I thought I settled on my 9mm recipe: I tried from 3.2 to 4.0gr of Titegroup, and settled on 3.8gr for 124gr AIM plated bullets. However, my OAL is about 1.085 instead of recommended 1.100, so the pressure would be a bit higher. The recoil doesn't feel excessive - certainly lighter than factory loads. However, after examining the fired brass, I see that most of the primers are flattened. Do I need to be concerned?
Flattened primers: a really bad sign?
- Thread starter aridan
- Start date
That's an overpressure sign right there.
For the same bullets I use 4.2gr Titegroup at 1.12"OAL and the primers look fine.
Thing is, in the small 9mm case a tiny change in the OAL makes a big change in volume and in the pressure.
Back off the bullet seating die a bit.
For the same bullets I use 4.2gr Titegroup at 1.12"OAL and the primers look fine.
Thing is, in the small 9mm case a tiny change in the OAL makes a big change in volume and in the pressure.
Back off the bullet seating die a bit.
What brand of primers?
Federal primers used to be soft and flattened more than other harder cupped primers. I used them when I reloaded more.
Primer splitting on the other hand is cause for concern.
Flattened primers as far as I know is not always a sign of high pressure.
I'm glad for the OP that you are familiar with and caught the OAL issue.
About the primer, flattening is a relative term, and without us seeing what it looks like a conclusion cannot be reached. I must also ask, flat compared to what? Are you comparing them to other loads you have tried, or the primers of factory loads. I don't know the load, so I can't say whether it's safe or not. Ultimately, however, if you believe that possibly a load is not safe in your firearm, then drop the charge a bit or change the OAL, though I don't see a difference of .015 affecting the pressure, and compare the two primers. Also, if you have a micrometer, you can measure the case head to see if it is out of spec, as "B" wrote.
One other question. If you tried 4.0 grains of titegroup and had no issues, with everything else the same, I can't see how you would have issues with 3.8 grains of titegroup?
One other question. If you tried 4.0 grains of titegroup and had no issues, with everything else the same, I can't see how you would have issues with 3.8 grains of titegroup?
Last edited:
I've been loading thousands of 9mm range brass and primer flowing is way too common while flattened primers are not.
Some samples from today's brass:
Same factory S&B ammo, different guns.
From left to right, the first two are flowing around the firing pin, the third doesn't. None of them is flattened.
Uh, I wish my photo skills were this good... Here are my S&B reloads with a factory S&B (this one fired by someone else's gun):
Guys, big thanks for the info. I AM using Federal primers. The felt recoil is mild, and the cases don't fly as far as factory loaded ones do. I don't know what a primer flowing is, does it indicate temperatures that are too hot? The OAL has to stay around 1.085: I had a couple of FTEs in my Shadow with slightly longer rounds.
One last thing: how do I measure the case head? No silly jokes, please.
Guys, big thanks for the info. I AM using Federal primers. The felt recoil is mild, and the cases don't fly as far as factory loaded ones do. I don't know what a primer flowing is, does it indicate temperatures that are too hot? The OAL has to stay around 1.085: I had a couple of FTEs in my Shadow with slightly longer rounds.
One last thing: how do I measure the case head? No silly jokes, please.
Buy a caliper, RCBS makes them and compare sizes around the base of the case to a new one.
Also: If the case refuses to go in the shell holder it is a good indication that the area around the rim is swelling, and either throw the case out, back down your loads or both.
Also: If the case refuses to go in the shell holder it is a good indication that the area around the rim is swelling, and either throw the case out, back down your loads or both.
I second that. Those primers are not excessively flattened. Probably the primers you are using are a bit softer than the factory S&B primers.
Case head expansion is measured with a blade micrometer accurate to .0001. I don't know that a caliper would work. I have looked through several of my reloading manuals and have noted that all of them give a detailed explanation of the process; so, I would look in your reloading manual for the answer to your question. I would have to say that it is not something easily done, chiefly because you need an accurate micrometer to register the very small values that might indicate excessive head expansion.
Case head expansion is measured with a blade micrometer accurate to .0001. I don't know that a caliper would work. I have looked through several of my reloading manuals and have noted that all of them give a detailed explanation of the process; so, I would look in your reloading manual for the answer to your question. I would have to say that it is not something easily done, chiefly because you need an accurate micrometer to register the very small values that might indicate excessive head expansion.
I just use my RCBS caliper. I only handload for pistol as of late. I think measuring to .001 places is enough unless you are into long range rifle sort of shooting. It's just a piece of a puzzle really. Along with chrono data, primer appearance, ejection and measuring your fired brass it all comes together to give an experienced shooter the information he needs to tell whether or not he is pushing things too far.
I fail to understand the link between longer OAL and Failure To Eject.
Did you eject unfired cartridges ?
Primer flowing around the firing pin is better known as cratering. It is a sign of overpressure as well but not in 9mm which is a high pressure cartridge.
People tend to call Federal primers softer but in fact the primer chemicals are more sensitive. Meaning they'll ignite on lighter strikes. Google primer sensitivity for a better explanation.
I meant Failure To Extract - but now that you've mentioned it, I think I'm confusing things here...
I shrunk the OAL because two out of about 250 rounds fired had failed to extract. The 1st time wasn't so bad - but the 2nd time I needed tools and help from the RO to have the stuck case removed. I barrel-tested almost all of my loads, and couldn't understand why some of them with OAL = 1.095 would pass, and some would fail. I have since fired another 200 with OAL = 1.085 and found no issues with extraction.
I think I'm on the wrong track here altogether, here's why. I only learned about the Glock Bulge a few days ago, when readying to reload .40S&W. Most of my 9mm brass is my own, from factory loaded S&B. However, some 30-40% of it is range-swept - mostly non-S&B but I didn't sort by headstamp. I'm sure that some of it was Glock-fired - I just never checked. I'm using Hornady sizing dies, so AFAIK I'm not resizing the case full-length.
Could this be my problem then? I can't say for sure unless I get something like the EGW undersize die. I don't have this problem with .40S&W because I ran all of them through a Lee FCD die first.
What do you guys think?
2 IM_Lugger: I hear a lot of people are loading at 1.090 and even lower. Being a reloading noob, I never questioned why. BTW, do you use a flat or curved seating stem with your AIM bullets? I've only tried the curved one so far, and found that my OAL varies anywhere from 1.083 to 1.095.
1) As far as flattened primers - those look fine for Federal primers - they are the softest;
2) OAL can be as per loading manual for the bullet you use or shorter, depending on if you hit rifling or not. I just loaded some Berry's 124gr and OAL is
1.1111" - funny, huh? But they work and I'm gonna stick with it.
3) I remember you had some seating-crimping issues with 9mm loads, is it still somewhat there? I'd recommend sorting by headstamp for various reasons, in your case you can prolly eliminate bad brass.
2) OAL can be as per loading manual for the bullet you use or shorter, depending on if you hit rifling or not. I just loaded some Berry's 124gr and OAL is
1.1111" - funny, huh? But they work and I'm gonna stick with it.3) I remember you had some seating-crimping issues with 9mm loads, is it still somewhat there? I'd recommend sorting by headstamp for various reasons, in your case you can prolly eliminate bad brass.
