Causes of OVERPRESSURE

[Coyote Shadow Tracker]

OVERPRESSURE signs in brass/primers.
Besides one of the common causes of having a HOT load. What are some of the causes of OVERPRESSURE?
Improper chambering
Bullet into the Lands
Tight necks
Tight neck chambers
???????????????
Also what are some Corrections/fixes for Overpressure causes?

 

[nksmfamjp]

Extreme humidity while reloading. I try to reload at 58-68F and 40-55% humidity. I have a humidifier to keep that acceptable in the winter. There are 1-5 days a year I don't throw powder because humidity is high, but this is rare.

 

[Frog4aday]

Bore obstruction or partial obstruction. Always look down the bore before firing if you've stuck anything into the barrel (cleaning rod, borescope, scope collimator, etc.) Just takes a moment to take a quick look on a bolt action or AR to be sure all is clear.

 

[Pdyson]

Signs of over pressure may be over annealed or soft brass. A few years back, I bought a new 28 Nosler Heritage rifle. I also bought a box of their match grade ammo, a set of Redding type S FL dies, and two 50-count boxes of premium Nosler brass.
After checking data on Noslers website, I took the new brass and loaded some accubond LR over 80 to 83grains of Retumbo to fire form brass and break in the barrel. I fired 80 and 80.3 but saw pressure signs at 80.6 (heavy bolt lift, shaving brass and Deep ejector marks. I went home and pulled 25 bullets. Re weighed my powder and found nothing wrong. So I loaded them again with imr 8133. Same thing! I went home and pulled bullets again. Velocity measurements were low both times. I suspected soft brass and confirmation came with a new box of Peterson brass. I was able to achieve full velocity without pressure signs. I should have sent the brass back to Nosler but I didn't, I threw over $200 worth of Nosler once and twice fired brass in the trash. I'll never trust them again.

 

[BallisticsGuy]

Wrong powder. ex. Thinking that IMR4350 is the same as H4350.

 

[Tidus56]

Not getting your chamber dried out after cleaning will give you signs of over pressure. I have only seen it once when I didn't get the bolt face dried off well enough. Just something to keep an eye out for.

 

[lancetkenyon]

Overcharge
Excessive fouling
Carbon ring at the throat
Too much headspace
Tight spot in the bore
Soft brass head (could cause inaccurate readings too)
Too much neck tension
Bullet weld
Hard into lands
Improper case sizing

 

[PddPdd]

Brass length over spec and bullet is being crimped when chambered.

Part of the answer may be to understand whether you are getting good velocities before reaching pressure or not?

 

[milboltnut]

I had jammed bullets open primer pockets, no other pressure signs. Stiff bolts from hot load. Excess recoil from hot loads. Had sooty primers from under charge. Had pierced primers from excess head space along with excess recoil.

 

[Pdvdh]

Reloading ammo while intoxicated.

 

[Buckys]

Barrel hydraulics - gun oil, etc.

 

[skipglo]

Compressed loads can be another cause with seating depth adding to it

 

[skipglo]

Good morning Muddy!

 

[Muddyboots]

Media left in case
Insects in case (yes, I had one - spider but caught it since powder height wrong)
Change in components (brass, primer, powder lot numbers etc.)