77grain smk cannelure

[fz1boxer]

i have a small stash of 77grn smk w/c and was looking at buying more.
the newer stuff i am seeing has what appears to be a lighter cannelure on the jacket.
did sierra change their specs on the 77smk?

[Fireglock]

I just opened a box I bought to try and what they call a cannelure is not what I would call a cannelure. It's a series of vertical and very light "indents" for lack of a better word.

[fz1boxer]

yea thats what it looked like
thanks

[sinister]

Some ass hat told the SOCOM ammo buyers that a cannelure groove is absolutely required for 77 grain Sierra Match King combat ammo (as opposed to proper case neck tension). Put one in and your accuracy goes into the toilet.

When it looked like Sierra would lose the contract to provide bullets for Mark 262 they relented and added crenellations -- cosmetic grooves that meet the letter of the requirement but don't throw accuracy down the shitter.

The customer may be stupid but he's always right -- it's his (and in this case your tax) money -- give him what he wants. The only real consequence is it adds cost per each round of ammo produced.

Capitalism at work.

http://i47.tinypic.com/25uifk9.jpg

[RictusGrin]

Some ass hat told the SOCOM ammo buyers that a cannelure groove is absolutely required for 77 grain Sierra Match King combat ammo (as opposed to proper case neck tension). Put one in and your accuracy goes into the toilet.

When it looked like Sierra would lose the contract to provide bullets for Mark 262 they relented and added crenellations -- cosmetic grooves that meet the letter of the requirement but don't throw accuracy down the shitter.

The customer may be stupid but he's always right -- it's his (and in this case your tax) money -- give him what he wants. The only real consequence is it adds cost per each round of ammo produced.

Capitalism at work.

http://i47.tinypic.com/25uifk9.jpg

And NSWC bought it hook, line and sinker. One employee caused it to be disseminated through the BN in '06 when I came up with a bunch of Mod 0 with no cannelure that didn't function in one soldier's M4. It was sure to blow up guns, M855 would damage the Mk.12's bore and AA53 would damage M4s.

This year I was still getting one hole 3-round groups when confirming zero, so it would seem that no meaningful damage has been done in terms of performance.

[sinister]

The good thing about using NSWC Crane for SOCOM procurement is you get Navy input.

The bad thing about using NSWC Crane for SOCOM procurement is you get Navy input.

[davey]

... And the punch line on the Mk262 is that you actually should be buying the Nosler version with the real cannelure. IIRC, the Nosler fragmented better than the Sierra from the get-go. The load isn't about accuracy, it's about introducing a stress point in the bullet jacket that promotes fragmenting. If Sierra hadn't been so arrogant and had put a cannelure on it like they were asked, it would have better lethality. My non-expert opinion is that Nosler got robbed.