pavman Posted September 14, 2009 Report Share Posted September 14, 2009 Friend of mine just called to say his Sako 85 has got to be cut back as the barrel swelled on the crown and they had to heat it to get the mod off, he was taking the mod off for a gen clean and found it hard and fast, took it to the smithy who said most likely cause was over oil which ignites and does the damage, anyone else had this Quote Link to comment Share on other sites More sharing options...
alexm Posted September 14, 2009 Report Share Posted September 14, 2009 Friend of mine just called to say his Sako 85 has got to be cut back as the barrel swelled on the crown and they had to heat it to get the mod off, he was taking the mod off for a gen clean and found it hard and fast, took it to the smithy who said most likely cause was over oil which ignites and does the damage, anyone else had this Not had this myself, but I was told the reason over oiling can cause this is because the bullet pushes a ring of oil up the barrel until such a point that it tries to overtake this ring, forcing it outwards at the same time a causing a pressure build up behind the bullet. Quote Link to comment Share on other sites More sharing options...
TheHunter Posted September 14, 2009 Report Share Posted September 14, 2009 I don't think i have missed anything as there are only two entries on this thread but why have you still got oil in the barrel when firing? Having oil in the barrel can cause a huge number of problems least of which is over pressure in the chamber leading to possible lethal results. Got away lightly me thinks. Quote Link to comment Share on other sites More sharing options...
Treestalker Posted September 15, 2009 Report Share Posted September 15, 2009 A mate of mine shot a 150grain bullet down .308 Sako barrel that was full of WD40. The bullet eventually pushed past the oil and left a ring-bulge that looked like a large marble was lodged halfway up the barrel. It also split the barrel between the holes where the rear sight had been attached. We were culling deer in a park when it happened and both the shooter and the deer lived to tell the tale. Don't ever know where the bullet went. The .308 shooter just forgot to remove the oil before going shooting. Quote Link to comment Share on other sites More sharing options...
Suffolk shooter Posted September 15, 2009 Report Share Posted September 15, 2009 Its called "dieselling" and hence why manufacturers recommend pushing a "lightly" oiled patch through. Not as uncommon as you think, but does tend to occur over a period of time rather than a one off. For that you'd need a serious amount of oil in the barrel Can happen in air rifles too. SS Quote Link to comment Share on other sites More sharing options...
manton Posted September 15, 2009 Report Share Posted September 15, 2009 Leaving the quantity of oil in a barrel required to produce bulges is just sheer madness. A high velocity bullet sees oil almost the same as an obstruction caused by mud or other thick substance in the bore . Disselling is rather different as the oil ignites under pressure similar to the action of a diesel engine but the pressures produced would not be high enough to damage a rifle barrel although they are high enough to damage the cylinder and piston in an air rifle. Quote Link to comment Share on other sites More sharing options...
Rem223 Posted September 15, 2009 Report Share Posted September 15, 2009 Its called "dieselling" and hence why manufacturers recommend pushing a "lightly" oiled patch through. Not as uncommon as you think, but does tend to occur over a period of time rather than a one off. For that you'd need a serious amount of oil in the barrel Can happen in air rifles too. SS Dieselling as I understand it in a (spring powered) air rifle is caused by ignition of low flash point lubricant as the air is heated by compression. The "dieselling" occurs behind the pellet. In the case of a centrefire rifle as Manton points out above the oil is causing an obstruction in the barrel in front of the bullet. Like this fine example... http://www.jesseshunting.com/forums/medium...rel-blowup.html Go easy on that oil! Quote Link to comment Share on other sites More sharing options...
TheHunter Posted September 16, 2009 Report Share Posted September 16, 2009 We are not looking at "dieselling" here we are talking about "Hydro-static lock" Where a liquid which can't be compressed is trapped by an energy force. The weakest point in the equation will give way, that could be barrel, bolt or even chamber if the bullet doesn't have a chance to leave the case. Quote Link to comment Share on other sites More sharing options...
DaveK Posted September 17, 2009 Report Share Posted September 17, 2009 Easy to avoid. After cleaning and before using it run a patch soaked in meths down the barrel. Then run clean patches through it until they come out dry. Hey ho, no oil up the barrel and fewer fouling shots needed to bring back to zero. Quote Link to comment Share on other sites More sharing options...
covlocks Posted September 17, 2009 Report Share Posted September 17, 2009 A recipe for corrosion - cleaning the barrel with meths and then pulling through until its dry. All is need after cleaning is a pull through with a very light oiled patch. Leaving a wet barrel is asking for it. I have seen a 762 barrel split because the guy who cleaned it thought he was doing good by drenching it in oil to protect against the rain. The barrel looked like an unzipped banana skin being held by a very ashen faced person. Very scary. Quote Link to comment Share on other sites More sharing options...
covlocks Posted September 17, 2009 Report Share Posted September 17, 2009 (edited) Double posted ..... Edited September 17, 2009 by covlocks Quote Link to comment Share on other sites More sharing options...
ferretmanabu Posted September 18, 2009 Report Share Posted September 18, 2009 What about just using a bore snake without oil? Quote Link to comment Share on other sites More sharing options...
MC Posted September 18, 2009 Report Share Posted September 18, 2009 Why oil the barrel at all? If you put oil up the spout at some point you will forget to dry it out before firing it and then you ask for trouble. On my 7.62 target rifle the barrel gets scrubbed out and swabbed until the patches come out as clean and dry as they went in. Then I out it away in the cabinet. I have a couple of the oil vapour tins that engineers used to used in the tool cupboards to prevent rust in my cabinets and I have never had an issue with rust on any metal parts of any of my guns. And that includes the one I use on the marsh. Quote Link to comment Share on other sites More sharing options...
Dunkield Posted September 18, 2009 Report Share Posted September 18, 2009 Why oil the barrel at all? Quote Link to comment Share on other sites More sharing options...
garyb Posted September 18, 2009 Report Share Posted September 18, 2009 Why clean it at all Quote Link to comment Share on other sites More sharing options...
DaveK Posted September 18, 2009 Report Share Posted September 18, 2009 (edited) A recipe for corrosion - cleaning the barrel with meths and then pulling through until its dry. So that's why that method is very widely recommended by some of the best respected shooters. :good: Read it again. After cleaning and before use, run it through with meths. Which part of "After cleaning" do you find difficult to understand? Edited September 18, 2009 by DaveK Quote Link to comment Share on other sites More sharing options...
Dunkield Posted September 19, 2009 Report Share Posted September 19, 2009 Why clean it at all :blink: So you don't get pitted cartridge cases Quote Link to comment Share on other sites More sharing options...
covlocks Posted September 21, 2009 Report Share Posted September 21, 2009 So that's why that method is very widely recommended by some of the best respected shooters. Read it again. After cleaning and before use, run it through with meths. Which part of "After cleaning" do you find difficult to understand? Well friend, after 30 years of owning, shooting and cleaning all sorts of weapons in the military, and sporting guns as a civvy, experience says after cleaning, pulling through with meths is a definate recipe for corrosion. I haven't seen all manufacturers recommendations, but would be interested to know how many say, clean it, oil it, and then pull it through with a jag soaked in meths. Even in a warm dry atmosphere, a dry barrel will corrode as there will "always" be an element of carbon residue in the barrel after cleaning. Carbon and steel just love to set up a nice little reaction which ends up with pitting, so that little coating of oil just excludes the air which is a necessary contributor to the corrosion. If you only put a little in, there is no need to pull through with meths. Quote Link to comment Share on other sites More sharing options...
DaveK Posted September 21, 2009 Report Share Posted September 21, 2009 Well friend, after 30 years of owning, shooting and cleaning all sorts of weapons in the military, and sporting guns as a civvy, experience says after cleaning, pulling through with meths is a definate recipe for corrosion. I haven't seen all manufacturers recommendations, but would be interested to know how many say, clean it, oil it, and then pull it through with a jag soaked in meths. Well experienced then. Well so am in a similar fashion so not really impressed with your claims there, sorry. Military service and firearms maintenance just doesn't impress me at all Cleaning weapons in the military is as much about ******** as it is about cleaning weapons. And who mentioned manufacturers recommendations? If you follow their blurb you'd never use your rifle. Even in a warm dry atmosphere, a dry barrel will corrode as there will "always" be an element of carbon residue in the barrel after cleaning. Carbon and steel just love to set up a nice little reaction which ends up with pitting, so that little coating of oil just excludes the air which is a necessary contributor to the corrosion. If you only put a little in, there is no need to pull through with meths. You no read (or can you?) I said pull it through with meths BEFORE USE. So are you saying that for the duration it is being used it will corrode? Watch my lips. Clean and oil it but before use run a meths coated patch through it followed by as many dry clean ones as it needs to have them come out dry and clean. You are now shooting a dry barrel. It should take less fouling shots to get back on target. In fact if you zero with a clean dry barrel it should be on zero anyway. :yp: Quote Link to comment Share on other sites More sharing options...
garyb Posted September 21, 2009 Report Share Posted September 21, 2009 So you don't get pitted cartridge cases :yp: Maybe..... although there's nothing wrong with the bore Quote Link to comment Share on other sites More sharing options...
covlocks Posted September 22, 2009 Report Share Posted September 22, 2009 If you only put a little in, there is no need to pull through with meths. I would say the same "watch my lips" but that would be stupid, dragging myself down to your level. Quote Link to comment Share on other sites More sharing options...
DaveK Posted September 22, 2009 Report Share Posted September 22, 2009 I would say the same "watch my lips" but that would be stupid, dragging myself down to your level. You've no idea what my level is but, believe me, you've dropped well past it. Enough. We're derailing this topic. Quote Link to comment Share on other sites More sharing options...
Paul223 Posted September 22, 2009 Report Share Posted September 22, 2009 This sounds like your friend has been oiling his moderator, which in turn has run a little in side the very top of the barrel, leading to hydro whatsit static something at the very end where the threads are, it is an idea to rotate the mod a few times over an hour or so after spraying oil inside to allow it to coat the inside of the mod and save the oil pooling I oil before putting away and dry patch out 'clean' before shooting, to remind myself a small rag is stuffed into the chamber with the rag tail out the action, stops any excess oil seeping into the wood work too. Quote Link to comment Share on other sites More sharing options...
manton Posted September 22, 2009 Report Share Posted September 22, 2009 In regard to cleaning a firearm with meths. Alcohol will remove all traces of protective oil and if there is any temperature changes in where the gun is stored a thin layer of water will form on the chemically clean metal which will cause rust and pitting . Quote Link to comment Share on other sites More sharing options...
TheHunter Posted September 22, 2009 Report Share Posted September 22, 2009 I am going to have to jump in on the side of DaveK here. Cleaning your barrel with an alcohol or petroleum based solvent "JUST BEFORE" firing is ideal. HOWEVER Leaving a barrel free of oil for an extended period isn't. I think the fulcrum here is the time frame, the removal of residue\protective oil just before use and not before storage. TH Quote Link to comment Share on other sites More sharing options...
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