Gonna Shoot a Wabbit Posted June 12, 2015 Report Share Posted June 12, 2015 (edited) Ey up pigeonwatchers I have a CZ550 in .243 that i have owned for 4 years now if i remember right. I use it for stalking, foxes and informal target shooting on our own ranges on land i shoot over. I bought it second hand and it was used exclusively for target shooting before i got it. it has given those years of faithful service so far with many foxes and deer brought to book. When i have shot targets i have never shot more than 4 or 5 shots without letting the barrel cool and i have cleaned the bore every 50 shots or so. i have fired approx 1000 shots through it. When i first got the rifle bullets damn near through the same hole at 100yds were possible if i did my bit but sub 1" groups were a cert. 4 shots would group nicely before the barrel heated up with the inevitable spread to follow. Ok some 4 years on i have noticed that cold barrel shots are on target but after shots 2 the groups open up. I have checked the usual culprits like bullets ( i am using the same reload i have always used), stock bolts, scope mounts, bipod clamp, mod is tight, etc etc. My shooting partner in crime dead eye duck has watched me shoot and i do not flinch, PARANOIA is certainly possible but To my eye it looks to me like my barrel is getting tired but this is my first centrefire rifle so i hope those with more experience can advise if this sounds the case? and if so who these days are recommended for a replacement. Many thanks GSAW Edited June 12, 2015 by Gonna Shoot a Wabbit Quote Link to comment Share on other sites More sharing options...
Underdog Posted June 12, 2015 Report Share Posted June 12, 2015 What is the crown like? Has the mod been left on and some corrosion got to the crown? Quote Link to comment Share on other sites More sharing options...
Dekers Posted June 12, 2015 Report Share Posted June 12, 2015 Who knows, but if it shoots well first shot the glib answer is who cares, how many shots do you need when after the fox or deer? Re barrelling is not uncommon but generally not cheap either, for many it is just as cost effective, or more so, to PX the rifle and start again altogether. Quote Link to comment Share on other sites More sharing options...
Rem223 Posted June 12, 2015 Report Share Posted June 12, 2015 If the barrel is on its way out, the first thing I have noticed is when you push a bore brush into the barrel. The initial part of the barrel is much tighter than the rest of the barrel where the erosion has pitted the throat. You might be able to see it if you have a good light, but really the only way to be sure is with a borescope. You may be able to get away with a thorough cleaning and get a bit more life out of it. However you dont know how many rounds the previous owner has put through it, and you say you have put a thousand rounds through it. I would say its toast. Quote Link to comment Share on other sites More sharing options...
Harnser Posted June 12, 2015 Report Share Posted June 12, 2015 The .243 is a hot round and will in some cases erode the barrel . A badley eroded barrel can be seen with a bore light . You don't say how inaccurate the rifle is shooting at the moment . If it will still hold a two inch group at 100 yards then you have more than enough accuracy for shooting deer . If it is worse than that ,then you need to be changing it . Harnser Quote Link to comment Share on other sites More sharing options...
Grandalf Posted June 12, 2015 Report Share Posted June 12, 2015 I must agree with Harnser on this one. I know it is nice to put neat little holes in a piece of paper but, at the end of the day, it is a hunting rifle. Years of life still in it if you can keep it sub tennis ball size at up to 150 yards. Good for fox and deer. Quote Link to comment Share on other sites More sharing options...
Bewsher500 Posted June 12, 2015 Report Share Posted June 12, 2015 lot of speculation and conjecture on the life of an unknown barrel round count alone doesn't kill barrels even over bore ones like .243 shot strings at targets, hot loads, double base powders, very high MV's with long bearing surface bullets all count towards poor bore condition the easiest and most likely culprit is throat and lead erosion, fire cracking and erosion of the initial lands to be honest though barrels that display poor accuracy as a result of these normally display it with every shot not after the first two. walking groups with hot barrels can often be a physical issue between barrel and stock that has come about with age, especially wooden stocks that have had bipods used or constant and regular action removal/bolt tightening. if your throat is eroded just work up some loads at different lengths again and test them if you think your accuracy node is 30 thou off the lands and you have eroded them back 20 thou......you are now at 50 thou with irregular lands...but like I say that would normally show in the first two shots not being close as before Also I dont get the comment of cleaning rods being tighter in the initial insert...they tend to be slacker due to the pronounced erosion in the throat...unless of course you are describing putting the patch in the muzzle end first!! Quote Link to comment Share on other sites More sharing options...
welshwarrior Posted June 12, 2015 Report Share Posted June 12, 2015 The .243 is a hot round and will in some cases erode the barrel . A badley eroded barrel can be seen with a bore light . You don't say how inaccurate the rifle is shooting at the moment . If it will still hold a two inch group at 100 yards then you have more than enough accuracy for shooting deer . If it is worse than that ,then you need to be changing it . Harnser The man talks sense. Quote Link to comment Share on other sites More sharing options...
Rem223 Posted June 12, 2015 Report Share Posted June 12, 2015 Also I dont get the comment of cleaning rods being tighter in the initial insert...they tend to be slacker due to the pronounced erosion in the throat...unless of course you are describing putting the patch in the muzzle end first!! Well you may not be able to grasp it but I had a shot out .17 Remington barrel that did exactly as described by the OP. A cleaning brush was significantly tighter in the throat area. I take your point that round count may not necessarily be the final arbiter, but neither you nor the OP know how many rounds were shot through the rifle before it came into the OP's possession. As I pointed out a bore scope would be the best option for examining the bore, but if it were my rifle I would be saving for a new barrel. Quote Link to comment Share on other sites More sharing options...
ZG47 Posted June 12, 2015 Report Share Posted June 12, 2015 Sounds like a warm barrel touching the stock. When a steel tube heats up, it lengthens. If you machine a barrel with taper to the muzzle and give it a minimum of free floating, lengthening of the barrel due to combustion heat can result in sideways pressure on the stock. That is why Paul Mauser changed from tapered barrels to stepped barrels and left a bit of longitudinal clearance in the stock at each point where the barrel diameter stepped down. Simple physics. Quote Link to comment Share on other sites More sharing options...
Redgum Posted June 12, 2015 Report Share Posted June 12, 2015 It may be worth starting again with the reloads, go back 10% and go up in 0.5 increments, its quite possible that a new batch of powder could be to blame, how many times have you used the brass ? Give the rifle a good soak with a good copper solvent like patch out, keep cleaning until patch is coming out clean. Check scope and barrel touching etc as mentioned above. Quote Link to comment Share on other sites More sharing options...
Bewsher500 Posted June 13, 2015 Report Share Posted June 13, 2015 Well you may not be able to grasp it but I had a shot out .17 Remington barrel that did exactly as described by the OP. A cleaning brush was significantly tighter in the throat area. I take your point that round count may not necessarily be the final arbiter, but neither you nor the OP know how many rounds were shot through the rifle before it came into the OP's possession. As I pointed out a bore scope would be the best option for examining the bore, but if it were my rifle I would be saving for a new barrel. OK fair enough but what would make it tighter at the throat? I can see it being rougher and feeling that way but I can not think of a single reason a throat or leade would get tighter Quote Link to comment Share on other sites More sharing options...
Gonna Shoot a Wabbit Posted June 14, 2015 Author Report Share Posted June 14, 2015 Thanks for your comments gents. the crown is in good order the barrel is free floated to the point that a thick piece of paper slips from the action all the way between the barrel and the stock ( should i enlarge it so that a thin piece of card slips through?) i have recently checked the OAL of the rounds that i reload and they are 15thou off the lands My recipe of 45grains of vit 160 for a 75grain bullet seems fine Group sizes at 100yds is an inch for shots 1-3 then they go wayward, so as harnser says i am happy with cold barrel shots on deer etc, but if the barrel is on the way out i would rather start saving before something horrible happens with a deer in the crosshairs and it aint pilot error I am on reload No7 (approx) of the current batch of cases i am just starting to get neck splits upon resizing This rifle has a nice piece of walnut on it and the trigger is sweet so i would rather get a new barrel rather than getting rid Quote Link to comment Share on other sites More sharing options...
Underdog Posted June 14, 2015 Report Share Posted June 14, 2015 (edited) The brass is getting on a bit then! But the first three are grouping. That says to me the barrel is OK but heat is making it walk. Remove the barrelled action and look for bright spots where the barrel has been touching the stock. I have never been pleased with clearance for just paper. 1/16"-1/8" clearance if I am having a floating barrel, especially wood. Your barrel will be quite hot by shot three and any slight movement towards the stock will change the harmonics on firing thus opening the group more than the original barrel/heat deflection......maybe! Edited June 14, 2015 by Underdog Quote Link to comment Share on other sites More sharing options...
welshwarrior Posted June 14, 2015 Report Share Posted June 14, 2015 Got to agree if you can't slide a piece of cereal packet between stock and forend it's a bit tight for my liking. Quote Link to comment Share on other sites More sharing options...
Bewsher500 Posted June 14, 2015 Report Share Posted June 14, 2015 Especially if you use a bipod Stock design now does nothing for integrity under load and you may be closing that gap considerably when shooting, increased as barrel heats up and moves Quote Link to comment Share on other sites More sharing options...
Harnser Posted June 14, 2015 Report Share Posted June 14, 2015 I think you are worrying about nothing . If your gun will shoot MOA at 100 yards then you have an accurate rifle for shooting deer and foxes. There are many who would like to have a rifle that will shoot that accurately . Carry on with it and enjoy . When it won't hold 2 inches at 100 yards then think a bout changing it . The gun has a long way to go before it becomes inaccurate and useless . Harnser Quote Link to comment Share on other sites More sharing options...
Gonna Shoot a Wabbit Posted June 14, 2015 Author Report Share Posted June 14, 2015 The brass is getting on a bit then! But the first three are grouping. That says to me the barrel is OK but heat is making it walk. Remove the barrelled action and look for bright spots where the barrel has been touching the stock. I have never been pleased with clearance for just paper. 1/16"-1/8" clearance if I am having a floating barrel, especially wood. Your barrel will be quite hot by shot three and any slight movement towards the stock will change the harmonics on firing thus opening the group more than the original barrel/heat deflection......maybe! Got to agree if you can't slide a piece of cereal packet between stock and forend it's a bit tight for my liking. Especially if you use a bipod Stock design now does nothing for integrity under load and you may be closing that gap considerably when shooting, increased as barrel heats up and moves Okly Dokly, when i next clean the rifle i will increase the gap accordingly. The brass doesnt owe me anything and if the above stock adjustment doesnt cure things then i will get a new batch of brass. I think you are worrying about nothing . If your gun will shoot MOA at 100 yards then you have an accurate rifle for shooting deer and foxes. There are many who would like to have a rifle that will shoot that accurately . Carry on with it and enjoy . When it won't hold 2 inches at 100 yards then think a bout changing it . The gun has a long way to go before it becomes inaccurate and useless . Harnser Thanks harnser, that puts my mind at rest a little. I will keep a weather eye on things and use this as a benchmark Quote Link to comment Share on other sites More sharing options...
Underdog Posted June 14, 2015 Report Share Posted June 14, 2015 I agree that the rifle is still shooting fine. I am only interested in discovering the new trend our friend has described earlier. :-) Quote Link to comment Share on other sites More sharing options...
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