I have lots of experience with CCI #41 primers, but no chronograph data. Sorry.
My favorite primer used to be the nickel plated WSR. It was a wonderful primer in AR mechanisms. Shot well and was considered "GI", which may or may not be true.
Then in 1999 Winchester changed to a "Brass" finish primer. I called Winchester then and asked what they had done to the new primer. They had redesigned the primer to make it more sensitive.
And they sure did. Loads that never bothered the nickel plated WSR were causing pierced primers in each ten round rapid fire sequence. Firing pins ain’t cheap either.
I had one slamfire with the brass WSR, standing. I dropped the round in the chamber and dropped the bolt. The rifle discharged into the dirt in front of the firing line.
Since then, I no longer drop the bolt on a round in the chamber. Standing, I will lower the bolt half way, and let go.
For sighting shots, sitting and rapid fire prone, I will put my sighting shots, one at a time, into the magazine.
In time, cutting my loads (by a grain and a grain and a half!) and following these loading disciplines, I used up the last of my brass WSR.
Still, I was not comfortable with those brass WSR’s and single loading at 600 yards. When you are slung up in prone, you don’t want to break position, and you don’t have a third hand to lower the bolt with the charging handle.
So I tried CCI #41’s. I called CCI about their “Mil Spec” primers and was informed that this was their military product line, introduced to the public during the Clinton primer scare . These primers were “less sensitive” than the commercial line, and they were magnum level primers. Which the old WSR were too.
With the CCI#41’s I was able to go back to my tried and true nickel WSR loads. I first started using them at 600 yards, and the CCI #41’s shot as well as any primer. The last 600 yard score I have had with them is a 197-?X. Last time I shot prone I was working on a perfect score till I had a wind eight and a position nine on the last three shots. Bummer, I really wanted a perfect score!
The load data I developed with WSR nickel plated, I have interchanged exactly with the CCI#41’s, and have had no pressure or function issues.
I have also used CCI standard primers, they shoot well.
Within this thread,
http://www.thehighroad.org/showthread.php?p=4627417, there is a description of a slamfire incident with factory Winchester .223's in a AR. It is my opinion that you do want “less sensitive” primers for mechanisms that have free floating firing pins. The AR falls into that category. "Insensitive primers" won't bother a military mechanisms, because those mechanisms have plenty of firing pin energy. Unlike some commercial actions with minimum firing pin fall, or what those coil cutting fools do to get a lighter trigger pull.