Interesting data with Magnetospeed

[mrh3s]

Well finally got a chronograph and tested some of my handloads. Purchased a Magnetospeed sporter and took it to the range today. Lets just say I was a little surprised at the numbers. A couple weeks back I worked up 5 different 10 shot loads using Ramshot Tac powder behind a 75gr Hornady BTHP. Im using lake city brass, preped with a Giraud tri-way trimmer and federal match primers that a friend gave to me. Worked from 23.4 grs up to 24.5 in .2gr incraments, mind you this was before the chrono, and found that 23.8 and 24.0 gave the best groups for that day at about .63 moa and slightly flattened primers. Settled on 24.0 gr and loaded up another 50 rounds. I used a Lee factory crimp die for 25 of them and did 25 without the crimp.

Well these were shot today in two strings of 6 shots with the following results.

Shot from a 18inch Dpms 1-8 twist heavy contour barreled AR15.

75gr Hornady BTHP with Lee Factory Crimp
Avg - 2845
High - 2866
Low - 2834
SD - 11
ES - 32

No crimp
Avg - 2817
High - 2842
Low - 2786
Sd - 17
Es - 56

So needless to say that seems way to hot for a semi auto. I was surprised by those numbers becuase when looking for load data numerous people loaded 24+ gr of Ramshot Tac and I believe even the website listed the max as 24.4. Any one else have any experience with this load combination. Also do you think the magnetospeed gives a higher MV due to it being actually at the muzzle as opposed to 10 - 15 feet away as with a normal chrony. In my mind that doesnt seem like that big of a difference, but ive been wrong before.

[Jct1911]

Actually seems about right velocity wise with near max loads. With varget I'm in the same range with that bullet in my 18" 3gun rifle. Mine also shoots about .6. 25.4grs TAC under a 55gr gives me about 3000fps.

[Dolomite_supafly]

If it shoots good and your primers are not doing anything funky I would be happy. Most times max, or near max, loads are not the most accurate loads.

[mrh3s]

Appreciate the replies, yeah first time with a chrono so was just a little suprised, primers were starting to flatten but weren't too bad. Definitely will have to load up some more for testing, what I found interesting was the rounds that were crimped using a factory crimp die showed an average of about 30 fps faster with a lower standard deviation across the string. Of course my reloading techniques are not super particular so a number of factors could have contributed.

Also ive always read that Federal primers are "soft" in relation to others, has anyone found this to be the case with their small rifle match primers also.