• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Overpressure? (Brass photos)

howabouttheiris

I had a range officer throw a fit when he inspected my brass and scolded me for excessive loads based on flattened primers.

I shoot a very reasonable .308 load of 43.7gn of IMR4064 and 168gn match bullets with large rifle CCI primers out of a Savage 12 F/TR . I throw with a powder measure onto a scale and weigh to the stick every time, so I don't believe there is a systemic powder issue.

I agree the primers are flattened some, but not really different than out of the box Federal Fusion hunting ammo (excluding the difference in color due to the lacquer that is on the federal)

I have included a photo of 2 of each fired this week and would be interested in opinions.
 

Attachments

  • IMG-1007.JPG
    IMG-1007.JPG
    252.5 KB · Views: 732
There's some primer cratering, sure, but it looks like a problem best solved with bushing the firing pin hole in your bolt face. The primers do not look excessively flattened and there are no ejector marks on the case. There's nothing that screams over-pressure to me, based on the photos, and your load is well within the limits of published data.
 
I’m not seeing anything that is a safety issue but I don’t think your pockets will last long at that pressure. I’d bush the firing pin to clean up the cratering and reduce the chances of a pierced primer. Range officer is a nosey jerk. I never joined the local range because of asshats like him. I went for an orientation and walked out after a couple of minutes. Guys like him are killing the sport. I never started competitive shooting because of the control freaks that run the range here.
 
Daveinjax said:
I’m not seeing anything that is a safety issue but I don’t think your pockets will last long at that pressure. I’d bush the firing pin to clean up the cratering and reduce the chances of a pierced primer. Range officer is a nosey jerk. I never joined the local range because of asshats like him. I went for an orientation and walked out after a couple of minutes. Guys like him are killing the sport. I never started competitive shooting because of the control freaks that run the range here.
Click to expand...
I can barely go out shooting in the middle of the dang forest without some clown from another state (I know these people from another forum) driving by to put up signs or spy on me to make sure I'm shooting in a direction he's okay with. I follow the rules and always shoot into massive burms/mountain sides that upon inspection seem to provide a 0 percent chance of my lead bullets ricocheting. Last time this guy and a convoy followed him and they pulled up at light speed and were disappointed to find me shooting in a safe direction and proceeded to tell me of others practicing unsafe methods and nailed several signs up all around me. Yes there are MANY tools in the world and this sport is not immune at all. Our public range isn't bad from what I can tell, their pretty rough and ragged.
 
270WinDude said:
I can barely go out shooting in the middle of the dang forest without some clown from another state (I know these people from another forum) driving by to put up signs or spy on me to make sure I'm shooting in a direction he's okay with. I follow the rules and always shoot into massive burms/mountain sides that upon inspection seem to provide a 0 percent chance of my lead bullets ricocheting. Last time this guy and a convoy followed him and they pulled up at light speed and were disappointed to find me shooting in a safe direction and proceeded to tell me of others practicing unsafe methods and nailed several signs up all around me. Yes there are MANY tools in the world and this sport is not immune at all. Our public range isn't bad from what I can tell, their pretty rough and ragged.
Click to expand...
And why are they putting up signs in a public forest ? Why are you putting up with their harassment in a public forest ? I’d have the law on them in a heartbeat.
 
Primer flattening is probably the least reliable pressure sign. You can get some information from it, but when all the other evidence says your load is fine, then it's probably fine. Those look normal to me - just slightly flattened. If they were mashed flat, I'd back off.

The cratering is not good, but it's more likely due to a sloppy Savage bolt face/firing pin than high pressure. On a well put together rifle, you don't see that unless pressure is really high.

Bottom line is that these signs get murky with factory actions in ways that they don't with customs. I'd watch for signs, but believe the books, more or less.
 
These are the main indicators of overpressure. Also a heavy bolt lift after firing. The 2nd show what you might see in a semi auto like an AR, a swipe mark as it ejects. The 3rd shows a primer thata isn't flattened but has a large crater. For the most part I ignore the primer but if I see any traces of the first 2 examples, I back the load down. (Just my opinion)
Overpressure.jpg
 
Nothing special in the way of pressure. Might just be a couple of those cases are just a bit less in headspace dimension. I have seen as little as a .001" headspace difference start some primers showing that "proud" pin indication.

A primer with a harder cup might also stop that issue. Frankly, I would just soldier on and to me that's not a big deal at all.
 
I think there is more of a problem with the Range Officer then the rounds . Power is more in his head then in your cases . Why was he looking over your shoulder ? Never saw that at my range . I've had guy's open there bolts an having the case head in the bolt face and the case stuck in the chamber, anyone have a stuck case removal tool for a 308 .

Only time the RO jumped on someone was for handling the firearm in a unsafe manner of racking the firearm with the action closed . People work up loads at the range , your cases seem fine . I would give him another chance . Chalk it up as a bad day for him.
 
T-shooter said:
These are the main indicators of overpressure. Also a heavy bolt lift after firing. The 2nd show what you might see in a semi auto like an AR, a swipe mark as it ejects. The 3rd shows a primer thata isn't flattened but has a large crater. For the most part I ignore the primer but if I see any traces of the first 2 examples, I back the load down. (Just my opinion)
View attachment 1059394
Click to expand...
In the first picture it looks like the rim is split. Is that a pressure sign or is it the shiney swirl mark?
 
It more like the head slamming into the bolt face pressing against the ejector plunger. Not good , overpressure flattening of the writing on the base.
 
I never go by primer appearance alone, even cratering WITHOUT flattening is most likely a bolt problem rather than a pressure problem.
I run a load in Win brass with either FED215 or WLRM primers, pressure is a little more with the Win primer, according to the pressure trace, BUT the Federal primers are ALWAYS much flatter then the Win primers ever are. In this particular rifle, excessive pressure is reached when a slight crater is seen without any other symptons, one more increase in powder normally has ejector marks with heavy flattening and very hard bolt lift.
Just recently I acquired a new match barrel, I proceeded to do a new work up and was unable to use my previous accuracy load in the barrel it’s replacing. I had flattened cratered primers, ejector marks and hard bolt lift while the previous load showed no evidence of over pressure.
I did not get a velocity reading which was perplexing at the time, the previous load showed me to be at about where the accuracy node was, but failed to prove that on target.

Cheers.
:)
 
I am an NRA certified RSO. (Whoopie right?) at our range we have a no shoot without an RSO present policy. (Insurance was cut in half when we set that into play) I have never ever in my life looked at anyone's brass...unless he says he doesn't want it and I need to reload something. My job is to make sure everyone safe handles, knows which way is 'down range' and practices safety in all they do.
 
You must log in or register to reply here.

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Classified Ads

Forum statistics

Threads
165,975
Messages
2,206,875
Members
79,233
Latest member
Cheeapet

Share This Page

Back
Top