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Gentlemen, I have been a little worried about my 30.06 for a little while now. the concern is that it seemed to shoot less consistently that it did when I first got it ( 4 years and about 1750 rounds ago); not only this but that it threw the first few shots from a clean barrel in all sorts of directions and needed more "fouling" shots than it used to. The groups have opened up lately as well, the rifle tending to throw a flyer type round away from the main cluster, but not bar very far admittedly. I've given it a clean to within an inch of it's life, solvents, bore foams , JB paste, you name it and I've probably used it. I took it to a friend with a bore scope and looking through it it was apparent that there was a bit of pitting in a few different sections of the barrel together with about2-3mm of fire-cracking in the beginning of the throat. The good news was apparently that I had indeed managed to clean it back to bare metal... In the opinion of the learned gentlemen here, is that what is causing the need for fouling shots and the reduction in accuracy? In what ways does pitting in the bore or fire-cracking in the throat affect a barrel's performance in general? | ||
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In the most basic of explanations, a rough bore will remove material from a bullet in such an uneven manner as to affect the flight of that bullet by forcing it to spin lopsidedly around it's axis. If the material or fouling is allowed to build with each successive shot, then every bullet that passes by will be affected by varying degree's causing groups to spread. _______________________________________________________________________________ This is my rifle, there are many like it but this one is mine. My rifle is my best friend, it is my life. | |||
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Do you have any idea of how deep the pitting actually is? And what the actual groove and bore diameters were when it was new? The reason I am asking is I am looking forward to possible cures...IF the barrel is the actual cause of the inaccuracy that age seems to be bringing to your rifle. If the pitting is a little bit of "frosting" rather than full-blown pits, and IF the bore/groove dimensions are still relatively tight, then I'd suggest lapping the barrel a bit just to see if that might help. It might, it might not. And if the barrel still has a groove diameter under .3086" or so, I might try two lapping sessions, the second more "vigorous" than the first, and only applied if the first didn't help. And after lapping, I'd try some of the larger .308 bullets on the market. (Some brands stay right around .308", while others run .3085" or larger.) If the barrel IS the problem, which it may very well not be...we haven't explored that possibility yet...and if lapping didn't work, I'd say you still have three more options. One, of course, is to rebarrel. A second is to rebore to something like 8mm/06 or .338/06, or even just .303/06 to clean the barrel up. The third is, decide whether your hunting and shooting really needs a more accurate barrel. If you just use it for deer hunting, unless you are in your twenties or early 30s, I'd suggest "Don't worry about it!!" It'd take a heck of a lot of pitting (more like pot holes) to make a 3.5 or 4 MOA rifle out of it, and even that is still plenty adequate for deer hunting. One thing about the aging of men and rifles is that they do that together, not one of them or the other, and they can do it together gracefully. Neither I nor my rifles are what we were when were younger (newer), but together, with patience, we can still kill deer just tickety-boo. And I can look at my old rifles and admire and appreciate the more than 50 years of service they have given me and the good memories I have of us together in the woods, on the prairies, and up among the hills. | |||
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Great post. Thanks Stephen | |||
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 Ac's got a handle on it. I have some really dark bore Mausers (MIL) That still shoot 3.000" groups at 100 yds. with open sights. If someone shots them that can see the sights and target together they shoot better.  roger  Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone.. | |||
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Thanks guys, AC in particular ( as always chief ).This was my centrefire rifle and I confess I don't think I've taken care of her as I should. The trouble was that she wasn't new when I got her and had been in storage for a while. Not being at all gun savvy I followed the advice of the chap who found the rifle for me and cleaned it only with a dry boresnake for a year to prevent the zero changing between a clean and dirty bore. We can shoot deer 364 days of the year here, with something always being in season, and I was shooting about once or twice a week. It is very difficult here to go and foul a rifle after cleaning and in any event I wouldn't have had the time as I'd rather be hunting. After a year or so of ownership I noticed the groups were opening up and so bought a proper cleaning kit and brushed and patched it down to bare metal before fouling it up and hunting for another season. I tended to clean it about once every couple of months thereafter with a pullthrough if it had been raining. What got me thinking was the acquisition of a brand new Sako varmint that shoots to the same POI whether fouled or clean. The bore of that rifle is as can be imagined absolutely spotless. It seems to me that if a rifle's bore is maintained in as new condition, assuming a fairly smooth finish like one would get from a custom barrel maker, the rifle should shoot to the same POI whether clean or fouled. I have to confess to not knowing the difference between pits and frosting. The marks in my bore looked like little bubbles mainly in the grooves of the rifling. The coverage isn't very large, about a dozen or so patches for maybe up to 5% of the bore in total. I hear you about not needing tiny group shooting ability for shooting game but this used to be a very consistent rifle and I'm a little upset at myself for not taking care of it better. I was unfortunately 30 this year and I would like to hang on to this rifle as it fits me very well and I shoot well with it. Needless to say this and the fact that it's in 30.06 has meant that it has been to three continents with my in 4 years and will probably have been to 5 by this time next year. In short although she's not the most expensive or well finished one can buy, she's a keeper. | |||
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Probably the throat is the problem. It results from use, there is no fix. If youlike the rifle spring for a good quality rebarrel. It will last you for several thousand more rounds. | |||
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With too much magnification any metal surface can appear to have gross flaws. You seem to be overly concerned over the bore being fouled before hunting. Maybe you need to shoot it at targets more to find out if it needs to be fouled or not. Performance at the target is really what you need to use as criteria to determine if your bore is ok. Shoot it and clean it. Keep it clean. Learn to zero the rifle with a clean dry bore. Then make the first shot count. Otherwise you have bought into a life time of allowing bores to slowly corrode. | |||
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Ghubert - Because of where you live, I don't know anything about whether anyone still in business there does any refreshing or reboring of bores (two different things). Here in the states for a variety of reasons, a lot of the folks who used to "refresh" bores have gone out of business. I suspect it is because of a lack of knowledge and too much money in the hands of the great mass of shooters, and maybe also a bit of too effective marketing by the folks who sell new barrels. Some of it is because many of the old gunsmiths/barrelmakers who used to give great personal service here have died of old age. At one time, a lot of the very best rifle barrel makers in this country would refresh barrels...that is, enlarge both bore (land) and groove diameters by a very few thousandths of an inch to eliminate very shallow pitting (otherwise known as "rust frosting"). If the throat was gone, they could either move the throat forward a bit, or if it was too far gone, of course they could set the barrel back a bit before doing the refreshing. There ARE still some folks in this country who rebore barrels as opposed to refreshing them. Usually, though, they don't want to go to the trouble of setting up their equipment, or don't have the right equipment, to follow the old grooves, so they insist on cutting to a new substantially larger size which takes out all of the old rifling before reboring the barrel, reaming it to exact size, and re-rifling it. Reboring in some ways is a lot easier and quicker (and more profitable) than just refreshing a barrel. And, of course, the quickest and easiest is just to sell, chamber, and fit a new barrel entirely. If anyone in England still does cut rifling the old way in a small shop where they don't cater to masses of customers and still do personal work for folks, from your description of your bore, I would prefer "refreshing" the bore and moving the throat forward to the degree necessary. If I couldn't get that done, then I would prefer reboring, which essentially still can give you the same exact chamber you started with (IF YOU WANT), only with a larger neck. Or you can have it both rebored and rechambered if you want a larger cartridge case while you're "improving" things. Either way the outside of the barrel will look pretty much like what you have now. I tend to develop emotional attachments to old rifles which have served me well, so I like to repair them without changing their appearance much if any. You can always rebarrel, of course, but then you could just buy another rifle too. Whatever you decide, for whatever reasons, it WILL be the best way for YOU, because it will give you something you will feel is YOUR decision, not someone else's. P.S.: Unfortunately your turned 30 this year? What with the state of world peace these days, I'd say that is danged fortunate!! You have 50 or more years on the hill to look forward to, not to mention the glorious 12th each year and a bit of fun with the birds (winged and otherwise)! Tell you what...I'll trade you ages, and throw in everything I have now or ever will have including my wife and daughter (but you HAVE to keep them!), excepting only one rifle and one gun. Let me know when to buy their flight tickets to London.... | |||
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I think this has happened already. I have put around 1750 rounds through this rifle on the target range and maybe 200 more in the field. The shooting characteristics are as described above, for clarity I shall summarise them: 1. On cleaning back to bare metal the rifle needs 5-10 fouling shots (depending on the load) to shoot usual sized groups to point of zero. 2. These cold, clean bore shots do not follow a predictable pattern, ie it is impossible to zero for the first shot. 3. Pitting, not too severe but deep enough to retain carbon if the barrel is cleaned using just ordinary solvent, brushes and patches. 4. Firecracking for ~2mm at the beginning of the throat. 5. Begins to lose accuracy after 50-60 or rounds or a month's average shooting. I'm beginning to think that starting with a new barrel and keeping it as you describe above, as I am doing with the new Sako, is the only real way forward. A peril of buying second hand guns, it seems! | |||
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Hi AC, Thank you for your, as ever, detailed reply. There are two makers of cut-rifled barrels in the UK, Border Barrels and Arthur Smith of Arms Restoration Services. I don't think they'd be interested in re-rifling or refreshing an old Tikka barrel, as much as it means to me it's quite probably not worth their shop time. It is sad to read of the situation in the US at the moment, I recently picked up a copy of Jack O'Connor's "Big Game Rifle" book and can see what you mean about the difference between those old craftsmen and a few of the "gun plumbers" around today. Arthur Smith actually falls into the former category, he's an old boy in Colchester running a one-man workshop with a Pratt & Whitney rifling machine in the corner. He makes all kinds of barrels for the trade and is the man to turn to for an odd or rare size. Unfortunately he seems rushed off his feet with trade orders all the time. It seems that a re-barrelling is going to be the only practical solution. I say it's unfortunate that I turned 30 because like everyone else I never thought it would happen to me!  For various reasons not worth going into, everything in "real life" became very serious rather quickly this year. Not least this bloody rifle! | |||
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Ghubert, Are you shooting moly? I hear and have read that if you shot moly and once you really scrub a bore, sometimes (not all rifles) require up to 10-15 fouling shots before the zero or the groups come back. If not, you could try taking a couple turn off the back of the barrel, rechamber, and get some fire-laping bullets. http://www.neconos.com/details2.htm They normally contain 4 or 5 grit grads but you probably only want to shoot the 3 finest grades. I personally do not fire lap myself, but it is a thought. Barstooler | |||
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The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Gunsmithing The effects of pitting in the bore?
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