First time working up a Grendel load

[acourvil]

What you should be looking for is a pressure transducer. "Pressure signs" are meaningless nonsense. This is especially true of loads run thru AR-15s. Given that the weakest link is bolt strength, the first "pressure sign" that you may encounter is sheared lugs and catastrophic disassembly of the rifle. Conversely, lots of guns will show flattened primers, ejector swipes, and other alleged signs of impending doom even with starting loads, due to variation in action timing and other issues that are not pressure. Just about any safe max load will blow primers on the third or fourth loading of Wolf Grendel brass. Not excess pressure. Soft brass.

Relying on "pressure signs" is akin to dowsing for water with a bent stick, except in that a failure in dowsing does not involve releasing 60,000 psi and a cloud of shrapnel six inches in front of your nose.

This and the following related comments are very educational, and I appreciate the information. However, it does not provide any practical advice related to load development, other than as a caution not to assume that a lack of pressure signs does not necessarily mean that the load is safe. I appreciate that caution; in fact, it was the reason for my post that started this thread.

Given, the information you provided, what is your advice for developing loads for the 6.5 grendal in a semi-auto platform? I'm already assuming that development will stay within published manuafaturer's guidelines.

[LR1955]

This and the following related comments are very educational, and I appreciate the information. However, it does not provide any practical advice related to load development, other than as a caution not to assume that a lack of pressure signs does not necessarily mean that the load is safe. I appreciate that caution; in fact, it was the reason for my post that started this thread.

Given, the information you provided, what is your advice for developing loads for the 6.5 grendal in a semi-auto platform? I'm already assuming that development will stay within published manuafaturer's guidelines.

AC:

There really is no need to develop loads blindly anymore. Ten years ago all we had was one set of data from Alexander and when a new powder came out, we used a combination of powder density / burn rate charts, our chronographs, visual means (brass and primer inspection), plus our intuition. Those of us who did this had a bunch of reloading time under our belts which mitigated the risk a little more.

Today there is no need to go through this because there is so much reloading data out on the Grendel that taking the risks we did is not necessary.

There are numerous threads on load development to include a couple on using chronographs to assist in finding good loads.

Run a search and look at any of the fifteen or twenty such threads but do ask when you find conflicting advice.

This isn't magic and is nothing different than any other cartridge, gas gun or not.

LR1955

[JASmith]

+1 !!!

AC:

There really is no need to develop loads blindly anymore. Ten years ago all we had was one set of data from Alexander and when a new powder came out, we used a combination of powder density / burn rate charts, our chronographs, visual means (brass and primer inspection), plus our intuition. Those of us who did this had a bunch of reloading time under our belts which mitigated the risk a little more.

Today there is no need to go through this because there is so much reloading data out on the Grendel that taking the risks we did is not necessary.

There are numerous threads on load development to include a couple on using chronographs to assist in finding good loads.

Run a search and look at any of the fifteen or twenty such threads but do ask when you find conflicting advice.

This isn't magic and is nothing different than any other cartridge, gas gun or not.

LR1955

[acourvil]

AC:

There really is no need to develop loads blindly anymore. Ten years ago all we had was one set of data from Alexander and when a new powder came out, we used a combination of powder density / burn rate charts, our chronographs, visual means (brass and primer inspection), plus our intuition. Those of us who did this had a bunch of reloading time under our belts which mitigated the risk a little more.

Today there is no need to go through this because there is so much reloading data out on the Grendel that taking the risks we did is not necessary.

There are numerous threads on load development to include a couple on using chronographs to assist in finding good loads.

Run a search and look at any of the fifteen or twenty such threads but do ask when you find conflicting advice.
LR1955

I'm not sure exactly what you are trying to say. I started by looking at manufacturer's published info, the info I found here in various threads on load development, and the info in the Grendel handbooks. I used known components in known combinations; I wasn't trying to develop loads blindly. I did see conflicting info on pressure, or at least I did not think it was all that clear. So I posted here to get some guidance, or maybe some reassurance. My apologies if you think I should not have posted.

This isn't magic and is nothing different than any other cartridge, gas gun or not.

LR1955

Thanks, that's clear.

[LR1955]

I'm not sure exactly what you are trying to say. I started by looking at manufacturer's published info, the info I found here in various threads on load development, and the info in the Grendel handbooks. I used known components in known combinations; I wasn't trying to develop loads blindly. I did see conflicting info on pressure, or at least I did not think it was all that clear. So I posted here to get some guidance, or maybe some reassurance. My apologies if you think I should not have posted.



Thanks, that's clear.

Acourvil:

I would go with the published pressures over what any handloader may think. We never had the advantage of Hornady for example, providing pressures and I believe Alexander used a different technique in his pressure determinations than most powder companies.

As someone said, very truthfully, don't go by 'pressure signs' on brass unless what you are seeing is out of the ordinary for that specific rifle. Gas guns are notorious for flattening or cratering primers and causing 'swipe marks' on brass or doing other nasty things to brass like denting shoulders and necks. So, we took such things into consideration when we had to kind of work blindly with a new powder.

Probably the best thing you can get to figure out if you are having pressure problems is a good (reliable) chronograph. Also, there are a couple of threads on using a ladder technique of determining the most efficient powder charge. That, combined with the chronograph is about the best way I have seen to figure out a good way to develop a load.

Also, there are a couple of threads on common powders that may get you started if you are in need of that type of information.

One thing though -- bump the shoulders back on your brass when you re-size. That seems to be the most common handloading problem encountered with the Grendel.

LR1955

[acourvil]

Thanks, that's very helpful.