Reaching maximum load safely

[dscoduc]

A visit to the reloading store today ended with me coming home with a new powder for my 6.5 Grendel. According to the shop guys the IMR 8208 XBR powder is generally known as the best powder for 6.5 Grendel for 120-123 grain.

After getting home I did a quick look on the IMR Reloading website and noticed the following data:

Starting load: 25.5Grs
Maximum load: 28.5C (What does the C stand for?)

Looking at some forum posts on 65grendel.com I found several posts where people recommended 8208 XBR with loads of 28 grains and 28.1 grains.

I am relatively new to the reloading world and have been weary to get up near the max loads. I would usually have started around 26 grains and likely would have never gone up near 28 grains, but now I am tempted...

What's the consensus on getting near the top of the max loads? The 28.1 grain recommendation is for the Hornady 123g SST which is what I am reloading so I feel like, from this guys experience, it would be a safe load...

Thoughts?

[Eljay]

C usually indicates a compressed load.

re: you main question - there are various traditional pressure signs. You look at the primers primarily for indications that there's a problem. If it seems clear you move up another tenth or whatever. The problem is that a) there's usually no real point to being at maximum and b) if you're going to load routinely at max... what if you load a tenth over by mistake? Two tenths? There's no margin.

But if there's a likely sweet spot a half grain under maximum... I can see doing that. Work your way up to the sweet spot, and if it seems like it's worth pursuing keep loading one tenth at a time up past it but before maximum to assure yourself that if you load just a tiny bit hotter than your intended sweet spot nothing bad will happen.

[silvertriple]

Starting load: 25.5Grs
Maximum load: 28.5C (What does the C stand for?)

The "c" stands for compressed, meaning the powder will be compressed at that charge weight. You'll hear it crunch when seating the bullet.

My grendel shot best with 28.2 gr xbr8208. I eventually stuck with varget.

[savagemann]

The C stands for "Compressed" Load.
You'll most likely hear a little powder crunch as you seat a bullet with the higher loads.
What I would do is evaluate what you want out of the load.
If you are going for long range accuracy, you may need the higher velocity of a heavier load.
If this were the case, I would start around 26gr and work up in .3gr increments until you get to the heavier loads. Once you get closer to max loads, work up in smaller increments.

If you are just going for the most accurate load for general 100-200 yard range use, start at the lowest and work up from there.

I personally have found my most accurate .223 loads with XBR around or slightly above max with a wide range of bullet weights.....but that doesn't necessarily apply to you and the 6.5 grendel. So work em up slow.

[dscoduc]

C usually indicates a compressed load.

Awesome, thanks for that...

So is there any concern with compressed loads? If I get the OAL too short and use a compressed load would this cause over pressure on my round and potentially damage my rifle?

I'm still at that stage of reloading where my first few rounds of reloads are fired with me squinting and hoping I didn't forget anything or misjudge anything... So the whole, near max loads, makes me a little squeamish...

[silvertriple]

I would recommend starting at least at 27.0 and work your way up in 0.3 or so increments until you start seeing pressure signs.

[jericho89]

c is compressed. that means that it will fill the case to the point that the bullet will be pushing on the powder.

[Fjold]

Compressed loads are not a big deal. I regularly shoot compressed loads of 80+ grains of Reloader 15 in my 375 H&H. I'm compressing a good 3/8" of powder after dropping it through a 6" drop tube.

Ideally you should be running as close to 100% of case capacity as possible to prevent the powder from changing position in the case. This can cause variations in the burn of the powder. Uniformity is the key to consistent accuracy.

[ar15barrels]

I am relatively new to the reloading world and have been weary to get up near the max loads. I would usually have started around 26 grains and likely would have never gone up near 28 grains, but now I am tempted...

What's the consensus on getting near the top of the max loads? The 28.1 grain recommendation is for the Hornady 123g SST which is what I am reloading so I feel like, from this guys experience, it would be a safe load...

Thoughts?

How many reloading manuals have you own?
Have you read the "how to reload" chapters?
They should ALL have taken you through how to recognize high pressure signs.

[dscoduc]

How many reloading manuals have you own?
Have you read the "how to reload" chapters?
They should ALL have taken you through how to recognize high pressure signs.

I own and have read through the Lyman Reloading Handbook, Lyman AR Reloading Handbook, and the 6.5 Grendel reloading book. I recall reading the info about pressure signs but I should go back and re-read. Thanks for the reminder.

[ar15barrels]

I own and have read through the Lyman Reloading Handbook, Lyman AR Reloading Handbook, and the 6.5 Grendel reloading book.
I recall reading the info about pressure signs but I should go back and re-read. Thanks for the reminder.

You have two different lyman manuals that will likely mirror each other and the 6.5 grendel reloading book is likely just load data compilations.
Pick up something different like a speer or hornady manual for a different perspective.
Even a 5-10 year old one is fine and they are cheap on ebay or amazon.
Reading the same information from multiple different writers will often help you gel with the information better.

[dscoduc]

I would recommend starting at least at 27.0 and work your way up in 0.3 or so increments until you start seeing pressure signs.

Thanks, likely what I will be doing.

[dscoduc]

You have two different lyman manuals that will likely mirror each other and the 6.5 grendel reloading book is likely just load data compilations.
Pick up something different like a speer or hornady manual for a different perspective.
Even a 5-10 year old one is fine and they are cheap on ebay or amazon.
Reading the same information from multiple different writers will often help you gel with the information better.

Great suggestion for older cheap books on ebay.

I looked at the Lyman Handbook and noticed the section that talks about the shiny ring around the base of the brass - exactly what I am seeing on some of my brass - that means a separation is eminent...

[Eljay]

Awesome, thanks for that...

So is there any concern with compressed loads? If I get the OAL too short and use a compressed load would this cause over pressure on my round and potentially damage my rifle?

I'm still at that stage of reloading where my first few rounds of reloads are fired with me squinting and hoping I didn't forget anything or misjudge anything... So the whole, near max loads, makes me a little squeamish...

It's mostly to warn you not to be surprised when you hear the crunch and think "uh oh, is it supposed to do that?". More to the point keeping the OAL correct is critical at any max load, compressed or not.

I think it's healthy to be nervous around max loads. I'm not saying don't go there, but do it slowly and read all you can about pressure signs. And if you're not sure stop shooting and post some pictures or something.

[dscoduc]

Great suggestion for older cheap books on ebay.

I looked at the Lyman Handbook and noticed the section that talks about the shiny ring around the base of the brass - exactly what I am seeing on some of my brass - that means a separation is eminent...

The attached picture is what I am seeing on some of my uncleaned brass now... Doesn't look like it's ready to break but the line shows pretty clear... maybe one more reload on these cases?