Bragging about overpressure

[nhenry]

I'm always on the lookout for lefty rifles, especially Rugers, Remingtons, and MRCs. Came across this last night. A rebarreled, bedded, accurate Ruger 77 MKII in 270 Win.
Reading the description, my eyes bulged.

This man is shooting the gun severely overpressure.

Barnes' load data for a 130gr TTSX and Superformance powder is listed at 58.3gr for a compressed load. The load in the picture is 1.2gr of powder over and 200fps faster than Barnes' book max.

Even the 270 WSM cannot get to 3400 with a 130 (according to Barnes' data).

To get to 3400 in my 280AI, I have to max out (safely) a 120gr TTSX.

Watch for pressure and be safe, guys.

https://www.gunbroker.com/item/979253785

 

[JD338]

Looks like someone is begging for trouble.

JD338

 

[Heavy Barrel]

Unless there's something I'm missing Gordon's shows 59.5gr of Superformance as near max.

 

[nhenry]

Unless there's something I'm missing Gordon's shows 59.5gr of Superformance as near max

Velocity = pressure in 99% of cases. Even in your calculation, you only get to 3072 fps, which is significantly lower than his advertised velocity. I ran it through GRT before posting as well.
This gentleman was using Peterson brass, which typically has a lower case capacity than others, which will bump up pressure with a higher load as well.

 

[gerry]

I agree excessive speed is a big pressure sign. The 25.5" barrel won't be able to safely get that much more speed, maybe 3200 fps would be tops.

 

[Dr. Vette]

Or, his Chrony is way off.
That's possible too.

My 270 gets 3300fps using the 117 Hammer Hunter with MRP. I have a hard time believing his speeds are accurate.
If they ARE accurate, that bolt must require a 2# hammer to open it.

 

[Heavy Barrel]

Velocity = pressure in 99% of cases. Even in your calculation, you only get to 3072 fps, which is significantly lower than his advertised velocity. I ran it through GRT before posting as well.
This gentleman was using Peterson brass, which typically has a lower case capacity than others, which will bump up pressure with a higher load as well.

That makes it tempting to ask the seller for photos of the head stamps on the fired brass.

 

[JD338]

That makes it tempting to ask the seller for photos of the head stamps on the fired brass.

Personally, I would pass on this rifle. You don't need someone else's ticking time bomb.

JD338

 

[RL338]

Shooting Chrony is not one I would believe the velocities from. Depending on brass volume he is a little high compared to Barnes data.

 

[TackDriver284]

Yikes, 3400 fps with a standard .270 pushing a 130 Barnes, that is too fast.

 

[Heavy Barrel]

Personally, I would pass on this rifle. You don't need someone else's ticking time bomb.

JD338

Agree.

 

[SJB358]

That’s a tough pull for a 270 Wby most days.

 

[highoctane]

Yep, 3400 fps is buzzing rattlesnake. Don't walk away, RUN!!!

 

[Johnly]

I was using GRT and with a 26" barrel and SF powder pushing a 130 NBT simulates to 3300+ if the rifle has a long throat.

My 270 is a Rem 700 with a 24" barrel and I shoot 130 NBT into tiny groups with 57 gr of RL-17 loaded to 3.378" and according to my LabRadar it's doing 3234 fps.
That's a long ways from 3400 fps, by still impressive. And I don't believe the pressures are as low as GRT calculates either, but the Fed 210GM primers still have radius (if that really tells you anything) and the soft Federal cases seem to be keeping tight pockets..

 

[300WSM]

Couple things of observation....

If you're considering this rifle then go for it.

Reviewing..
He is showing using a ttsx 130gr.
Barnes doesn't list Superformance for that bullet.
Moreover...
They do list it for the 129gr LRX bullet.
The 130gr TTSX has a .050 shorter COAL listing than the 129gr...

That all said I believe he's got inaccuracies with his Chrony.
Battery? Lighting? Just old?

Who knows...


Looking at other pictures it appears he's a shooter.
Many boxes of Berger bullets. He's measuring his group size. He's logging shot strings...
He's done a re-barrel on it.

I'm not saying he's safe but I'm also not saying he's unsafe.
We've no idea the safety practices of said Ruger MK77 owner in left hand.

The pictures...to me...
Indicate someone that has some experience shooting and loading.

Most...not all...but most reloaders don't buy powder by the keg, have two stacks of Berger bullets, etc.

In other words a green hand loader would have a pound or two of something and a couple boxes of Hornady bullets (because nothing else is available)

If he's an experienced shooter I'd like to think for the sake of life and limb and the other range participants he'd also recognize unsafe pressures.

If the rifle is of interest that superficial IMO Chrony reading wouldn't scare me off and once you get it you know you'll be safe with it.

Good luck my friend

 

[nhenry]

Couple things of observation....

If you're considering this rifle then go for it.

Reviewing..
He is showing using a ttsx 130gr.
Barnes doesn't list Superformance for that bullet.
Moreover...
They do list it for the 129gr LRX bullet.
The 130gr TTSX has a .050 shorter COAL listing than the 129gr...

That all said I believe he's got inaccuracies with his Chrony.
Battery? Lighting? Just old?

Who knows...


Looking at other pictures it appears he's a shooter.
Many boxes of Berger bullets. He's measuring his group size. He's logging shot strings...
He's done a re-barrel on it.

I'm not saying he's safe but I'm also not saying he's unsafe.
We've no idea the safety practices of said Ruger MK77 owner in left hand.

The pictures...to me...
Indicate someone that has some experience shooting and loading.

Most...not all...but most reloaders don't buy powder by the keg, have two stacks of Berger bullets, etc.

In other words a green hand loader would have a pound or two of something and a couple boxes of Hornady bullets (because nothing else is available)

If he's an experienced shooter I'd like to think for the sake of life and limb and the other range participants he'd also recognize unsafe pressures.

If the rifle is of interest that superficial IMO Chrony reading wouldn't scare me off and once you get it you know you'll be safe with it.

Good luck my friend

Barnes lists the 130gr TTSX and superformance under 270 win. They don’t under 270 WSM.

I’m not too interested in it, just wanted to put out the PSA because those are not normal velos, and even the most experienced loader can look past pressure signs (especially when selling a rifle for more than it’s worth)

 

[FOTIS]

TINSTAAFL

This is the first word I write in big bold letters on the whiteboard when I teach Handloading 101. Of course all my students wonder what the heck it means. When we get to the pressure subject I reveal it.

Velocity is a biproduct of pressure (all other things being equal) therefore
There Is No Such Thing As A Free Lunch!
Yes speeds in equal length barrels may vary a bit but not 200 fps. That is nonsense.

 

[hunter24605]

I'm reminded of when Bugs Bunny was checking for dud bombs by whacking them with a hammer




.

 

[Joec7651]

This is why I try to put a couple benches between myself and other shooters when at a public range. Essentially, every round with that load is a proof load.

 

[DrMike]

I'm reminded of when Bugs Bunny was checking for dud bombs by whacking them with a hammer




.

I don't like this GIF. I keep waiting for Bugs to find one that isn't a DUD!