Pressure signs not showing at Max load

[chickm1]

The flattening is very minimal, but it is there. Not like he was 2 grains over max load, but there is slight flattening.

 

[jasonco]

[QUOTE="Cratered primer is not an indication of over pressure.

A cratered primer is caused by material from the primer cup, being forced back into the firing pin hole, upon ignition. This occurs from too high a pressure in the case. Flattened primer, is from the same thing. Although the flattening on this primer is minimal, it is there. He has just barely exceeded max pressure. You can shoot, but over time, he will have increased head space and will shorten the life of his barrel throat.[/QUOTE]
And that is dependent on choice of primer.

 

[robpiat]

I'm at 2.808 right now. The throat is so long I run out of case before touching the lands.

As I said above, My Hornady 140s are 2.925 in a tikka which is .020 off the lands. Longer oal, more powder, lower pressure.

You have to look a carefully at bullet shape and find one suited for a long chamber. The Hornadys for iinstance are better than a similar weight SMK which is more secant ogive (longer,pointier)

I currently have a 22 cal barrel that was engineered around SMK and won't work well with Berger/Hornady shaped bullets.

 

[chickm1]

A cratered primer is caused by material from the primer cup, being forced back into the firing pin hole, upon ignition. This occurs from too high a pressure in the case. Flattened primer, is from the same thing. Although the flattening on this primer is minimal, it is there. He has just barely exceeded max pressure. You can shoot, but over time, he will have increased head space and will shorten the life of his barrel throat.

And that is dependent on choice of primer.[/QUOTE]

 

[jasonco]

The only true way to gauge cartridge pressure is with a pressure trace device or for use peasants a chronograph. I use a chronograph 100% of the time during load dev and at the loading bench, when I punch out the primers, by the the tension at which they come out of the case and a primer pocket GO-NO GO Gauge.

 

[chickm1]

Some primers have softer cup material, than others. But, if you look at the pictures, you will see, not only the cratering, but the pits across the face of the primer. That whole primer was hot enough, and pushed back against the bolt hard enough, that every grain of dirt on the bolt face, was copied onto the primer. But, hey, that is my opinion. Do what you want.

 

[J E Custom]

Yes, you do in fact have pressure signs on that brass. I see an obvious ejector mark (starts between the two oo's on "creedmoor" and ends between creedmoor and hornady) and cratered primer. I'll post your picture bigger. Don't load any hotter, your at/over max. View attachment 145057

Looked at the pictures again and it looks like you have a little pressure marking at the ejector hole. There is slight scuffing in this area if you look close you will see the circle at or Area of the case.

J E CUSTOM

 

[Royal Knight]

Every newer remington will crater primers like this. For some reason they bevel the firing pin hole. OP please post a picture of your bolt face.

 

[MOOSE39465]

The only true way to gauge cartridge pressure is with a pressure trace device or for use peasants a chronograph. I use a chronograph 100% of the time during load dev and at the loading bench, when I punch out the primers, by the the tension at which they come out of the case and a primer pocket GO-NO GO Gauge.

I plan on bringing the chronograph next range trip. Now that I found a bullet that will group at 100 yards it's time to move out a fine tune. Thanks for the advice.

 

[robpiat]

Every newer remington will crater primers like this. For some reason they bevel the firing pin hole. OP please post a picture of your bolt face.

I also see ALOT worse with Federal GMM factory ammo in many guns.

 

[bdcoon]

You aren't at max charge with 40.5gn of H4350, 140-143 bullet and Hornady 6.5 brass. For whatever reason, the loads were "dumbed down" and 42gn of H4350 is nominal. 43gn is achievable, in my three 6.5 Creedmoor's. Work up in .3 increments.

Cratered primer is not an indication of over pressure.

Huh? I'm confused, why are you suggesting that cratered primers are not an indication of over pressure? I don't mean to be argumentative, I'm just trying to understand where you're coming from.

 

[Clem Bronkoski]

Whoops I forgot to add,,, I have 2 loads I work with,,, hot Sumner day loads,,, and frozen cold winter loads...
That way I get good mileage out of my brass with out eating primers...
-36 to -40 allows for a spike in powder.

If you develop your load correctly temperature shouldn't change your POI dramatically. The OCW method of load development is a way to make your load more stable.
In order to detect any pressure signs you have to have a baseline to compare your visual assessment on. As for the primer cratering, that could be common to that particular rifle. How do the primers look at a lighter charge? The still rounded edges of the primer is what I am looking at. I'd be more concerned if you had a flattened, extruded, or pierced primer. Definite pressure indicators.
Also I don't believe that the slight imaging of the ejector shown is a valid pressure indicator. I would expect a more visible image as a pressure sign such as a raised bump on the case head from the extractor. My edit: Another indication of excessive pressure is a "sticky" bolt.
From my experience almost all manual recorded maximums are well below the actual maximum pressure of most rifles. This is a liability limit by the manufacturer. I have reloading manuals from various bullet manufacturers (Hornady, Speer, Nosler) from 50+ years ago that have max loads for the same bullet/powder combination several grains higher than that of the latest manuals. You need to know what you're looking for in reading pressure indicators. And I'm not advocating that it is safe to exceed recommended maximums. I'm saying if you choose to do so you need to approach cautiously, in small increments, examining each and every fired case.
Here is a good article on reading pressure signs. http://www.massreloading.com/reading_pressure_signs.html

 

[stljc2]

Rifle-Remington 700 6.5 Creedmoor
Bullet-142 Grain Accubond long range
Power-H4350

Went to the range today and done some load development. I was pleased to see my rifle really liked the Accubond long range bullet. When I got to the max load on the Nosler website I examined the cases and was surprised I didn't see any pressure signs. My question is what now? Should I just start increasing to powder charge until I see ejector marks or stop at max? I posted a picture of a case so you could see for yourself.

Besides group, which if it's good. what was the velosity? Was it where you want it for performance?

 

[Havard]

It's a factory Remington SPS with about 75 rounds down.

Moose, I'm loading for the same exact rifle, but different recipe. FYI, I hit pressure early (I think so??) with RL-16 also. 42.7 grains, and I got slight ejector marks and the group opened way up. 42.2 grains shot less than 1/2 and inch and the brass looked perfect. Max charge was supposed to be 43.4; I didn't even bother to shoot the last group. Hope this helps...