Over pressure sign???

COLTSFANATIC1

COLTSFANATIC1

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Do these primers have the over pressure / increased pressure signs. The load shoots really well and I don’t have any sticky bolts.

If this is a over pressure sign, it would be wise to back down the load, does anyone run hot loads due to the good group results. Other than the rifle blowing up, when is a load to hot.

Appreciate any and all advice. 62104ED3-08AA-4454-81C9-D10002E74F87.jpeg
 
"Reading" primers is a fool's game. The ones in the picture might indicate excessive pressure. Or they might indicate soft primers. Or excessive bushing gap. Or massive overpressure. Or nothing at all.

Primers - along with all the other pressure guessing "tools" - are almost useless compared with a chronograph and a loading manual. If those primers came out of a gun which was used with published loads, and which ran at the expected speed, then everything is fine. Otherwise, only the good lord knows what the pressure might have been.
 
What does the bolt face look like?

Are they different loads or just different primers, what are we looking at difference wise. Or what is different about the right column vs all the others?
 
COLTSFANATIC1 said:
Do these primers have the over pressure / increased pressure signs. The load shoots really well and I don’t have any sticky bolts.

If this is a over pressure sign, it would be wise to back down the load, does anyone run hot loads due to the good group results. Other than the rifle blowing up, when is a load to hot.

Appreciate any and all advice. View attachment 1197651
Click to expand...
Primers aren’t the best way to determine if a load is over pressure. And while some may see the cratered primers as a possible sign, the edges of the primers are still rounded (as opposed to flattened), and there is no sticky bolt lift I would probably think they are okay. The cratering of primers can also be caused by an undersized firing pin or an oversized firing pin aperture in the bolt face. You could have a gunsmith check those.
Also, I can’t help but notice you have 3 different kinds of brass. Not all brass is created equal, you might try weighing the cases or measuring the water volume. They do have varying case capacity, and what might be safe in a Winchester case could be pushing it in a PPU case.
The last tool is a chronograph. Compare the velocity of your loads to similar (or exact) published loads. Pressure is what makes velocity, and if your speed seems exceptionally high, you may be in the danger zone.
One other option is measuring case expansion and comparing it to known safe loads or factory ammo.
 
Last edited:
jmorris said:
3C888517-6044-4A40-A8BF-28FBFE32482F.jpeg B96A604C-8EA0-465E-92BD-229EC3619816.jpeg What does the bolt face look like?

Are they different loads or just different primers, what are we looking at difference wise. Or what is different about the right column vs all the others?
Click to expand...
Attached are photos of the bolt face.

The column on the right was a full grain lighter than the rest.

2ndtimer said:
The last tool is a chronograph. Compare the velocity of your loads to similar (or exact) published loads. Pressure is what makes velocity, and if your speed seems exceptionally high, you may be in the danger zone.
One other option is measuring case expansion and comparing it to known safe loads or factory ammo.
Click to expand...

These are all loaded with published load data, expansion is not excessive, and everything chronos is n range of where it should be.

frogfurr said:
What are you shooting? Factory ammo or reloads?
Click to expand...

They are all hand loaded non factory ammo.



It seems that the primers are probably fine and not signs of excessive pressure, since everything else is reading normal. This is why I asked the question, I appreciate everyone’s response. Thanks
 
Leave it to me to be the odd man out.
I had an instance with overpressure on my .380ACP once. Primers were cratered exactly like that. I took a photo and sent it to Speer, who recommended I start backing off my loads a tenth of a grain at a time until they disappeared...and they did...after about five tenths. I might suggest the same? If they don't go away, then at least you know it's not an overpressure issue.
 
Captain*kirk said:
Leave it to me to be the odd man out.
I had an instance with overpressure on my .380ACP once. Primers were cratered exactly like that. I took a photo and sent it to Speer, who recommended I start backing off my loads a tenth of a grain at a time until they disappeared...and they did...after about five tenths. I might suggest the same? If they don't go away, then at least you know it's not an overpressure issue.
Click to expand...

I think I’ll take that advise! Thank you.
 
COLTSFANATIC1 said:
I think I’ll take that advise! Thank you.
Click to expand...
My anecdotal evidence: I have a Remington 700 SPS Varmint chambered in .223 Remington. From the day I got it, it has cratered primers in pretty much ANY ammo fired in it beyond weak starting loads, including multiple brands and bullet weights of factory ammo. None of which was loaded to higher than recommended loads for the bullet weights used. Clearly it is an issue with the rifle, not the loads. But it has been quite accurate over the years, so I have never bothered to address the cratered primers.
If you are satisfied with the velocity, accuracy and consistency of the loads in the right column, great! Go with those. But don’t assume that the other loads are over pressure just due to the cratered primers. Just wondering, does factory ammo show cratered primers?
 
COLTSFANATIC1 said:
The column on the right was a full grain lighter than the rest.
Click to expand...

That seems to reduce the pressure enough that they are not extruding into the chamfer on the bolt face.

78B7379A-263A-44B4-B76C-E8769A231429.jpeg

I don't see a lot of signs that the case is flowing into the ejector hole though.

7CE906DA-7A80-405A-A589-A3D5F4AAC9E7.jpeg

Out off curiosity, could you weigh the cases on the left, then fill them with water to the rim and weigh them again? Wondering what the internal volume difference is between the Hornady and PPU brass, in grains of H20.
 
COLTSFANATIC1 said:
Do these primers have the over pressure / increased pressure signs. The load shoots really well and I don’t have any sticky bolts.

If this is a over pressure sign, it would be wise to back down the load, does anyone run hot loads due to the good group results. Other than the rifle blowing up, when is a load to hot.

Appreciate any and all advice. View attachment 1197651
Click to expand...
Do you have a ways to measure the FP hole ( pin gauges) and FP (micrometer) to determine if you have excessive clearance? Primer flow can be a indication of over pressure but it can also be from too much clearance. You normally want a Max of 0.002" clearance. Once you get more than that you will get primer flow even on low pressure rounds. If excessive clearance have it addressed if your going to shoot this rifle a lot. Eventually you will run across some primers that have a weaker cup and blow through. Then you start damaging your gun.

Looks like you still have rounded primer edges which is a indicator your good. A few look flatter than others but being mixed brass this can be expected. Sort brass by mfg, or by case volume. Internal volume is what you need to be concerned about. But with a big case like the 300 Win Mag, there is lots of volume so small differences is probably not going to be a problem.
 
jmorris said:
Out off curiosity, could you weigh the cases on the left, then fill them with water to the rim and weigh them again? Wondering what the internal volume difference is between the Hornady and PPU brass, in grains of H20.
Click to expand...
I’ll do this and reply with my findings.

Blue68f100 said:
Do you have a ways to measure the FP hole ( pin gauges) and FP (micrometer) to determine if you have excessive clearance? Primer flow can be a indication of over pressure but it can also be from too much clearance. You normally want a Max of 0.002" clearance.
Click to expand...

I don’t have any pin gauges, should get some I suppose. I can try and check it with a micrometer. Stay tuned.

N555 said:
How many reloads do you get before the primers start going in suspiciously easy?
Click to expand...

Some primers start going in easy around the 4th load or after. I haven’t had anything to loose or want to fall out. I’ve actually only experienced that when loading for 410 shot shells.
 
COLTSFANATIC1 said:
I’ll do this and reply with my findings.



I don’t have any pin gauges, should get some I suppose. I can try and check it with a micrometer. Stay tuned.



Some primers start going in easy around the 4th load or after. I haven’t had anything to loose or want to fall out. I’ve actually only experienced that when loading for 410 shot shells.
Click to expand...
If they seem to go in a bit easier on the 4th firing that's not bad. Ideally they're still going in nice and snug even on the 6th to 8th firing, but sometime you find most accurate load a little over the max book powder charge. Hey at least they're not falling out on the 3rd loading.
If you get some cheddite 209 primers they're about one thousands bigger than domestic 209 primers, probably get one more firing out of your 410s.
 
COLTSFANATIC1 said:
These were loaded up with

168 gn Hornady BTHP
CCI #200 LRP (silver) Win Match Grade LRP (copper)
Right column 78 gns IMR 7977
The rest 79 gns IMR 7977
Click to expand...
Hodgdon's reloading site says use a magnum primer with that load. They used Winchester, but I think that would be CCI #250, not #200. Maybe it has a harder cup? Never used them, and I don't do that cartridge, just throwing in food for thought.
 
At this point , as much as it might hurt your wallet I would get a box of factory ammo and shoot a couple-three rounds and compare to your reloads. That will tell you fast if the bolt face/FP hole is the problem. I see regular primers with rounded edges and flow around the primer due to too large a hole. But I have been wrong before so this with a couple grains of salt. Also you will usually find two nodes of accuracy between min and max charge. I find the lowest one is usually the widest and therefore most stable. My reloads are centeted on that node for best accuracy. Just sayi'n.
 
FROGO207 said:
At this point , as much as it might hurt your wallet I would get a box of factory ammo and shoot a couple-three rounds and compare to your reloads. That will tell you fast if the bolt face/FP hole is the problem. I see regular primers with rounded edges and flow around the primer due to too large a hole. But I have been wrong before so this with a couple grains of salt. Also you will usually find two nodes of accuracy between min and max charge. I find the lowest one is usually the widest and therefore most stable. My reloads are centeted on that node for best accuracy. Just sayi'n.
Click to expand...

I’ll get some factory ammo and try it out.

If the pin hole is the issue, would this be an issue that I would need to fix? Would it be fine as long as I back down the load until the primers dont show the overflow ring?
 
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