Pressure signs on primers

[mattd]

Was making up hunting loads for my 1911 45acp, 200g Mihec HP and CFE Pistol.

Started at the bottom and worked my way up. I was looking for flattened primers each time and any other typ sign a of pressure. Everything went great shooting and they were accurate loads. No big recoil.

On the last and hottest rounds, i noticed scalloping on the primers. Like the gas blew threw the bottom it looks like. On closer inspection the primers aren’t flattened (what I typ see when I get too hot), but they all look suspect, even the lighter rounds. I loaded to what the book calls for, 1.225”, but that was just a generic 200g bullet.

Since they shot great, and it’s a powder capable of higher FPS, should I load longer and try again, or abandon this effort?

The CFE Rounds are the groups of 3 to the left, the group to the right is 5.5g of 231 and those look normal.

[VariableRecall]

I prefer Win231/HP-38 for my .45 ACP loads. Perhaps CFE pistol runs a pressure curve that makes your cartridges more sensitive to pressure spikes? I’ve never had a blown primer with 231.

[MostlyLeverGuns]

Checking for pressure using primer appearance in the 45 ACP is risky. Most primers won't change appearance until you are well past the 21000 psi of standard pressure or the 23000 psi of the +P loads. 'SOUPING UP' a 1911 45 ACP may not provide significant gains in performance and can beat your gun up. Stick to 'book' loads for powder charge and OAL for best results. Tinker with OAL is sometimes needed for reliable function with SOME bullets, like the 200gr SWC like the H&G 68. An extra 50-75 fps does not get you much for power or trajectory with the .45.

[Milky Duck]

apparently...the way we have been using primers as pressure indicaters for years "is all wrong" and doesnt work...according to many out there now...you "just have to use a chronograph" and plot curves on a graph and look for flat spots and drops in velocity or your just an old fashioned fuddy duddy who knows nothing....apparently.

now me personally
if primers start to look different...I believe things are getting warm so will back off.

[P Flados]

The 45 ACP is only rated 21,000 psi.

The primers you are using are also suitable for use in a 44 magnum.

Think about it. If you are seeing consistently flattened primers in a 45 ACP, you might be approaching the 44 magnum pressure limit, 36,000 psi.

Using multiple sources for load data (and only use data with pressure reported in psi) and combining that with making sure your chrono data does not exceed what you would expect is a good approach to staying under the limit. Looking for "pressure signs" works in higher pressure rounds, but is normally not really worth much for low and mid pressure cartridges.

If you really like a specific load and want a best estimate for pressure and velocity using a tool like Quickload, it can be done for most powders (my version does not have CFE Pistol). You would need to provide barrel length, bullet weight, bullet length, cartridge AOL, powder and charge.

I ran the following for comparison: 5" barrel, 200 gr, 0.545" long bullet, 1.225" AOL, 5.5 gr 231 and got 862 fps at 13,027 psi. It predicted 6.9 grs of 231 would get 1023 fps at 20482 psi. For a +P load, 7.8 gr is predicted to give 1082 fps at 22,600 psi.

[M-Tecs]

Personally if it was mine, I would check neck tension to ensure the bullets were not pushing back from recoil. Since it only happened with CFE Pistol that may not be your issue. On some of the blanked primers it looks like the firing pin hole is on the large size???? Light firing pin springs cause smears and light slide springs causes timing issues.

My 10MM and 460 Rowland primers don't look like that. The 10mm is 37,500 PSI and the 460 Rowland is 40,000 PSI. I will be surprised if it's a pressure issue verse timing?

https://forums.brianenos.com/topic/105322-primer-smear/

[243winxb]

CFE- 200 gr lead @ 7.4 to 8.2 grs 1142 fps is a top loading. Your primes show flow. Mostly slide marked primers, as the action opens. May try a slightly heavier recoil spring?

Make sure bullets are not into the rifling.

What primer? I like WLP. Blue Dot @ 10.5 gr, 200 gr lswc primers look about the same.

[35 Whelen]

Someone please explain how a large pistol primer "knows" to flatten when a 45 ACP load reached its maximum of 23K psi, but at the same time when loaded in a .44 Magnum "knows" to NOT flatten until pressures reach 40K psi.

35W

[M-Tecs]

Someone please explain how a large pistol primer "knows" to flatten when a 45 ACP load reached its maximum of 23K psi, but at the same time when loaded in a .44 Magnum "knows" to NOT flatten until pressures reach 40K psi.

35W

Same for 45 Colt at 14,000 PSI.

[243winxb]

The 1911 45 ACP inertia firing pin does not stay in contact with the WLP. Allows flow of primer. Flow(ACP) different then flattened (44Mag). Both pressure signs.

The 44 mag M29 firing pin/hammer nose stays in contact with the primer a lot longer. A full pressure loading will even produce hammer bounce. A 2nd bump from the firing pin. Bounce can be seen in slow motion on Youtube.

[M-Tecs]

That doesn't explain why the same primer in a 45 ACP shows "pressure" in a 1911 above 21,000 PSI for standard or 23,000 PSI plus P yet in the same 1911 platform a 10 MM at 37,500 PSI or a 460 Rowland at 40,000 PSI doesn't?

Them primers is way smarter than I realized.............................

[slughammer]

Take your firing pin out and weigh it. A steel pin weighs about 60gr, a titanium pin weighs only 30gr.

Some manufacturers use the lighter titanium pins to pass drop testing.

A steel pin has more mass and will dwell in the primer during the peak of the pressure curve, the result will be a primer with an indent shaped like the firing pin.

A titanium pin may retract too fast and allow the primer to flow into the firing pin hole, the barrel then unlocks and smears or shaves the material that was pushed into the hole.

Sent from my SM-G781U using Tapatalk

[mattd]

Lots of great info! I was firing my SBH w full power loads of 2400 and a 429421 right before these shots. Same CCI primers. No issues there.

Don’t have my head wrapped around it yet, but primer swipe I need to look into.

Thanks!

[243winxb]

Factoty 9mm gun & ammo. Photo- When reload matches factory, i stop increasing the powder charge. The target will not notice the lower velocity.

Primer flow into firing pin channel. If reloading to a higher pressure, the primer may "Blank". Meaning -a hole is produced where the firing pin made contact. This piece of metal may enter the firing pin channel or fall into the action.

Yes, the diameter of the firing pin channel could be smaller. I think this G3C firing pin retracts after the strike? Allows flow?

[243winxb]

Someone please explain how a large pistol primer "knows" to flatten when a 45 ACP load reached its maximum of 23K psi, but at the same time when loaded in a .44 Magnum "knows" to NOT flatten until pressures reach 40K psi.

35W

45 acp flow as a pressure sign.

The military has said, firing of primer, no powder, may produce 23,000 PSI in the pocket. https://discover.dtic.mil/

No flash hole on this round.

[Baltimoreed]

The backing out of the primer when it is fired, it flowing around the firing pin into the space between the pin and frame [cratering] and then being reseated into the pocket when the case moves to the rear [edge flattening] is what makes the various deformities on the fired primer. Normal loads don’t deform primers but warm to hot will. Plus there are hard and soft primers that will deform at different pressures. You can’t make generic comments about loads messing with primers unless you know that the primers are all the same manufacture. Federals are considered softest while cci are the hardest. I run cci but like easy loads.

[M-Tecs]

Factoty 9mm gun & ammo. Photo- When reload matches factory, i stop increasing the powder charge. The target will not notice the lower velocity.

Primer flow into firing pin channel. If reloading to a higher pressure, the primer may "Blank". Meaning -a hole is produced where the firing pin made contact. This piece of metal may enter the firing pin channel or fall into the action.

Yes, the diameter of the firing pin channel could be smaller. I think this G3C firing pin retracts after the strike? Allows flow?

Thanks excellent photos to illustrate that this is a spring, timing and or firing pin hole length/size/weight issue and not a pressure issue unless we are to believe factory ammo is routinely sent out above SAAMI max.

[P Flados]

FYI,

I reload primers.

I use range pickup brass as one source of spent primers.

I have inspected a lot of factory ammo primers as fired from a lot of different guns. Primer appearance can be all over the map depending on the gun the ammo is fired from. I do not see any value in "reading" primer appearance without a good "reference appearance".

Primer appearance can be used to estimate pressure for one specific gun when a "reference appearance" is established. If someone exactly duplicates a published load, the primer from this load can be used as one reference point. To be accurate it would probably be better to duplicate more than one "known" load. Running a ladder up to the reference load also gives you reference primers for comparison. The primer appearance will probably change as pressure is increased and specific details may become apparent at specific points. For example, onset of cratering may occur at a specific point in the ladder (say 0.8 grs under max).

The above is not all that that easy and may or may not be conclusive for a given gun at the desired pressure. Most are not willing to go to the effort to carefully "do it right".

[M-Tecs]

FYI,

I reload primers.

I use range pickup brass as one source of spent primers.

I have inspected a lot of factory ammo primers as fired from a lot of different guns. Primer appearance can be all over the map depending on the gun the ammo is fired from. I do not see any value in "reading" primer appearance without a good "reference appearance".

Primer appearance can be used to estimate pressure for one specific gun when a "reference appearance" is established. If someone exactly duplicates a published load, the primer from this load can be used as one reference point. To be accurate it would probably be better to duplicate more than one "known" load. Running a ladder up to the reference load also gives you reference primers for comparison. The primer appearance will probably change as pressure is increased and specific details may become apparent at specific points. For example, onset of cratering may occur at a specific point in the ladder (say 0.8 grs under max).

The above is not all that that easy and may or may not be conclusive for a given gun at the desired pressure. Most are not willing to go to the effort to carefully "do it right".

Agree 100% with the higher pressure loads in rifles. Reading the primer provides valuable information. In low pressure loads like 45 Colt at 14,000 PSI or under not so much. Same for lower pressure semi-autos loads. Most handgun primers don't start showing actual pressure indicators until above 40,000 PSI. In rifles that about 65,000 PSI. Your 1873 first gen Colt and your 1873 trapdoor will be in pieces long before you get "pressure indicators" from your primer.

Both of my Sig 365 XL's have fairly heavy firing pin drag marks. They are both 100% reliable and I could care less about the drag markets.

[414gates]

It is not possible to determine pressure by looking at primers. If it was, strain gauges would not be necessary.

For your pistol, if the primer is not perforating, if the primer pocket is not expanding or if the primer is not being blown out, it is not too hot.

The barrel link on your 1911 will break when the load is too hot for the pistol.

Having said that, it is prudent to verify at what point your reloads are now by checking velocity.