.243 vs. .308 barrel wear @ same velocity range?
- Thread starter ba_50
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ba 50: I have no "hands on experience" with a 308, but had 2 243 Winchester barrels. First was a chrome-moly Douglas: at a documented 1400 rounds, it was toast. Replaced it with a stainless Shilen, and it also lasted 1400 rounds, although at around 850 rounds, accuracy started to drop-off, and copper fouling increased. Since then, acquired a "hawkeye" borescope and went into both barrels for a close-up inspection, they had been in the closet). Heavy fire-cracking in front of chamber mouth, and little or no lands for the first 1" to 1 1/2". Loads were always on the mild side, 37 grs. IMR 3031 with the Sierra 75 gr. hp # 1510 was the accuracy load for both. The reasonthe 243 is not "one of my favorites". Never looked back after the excellent 6BRs I have now. Hopefully someone with 308 experience can chime-in, although several yrs. ago Kevin Thomas, of Sierra bullets did an exhaustive test, published in PS) on barrel life of 5 308 barrels. They all started to go downhill around 3800 rds., and by 4100 were all scrap.
ba 50,
The 243 will always wear out faster because of the smaller bore diameter. The other problem with the 243 is a short neck an steeper shoulder angle. Both of these are known for faster throat erosion and then when you throw in a small bore diameter you have a situation where you get fast throat erosion.
Both of my 308VSs went to 4000+ rounds before they gave up the ghost. I now have a 243 with a 6XC neck and shoulder on it an I shoot the slow burning powders through it. I have over 2000rds through it an its still shooting fine. However I have not got it to the point where its been to hot to touch when shooting. This is also a big factor in throat erosion.
The 243 will always wear out faster because of the smaller bore diameter. The other problem with the 243 is a short neck an steeper shoulder angle. Both of these are known for faster throat erosion and then when you throw in a small bore diameter you have a situation where you get fast throat erosion.
Both of my 308VSs went to 4000+ rounds before they gave up the ghost. I now have a 243 with a 6XC neck and shoulder on it an I shoot the slow burning powders through it. I have over 2000rds through it an its still shooting fine. However I have not got it to the point where its been to hot to touch when shooting. This is also a big factor in throat erosion.
I conducted my own little experiment using a borescope and a new .308 barrel along with a .243 A.I. barrel and the results were interesting. Bear in mind, I was fireforming rounds in the .243 A.I. but after 40 rds., there was the beginning of firecracking in the freebore area. The .308 barrel has exhibited no firecracking at all.
Chino69
Chino69
chino69: Similar to my "experiment" a little over a year ago. Bought a new Savage 12BVSS, 243, and with milder loads,37 grs. IMR 3031 w/ Sierra 75 gr. hp #1510) watched firecracking progress in the leade area with my borescope. At 400 rounds, pulled it off, set-back 7/8", and rechambered in 6BR. Was able to save the barrel, and it's a great shooter now, but had I waited any longer, the barrel would have been unusable because of the extensive firecracking. Chalk uo another "Win" for the "Hawkeye" borescope: best investment I ever made, never regretted the purchase.
I have about 1300 hard rounds shot at sniper matches through my .243 sending 115 DTACs out at around 2980fps and it still shots great. The rifle has been shot so hot you couldn't touch the barrel. Every 300 rounds I send two Tubb TMS rounds down it and it is still shooting 1/2 MOA or better. I actually won the best 3 shot group trophy at the Idaho State Sniper Challenge this past weekend with a group at 100 yards that measure .250" from outside to outside so subtract the .243 and it was .007". Granted this is the best group I have ever shot in my life PERIOD but still not bad for a tube that has been shot fast and hard. I also have a couple of friends who have over 3000 rounds through their .243s and they send the 115s out at around 3100fps at sniper comps.
Granted the .308 will get more barrel life but the .243 will run longer than most think. That said barrels are a disposable quantity like ammo. Get what you want out of them and replace them. If you want longer barrel life go with the .308 but if you want better ballistics and don't mind about shorter barrel life than go with the .243.
Also if anyone was wondering my barrel is a 7.5 twist 27" Schneider SS.
Granted the .308 will get more barrel life but the .243 will run longer than most think. That said barrels are a disposable quantity like ammo. Get what you want out of them and replace them. If you want longer barrel life go with the .308 but if you want better ballistics and don't mind about shorter barrel life than go with the .243.
Also if anyone was wondering my barrel is a 7.5 twist 27" Schneider SS.
Rob01,
I couldn't agree with you more. I had a 260 Pac Nor barrel that I shot in comps and the barrel had a defect in it that caused it to have a piece of land flake out of the barrel just ahead of the throat area. When this happened the barrel was close to 1700 or 1800rds.
Pac Nor replaced the barrel at no charge to me.,Great customer service) The original barrel was 26"s long and I wanted to see what a 22" barrel would do at 1000yds so I sent it to my smith to have him cut 4"s off the chamber end and rechamber it.
When he got the barrel he called me back and said the barrel was "JUNK" it had fire cracking for about 12"s down the barrel!! I told him what I wanted to do and that I didn't plan on shooting it that much. More of a test thing to see if a 260 would shoot to 1000yds with a 22" barrel. So he did it for me and that barrel went from being a consistant .6moa rifle to a .4moa rifle!! I could not belive how well it shot.
When I had it bore scoped at a shoot the guy doing it looked at it and then showed me what it looked like and I couldn't belive it. It looked like a dried up lake bed and was actually black for about 8"s up the barrel but damn it shot good!!! I wound up putting another 800rds down it before taking it off at the start of my shooting season. It was still shooting damn tight groups when it was removed. So go figure.
I couldn't agree with you more. I had a 260 Pac Nor barrel that I shot in comps and the barrel had a defect in it that caused it to have a piece of land flake out of the barrel just ahead of the throat area. When this happened the barrel was close to 1700 or 1800rds.
Pac Nor replaced the barrel at no charge to me.,Great customer service) The original barrel was 26"s long and I wanted to see what a 22" barrel would do at 1000yds so I sent it to my smith to have him cut 4"s off the chamber end and rechamber it.
When he got the barrel he called me back and said the barrel was "JUNK" it had fire cracking for about 12"s down the barrel!! I told him what I wanted to do and that I didn't plan on shooting it that much. More of a test thing to see if a 260 would shoot to 1000yds with a 22" barrel. So he did it for me and that barrel went from being a consistant .6moa rifle to a .4moa rifle!! I could not belive how well it shot.
When I had it bore scoped at a shoot the guy doing it looked at it and then showed me what it looked like and I couldn't belive it. It looked like a dried up lake bed and was actually black for about 8"s up the barrel but damn it shot good!!! I wound up putting another 800rds down it before taking it off at the start of my shooting season. It was still shooting damn tight groups when it was removed. So go figure.
Rob01 said:
What did they use to measure group size? Regular calipers? That'll add a fair amount to the group, but still fine shooting.
I've measured my share of bullet holes and can say that outside-to-outside group measuring is the worst way to do it, since the hole in paper seems smaller than actual bullet -> you measure the groups to be smaller than they actually are. Of course you can overcome this limitation by using proper tools.
Yes it was a regular caliper as it was a sniper match and not a benchrest match so super precise group measuring devices weren't on hand. That said I measured it also and I went to the outside of the dark ring not the actual cut and got the .250" so it was pretty close to what it should be. Even if it was .1" instead of the .007" it was still the best I have ever shot 
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