PDA

View Full Version : magnum primers



shooter 70
03-25-2009, 07:39 PM
I recently loaded a load from ken waters petloads 22-250 41.5grn ww760 fed215 primers 52grn matchkings seated .025 off lands. petloads suggested rem mag primers instead of federals. the fired cases showed signs of excessive pressure anyone have any comments

lotech
03-26-2009, 06:26 AM
Win 760 and H414 are the same powder and I've used much of it over the past twenty years or so in both the .22-250 and the .220 Swift with bullets in the 50-to 55-grain weight range. I have always suspected lot-to-lot variation with this powder is somewhat greater than with many others but I continue to use it because of very fine accuracy. Chronographing reveals greater discrepancies with this powder than with most others when I compare my figures with book figures. I have read reports that this powder is quite temperature sensitive, but I can't confirm that. My loads with both cartridges are usually 1-3 grains less than some reputable sources suggest. Don't have my data handy at the moment, but with most 50-grain bullets in the .22-250, a 39-40 grain charge is tops using a CCI large rifle primer. Never needed a magnum primer, though I know they are often suggested. You might back off your load a bit without changing your primer. I'll bet your high pressure signs disappear or at least decrease.

shooter 70
03-26-2009, 06:54 AM
thanks for info lotech i expected that to be the problem does anyone have any info on seating depth. ihave been playing with .020,,025,.030 and have consistantly had one flyer in 5 shot groups

Larry Elliott
03-26-2009, 12:47 PM
It's been a long while since I loaded for a .22-250, but I tried H414 in the last one I had and used standard primers. I haven't used much W760, but was told by a rep from Hodgdon at an NRA show in Seattle that the only difference between W760 and H414 was the difference between lots of either.

There ARE differences between lots of those powders that I consider significant, and they are extremely temperature sensitive. The last time I used it a load was developed at ~75 with no signs of excessive pressures then shot at 85-95 degrees with pressures that were right on the border of excessive. When I got home I tried to duplicate those pressures, and could not get enough H414 into a .22-250 case to do that at 75-80. I used the same powder in a .243 at the same time and had to use 3 gr more powder to get the same pressure signs.

That was the last time I used H414 or W760.

brian roberts
03-26-2009, 02:52 PM
the "same" powders as well, but I notice that in any cartridge in a loading manual where both are used, there is usually a disparity in their respective charge weights. I do have a .22-250, and I do use 41-41.5 H414, a 53 Hornady, and a WLR primer, but I worked up to that load, and I seat off the lands slightly. Also, when you look at the charts in Waters' book, he usually has two, and sometimes as many as 4-5 charge weights of one powder/bullet combo and the velocities along the way, so one can get an idea as to what's going on. Also, with some powders, I have regularly worked up a load in 95-100 degrees, just so I could see what would work in the differing temperatures. Don't use the Matchkings on pests, they don't do that great in 14" twists. I don't know if you just, "picked" that load out of his book or not, but if you did, you might consider in the future just dropping down about 1 1/2 to 2 grs., and working up. An old trucker once told me, "When you hurry up, you screw up" And even in handloading, I found out, he was right.;)

shooter 70
03-26-2009, 03:18 PM
thanks 4 info guys will work up a few different loads with standard and mag primers. rifle is 12lrpv any comments on seating depths have not tried any thing under .020 off lands shoots good groups but always have 1 flyer

J. Pendergraft
03-26-2009, 05:20 PM
It's been a long while since I loaded for a .22-250, but I tried H414 in the last one I had and used standard primers. I haven't used much W760, but was told by a rep from Hodgdon at an NRA show in Seattle that the only difference between W760 and H414 was the difference between lots of either.

There ARE differences between lots of those powders that I consider significant, and they are extremely temperature sensitive.

Larry,
I used W760 almost exclusively in 22-250 years ago. It was very accurate but it surely was temperature sensitive as you say. I had about 1500 rounds loaded and visited Montana to shoot dogs. The weather turned hot and during the heat of the day I could hardly open the bolt on a 700 action. I continued shooting and galled the lugs as a result. As I recall my load was about the same as the load posted by the thread originator.