Be Careful Of What You Use To Seal Your Shotshell Crimps!

<P style="MARGIN: 0px">I worked up a 1 5/16 oz. 10ga. load last Fall which patterned consistently well and was chronographing about 1550 - 1570 fps.&nbsp; I put a Tyvek patch over the shot and used some oil based polyurethane finish to seal the primers and the crimps.</P> <P style="MARGIN: 0px">&nbsp;</P> <P style="MARGIN: 0px">I had a chance to use those shells at the end of the southern zone goose season and I wasn't getting the knock down effect that I had expected from the patterns I had shot earlier.</P> <P style="MARGIN: 0px">&nbsp;</P> <P style="MARGIN: 0px">After the season was over, but while it was still cold, I fired several shells on the pattern board and got terrible patterns.&nbsp; I picked up the fired wads and noticed that the plastic was very hard, which I attributed to the cold temps, and assumed the wads were not opening properly in the cold, which accounted for the good patterns in the 70 degree Fall, but the bad patterns in the 20 degree cold.</P> <P style="MARGIN: 0px">&nbsp;</P> <P style="MARGIN: 0px">A couple of weeks ago, after working up a new load for the 10ga., I started disassembly of the previously loaded 10ga. shells.&nbsp; I use a hemostat pushed through the crimp center and levered around the perimeter of the crimp to open up the plastic so I could dump the shot and remove the wad and powder.&nbsp; The crimps were very difficult to open, much more so than usual.&nbsp; I set up the chronograph and fired several to see what was the effect of the hard to open crimps on shell velocity.</P> <P style="MARGIN: 0px">&nbsp;</P> <P style="MARGIN: 0px">What I found&nbsp;was that my loads, previously chronographed at 1550 - 1570 fps. were running in the low to mid 1700's. One shot was over 1800 fps.<IMG src="http://www.websitetoolbox.com/images/boards/smilies/eek.gif" align=absMiddle border=0></P> <P style="MARGIN: 0px">&nbsp;</P> <P style="MARGIN: 0px">I opened a couple of shells to break the adhesion of the polyurethane, recrimped them and fired them over the chronograph.&nbsp; Those were around 1570-1600 fps.</P> <P style="MARGIN: 0px">&nbsp;</P> <P style="MARGIN: 0px">Needless to say, I won't be using polyurethane any more&nbsp;to seal crimps.&nbsp;</P>

 

<P>I tried fingernail polish, but it seemed too slow to apply for my liking.&nbsp; I switched to a 50/50 melted parafin-vasoline mixture spread across the crimp.&nbsp; It worked well to seal the crimp, but when I opened up some shells, I noticed sometimes it would seep past the Tyvek patch and congeal with the shot.&nbsp; This year, I am going to cut some paper patches with a arc punch, dip them one at a time into the melted mix and stick it onto the crimp while it is still hot.&nbsp; The vaseline helps plasticize the parafin and makes it sticky.&nbsp; If it will stick to the crimp, it may do the job.</P>