auquhollie Posted July 8, 2008 Report Share Posted July 8, 2008 Just found a handfull of R P Brass (remington) last week and thought ide tr them out in the 243 ack. Loaded them up with 43gr of N160 (usual FF load). When i fired them to fire form the brass i noticed a line on the case. Have a look Some of the lines on the cases you can feel with your nail. I fire formed 3 Lapua brass at the same time and they formed fine without any lines. So i guess its the brass not the rifle, but why would this happen ?. Im scared that if i fire them again the case might come apart. Ads Link to comment Share on other sites More sharing options...
Guest northernchris Posted July 8, 2008 Report Share Posted July 8, 2008 Stop being a tight arse jock and bin it and load up some new Lapu brass,so 43.0gr of N160 is your fireforming load what bullet are you running in front of that charge and whats your full power load? Link to comment Share on other sites More sharing options...
Ronin Posted July 8, 2008 Report Share Posted July 8, 2008 If the line wasnt there beforehand on the cases and your chamber is clean, I suggest that the mark is in the chamber and it looks to me like a spec of swarf has found its way bettween the reamer and metal during the final stages of cutting. Its too uniform and circular to be just crud on the brass or chamber I think. If it causes issues with extraction the it could be polished out although that depends on how deep the scoreline (if it is that) is - otherwise recut chamber and all the rest of the machining that goes with it. Maybe there are other ideas? Link to comment Share on other sites More sharing options...
Andrew Posted July 8, 2008 Report Share Posted July 8, 2008 "Found a handful of Remington brass..." as in, of undetermined origin?? I hope not! Never use even once fired brass when forming for a wildcat as things like this tend to happen.~Andrew Link to comment Share on other sites More sharing options...
MarinePMI Posted July 8, 2008 Report Share Posted July 8, 2008 Case head separation. Don't use the brass for your AI, it'll separate and leave you with a half stuck case (possibly) in the chamber. Brass appears to be too hard... I'd also say (if it was virgin brass, which it isn't) that your either bumping the shoulder too far back and/or not seating the bullet into the lands and grooves to allow the case to fill the chamber properly. The case is having to strech forward vs. outward to fill the chamber... YMMV... Link to comment Share on other sites More sharing options...
PeteL Posted July 8, 2008 Report Share Posted July 8, 2008 Ads, Firstly, have you tried the old paperclip routine to determine whether the mark is also inside the case?. If it is, do not use those cases, it may well be that you have a case separation waiting in the wings. Secondly, if the mark does not appear with Lapua cases, it obviously cannot be the chamber. Chuck 'em out, better safe than sorry!. Peter Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted July 8, 2008 Report Share Posted July 8, 2008 as said by someone else its case head separation Link to comment Share on other sites More sharing options...
auquhollie Posted July 8, 2008 Author Report Share Posted July 8, 2008 Ads,Firstly, have you tried the old paperclip routine to determine whether the mark is also inside the case?. If it is, do not use those cases, it may well be that you have a case separation waiting in the wings. Secondly, if the mark does not appear with Lapua cases, it obviously cannot be the chamber. Chuck 'em out, better safe than sorry!. Peter I agree, These cases are brand new, the lapua cases fired on the same session are perfect condition. I think maybe the head wasnt out to the lands and as stated up top the case might have stretched up and not out. Will try the paper clip trick and see, however the cases are being filed under B1N if only to stay on the safe side. I do have Lapua brass sitting here (new) but dont want to fire form them in a chamber that is about to get binned. Ads Link to comment Share on other sites More sharing options...
eldon Posted July 8, 2008 Report Share Posted July 8, 2008 Why dont you just section one for the sake of 2 minutes with grinder/saw/file etc and all will be revealed if only for curiosity. I'm with the ones above, case head separation, close shave. Link to comment Share on other sites More sharing options...
Guest varmartin Posted July 8, 2008 Report Share Posted July 8, 2008 Yep.......your bullets weren't in the lands...... Link to comment Share on other sites More sharing options...
auquhollie Posted July 10, 2008 Author Report Share Posted July 10, 2008 Cheers guys for the replys. Looks like i should have had them out into the lands. Something else ive noticed..... I have been given some brass that is once fired and i wanted to test them out to see how the brass faired. I tried to chamber a case into the rifle (gently) and it wouldnt go all the way. Fireformed to the other chamber i guessed so i went and full lengthed them. They still wont chamber in the rifle. When i chamber the case it seams to go in fine untill the last 4 mm and then it sticks. When you full lenght the case should it re-size right down to the head of the case ? or stop 5mm from the head ?. Ads Link to comment Share on other sites More sharing options...
Redfox Posted July 10, 2008 Report Share Posted July 10, 2008 Normally stops before the head as that part is contained within the bolt head not the chamber. Pistols & Pistol cals with straight walled cases are different. Redfox Link to comment Share on other sites More sharing options...
auquhollie Posted July 10, 2008 Author Report Share Posted July 10, 2008 so why not chamber in the rifle then ?. My own rounds still chamber fine. Link to comment Share on other sites More sharing options...
Guest varmartin Posted July 10, 2008 Report Share Posted July 10, 2008 Does your full length sizer size all the neck ? Does the chambered round show damage to the neck ? Link to comment Share on other sites More sharing options...
auquhollie Posted July 10, 2008 Author Report Share Posted July 10, 2008 Does your full length sizer size all the neck ? Does the chambered round show damage to the neck ? What i done to start with was prep the cases (ie) flash holes. primer pockets and then neck sized the cases. After this i loaded up a few cases to see how they shot. When i chambered a round they would go all the way in. I then tried full lenght sizing them, still no joy. Chambered round doesnt show any sign of damage round the neck at all. ive taken dimentions of a case that chambers fine and the once fired one that wont chamber all the way in. (it will chamber untill the last 5mm). Dimentions are :- ok case (fireformed) neck diam = 0.273 length case = 2.035-5 top of shoulder = 0.455-5 case head = 0.466 bad case (has been full lengthed) neck diam = 264 length case = 2.038 top of shoulder = 0.448 case head = 0.465-5 Link to comment Share on other sites More sharing options...
auquhollie Posted July 10, 2008 Author Report Share Posted July 10, 2008 right, got another pic for ya..... This is a case that wont chamber fully. There is a line appeared on the bottom of the case after it is tried in the chamber. Im guessing that the line is the stick bit were it wont chamber any further ?. Above the line measures = .465 below the line = .466.5 so 1.5 thow bigger below the line. But when i try and full length them further down the case dents appear on the case neck Link to comment Share on other sites More sharing options...
Ronin Posted July 10, 2008 Report Share Posted July 10, 2008 Ads I think, despite my wrong suggestion first. That you should use NEW VIRGIN brass and seat bullets so they crush inmto the lands forcing the case base against the bolt face, you should get perfect fireforming. You also need near max load (in non ackley pre formed brass) DONT SKIMP ON BRASS - not worth it mate Link to comment Share on other sites More sharing options...
auquhollie Posted July 10, 2008 Author Report Share Posted July 10, 2008 AdsI think, despite my wrong suggestion first. That you should use NEW VIRGIN brass and seat bullets so they crush inmto the lands forcing the case base against the bolt face, you should get perfect fireforming. You also need near max load (in non ackley pre formed brass) DONT SKIMP ON BRASS - not worth it mate Im starting to agree, I didnt want to use the Lapua brass as yet as the rifle will be getting re-barreled soon and didnt want the new brass fireformed to this chamber. Bug bugger it, ill just use 25 out of the box and be done with it. Would still like to know why it wont chamber though, for future.... Cheers Ads Link to comment Share on other sites More sharing options...
colin Posted July 10, 2008 Report Share Posted July 10, 2008 just scrap them Link to comment Share on other sites More sharing options...
auquhollie Posted July 10, 2008 Author Report Share Posted July 10, 2008 just scrap them I have but still want to hear veiws on why it wont chamber!!! Link to comment Share on other sites More sharing options...
MarinePMI Posted July 10, 2008 Report Share Posted July 10, 2008 I'll take a stab at it for you... When the round is fired, the case is pushed back while the front is stretched to fit the chamber. In doing so, I'd wager that the brass that is left at the base is so work hardened (and with a weak spot being thin) the base of the shell has expanded but will not spring back. There's not enough material in the weak spot (the ring) to apply the pressure needed for the case to spring back to original shape. Cases are drawn from brass flat stock, which induces a fair amount of stress. Also, when fired, the case is constantly being pushed out. The case is always wanting to open up (to some degree) but the shape and thickness of the brass contain the stress. Now that the brass has been weakened, the case wants to push out, and now can due to the weak thin ring. Hence the base ends up larger, or bulged and will not rechamber (especially a well cut, min. spec chamber). Think of it this way. It's the same principle as having too thin a profile in a barrel at the muzzle end. Stress (induced by the rifling process) pushes out (radially) and when a barrel with a lot of stress (i.e. not stress relieved and/or broach cut too fast/hot) is profiled too severly you can actually have a measurable flaring of the muzzle where the I.D. is larger at the muzzle than near the throat. Stress pushes that muzzle I.D. open. The same can happen with brass casings. YMMV... Link to comment Share on other sites More sharing options...
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