have.

 

[wbm]

I honestly think that the H1000, 30 degree shoulder and the longer neck helps with barrel life.

You are honestly mostly right. The problem with the 243 is the shoulder angle and the short neck. A few years ago Precision Shooting Magazine did an article on just that. It is throat erosion that plagues the 243. The throat goes before the barrel and the more powder you burn the faster it erodes. The shoulder angle combined with the short neck focuses the burn forward of the case necks onto the throat. If you go with a larger shoulder angle and a longer neck then the problem is mitigated and throat erosion is reduced. That's why the 6MM Remington with a 26 degree shoulder and a longer neck is a better idea than the 243 Winchester with a 20 degree shoulder and short neck.