TONY R Posted February 26, 2016 Report Share Posted February 26, 2016 I notice on a lot of modern 20 bore cases from fiocchi chedite cases etc, that the crimp folds can often have a split clean throughat the bottom of the folds just above where the roll would be. It can be they split along the fold sometimes when adding the wad and it can make for a fold being out of the crimp not just uggly but it alters pressure too. What cases are best to look for with a little more strength in the cases, as i say i have noticed it with a few fiocchis and chedite type cases but i will say not in all the loadings. Any others noticed this? Quote Link to comment Share on other sites More sharing options...
Continental Shooter Posted February 27, 2016 Report Share Posted February 27, 2016 Hi Tony, This normally happen when the crimp is too sharp or pushed too hard. in these cases the cut is a micron or two dipper than it should be and, when the column unfolds the crimp, the plastic breaks. in term of pressure, a weaker closure will drop the pressure 40-60 bar which, however this ca be easily compensateby by closing your shell 0.2/0.3 mm deeper than you normally would. Please remember when closing not to go any deeper than i mentioned as the pressure will increas proportionally the deeper you close: for instance a shell at 58mm will give you X pressure, if you close at 57mm you will have will have a pressure of X+100 bar (+/-). Cheers, Quote Link to comment Share on other sites More sharing options...
TONY R Posted February 27, 2016 Author Report Share Posted February 27, 2016 Hi Tony, This normally happen when the crimp is too sharp or pushed too hard. in these cases the cut is a micron or two dipper than it should be and, when the column unfolds the crimp, the plastic breaks. in term of pressure, a weaker closure will drop the pressure 40-60 bar which, however this ca be easily compensateby by closing your shell 0.2/0.3 mm deeper than you normally would. Please remember when closing not to go any deeper than i mentioned as the pressure will increas proportionally the deeper you close: for instance a shell at 58mm will give you X pressure, if you close at 57mm you will have will have a pressure of X+100 bar (+/-). Cheers, Well that adds up as i did notice the chedite T1s were common for spliting in the way i discribe, and they are prety high performance . i have loaded the 20 a long time and must say i have only noticed this about the past 4 or 5 years perhaps a little longer. Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted February 28, 2016 Report Share Posted February 28, 2016 The plastic is getting less dense. Less dense is less polymer which is cheaper. Some shells I fire are once and done. Quote Link to comment Share on other sites More sharing options...
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