Not the ballistics expert so I cannot give the technical reason for what happened. But I know sure as heck it happened. Cost me 3 triggers, knocked me out of a 2 day match and it was the same load from the same lot that I had been using but temp and humidity were higher. So was pressure and MV. At that match I watched about 20 other guys using RL 22 go the same grief only not as bad in most cases.
Bottom line if it works for you then do it, but if it jumps up and bites you later then do not be surprised either.
You're right, it never gets that hot up here where I'm at, if it's over 80 deg F it's hotter than hell. I have now way to know what RL22 does over 90 deg F, just 75 and down below...
Did you have a hot batch that in sorts was maybe unpredictable? I've never read posts of RL22 or 25 behaving that way from anyone. Maybe slightly larger bullet dia in a different lot? I know I've measured Sierra's that varied .0003" or more between batches. Firing pin protruding too far? Too much headspace? Who the hell knows, it just doesn't sound like that's the normal behavior for this powder. Have you ever spoken to Alliant about this?
Got a pound of the bad lot also. wiped out about 60 cases one weekend. Threw it away, got a lot that shot good and bought 5 more pounds of same lot. Same bullet, primer etc. Firing pin was same and protusion checked, headspace was same, lapua brass was same, bullets were same and sorted by bearing surface lenght, shoulder bumped .01 etc. Absolutely nothing changed except temp and humidity.
Plus lot of other RL shooters were "enjoying" the same problems only not as bad that weekend.
If it shoots good then shoot it, if you get caught oh well.
No expert here either, I have been using the Re25 in my 408 and was told by many that every time you change lot nums you have to start over with the loads. I have never done that with my smaller cals in the past. The 408 eats lots of powder so i had to change lots several times, found big differences between lots. vel changed over 100 fps, my groups changed, thought there was somthing wrong with the gun. Found another can of the original lot # and WHooHoo the groups were back. Been using some Retumbo also and have found a small difference in their lot mumbers also. So far i like the retumbo better at least in this gun.
Just my experience,,,
Bounthunter- I will agree with what you said.
I won't fix it until it is broke! It doesn't generally get as hot here in NY as in Va so you may have that little extra that sends ya over the edge. Hey bumping your shoulders .010 seems like alot to me!!! Am I wrong or could that be a typo? I am familiar with them. Do it all the time!!!
Everyone, thanks for all the opinions. The negative experiences scare me but my rifle seems to like this powder so much that I will continue to develop this load with the 190 SMK and Re22.
My fiance is getting me a new chronograph for Christmas since my old one died in it's sleep during the time my rifle was being rebarreled. I will check velocities during the coldest days of the Winter and occasionally as the weather warms and during the heat of Summer. I will also keep a record of different lot #. I will try to stay on top of the changes before they bite me in the ass.
I have H4350 on hand and will swith back to it if it seems necessary. However my new chamber is such that I cannot seat the SMKs long so probably could not reach my velocity goal. With my last barrel using col of 2.96" my pressure was about equal with factory loads judging by case expansion and primer appearance.
Today I tested 69.5gr Re22 SMK190 molyed COL 2.861" and pressures seem to be less than factory load. My primers still show some contour on the edge and case miked .5535; Factory load primers are very flat and cases mike .554". I estimate velocity was in excess of 3000 fps by recoil. I will try to borrow a chrono next week as I fine tune my load.
Rapid fire is the crutch of an incompetent marksman. ONE SHOT, ONE KILL