This is my second batch of 308 reloads. The rifle is a Remington 700 with 26" heavy barrel. The cases are Kaleo Arms processed brass, CCI primers, Sierra 150 grain Game King Boat Tail bullets and Varget. The unfired rounds have 46 grains Varget (ran out of time to shoot), then 45.5, 45, 44.5 and 44 grains. There was at least one round in each load that the primers flattened with square edges (top row). The same thing happened on my first reloads so I wrote the powder charge on each case so I am sure I didn't mix up the charges. Is this normal, I thought the flattening and square edges happens when getting to the max charge.

Are they staying flat against the base or have they come out slightly? I don't see any cratering which to me is usually the first sign of a too hot load.

They are flat with the base, not pushing out or bulging.

Looks just on the fringe of being ok.  How did you do your powder charge?  Throw or weigh each ? 

Varget is notorious for not metering well. 

Also, with LC/military cases, the wall is thicker. This reduces interior volume, and thus, increases pressure.  It is usually recommended to reduce maximum allowable charge for such brass.

I should give you my FGMM brass.  I was saving them for when I eventually started reloading, but that was like 5 years ago now. Might as well give them to someone who can put them to good use. 

Looks just on the fringe of being ok.  How did you do your powder charge?  Throw or weigh each ? 
Varget is notorious for not metering well. 
Also, with LC/military cases, the wall is thicker. This reduces interior volume, and thus, increases pressure.  It is usually recommended to reduce maximum allowable charge for such brass.

I weighed each charge + or - .1 grain. The COL was 2.80" with the shortest at 2.796". I weighed the fired cases with spent primers, mostly 180 to 181 grains with four cases at 184 to 186 grains. The cases with the flattened primers were the lighter cases. I haven't fired my highest powder charge yet and I'm not worried but was just wondering about some primers read being "on the fringe of being okay" and most primers read fine on the four different charges. I would expect to see the signs of high pressures only the higher charges with some consistency, but then I am still new to this.

BTW, this is my first experience with a center fire bolt gun (other than Inspector's Mosin) and I am hooked . . . love it!

Mahalo for the replies   

looks OK

Inspector's Mosin tends to hook a lot of people.        

You stated CCI primers and not sure if this applies but... I use quite a bit of SRPs and the CCI 400s are very soft and will flatten even with a moderate load, weel under most book max. Their BR4s and 41s are much harder. I'm told the 450s are similar. I'm not sure if the same holds true for their 200s and BR2s.

The ones on the top row look a touch flat.  Not sure how you had them set up in the rows.  They look fine though.  How was the groupings?  There is still radius on the edge and doesn't look like any catering or brass flow. Looks ok

Inspector's Mosin tends to hook a lot of people.        

Hey NOW!!!!! 

BTW, this is my first experience with a center fire bolt gun (other than Inspector's Mosin) and I am hooked . . . love it!

Mahalo for the replies   

That Mosin is a Piece of Shit and my favorite gun.    Poor thing has been sitting in my safe for months now cuz I have not had the time to reload. 

I agree with Bushido's assessment BTW. I have been using Federal's which are notoriously soft and seems to flatten just by looking at them sideways. I have been using up the Feds and started using the CCI SRP's and found they flatten almost as easy. Even with modest loads. Knowing the loads are well below published maximums and all other safety precautions being followed I decided it is okay to have some flattening (But not all flattened). BTW, I have tried the CCI 41's and found they do not flatten like the others.

Just to be clear, there's no problem with flattening the primers, right? That's more a characteristic of the material that the primer is made from. Bulging and cratering are problems.

Just to be clear, there's no problem with flattening the primers, right? That's more a characteristic of the material that the primer is made from. Bulging and cratering are problems.

Not from my standpoint. If I shot 10 rounds of the exact same load and one primer was flattened I would not be terribly concerned depending on which brand/type it is. But if every (or almost every) primer is flattened then I would be concerned no matter what brand/type it is. I would try the exact same load with a known harder primer and determine if there is still flattening occurring. If so then it has nothing to do with the characteristics of the primer material. And it has everything to do with an over pressure situation. If there are no signs of flattening with the harder primers I would then consider the flattening being caused by the brand/type of primer. These signs of over pressure are not black and white and need to be examined carefully and diagnosed carefully.

Flattening is a beginning sign of over pressure. One must use judgement and experience to properly read the signs. I applaud Dogman for asking this question. He is learning some valuable information from the experienced hand loaders here. Just like I learn from all of them. 

450s are the small rifle magnum.  Nice hard cup, I use those in Lapua small rifle .308 brass for some hot 155 grain loads.  It handles.

Wolf or PMC large rifle primers are good stuff too.  They net low ES/SD numbers, are budget priced, and have sufficiently hard cups.

For floating firing pin type rifles, I'd avoid using soft primers like federal.  Slamfires are not unheard of.

For Garand or AR I use the CCI military primers of the appropriate size.  They are hard enough to avoid slamfires when incidentally struck by the floating firing pin.

For floating firing pin type rifles, I'd avoid using soft primers like federal.  Slamfires are not unheard of.

I was having slamfire problems last time. I figured it was the adjustment on my trigger but could be the Federal Match primers I'm using. Time to switch to CCI.

Johnny talks about flat primers in his latest video and compares the results between his Tikka and Savage.

https://youtu.be/D5xyzYVwS10?t=32m14s

Putting this out there for information purposes. https://sierrabulletsblog.com/2015/08/12/reloading-101-case-diagnostics/

Thanks for the replies guys. Here is a better photograph of the 44 grain charge. The case on the left is the case from the top left of the original photo and typical of the cases at the top row from that photograph, so at least one flattened primer per 44, 44.5, 45 and 45.5 grain charge. The case on the right is typical of the majority of the rest of the cases. I still plan on shooting the 46 grain charge. I am taking into account all the replies but if the majority of the primers were flattened on a max charge as in the photo, would they still be considered on the safe side?

Thanks for the replies guys. Here is a better photograph of the 44 grain charge. The case on the left is the case from the top left of the original photo and typical of the cases at the top row from that photograph, so at least one flattened primer per 44, 44.5, 45 and 45.5 grain charge. The case on the right is typical of the majority of the rest of the cases. I still plan on shooting the 46 grain charge. I am taking into account all the replies but if the majority of the primers were flattened on a max charge as in the photo, would they still be considered on the safe side?

I am still a little perplexed as to why one case in each charge weight had a primer flatten to that extent... 

The one on the left looks as though it's reaching a limit, as it looks like the primer is flowing out of the pocket.

In my loading all primers of the same charge look about the same....

Few more questions.  How are you measuring OAL?  Did you measure from the base of the case to the tip of the bullet?  If so did you adjust the seater die to make all the rounds the same exact OAL?