Quickload velocity prediction

[RockyMtnMT]

7 loads is good for any brass for top end loads.

I guess I missed it, did the op say he is getting 7 reloads on the 70g rl26 load that is in question?

Steve

 

[Pdvdh]

Pretty sure that the yield strength of brass is NOT set in concrete. There are many, many alloys of brass and tempers that all affect the yield strength. Now, if we are talking about one specific lot and batch of brass that has been treated the same it's whole life then absolutely it's a solid baseline as to what load/pressure is acceptable. 7 loadings would be VERY acceptable to me for high end loads.
By the way, I don't have quickload either but the data I've used from it seems to be accurate. I'm consistently a couple grains of powder over predicted velocities, which I will attribute to moly coated bullets.

The brass used to manufacture casings can vary in yield strength, but the value is set in concrete compared to any other model that attempts to predict case pressure and the resultant MV.
I know there are differences in the absolute yield strain of brass, which is why I use RWS and Lapua, when it's available. I know the yield strength can vary with use over time, which is why I periodically anneal case necks.
Yet I also know the brass case head will deform and yield to pressure before any other component of the ammo or the rifle, as pressure increases to unsafe levels.
No matter the make, model, or life cycle of the brass casing.

 

[desertcj]

7 loads is good for any brass for top end loads.

I guess I missed it, did the op say he is getting 7 reloads on the 70g rl26 load that is in question?

Steve

Phorwath just threw out 7. I was just agreeing, ya 7 times is good for top end loads.

 

[RockyMtnMT]

Phorwath just threw out 7. I was just agreeing, ya 7 times is good for top end loads.

Ok. I still want to see a good chrono reading of the load in question.

Steve

 

[Pdvdh]

We're gonna be disappointed if less than 4,000...

 

[fisherman983]

Fired 7 shots over a shooting chrony chronograph.
Avg was 3333, but es was horrible. Es was 81, so thats not gonna work. Back to the drawing board

 

[can1010]

your exactly right , that's why I said I have it adjusted to my powder lot . it's been brought to my attention that guys are finding rl26 burn rate to be about .368 , I found mine to be .371 . quickload has it at .331, if I remember right . what ba are you using for RL26 ?

I used the factory default settings and his length and capacity. check your weighting factor in first box it is set for standard cartridge 264 win mag is known as the original overbored barrel burner change from 0.5 to 0.33 and you will see how close it really was.

 

[Pdvdh]

Fired 7 shots over a shooting chrony chronograph.
Avg was 3333, but es was horrible. Es was 81, so thats not gonna work. Back to the drawing board

Thanks for reporting. How'd the cases do? Case heads flow into any bolt face recesses? Stiff bolt lifts?

Not quite 4,000... but moving right along.

 

[jimbires]

I used the factory default settings and his length and capacity. check your weighting factor in first box it is set for standard cartridge 264 win mag is known as the original overbored barrel burner change from 0.5 to 0.33 and you will see how close it really was.

you're right .
I've never changed the weighting factor in quickload , and my powders always aligned to velocity pretty close without changing the "BA" . RL26 is the first powder I've worked with that was so far off I made changes to the "BA" to get charge weight to match up with velocity . I see changing the weighting factor considerably lowered the pressure , I think his load is 69000 with the weighting set to 0.33 . which makes sense since he didn't have over pressure signs on the brass case .by me changing the "BA" I had his velocity about perfect , but my pressure was through the roof . I learned something , thank you . Jim

 

[fisherman983]

Thanks for reporting. How'd the cases do? Case heads flow into any bolt face recesses? Stiff bolt lifts?

Not quite 4,000... but moving right along.

Bolt lift was butter smooth, cases appeared to show no signs of pressure. R26 gives me more speed than R33 but I'm still looking for accuracy with good es. The search continues

 

[cape cove]

If you can get some Norma 217 this might be a good powder. I used it in my 7mm Weatherby mag and got good results for accuracy and velocity.