It's almost as if my firing pin hole has a burr or something and gouges the primer and case head as it's ejecting. If you look closely, (it's a crappy iPhone pic, sorry) the gouge is a present on every case and they are all pretty uniform. I'm pretty sure it's not a pressure issue as these were starting loads. 6.5-6.7 Win Autocomp, mixed cases, 165 Montana gold JHPs, CCI and Win SP primers. Anyone else have this problem? Is it even worth worrying about or just keep shooting it?
Anyone else's S&W M&P 40 hard on brass?
- Thread starter 0311@LAR
- Start date
Start reading about primers here
http://38super.net/index.html
Your picture is not great for me, I cant tell squat. Looks like a slight smear but pistol primers are hard to read sometimes
.40 S&W is way to pressure sensitive to work with for me without a chronograph. Without one reading primers is like me trying to read braille...
My best example, 3 different .357's
Same load (10 grains of Blue dot, yes old school shit) 158 LSWC
All three guns slug identical, one is a 3in barrel and the other 2 are 6"
One gun leads bad
One flattens primers
The other shoots 1" @ 25 yards(perfect primers/no leading)
Both 6" guns shoot relatively the same velocity, the 3" gun obviously shoots slower(Not by much)
All three guns show different primer characteristics, none of my chrono data leads me to think that any of these loads are excessive in pressure.
They all display strange differences in primer characteristics but none of them are excessive loads...
I am not saying that your loads are "over" but the simplest thing in my opinion is get a chronograph, if you don't have one available then turn down the load to see what happens to the primers.
Do they look like this?
http://www.ar15.com/forums/t_6_42/364669_.html
http://www.ar15.com/archive/topic.html?b=5&f=16&t=122963
http://38super.net/index.html
Your picture is not great for me, I cant tell squat. Looks like a slight smear but pistol primers are hard to read sometimes
.40 S&W is way to pressure sensitive to work with for me without a chronograph. Without one reading primers is like me trying to read braille...
My best example, 3 different .357's
Same load (10 grains of Blue dot, yes old school shit) 158 LSWC
All three guns slug identical, one is a 3in barrel and the other 2 are 6"
One gun leads bad
One flattens primers
The other shoots 1" @ 25 yards(perfect primers/no leading)
Both 6" guns shoot relatively the same velocity, the 3" gun obviously shoots slower(Not by much)
All three guns show different primer characteristics, none of my chrono data leads me to think that any of these loads are excessive in pressure.
They all display strange differences in primer characteristics but none of them are excessive loads...
I am not saying that your loads are "over" but the simplest thing in my opinion is get a chronograph, if you don't have one available then turn down the load to see what happens to the primers.
Do they look like this?
http://www.ar15.com/forums/t_6_42/364669_.html
http://www.ar15.com/archive/topic.html?b=5&f=16&t=122963
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Appears to me to be a little "wipe" from the firing pin. That suggests maybe unlocking a little prematurely. Your pic isn't the greatest but I don't think you have a pressure issue. I have a M&P40 Pro but, unfortunately, have had no time with it at the range.
Looks alot like my sons S&W 40 brass ( primers ) Even his reloads do the same,and his loads are in the mid range for a hand load.So I 'll take a guess to its just the way they made it,and how it comes out looking.Maybe some more M&P owners will post and add to this.
