Speed Anomoly!!

[Envillegc1]

The Vihtavuori data is simply not worth the paper it is printed on. No use quarrelling about the accuracy of scales in this case either.

View attachment 362004

Wow that’s bang on the results we got. That’s very interesting. Can I ask what software this is?

 

[Will the chippy]

That will be quick load which you have to pay for. Look for Gordon's reloading tool online. It's free and very similar to quick load. Only to be used on a laptop tho. It's excellent.

 

[Envillegc1]

That will be quick load which you have to pay for. Look for Gordon's reloading tool online. It's free and very similar to quick load. Only to be used on a laptop tho. It's excellent.

Cheers

 

[25 Sharps]

We were bench testing against factory loads on the same day which all produced figures close to box stated speeds. Loads were done in conjunction with Hornady loading tables, Vhit data sets. Which is why we were both a little surprised with the results.. much scratching of heads has thus ensued!

checked the scales with a number of bullet heads from 90gr to 35gr. All where there to within 0.1gr.

Beam scales or electronic?

 

[Selous]

Yes I always calibrate and check the digital with the check weight, I don't use them to reload as I use the rcbs scales. There good enough to tell me if I'm at 32 grains or 37 grains for instance.

But a 5 grain anomaly could be truly catastrophic! Especially if loading relatively small cartridge cases. Anything that truly only give a measurement plus or minus 2.5 grains has no place on a loading bench!

 

[trickie]

Could the speed difference be related to the seating depth of the bullet? On Gordon’s, that shows a considerable fps change if I load my 6.5cm long or short?
Factory ammo is normally fast in the box than in the barrel, if your getting a spot on reading using factory, I’d say that’s a win.
I shoot Tikka barrels and they show slow against factory ammo forecasts, but within 10/15 fps on Gordon’s.

 

[Selous]

getting back to the OP load data from powder manufacturers is often inaccurate compared to real life due to differences in powder batches, case and chamber volume, barrel length, chronograph type etc etc. The same goes with velocity on the box. As an example I recently chronographed a low velocity factory cartridge that was meant to produce 222 m/sec (728 ft/sec) but only produced 150m/sec (495ft/sec)! You are quite lucky if you actually get the published velocity in my experience

 

[Eddie P]

On balance scales it's easy enough to be 5 grains out. I check mine with cheap digital just so I know I'm in the ball park.

I do the same, I don't trust digital scales to be fully accurate, but they do agree with what I think I'vevset the lever balance at.

 

[Envillegc1]

Beam scales or electronic?

Beam

 

[25 Sharps]

Beam

So potentially the beam could be set wrong, although an unlikely coincidence to happen twice for one load session

 

[Will the chippy]

I would say unlikely as steff shows on the quick load data.

 

[Smellydog]

FFS, just fill the case with 550....

 

[Selous]

FFS, just fill the case with 550....

 

[Smellydog]

No it won't explode. If anything it's more dangerous the load he has been loading!

 

[zambezi]

58 gr Vmax with 42gr N550. Disappoingly this was down at 3100 fps

Gordon's Reloading Tool is a free app akin to QuickLoad.

Using the same parameters as per post #15, GRT also suggests that the load above will generate an MV around 3133fps from a 22" barrel.

One thing to note: QuickLoad and GRT disagree on the length of Hornady's V-Max 22411 58gr projectile. Which might explain why GRT declares the seating depth to be too small. Not really sure.

I have found GRT to be pretty much on the money with all loads I have chrono measured in the field for .223, 6.5x55mm, 30.06, 6.5PRC and .375H&H.

 

[Will the chippy]

Gordon's Reloading Tool is a free app akin to QuickLoad.

Using the same parameters as per post #15, GRT also suggests that the load above will generate an MV around 3133fps from a 22" barrel.

One thing to note: QuickLoad and GRT disagree on the length of Hornady's V-Max 22411 58gr projectile. Which might explain why GRT declares the seating depth to be too small. Not really sure.

I have found GRT to be pretty much on the money with all loads I have chrono measured in the field for .223, 6.5x55mm, 30.06, 6.5PRC and .375H&H.

View attachment 362107

I use this, and it's been superb. I often look at the burnt powder too, and if it's under 95% it's going to be burning in your mod or a big muzzle flash. The node recommendations are a good indicator too.

 

[Envillegc1]

Gordon's Reloading Tool is a free app akin to QuickLoad.

Using the same parameters as per post #15, GRT also suggests that the load above will generate an MV around 3133fps from a 22" barrel.

One thing to note: QuickLoad and GRT disagree on the length of Hornady's V-Max 22411 58gr projectile. Which might explain why GRT declares the seating depth to be too small. Not really sure.

I have found GRT to be pretty much on the money with all loads I have chrono measured in the field for .223, 6.5x55mm, 30.06, 6.5PRC and .375H&H.

View attachment 362107

Thanks for this. I have now downloaded this and it pretty much tallys with the results on the chrono.
I am playing around tonight trying to see how Vhit get to there stated speeds for loads!!

 

[Laurie]

The Vihtavuori data is simply not worth the paper it is printed on. No use quarrelling about the accuracy of scales in this case either.

View attachment 362004

N550 is a powder for which I NEVER believe QuickLOAD on its default settings - and the errors are 'wrong direction', that is MVs / pressures are way, way understated and the max charge weight way, way too high.

 

[Heym SR20]

Lighter bullets provide less resistance to the powder, so powder doesn’t reach proper pressures as the burning chamber expands too fast for powder to keep up resulting in lower velocities than expected. It may also be that the test barrel had a tighter bore than the one in your rifle.

A faster powder is needed for lighter bullets.

 

[Bowland blades]

Good Evning one and all.
My friend and I are seeking some advice about a reloading query / quirk we have come up with on our 243's.

At the Stalking Show, a purchased the new Gamin unit.
So on Sunday we decided to go and check to see what speeds where like when measured vs book and box data.

I first benchmarked the Chrono with 22LR, and it was on the money.

I then put my factory 50gr 22-250 rounds through it, and adjusting for barrel length, again bang on.

We then statred on the 243.
First up was 58 gr Vmax with 42gr N550. Disappoingly this was down at 3100 fps. Given the load, we should have been north of 3500fps, maybe more given at 44gr it should be 3800fps.
Then we tried factory load 95gr ELD-X, again bob on vs the packaging
Then we tried 75gr homeload and again speed was well down.
Sako Gamehead factory load up next and again bang on.

We have been scrating our heads for two days trying to figure out what we are doing wrong?
I am two years into loading, but my friend has 20 years experience.

The results where the same in both rifles, Mauser/Sauer.

I have heard that maybe we have not reached a critical pressure build up, dont know if this is true or not?

Finally, the recoil on the 58s was like a soft 223.
Also the report vs that of the 22-250 was makedly quieter.

Any thoughts?

Never ever trust factory ammo claims regards speeds from your rifle , the lucky situation is finding the two match ! Of course altitude and pressure have a play but its really tossing a penny what your getting without a chrono
Far more than speed we need to look at consistency anyhow . Lapped bores can be a tad faster and crusty / rusty etc slower even with the best ammo