Pressure Sign on Factory Hornady Super Performance

[finnbear270]

Takes a little while to load this, but well worth a read. (It's not just about blown primers)
Understanding Pressure :: Primal Rights, Inc

 

[Hook'N'Bullet]

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…

They are definitely running faster than the super hammerheads. Chronied the SSTs at 2870 fps whereas the super hammerheads are at 2740 (average over 5 shots of course)

 

[75]

View attachment 340375

Really useful photo - should be a sticky somewhere for all the flattened primer questions that come up!

 

[Hook'N'Bullet]

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.

Surely factory ammo wouldn't be loaded to the absolute limit though?

 

[Hook'N'Bullet]

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.

No majority of the bolt lift was fine, just the odd 1 or 2 out of the lot. At random intervals too.

 

[Hook'N'Bullet]

It's a shame because I want to use them, bought 3 boxes at 50 euro each plus shipping the gun is a tack driver with them too

 

[Hook'N'Bullet]

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.

The primer on the right in my OP does look a bit flattened in fairness. Don't fancy damaging my rifle . In all honestly, would you still shoot them?

 

[andyk]

Hard to know what you want to hear really.

There’s no magical difference between factory and homeloads. Evidence of the case head being pushed back into the ejector holes and wipe marks are classic over-pressure signs. Any guidance on homeloading would say to stop and evaluate if you see that. So, if you want the ‘by the book’ answer, it’s got to be to stop using them until you’re happy they’re safe.

Of course, Superformance is a popular ammo and plenty use it without issue, so you’re probably fine. If you did have trouble though, you couldn’t say with a straight face that you hadn’t had any warning though.

 

[Hook'N'Bullet]

Hard to know what you want to hear really.

There’s no magical difference between factory and homeloads. Evidence of the case head being pushed back into the ejector holes and wipe marks are classic over-pressure signs. Any guidance on homeloading would say to stop and evaluate if you see that. So, if you want the ‘by the book’ answer, it’s got to be to stop using them until you’re happy they’re safe.

Of course, Superformance is a popular ammo and plenty use it without issue, so you’re probably fine. If you did have trouble though, you couldn’t say with a straight face that you hadn’t had any warning though.

Yeah I see where you're coming from. I'd rather not have a catastrophic failure - I might see if I can return them to the shop and swap them out for something else. Maybe some of those Nosler BTs. I've shot two groups with them and they were also tack drivers.

 

[olliehopes]

It also doesn't help that Hornady use some pretty soft brass. I doubt one of the main manufacturers of ammo would willingly make cartridges above SAMMI recommendations.

 

[Hook'N'Bullet]

It also doesn't help that Hornady use some pretty soft brass. I doubt one of the main manufacturers of ammo would willingly make cartridges above SAMMI recommendations.

That was my thinking too

 

[olliehopes]

That was my thinking too

If it does end up with a catastrophic demise of your rifle, hornady will have to replace it!

 

[Polar Lynx]

I belive/think it is extra important with 'hot' ammo to make sure cartridge chamber is really clean so that cartridge will end up at close into barrel. If dirt/lead/copper is built up in chamber then cartridge will be getting a back position and flattend primers will occur.

 

[finnbear270]

Yeah I see where you're coming from. I'd rather not have a catastrophic failure - I might see if I can return them to the shop and swap them out for something else. Maybe some of those Nosler BTs. I've shot two groups with them and they were also tack drivers.

You will probably see the odd one like the "Three o'clock" one from other manafacturers, if no stiff bolt lift I would not have any worries.

 

[Kersnow]

Just had similar with 243, took the last 11 rounds back and was given a new box of 20 from a different batch to try.

The ones i took back were being sent back to the supplier.

 

[vpk999]

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

Send them. That all look fine to me.

 

[tim@tcs]

I recall an Enfield Enforcer letting go dramatically with CBC 308
Which turned out to have been loaded with pistol powder at the factory! It took a year or so but the owner was compensated. This was in the mid 90’s

 

[Foxyboy43]

Not rifle but after the routine standard denials last year 7 semi auto pistols of differing makes were quietly replaced in NI by a certain ammo manufacturer - so it does happen.

 

[Hook'N'Bullet]

Here's an update, shot some groups with the Superformance SSTs. The gun does not like the spicy ones as you can see from the group and pressure signs on the cases.

The spicy ones seem to be coming from a box I bought about a year ago. The newer boxes don't seem to have this issue and shoot true

(Ignore the bottom targets, that was a mate zeroing his 6.5CM

 

[6.5-06 TIKKA]

You could shoot over a chronograph for reference.
Then contact Sako if required.
Note the batch number and ask if anyone else have had issues.

I had one batch of Sako 22ppc factory ammunition that was so overloaded it would eject the case and the primer separately.
Other friends that used this batch had the same issues.