Pressure Sign on Factory Hornady Super Performance

[Hook'N'Bullet]

First time shooting 150gr Hornady Superformance SSTs in .308Win. Are these pressure signs? I know they are loaded a bit hotter than standard factory ammunition but some seem to have marks on the head stamp and stuff bolt lift. Is it something to worry about?

Shot out of a Sako S20

 

[levigsp]

First time shooting 150gr Hornady Superformance SSTs in .308Win. Are these pressure signs? I know they are loaded a bit hotter than standard factory ammunition but some seem to have marks on the head stamp and stuff bolt lift. Is it something to worry about?

Shot out of a Sako S20

View attachment 340348

question, is you gun barrel clean?

 

[Stumpy2]

Does the rifle do the same thing with other brands?

 

[Foxyboy43]

Bit of a mix but the rhs cases at 4 and 6 o’clock defo look high pressure to me. There are also a couple on the lhs showing (extractor?) marks too.
I think these rounds have a bit of a mixed history with “hot” being a common descriptor…

 

[1894]

Not unheard of with that ammo.
Pressure is pressure regardless of being factory ammo.
Do not shoot more of it

 

[User00044]

Not unheard of with that ammo.
Pressure is pressure regardless of being factory ammo.
Do not shoot more of it

^^^^^^^^this^^^^^^^

I had some .243 Superformance ammo' a few years ago that locked the bolt up !

 

[C h r i s]

The only case that would concern me is the one at 3 o clock on the far right, was this perhaps the last round fired? I've seen this many times before with 'hot' loads through a dirty barrel.

 

[Smellydog]

They are fine, stop worrying.
Dear lord.....

 

[NullMac]

Well yes they are a bit beyond the limit. If that was on a cold day I would not be shooting them on a hot one or out of a hot chamber. If that was one string, was the bolt lift getting hard on the last shots as the chamber got hot? Be careful.

 

[Smellydog]

Bring your rifle and ammo to me, I'll shoot them for you

 

[Lancaster]

Most look OK-ish, but the 3 O-Clock one looks decidedly iffy due to the combination of the smears on the head and the flattened primer.
If I was working up a load they would be the signs suggesting that I back off a bit.

 

[1894]

Max SAAMI pressure for 308win is 62,000psi
Most internet sources estimate sticky bolt lift is in the range 64,000 to 70,000psi
You are almost certainly appreciably over pressure.
Add in wet ammo, a bit of oil in the bore and an outlier in charge weight and kaboom.

 

[Smellydog]

So err, how did the rifle cope at proofing?

Yer all wusses, show me the last rifle that went KaBOOM you all think will happen using this ammo.

 

[finnbear270]

I wouldn't have a hissy fit over them, look OK to me.

 

[Len the dog]

According to SAAMI standards for 308Win, the maximum pressure, as already stated, is 62,000psi. The MINIMUM average proof testing load is 83,000psi.
With any commercially available ammunition it is not, as SD so succinctly put it, going to go KABOOM!

 

[jthyttin]

Short of KABOOM, there are several things that can ruin your day (or life) with overpressure ammo. Personally I wouldn't use ammo that shows brass flow (ejector swipes etc.)

 

[finnbear270]

A properly "Flattened" primer will usually look like it's part of the brass case head ... bit like the metal appears in two & one pound coins, not like the ones shown in OP, that have clearly a groove around the primer.

 

[finnbear270]

 

[Hook'N'Bullet]

question, is you gun barrel clean?

Clean enough - Gun was bought new this year, has maybe 2 boxes of ammo through it. I don't deep clean with solvents until after the season. Just a few passes on the pull through after each outing. Its shooting ragged holes with these SSTs and Super Hammerheads

 

[Hook'N'Bullet]

Does the rifle do the same thing with other brands?

No, have shot Sako Super Hammerheads and Federal Prem. Nosler BTs and no marks on the brass