Lapua Brass - soft?

[med358-boise]

I have used various brass - federal, hornady, winchester, lapua, norma, sig across probably 15 cartridges and two dozen rifles. I am not a find my max pressure and then back down from there type of loader. I normal start low and load a few safety check rounds and then run an OCW from just below mid-point up to book max if I need to.

Only with Lapua brass (308 - two different rifles, 7mm-08 1 rifle, 6.5x55 1 rifle) have I experienced the following with loads around 1 to 1.5 grains below book max and on up to book max: No sign of any flattened prior, no chrono'd excessive velocity but stiff bolt lift and ejector marks.

Thoughts?

 

[Calvin45]

I have used various brass - federal, hornady, winchester, lapua, norma, sig across probably 15 cartridges and two dozen rifles. I am not a find my max pressure and then back down from there type of loader. I normal start low and load a few safety check rounds and then run an OCW from just below mid-point up to book max if I need to.

Only with Lapua brass (308 - two different rifles, 7mm-08 1 rifle, 6.5x55 1 rifle) have I experienced the following with loads around 1 to 1.5 grains below book max and on up to book max: No sign of any flattened prior, no chrono'd excessive velocity but stiff bolt lift and ejector marks.

Thoughts?

LAPUA brass (and Peterson) have less internal volume than most. Thicker case walls. So an equal powder charge in say Norma or Winchester brass will generate notably less chamber pressure (and velocity) because it's the same amount of powder in a higher capacity case.

 

[liber]

Is this new brass? I was thinking they possibly need trimming if not.

 

[lancetkenyon]

Lapua is my #1 choice if they make it in the cartridge I am using. If you are getting stiff bolt lift and ejector with Lapua, you are over pressure. As @Calvin45 stated, they use slightly thicker brass, so less case capacity compared to others. If you are looking at load info, everything must be exactly the same. Even then, too many variables to be definitive like brass lot, powder lot, barrel bore diameter, etc. Reloading books are a guide, not a Bible.

 

[Pdyson]

Lapua is my go to brass followed by Peterson, Alpha, followed by ADG and Norma.
I'm wondering if this problem showed on your 1st firing on new brass or your reloads. This is probably an uneducated wild guess but If it only shows up on reloads your die may not be sizing all the way down to the base. Granted, This typically leads to clickers but if bad enough could cause a stiff bolt lift. Lube, solvents or water in the chamber can also also brass to slide back into the bolt face before sealing against the chamber wall showing pressure signs minus the cratered and flattened primers.

 

[med358-boise]

Lapua is my go to brass followed by Peterson, Alpha, followed by ADG and Norma.
I'm wondering if this problem showed on your 1st firing on new brass or your reloads. This is probably an uneducated wild guess but If it only shows up on reloads your die may not be sizing all the way down to the base. Granted, This typically leads to clickers but if bad enough could cause a stiff bolt lift. Lube, solvents or water in the chamber can also also brass to slide back into the bolt face before sealing against the chamber wall showing pressure signs minus the cratered and flattened primers.

"clickers"? Not familiar with that terminology.

 

[med358-boise]

And yes it is new brass that has been sized and trimmed. This has occurred during load development.

 

[cohunt]

"clickers"? Not familiar with that terminology.

Seach it, it's discussed quite a bit here

 

[liber]

"clickers"? Not familiar with that terminology.

As @cohunt suggested, you should search it to get a better answer, but this problem happens mostly at high pressure, where part of the case sticks to the chamber wall, and presents a distinguishable click when you pull the bolt back to eject. This has also been a problem with nickel plates cases from Starline on the 6.5 Grendel as well as 300 blackout. I've been shooting the plated cases in 300 blackout and don't see that issue, using Hornady CX bullets. Hornady uses nickel plated brass on their Outfitter series I believe. I shoot mostly hand loads.

The nickel cases look cool though, I call them Lone Ranger Bullets as they do look like silver bullets, well, silver cases...mine look like copper bullets...

 

[med358-boise]

The nickel cases look cool though, I call them Lone Ranger Bullets as they do look like silver bullets, well, silver cases...mine look like copper bullets...

That is why I always carried Winchetser Silvertips when on duty on Halloween night? You know, in case of werewolves

 

[Dirtrax]

I'm going with the new, previously unfired explanation. The stretch in the brass causes greater bolt thrust. Your third firing should should be closer to what one would expect from subsequent shots.
This assumes proper shoulder bump.

 

[liber]

That is why I always carried Winchetser Silvertips when on duty on Halloween night? You know, in case of werewolves

As a kid I worked for my family in a liquor store, and I can say without question that a full moon has some strange effects on people. All of the LEOs I knew in that area when I was a kid said the same thing...not all full moons, but some can bring out the worst...

 

[med358-boise]

As a kid I worked for my family in a liquor store, and I can say without question that a full moon has some strange effects on people. All of the LEOs I knew in that area when I was a kid said the same thing...not all full moons, but some can bring out the worst...

There is actually a simple and "scientific" explanation for this. Humans relative to other animals have poor night vision. When there is a very bright full moon, we can see better at night; hence we are more comfortable being out at night. More people out, more interactions with others, and a better operating environment = calls for service/more crime.

 

[Calvin45]

As a kid I worked for my family in a liquor store, and I can say without question that a full moon has some strange effects on people. All of the LEOs I knew in that area when I was a kid said the same thing...not all full moons, but some can bring out the worst...

Oh it does! Father of four young kids, some nights if all of them are being absolutely hyper and fighting each other and causing mayhem more than usual my wife and I look at each other and realize at the same time

"Oh….its a full moon, isn't it…."

My mom used to work at a nursing home. They observed a very real increase in violent incidents involving schizophrenic patients as well as Alzheimer's patients attempting to sneak out of the facility in pajamas at -30 outside, which would have been very bad and possibly ended in someone freezing to death indeed.

My wife worked in public low income housing for a while and as such worked with the RCMP and social services a lot, lots of issues with crime and drugs and domestic violence and mental health disturbances. Many of the social workers and police officers are absolutely convinced there's a spike in "events" surrounding the full moon, heck one cop that she knew said they have it marked down at the precinct!