Home Forums Hunting & Shooting Competitive Shooting 1000 yd BR - Ruined the Throat

Brian,

I have a LW barrel on my 338 Win, and it seems very sound. I haven't had significant throat movement in over 580 rounds. I think with the Stoney Point, the seating depth has increased .006 to .008" over that time, and most of that was probably just the sharp edges of the rifling smoothing up a bit. Now I still haven't found a load that I am happy with, but if I were to accept 2600-2650 fps, this barrel will shoot 225 grain Partitions into 1/2" 3-shot groups. I have still not found the majic woth 225 grainers at 2800 fps, but it must be there somewhere..........

Celt has done a bunch of testing with LW barrels. Based on his own research and experience, he says it is not uncommon for a factory barreled 300 RUM to not shoot well after 600 rounds. The last I talked to him about it, he said a LW barreled 300 RUM was still shooting well after 1200. Both John Ricks and Celt have told me LW barrels are made of a harder steel than many.

The biggest thing I wish I had done different on my 338 was buy my own reamer, one made to John's specs--I really like how John has his reamers ground.

Blaine

Flinch,

Good points. I don't really disagree with you (much), but the context is important. Let me try to be more accurate (pun intended) <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Maybe you'd feel better if I called this an "erosion of rifling" or just a "change in seating depth". Maybe the term "throat erosion" is better left to a description of the throat's actual condition (IE, rough and full of minute cracks) as opposed to how I am using it, which is a description of the rifling wearing away near near the throat area causing a corresponding increase in bullet seating depth. If that is your point, then it is well taken, but don't let that go to your head too much <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />. Of course, then the title of this thread gets kind of long: IE, "1000 yd BR, Huge Change in Seating Depth Due to Excessive Wearing of the Rifling Immediately in Front of the Throat and Thus Ruining the Barrel for 1000 yd BR Competiton in it's Present State".

Now, if I borescope this barrel I would not expect to find the cracked and rough throat area one often finds after a couple thousand rounds. And like I posted already in this thread:



However, in a 1000 yd BR rifle, which is the context of this thread, you just cannot use a barrel that increases bullet seating depth .300" per match. And I can promise you the rounding of the rifling's edges does not account for anywhere near .300". I have seen .010" even .020" right off the bat, and I have always expected that was the rounding or smoothing of the front edges of the rifling you mentioned. However, bullet seating depth increases usually slow dramatically after that. Other shooters have related similar experiences in this area. But .300" just a rounding of the rifling? Maybe in a 155mm Howitzer........

The level of precision in these rifles often requires bullets either touching the lands or very close, and that is no longer possible with the 6mm barrel in the shape that it is in. 1/2" 5-shot groups at 100 yds with extreme velocity spreads of 50+ fps does not cut it here. The first thing the guys I was shooting with said was "good shooting". The second was, "you need to get you load sorted out. Are your bullets touching the lands?" More than one guy asked me that.

If I were to recut this chamber and keep using this barrel in 1000 yd BR, why should I expect the bullet seating depth to NOT increase the next match like it did the last?

Now, the last 10 shots out of this barrel did go into 12" at 1000 yds, and who knows, that may still translate into 1/2" or better 3-shot groups at 100 yds. If I were using this as a hunting rifle--which was the original intent--I may still be shooting it. So in the sense of it's usefulness as a hunting rifle, the barrel is not really "ruined." However, a 12" 10-shot group in 1000 yd BR is below average.

I agree, we have all shot rifles with so many rounds through them not only could you not get the bullet close to the lands, there's wasn't much left at the muzzle either. And yes, many of these rifles shoot well for their given application. Chances are these weren't 1000 yd BR guns. A common sentiment for 1000 yd rifles is something "wow, that barrel has lasted in excess of 1500 or 2000 rounds and is STILL shooting well. Amazing".

Anyway. I'll think about using the term "throat erosion" a bit differently. Then again, I may stick with it just to keep spinning you up..... <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />

Blaine,

if you'd like to get rid of that worn out barrel, I'd be glad to pay the shipping if you'd like to send it to me... <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

Blaine,

Talk to one of your jet engine mechs, and see if he'll run a boroscope down your barrel. Given the nature of the Air Force, they may even have the type that you view on a small TV and perhaps you can even record it on a VCR. The CG hanger were I used to work has that set up, I bet your guys have something better.

Oh great, thanks Flinch........now where am I suppose to get my deals on "shot out" barrels? Leave Blaine alone so I can pick up his scrapes. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

I hunted last weekend with a big game guide from Australia that also does cull hunts in the outback where they shoot thousands of rounds a day and his comments mirrored yours. If anyone is hard on equipment it would be him, it took him 45,000 rounds to finally wear out a Remington 700 extractor on a .308..................and they said it couldn't be done.

Beat me to the punch. I could go shipping + 25 <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> dang junk barrel. Bet it'd be hell on crows with 55g B Tips.

Spike, how did that barrel look after 45,000 rounds? Was the "throat" advancing on it? You can have his shot out barrels. I think they have been cleaned to death, rather than shot to death <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

Blaine, I just attended a BR match as a spectator. I talk to a LOT of the shooters about barrel life etc. EVERYONE of the competitors get 1,000-1,500 rounds out of their barrels before they are no longer competative. That doesn't mean shot out, that means they don't hold 5 shot groups lower than in the 2's. But your throats are severly advanced and shot out at 200-400 rounds. You are doing something wrong buddy. Perhaps cleaning them wrong or too much. Something is amiss here. Flinch

Flinch, what kind of barrel were each of the competitors using?

Flinch,


"Something is amiss here." That is what I am trying to sort out. Most of the 1000 yd guys seem to get at least 1500 rounds before the accuracy goes away. Most have very little throat lengenthing.

I am a bit suspicious of using Rem Bore Cleaner, but Krieger themselves says abrasives are okay. However, I plan on using RBC much less. Most of the guys here only use it when the barrel becomes excessively fouled.

I am also becoming paranoid about using a tight patch, though it seems a stretch to think a tight patch could wear out rifling at the throat........

Not to many guys use Pac-Nors, and many seem to feel Lilja's are also a bit soft. Kriger, Broughton, and Hart are commonly used and all seem to have good life.

No one shoots a 6mm Rem, the thought is it has too much case capacity for it's bore size. Alos, maybe I was pushing it too hard........

Also, the barrel contours ar heavier, and my 6mm barrel become hot after each of the three 5-shot strings in light gun, and very hot after each of the three 10-shot strings.

The 6.5x284 Krieger barrel I have now doesn't get anywhere near as hot after a 5-shot string as the 6mm barrel, and after the first 48 rounds, the throat has only advanced .005" (ish), which is what I expect is the rounding of the rifling.

You know, I thought I had all this sorted out several years ago when the Sendero in 300 Win I had went 825+ rounds with only about .010" of throat movement. Also, I had almost convinced myself that the 7 mag's .040" would have been okay if I had just not shot five-shot strings with it.

I'll have a borescope to use NLT Sat 12 Feb, and I'll post what I see.