When does velocity not equate to pressure?

[bowjijohn]

Of course it does - always

However-may I offer my own application to the 'Wally Award' ?

Today I was playing with peregrine VRG1's out of a 9.3 x 62

I usually load 62 grains of RL 17 for my Nosler partitions

Aha says I - know they are a about a mile longer so compressive loads are bound to be an issue

Now I don't have distance to the lands as a guide - my barrel is from the same school as Linda (the Linda - as in its got a deep throat ??) - If you are under 50 - never mind

I do have a mag size - so that became by COAL guide

So - having consulted all the 'recipe books' and QL - I chose to start my load dev at a load of 58 grains - 4 below my standard charge for the Noslers

QL gave me the thumbs up and a predicted MV of 2350 - a bit higher than I need but QL tends to over estimate MV and if it proves correct ''I can always drop the load a bit' says I

One round at 25m

BANG

Recoil much the same as ever

Case had no signs of pressure - all good

No stiffness to the bolt - no probs with extraction

Glanced at the reading on the Magneto V3 - velocity read 3350 !!!!

Went home for a beer

 

[Joker12]

Improperly using powders with fast burning rates in cartridges that aren't suitable can result in very high (quick) peak pressure and not high velocity.

 

[flatwater bill]

Bowj......did you drink beer before the velocity testing as well?
FWB

 

[bowjijohn]

Bowj......did you drink beer before the velocity testing as well?
FWB

I wish !

Do you - or does anyone think - that exhaust gases can/might interfere with measured velocity with a magneto?

 

[bowjijohn]

Improperly using powders with fast burning rates in cartridges that aren't suitable can result in very high (quick) peak pressure and not high velocity.

This is the exact opposite

RL 17 is not an impropriate powder for 9.3 x62

I had a high velocity reading with other indicators suggesting low (or not excessive) pressure

 

[dchamp]

I'm curious, what weight bullet did you use, 230, 250 or 286. Did you try turning off your magneto speed and check its setup. Did you shoot it a second time and/or try a different chronograph. I would suspect something with the chronograph was out of wack.

 

[bowjijohn]

Improperly using powders with fast burning rates in cartridges that aren't suitable can result in very high (quick) peak pressure and not high velocity.

This is the exact opposite

RL 17 is not an inappropriate powder for 9.3 x62

I had a high velocity reading with other indicators suggesting low (or not excessive) pressure

I'm curious, what weight bullet did you use, 230, 250 or 286. Did you try turning off your magneto speed and check its setup. Did you shoot it a second time and/or try a different chronograph. I would suspect something with the chronograph was out of wack.

286 grain

I did not shoot again

That was such an an unacceptable reading that I assumed that I'd got something badly wrong

I've pulled all the rounds and checked loads to see if that was an issue - no

I've only been using RL 17 recently , so cross contamination is not the issue

I re ran the QL calcs to ensure that I was not way out on loads

I will reseat to 20 thou short of mag box internal measurements and drop a couple of grains and try again

Very happy to hear from other people using RL 17 and 286 grain peregrines.

I have clearly got something very wrong

 

[BourbonTrail]

I didn’t realize that Weatherby made a 9.3…

Sounds more like the magneto was off.

 

[flatwater bill]

I had an 8800 FPS vel on my old chrony once.....FWB

 

[Opposite Pole]

I’m guessing incorrect reading by the chrono. Velocity that high with this kind of projectile weight would surely leave an impression on the brass and your shoulder. Brass looks fine and you’ve mentioned recoil was normal.

 

[JimP]

While working up a load for my .340 Weatherby I was using some IMR 4831 and started to see pressure signs before I reached the velocity that I wanted to see. I switched over to RL 22 and achieved the velocity at a lower pressures.

It's interesting in that the loading that I am now using isn't even listed on the manuals site anymore, so once I go through the rest of my powder out of the jug I'll need to build it back up with a new lot number.

 

[Joker12]

This is the exact opposite

RL 17 is not an impropriate powder for 9.3 x62

I had a high velocity reading with other indicators suggesting low (or not excessive) pressure

R17 may very well be a good powder in the 9.3x62. There isn't a lot of published data for it in many cartridges. It works quite well in the 375 H&H. It was developed for the short mags but works well with higher velocities in many other cases as well. The proof is not in published data but in how well it actually works. Perhaps you discovered something useful.

 

[shootist~]

I agree that the Magneto speed is probably suspect, and also agree that it was a good time to stop.

I would absolutely set about to find how far off the lands you were - if only to verify you were not jammed in. If no Hornady Ctg Headspace tool, do it the old way:
Partially split a case neck with Dremel, load super long and chamber...eject and measure, repeat x2. This actually gives a COL at slightly jammed-in - maybe ~ .020" depending on neck tension.

FWIW, 60.0 grains of RL17 gave me 2,301 fps with 300 grain A-Frames with no issues. Well under the projected V in my CZ550.

And Linda was a good ol' girl - or was that Sally?

 

[dchamp]

This is the exact opposite

RL 17 is not an inappropriate powder for 9.3 x62

I had a high velocity reading with other indicators suggesting low (or not excessive) pressure


286 grain

I did not shoot again

That was such an an unacceptable reading that I assumed that I'd got something badly wrong

I've pulled all the rounds and checked loads to see if that was an issue - no

I've only been using RL 17 recently , so cross contamination is not the issue

I re ran the QL calcs to ensure that I was not way out on loads

I will reseat to 20 thou short of mag box internal measurements and drop a couple of grains and try again

Very happy to hear from other people using RL 17 and 286 grain peregrines.

I have clearly got something very wrong

A few months back I developed a load for the 9.3x62 using 325gr Norma Oryx bullets at 3.335" COAL. The highest load I tried was 63.0gr's of RL17 without issues and going 2376fps in a 22" barrel. Best accuracy was around 60.3gr's of RL17 at 2275fps.

 

[375 Ruger Fan]

You didn't happen to loan your rifle to Alec Baldwin by any chance?

 

[Alistair]

That's almost certainly a misread.

No way in hell you'd gain an extra 1000fps in a 9.3 without at the very least totalling the case and blowing out the primer.

Even then, I honestly don't believe it'd have the powder capacity to achieve that, definitely not with rl17.

That bullet weight and that velocity would yield north of 7000ftlb, significantly more than a 500ne. You'd notice a difference in recoil, I guarantee.

 

[Bob Nelson 35Whelen]

This is the exact opposite

RL 17 is not an inappropriate powder for 9.3 x62

I had a high velocity reading with other indicators suggesting low (or not excessive) pressure


286 grain

I did not shoot again

That was such an an unacceptable reading that I assumed that I'd got something badly wrong

I've pulled all the rounds and checked loads to see if that was an issue - no

I've only been using RL 17 recently , so cross contamination is not the issue

I re ran the QL calcs to ensure that I was not way out on loads

I will reseat to 20 thou short of mag box internal measurements and drop a couple of grains and try again

Very happy to hear from other people using RL 17 and 286 grain peregrines.

I have clearly got something very wrong

@bowjijohn
Try another chronograph.
If both give the same reading and low pressure and recoil RUN, DONT WALK, RUN to your local gunshop with the lot number of the powder and buy every container they have.
Cfe223 in the Whelen works well but I might have to get some of that powder.
Something is wrong somewhere and my guess is the chrono or the set up.
Bob

 

[Tra3]

That level of speed would make a solid mushroom on impact! And you’d have about 150 ft/lbs of recoil. You might want to wear a mouth guard and a hockey helmet next time you shoot those rounds. Heck, with a light bullet maybe you’d get over 4000fps and could use it for a prairie dog hunt!

 

[Areaonereal]

I had a crazy reading on a chronic last year….showing 300 FPS less than normal on a sting of shots…..Replaced battery. Corrected the issue

 

[sgt_zim]

Of course it does - always

However-may I offer my own application to the 'Wally Award' ?

Today I was playing with peregrine VRG1's out of a 9.3 x 62

I usually load 62 grains of RL 17 for my Nosler partitions

Aha says I - know they are a about a mile longer so compressive loads are bound to be an issue

Now I don't have distance to the lands as a guide - my barrel is from the same school as Linda (the Linda - as in its got a deep throat ??) - If you are under 50 - never mind

I do have a mag size - so that became by COAL guide

So - having consulted all the 'recipe books' and QL - I chose to start my load dev at a load of 58 grains - 4 below my standard charge for the Noslers

QL gave me the thumbs up and a predicted MV of 2350 - a bit higher than I need but QL tends to over estimate MV and if it proves correct ''I can always drop the load a bit' says I

One round at 25m

BANG

Recoil much the same as ever

Case had no signs of pressure - all good

No stiffness to the bolt - no probs with extraction

View attachment 439954

Glanced at the reading on the Magneto V3 - velocity read 3350 !!!!

Went home for a beer

my recent trials with 285 gr Norma Oryx and 2000MR (starting at 58.5 gr) went much the same way. 5 shots, about 3350, about .7 MOA. Packed up all my crap, went back to the cabin, had a brewsky myself.

Curious - I found "Gordeon's Reloading Tool" and have been playing around with it. Have you (or anyone here, for that matter) ever tinkered with it, and if so, how accurate did you find it to be?