Barrel life of a 6PPC

[SS427]

I've read that the barrel life of a 6PPC can go south after less than 1,000 rounds. What are you guys finding with your rifles? And if accuracy is dropping off, exactly how much worse are the groups?

On the other hand, I read stories of 6BR barrels lasting quite a bit longer. Why would that be? Velocity out of the two are fairly close....

 

[BoydAllen]

I think that the life of a 6PPC barrel depends on several things. One thing that comes to mind first is frequency of cleaning, and the equipment and materials that are used to clean, and the technique employed. Also, I think that some powders may be easier on barrels than others, and pressure levels may also be a factor.

Another variable might be whether bullets are coated. Several years ago, I spoke with a shooter, that generally does well, who has been coating bullets with moly and wax, using the NECO process, since it first became available. He sand that the barrel that he was in the process of cleaning (which he did with bronze brush, patches and solvent, after every group) had over 2,000 rounds on it, and was still giving good accuracy. Later that weekend I took a picture of him holding a remarkably small 200 yd. group, that he had shot under conditions that Gary Ocock described as being the worst mirage that he had seen in 25 years of shooting Benchrest, so I think it fair to say that his assessment his barrel's accuracy was accurate.

Another thing that you might want to consider is how well would a 6BR do, in the matches that it usually would be used at, if it was in a 1/4 moa rifle, and the same question asked of a 6PPC.

 

[SS427]

I was hoping you would post some thoughts Boyd.

I'm approaching this with a couple things in mind....I don't shoot in competition and probably won't any time soon. But I'm addicted to shooting small groups, however I would sacrifice a little accuracy for barrel life. So if that means not loading at maximum pressures, that is probably what I would do.

I use N133 in my 6BR and assume I would use N133 in a 6PPC. Is this powder hard on barrels? As for cleaning, I'm pretty sure I don't hurt my barrels while cleaning. I use a Lucas bore guide and have studied all the posts on how to do it right.

I would not shoot coated bullets.

I'm not sure what you are asking me to consider in your last paragraph. I must be missing something.

 

[BoydAllen]

The 6BR is more of a 600 yd. and 1,000 yd. cartridge. At those distances there is a greater chance of the average group being enlarged by the wind, than at shorter distances. This would mean ,I believe, that a rifle that could shoot 1/4 MOA would be more competitive, on average, than at a 100-200 yd match, where a rifle needs to be capable of teen aggs. under the best conditions to be in the running for top spots. If two rifles were to start out equally accurate, one a slow twist PPC, the other a fast twist BR and they both were shot at their appropriate distances, the more stringent requirements of the shorter range matches would dictate a shorter useful competition life for the PPC. On the other hand, if you hold the same standards for both, I don't think that you would see much difference, and if anything the slightly smaller case should have the advantage. As to 133, to keep things a little simpler for a couple of friends that are just getting their feet wet, with very well built PPCs, I started them out with 322 extreme, at a weight given to me by a long time competitor, and a seating depth that my experience suggested. They are both good trigger pullers, and have both turned in as many teen practice groups as I believe that they would have with 133. I started both out with 68 grain Bergers, with marks on their bullets that are about a third as long as wide. They made small adjustments in powder charge, and were off to the races. Their next assignment is to shoot more in bad conditions, and to use more sighters, and to not do any preloading (which seems to be the hardest habit to break).

 

[fdshuster]

Shilen stainless, heavy contour, .262" neck, standard load of 28.5 grs. N133, 68 gr. Berger's seated to touch, 205's, cleaning seldom after more than 20 rounds, bore guide, coated rods, etc. Was excellent 'til approx. 1800 rds. fired then started to get an occassional uncalled flyer, and a little more difficult to clean (copper). Kept monitoring throat with my Hawkeye and saw more erosion and the beginning of firecracking. Gave up on it at a recorded 2410 rounds. Set it back from 24" to 20", rechambered, this time with a .272" neck, and it's again shooting nice very tiny groups. Not good enough to use in a match, but good for informal and off-season use.

 

[BoydAllen]

If you are concerned about barrel life, I wouldn't be so quick to reject bullet coating. I don't, because I am not spending a lot of my time at the range these days, and because the rifling form of a couple of my barrels seem to need hot loads, and coating bullets would undoubtedly introduce a case capacity issue....but if I invest in a new barrel, and I am convinced that it is a good one, I may do some experimenting with one of my older barrels, that has more conventionally shaped lands.

The fellow that I mentioned in my earlier post, had used moly with wax for a long time, and reported that even though he was not following Walt Berger's suggested cleaning regimen, that he was of the opinion that he was seeing significantly longer barrel life as a result.

Some years back, when I shot factory coated bullets in a .222, I ran into a problem caused by accumulated powder fouling that caused me to stop using coated bullets. If I had known that I could have cleaned more conventionally,and still had the benefit of the coating, I would have avoided the problem, and might be still using those bullets.

The other reason that I probably stopped is that I started playing around with other brands of bullets, in my 6PPC, and I didn't want to tool up for coating. These days, I would want to play with HBN. I don't know what the results would be, but I do find it interesting. Friends who have played with this as a bullet coating tell me that the coated bullets are so slick that you have to pay more attention to how you pick them up.

 

[mikecr]

I think the potential life of a 6PPC is affected by these in order:
1. Performance expectation
2. Shot rate
3. Pressure

Frequent cleaning might increase life, if life actually comes down to carbon impingment/restriction. I don't know. But it's always seemed illogical those claims that barrels are killed by 'overcleaning'...
I haven't seen this either.

Anyway, just adding another view.

 

[fdshuster]

mikecr: I was also concerned about muzzle crown damage on the 6ppc when it had 2410 rds. fired, and before setting back and re-chambering. Checked it with the Hawkeye and to me it looked as new, but asked the 'smith to also check it out & re-cut the crown if he thought it was necessary. It was not, left untouched, and continues to shoot extremely well. So much for the idea that the cleaning rod exiting the bore will damage the crown at the 6:00 position. In this case it did not.

 

[SS427]

Boyd, I think I understand now. If you were to hold the 6BR to the same accuracy standard as the 6PPC barrel, they would wear out at about the same rate. So in reality they will both last about the same number of rounds for what I’m currently doing. That is useful information to base my next rifle buying decision on.

I tried H322 in my 6BR (13.5 twist) and couldn’t get it to shoot. I got much better results with N133. Did you encourage these guys to use H322 because it is easier to tune? I’m a little confused as to why you wouldn’t just have them use N133. I don’t think you answered my original question: Is N133 hard on barrels?

I’ve tried 68 grain Bergers in my 6BR and they don’t group worth a darn. I loaded them at the lands only to date. Is there a secret to getting them to shoot better? My go to bullet is the Sierra 70 gr match bullets. This spring I plan to try some Barts or Brunos.

I’ve started shooting in less than idea conditions and while I can’t say I can read the wind and know what it will do to the bullet, I will say I can identify and wait for similar conditions. I always preload…I know rookie move, but I don’t have enough room in my car to haul all the crap I currently like to take, let alone reloading gear. I may have to bite the bullet and start driving my truck to the range.

Frank - as always useful information. 1800 rounds sounds pretty good. I found your comments about the group size difference between the .272 and .262 necks in another thread very interesting. Seems like I’ve read some of the PPC shooters are switching to a .268 and .269 neck. Any opinion on that? I too exit my cleaning rod, so I like what you had to say about that too. I will probably be sending you an email picking your brain again. I know I haven’t emailed you in a while, but I don’t like to pester you. I suspect quite a few people ask you questions.

None of the guys at my range are serious about small groups, so I never really know how mine compare to what can be shot. I’ve attached my latest effort, which is a little better than typical. Any comments on that would be appreciated.

 

[BoydAllen]

Where were you on seating depth on the Bergers? I chose 322 to start because I knew that it would shoot well, and possibly be less affected by the powder being exposed to varying humidity and temperature. Another thing...I have heard that 133 likes humidity and can get squirrelly (sp?) when the humidity drops below a certain level. Local conditions run on both sides of that line, and I like to keep it as simple as possible for a new shooter. Tune up a load, an spend a lot of time at the range learning to speak flag. While I am at it, just exactly how do you work up a load...from scratch?

Nice groups...flags?... loading at range?
Friends with slow twist BRs have found that under good conditions they can beat Sierra 70s with custom bullets. Their groups were similar to yours. You may have more there than you realize. That is why I asked about the work up. I know the Bergers shoot. I have seen them do it many times in many rifles. How low did you start with the 322, and how far up did you go? How big were the changes that you made in charge weight.

 

[SS427]

Groups were shot with simple ribbons mounted on a dowl. All my ammo is loaded at home from the day before to weeks ahead of time.

I was loading the Bergers at the lands, using a Hornady gauge to find the lands. I never backed them off or jammed them, but did try a number of powders including N133, N135, and Varget. I varied the powder weights up and down, and even ventured into some hot loads that didn't show any signs of pressure. Similar results with all of them. I double checked my records and discovered I never tried H322 with the Bergers. I'm sure I made that decision because H322 didn't work that great w/ three other bullets (Sierra 70 grain match, SBK and Nosler BT - 28-30 grains of powder) and the Bergers were not shooting w/ the three powders I tried. I only beat my head on a wall for so long, and since the Sierras were shooting much better, I went that route.

The Sierra 70 grain match bullets with H322 and Varget were shooting in the 3s and nothing much better. With N133 and N135 I started getting groups in the 2s and an occasional group in the 1s, while still getting a few in the 3s. I seat these at the lands. I tried backing them off .005 and jamming .005 and the results were not as good. I tried 25 of each and the 5 group aggs was not as good.

My 70 grain Sierra match 6BR load came Frank Shuster. (He suggested the same with the Bergers as a starting load.) He recommended starting at 30 grains w/ N133 seated at the lands. I tried going up and down in powder charges w/ N133 and his recommendation of 30 grains just worked from the very start. I've never tried a ladder test, if that is what you are asking. As for other rifles I've developed loads for, yes, I start from scratch with some general advice regarding powders and bullets.

 

[BoydAllen]

Looks like you got some good advice on the load for the Sierras. Good for you on the ribbons and dowels, now if we can just get you to try loading at the range
I have had good luck with the Bergers with land marks on the bullets that are about one third as long as wide. Loading at the range is easy, and it lets you try a lot of ideas in a short period of time. With my bench rifle, if the wind is easy, i have enough confidence in my rifle to test with 2 shot groups, until something looks interesting. This, after I have run a one shot per charge pressure accuracy test, on the same target, shooting carefully, starting low, with .3 gr. charge changes.

 

[rain164845]

How do you load at the range and get accurate measurements on your scale with wind?
Joe

 

[BoydAllen]

I am able to throw the powders that I use with my 6PPC. When working with with powders that have larger grains, usually when helping friends work up loads for their hunting rifles, I have what I call a scale wind box. (my own design, built by a friend)It has a sliding glass front cover. The trickler is inside with the scale but its handle sticks out the side.

 

[rain164845]

ah! That's nice. Good idea too.
Joe