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+--- Thread: Qwik load help requested. I BLEW ONE UP! (/showthread.php?tid=24280)
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Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-15-2022
I had an UGLY case separation.
The brass had been used 20-25 times, so it is suspect.
It was also the 1st round of that load, so that is also suspicious.
It is a 6 grendel, and the load data was 6arc. I started .3gr over ARC max thinking I would have plenty of margins.
Can someone plug this into their program and see if I was way out of bounds?
Lapua brass, 28 gr of lt-32, and a 75 gr bullet.
THANKS, Bat
Qwik load help requested. I BLEW ONE UP! - LRRPF52 - 02-15-2022
Quick Load wont have any usable data for that since it seems to need custom calibrating for short, fat cases.
Always work up a load with published start loads or 10% below max, using 1% case capacity increments over a chronograph.
WARNING: QuickLOAD is a computer simulation of centerfire cartridge performance. YOU MUST NEVER just plug in the numbers and use QuickLOADs output for a load recipe. That is foolish and dangerous. There are many reasons why the data QuickLOAD generates may not be safe in YOUR gun. Before loading live ammunition, you should always check with the powder-makers most recent load data. In fact, you should check multiple sources if possible, and consult with individuals who actually load for that cartridge. Sierra Bullets offers free load maps which, in general, are fairly conservative. Even when using manufacturers load data, start 10% low and work up. Differences in brass, primer brand, and seating depth can make huge differences in pressure. Always reload conservatively and always double- and triple-check QuickLOADs output against reliable load data supplied by the powder-makers.
Qwik load help requested. I BLEW ONE UP! - Klem - 02-17-2022
BR,
Need more info for a pressure prediction.
- What is your H2O case capacity?
- What bullet?
- What COAL?
Why do you want to load them hotter than safe limits?
Klem
Qwik load help requested. I BLEW ONE UP! - lazyengineer - 02-17-2022
FWIWgordons doesn't have LT32. Don't know about QL.
Qwik load help requested. I BLEW ONE UP! - jasper2408 - 02-17-2022
My version of Quickload (3.9.0.15 about a month old) doesn't have either one of them listed either. I did a search and found this post that might be helpful.
https://forum.accurateshooter.com/threads/quickload-reverse-engineering-powder-parameters-for-accurate-lt-30-and-lt-32.4052451/
I haven't done any Quickload setups, as there is no 6mm Grendel listed either, to see how close the data from the reloading manuals lines up with my added powder Quickload data. I did add both powders to my powder database like the forum post instructed.
One other thing in my version of Quickload, the default for 6.5 Grendal case capacity is 37.50gr of water. I am assuming that they are using a fired unsized case to measure with. I don't have any fired/unsized cases on hand so am not able to check this assumption.
Qwik load help requested. I BLEW ONE UP! - lazyengineer - 02-17-2022
jasper2408 Wrote:My version of Quickload (3.9.0.15 about a month old) doesn't have either one of them listed either. I did a search and found this post that might be helpful.
https://forum.accurateshooter.com/threads/quickload-reverse-engineering-powder-parameters-for-accurate-lt-30-and-lt-32.4052451/
I haven't done any Quickload setups, as there is no 6mm Grendel listed either, to see how close the data from the reloading manuals lines up with my added powder Quickload data. I did add both powders to my powder database like the forum post instructed.
One other thing in my version of Quickload, the default for 6.5 Grendal case capacity is 37.50gr of water. I am assuming that they are using a fired unsized case to measure with. I don't have any fired/unsized cases on hand so am not able to check this assumption.
Thanks for that
Qwik load help requested. I BLEW ONE UP! - Klem - 02-17-2022
Yes, was looking at that too - Jager's 10% paper adjustment using 2015 as a start. Then using the Grendel as the parent case and changing the water capacity to whatever Bat Rastard measures it at. Then encouraging a 10% low and work up discipline.
Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-18-2022
Klem Wrote:BR,I will try and get H20 capacity.
Need more info for a pressure prediction.
- What is your H2O case capacity?
- What bullet?
- What COAL?
Why do you want to load them hotter than safe limits?
Klem
The max load I was exceeding was 6arc. The ARC is smaller than the Grendel, I was presuming the bigger case would account for the higher load.
OAL was 2.100
Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-20-2022
Klem Wrote:Yes, was looking at that too - Jager's 10% paper adjustment using 2015 as a start. Then using the Grendel as the parent case and changing the water capacity to whatever Bat Rastard measures it at. Then encouraging a 10% low and work up discipline.
Water capacity is 34.8 grains. I used a fired case and filled it to the top.
75 grain Speer HP #1510
COAL 2.1
Qwik load help requested. I BLEW ONE UP! - jasper2408 - 02-20-2022
Bat Rastard Wrote:Water capacity is 34.8 grains. I used a fired case and filled it to the top.
75 grain Speer HP #1510
COAL 2.1
The #1510 bullet is a 75gr Sierra bullet. The Speer 75gr bullet is #1205.
Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-20-2022
jasper2408 Wrote:The #1510 bullet is a 75gr Sierra bullet. The Speer 75gr bullet is #1205.
You are correct sir. It's a Sierra. I had to remember details whilst climbing the stairs to the computer room, and failed.
This getting old thing is taking its toll on me. LOL
Qwik load help requested. I BLEW ONE UP! - jasper2408 - 02-20-2022
Bat Rastard Wrote:You are correct sir. It's a Sierra. I had to remember details whilst climbing the stairs to the computer room, and failed.
This getting old thing is taking its toll on me. LOL
No problem, am there and doing that too.
Qwik load help requested. I BLEW ONE UP! - JASmith - 02-20-2022
Bat Rastard Wrote:I had an UGLY case separation.Where was the separation?
The brass had been used 20-25 times, so it is suspect.
It was also the 1st round of that load, so that is also suspicious.
It is a 6 grendel, and the load data was 6arc. I started .3gr over ARC max thinking I would have plenty of margins.
Can someone plug this into their program and see if I was way out of bounds?
Lapua brass, 28 gr of lt-32, and a 75 gr bullet.
THANKS, Bat
Can you post an image or so?
I ask because 20-25 uses of a case cab lead to metal fatigue and failure even when using light loads.
Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-20-2022
I will try to figure out the picture posting when I get home.
Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-21-2022
I failed to get pictures posted. It has to do with my lack of computer skills. If someone wanted to volunteer to pm me there phone#, I can text them pictures to post.
Qwik load help requested. I BLEW ONE UP! - lazyengineer - 02-22-2022
Bat Rastard Wrote:I failed to get pictures posted. It has to do with my lack of computer skills. If someone wanted to volunteer to pm me there phone#, I can text them pictures to post.
At present, my best route to free image posting is to use:
postimg.cc/files
Qwik load help requested. I BLEW ONE UP! - Klem - 02-22-2022
BR,
With your info the computer predicted max pressure is 50,232lbs. Max SAAMI pressure for the 6ARC is the same as the Grendel, 52K lbs.
[ATTACH=CONFIG]18662[/ATTACH]
This is Jager's recommended powder tweak for LT32, on the other forum.
[INDENT]LT-32:
1. Heat of Explosion / Potential = 3754
2. Ratio of Specific Heats = 1.2370
3. Burning Rate Factor (Ba) = 0.6545
4. Pro or Degressivity Factor a0 = 3.2400
5. Progressive Burning Limit z1 = 0.387
6. Factor b = 1.9175
7. Propellant Solid Density = 1.560
8. Load Density (calculated factor) @ 100% Fill Ratio = 0.880[/INDENT]
Don't take this as gospel - there are a lot of tweaks here and each can confound the final result like tolerance stacking. I used Grendel as the parent case, A2015 as the parent powder, and your water filled case capacity. If you go even further and match the load density with Jager's then the peak pressure is slightly lower at 49K lbs.
If you trust that the load was OK then the case coming apart was from something else, like insipid case separation - Too much headspace. 25 reloads and that case is doing better than most, but by then even if you sneeze it will come apart.
Do you measure headspace? The difference between headspace before and after firing?
Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-22-2022
Thanks all, and especially Klem!
The case separated at the base.
I inspected several other cases with a paper clip. After about 20 of them I thought I found something in one of them. I sectioned the case, and I couldn't see anything because it was black in there. I tumbled the pieces and there was a shiny ring at the base. (which is where the other case came apart) I took the sectioned cases to work and examined them under magnification and found it was indeed cracking there! A co-worker, whose job it is to find cracks in metal, agreed it was cracking there.
I believe the mystery is solved!
I do measure headspace and size appropriately. That brass had only been pushed back .0015" and annealed often.
Qwik load help requested. I BLEW ONE UP! - Klem - 02-22-2022
BR,
It sounds like what you are doing with case prep is best-practise. But as we know cases don't last forever. 25 hammer blows of 50K lbs is going to harden the case and stress it along fault lines.. Annealing is only done to the top part of the case so that won't help longevity. Sounds like the splits are occurring at the junction of the web and the case. Just normal ageing.
Qwik load help requested. I BLEW ONE UP! - Bat Rastard - 02-22-2022
My plan is to inspect the prepped and primed cases. Those that pass inspection, will be fired one last time and retired.
I figured out the pictures!