Pressure signs not showing at Max load

This is one of those technical things that says...just stop! Sure you can go higher and be OK. But that one day an extra pebble of powder falls in or the atmospherics are a little warmer than you thought. You leave a cartridge in the already hot chamber a few seconds longer. If you need more speed get a bigger cartridge. I know two people who've pushed that one more grain envelope. One has three useable fingers on one hand now and the other wears a cool pirate patch on one eye. He cant walk well on uneven ground because his depth perception is gone. Why push it? As one post clearly shows you have a max+ load and you didnt know the obvious signs. Just stop.
 
codyadams said:
Blown up more.View attachment 145058
Click to expand...

Very nice photo and analysis. If I had a good camera, I'd show the cases of factory .223 WSSM; flat primers, a little lip around the firing pin indentation, but no ejector marks. "Pressure signs" can be subjective if you have soft or hard brass. Only way to know is to use Pressure Trace https://www.shootingsoftware.com/pressure.htm or the expensive Oehler 85 https://oehler-research.com/system-85-ballistic-instrumentation/.
 
Any time you see a ejector mark on the base of the case it means the pressure was so great the brass flowed into the ejector hole. This means the brass stretched beyond its elastic limits for that brand of brass. And if you took a before and after measurement of the base diameter just above the extractor groove you would see a increase in diameter.

Bottom line your brass will not last as long and your primer pockets will stretch out of shape.

Below is from accurateshooter.com and this long range shooter increased the load until he got brass flow into the ejector. He then backed of the load 1 or 2 grains after finding the elastic limits of the brass. And ejector marks vary by brass hardness and Lapua is noted for having harder brass.

KtO65uH.jpg


Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/rel...-trick-monitoring-pressure-your-rifle-reloads
 
MOOSE39465 said:
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.
Click to expand...
41.5 GRS and you will not see pressure either
 
skipglo said:
41.5 GRS and you will not see pressure either
Click to expand...

Sorry to disagree Skipglo. That is a dangerous statement! You or anyone else can't make that statement with out having the rifle in hand and the opportunity to work up a load. He is already showing pressure signs at 40.5

He could have a tight barrel, a tight neck, bullet seated into the lands, etc. Any number of things could cause his rifle to be on the edge of too much pressure.

I have always had a policy of not quoting loads that are not in a book somewhere. If you do, you can be held liable if someone hurts themselves. Let the manufactures take that risk.
 
You guys are getting too hung up on group size. Please do some research on Optimal Charge Weight (OCW). I used to do the same thing. This changes my whole prospective on load development. Yes, that group is perfectly fine for 100, even 200 yards. But at 300 and beyond you may be missing a whole bunch.
And Moose as far as cratered primers being a pressure indication, its usually not. Any slop in the bolt face and firing pin will cause a primer to look cratered. You saw the earlier post. Those cases you showed DO NOT show any signs of excessive pressure.
Instead of wasting your time and money shooting and looking for the smallest group, I urge you to look at the link I posted earlier regarding Dan Newberry's method of getting your optimum charge weight. Then I hope, like me, you will see the light.
 
MOOSE39465 said:
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.
Click to expand...
Just looking at fired cases will not give you an accurate reading.
The only way we reloaded have a judging pressures is by measuring a factory case fired in your chamber with a 0.0001" micrometer.
When you fire several cases of factory ammo, measure your case expansion , average this number.
When you are starting with your minimum load and working up, measure your fired hand load with the 0.0001" micrometer, once your hand loaded cases expand the same as your factory cases then you have reached the maximum load in your chamber and components.
 
Here is what I would do in your instance. Load all the following rounds .010" off the lands. Then:
1. Load 2 or 3 rounds with the following charges of H4350 and your 142 gr AB (your preferred bullet and powder) Charges 38.0, 38.8, 39.6 gr. These will be your sight in shots. Note, the extras will be so you can group around your point of aim with these 3 charges.
2. Now, load 3 rounds each of the following charges: 38.3, 38.6, 38.9, 39.2, 39.5, 39.8 40.1, 40.4, 40.8, and 41.1 (your last charge should be one step above your max listed charge.) Note: Its a good idea to write the charge weight on the case. You never know. You may drop your bullet box and you have a mess of different charges scattered on the ground.
3. Set up 10 target dots plus your sight in dot. Shoot your sight in shots (one of each charge from #1 above), adjust your scope as necessary and confirm with another group.
4. Now shoot a round of charge 1 at target #1, one round of charge 2 at target #2 until you have fired one shot of each charge at each target.
5. Allow the barrel to cool and reverse the round robin shooting starting by shooting charge 10 at target #10 and working your way back to target #1 with charge 1.
6. Then start again at target #1 after a cool down.
EDIT: I forgot to add - CHECK EACH CASE AFTER FIRING FOR EXCESSIVE PRESSURE.
You will notice that the center of your groups will drift off your point of aim and then begin to work back to it. DO NOT WORRY ABOUT GROUP SIZE.
Record the distance from the center of your group to the center of your aim point. The 3 groups closest to your aim point will be your optimum charge weight. So you will load in the center of this range. This will give you the most stable load. With your combination of bullet and powder, the load is the most heat and pressure stabilized because the bullet is leaving the barrel when the reverberating barrel harmonic (shock wave) is back at the chamber and your barrel is at its most stable point.
Your group size can now almost surely be reduced by adjusting your OAL in .005"-.010" increments.
I hope this helps. If anyone else has anything to add please do so.
 
Last edited:
MOOSE39465 said:
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.
Click to expand...
going faster is not always a good thing. just me, but I would focus on grouping more than speed some times going faster can cause your grouping to open up.
 
I have seen with Hornady 6.5 brass they won't show pressure signs, they just pop the case heads. I got 250 rounds of the nicest looking once fired Hornady Amax factory loads back from when they were having pressure problems. Second loads looked good but 3rd the bright ring showed up and 1 split about half way around the case. I don't push 6.5 Hornady brass to the max anymore, I'll hot rod my .260 AI first.
 
Nitroman said:
Very nice photo and analysis. If I had a good camera, I'd show the cases of factory .223 WSSM; flat primers, a little lip around the firing pin indentation, but no ejector marks. "Pressure signs" can be subjective if you have soft or hard brass. Only way to know is to use Pressure Trace https://www.shootingsoftware.com/pressure.htm or the expensive Oehler 85 https://oehler-research.com/system-85-ballistic-instrumentation/.
Click to expand...
This is true, but anytime you see ejector marks (more important than primer craters imo) then the brass is being pushed close to it's max. Doesn't necessarily mean you have reached max SAAMI or CIP pressure, just that the brass is being pushed, and the brass is the limiting factor. If the brass is so soft that you blow a primer or get stuck brass at 64,000 psi, but SAAMI max pressure for your cartridge is 65,000 psi, then you can't load to a max load of 65,000 psi, it doesn't matter if the cartridge is designed around 65,000 psi, the components of the cartridge are being pushed to far to do that.

I would bet that the majority of people on this site are loading to pressures well above what SAAMI or CIP state is max pressure, with perfectly acceptable results. If they are using strong Lapua, Peterson, ADG, or whatever brass that withstands the pressure, then as long as they are not pushing the threshhold of the action, that is fine. But the fact is that softer brass will not be able to hold up to the pressures that high quality brass can, so therefore the two ends of the spectrum (weak vs strong brass) will have different max loads.
 
Clem Bronkoski said:
Here is what I would do in your instance. Load all the following rounds .010" off the lands. Then:
1. Load 2 or 3 rounds with the following charges of H4350 and your 142 gr AB (your preferred bullet and powder) Charges 38.0, 38.8, 39.6 gr. These will be your sight in shots. Note, the extras will be so you can group around your point of aim with these 3 charges.
2. Now, load 3 rounds each of the following charges: 38.3, 38.6, 38.9, 39.2, 39.5, 39.8 40.1, 40.4, 40.8, and 41.1 (your last charge should be one step above your max listed charge.) Note: Its a good idea to write the charge weight on the case. You never know. You may drop your bullet box and you have a mess of different charges scattered on the ground.
3. Set up 10 target dots plus your sight in dot. Shoot your sight in shots (one of each charge from #1 above), adjust your scope as necessary and confirm with another group.
4. Now shoot a round of charge 1 at target #1, one round of charge 2 at target #2 until you have fired one shot of each charge at each target.
5. Allow the barrel to cool and reverse the round robin shooting starting by shooting charge 10 at target #10 and working your way back to target #1 with charge 1.
6. Then start again at target #1 after a cool down.
EDIT: I forgot to add - CHECK EACH CASE AFTER FIRING FOR EXCESSIVE PRESSURE.
You will notice that the center of your groups will drift off your point of aim and then begin to work back to it. DO NOT WORRY ABOUT GROUP SIZE.
Record the distance from the center of your group to the center of your aim point. The 3 groups closest to your aim point will be your optimum charge weight. So you will load in the center of this range. This will give you the most stable load. With your combination of bullet and powder, the load is the most heat and pressure stabilized because the bullet is leaving the barrel when the reverberating barrel harmonic (shock wave) is back at the chamber and your barrel is at its most stable point.
Your group size can now almost surely be reduced by adjusting your OAL in .005"-.010" increments.
I hope this helps. If anyone else has anything to add please do so.
Click to expand...
Thank you Clem for the info. I will give it a try Friday.
 
You have to be careful when you load max and then take your rifle to desert and shoot during 110F weather
 
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