Flattened primer help

[tacticalpanda]

Sorry if this is a bit long but want to get as much info to you as possible.

Saturday I was at the range with my Savage 10 in .308. I haven't shot this gun in over a year and was getting a hard to lift bolt/stuck bolt. When I looked at my brass I was getting flattened primers. Don't remember this problem when I last shot the gun and the reloads were the same as I have always shot.

The reload was as follows
Federal brass
Nosler CC 168g
43.4g IMR 4064
CCI Primers #200

EDIT: Went back Sunday and shot at 54 different lengths 2.200, 2.210, 2.219, 2.230, 2.239. All using the 43.4g charge and still had flattened primers and stuck bolt handle problems

Monday:

Brass was trimmed to a length of 2.006 with a C.O.A.L. of 2.770 roughly. Using a comparator all the rounds were exactly the same +/- 0.01. Touching the lands it measures 2.239 using the comparator and the rounds were backed off 0.020 and measuruing from the ogive and all were loaded to 2.219.

So I went back today to redo the OCW test using 43.4 as my max charge. Charge weights were as follows 40.5/41.0/41.4/41.8/42.2/42.7/43.1/43.4. I was 0.020 off the lands in my length. I also used two different scales to confirm actual charge weight, something I haven't done before but wanted to double check.

In almost all weights I was getting some flattened primers and a stuck bolt handle but then in others I was not (EX: in a 5 shot group I would have 1 or two that would be hard to extract with flattened primers and then the other 3 would look fine). I can post a picture of the spend brass later today. Anyone have any idea of what would cause this? I then put 20 rounds of Federal Gold medal Match through the gun and didn't have on flattened primer and every round was easy to extract so I am guessing the error lies with me somewhere.

Anyone have any ideas?

Sorry just noticed I put this in the Depot by mistake.

Pics below (hopefully you can see the flattened primers)
charges of each row, left to right, 40.5, 41, 41.4, 41.8, 42.2, 42.7. 43.1, 43.4
You can see the bottom 41g charge has a flattened primer, which is only 1g above the min charge according to lyman.

 

[remiglockoholic]

Try increasing your OAL to reduce pressure.

 

[tacticalpanda]

Try increasing your OAL to reduce pressure.

Sorry forgot that part will see update in first post.

 

[shoot4fun]

Powder charge appears close to low end. Do COAL of FGMM 168 match you reload? Your COAL seems short, as most all my manuals recommend 2.80" COAL. My load actually hit 2.85" COAL. Brass old? Could primer pockets be worn out and loose? Brass fired in other rifles? Did you check shoulder bump on brass? Maybe FL sized brass incorrectly and head space not happy. Could be lots of things.

 

[tacticalpanda]

Powder charge appears close to low end. Do COAL of FGMM 168 match you reload? Your COAL seems short, as most all my manuals recommend 2.80" COAL. My load actually hit 2.85" COAL. Brass old? Could primer pockets be worn out and loose? Brass fired in other rifles? Did you check shoulder bump on brass? Maybe FL sized brass incorrectly and head space not happy. Could be lots of things.

Lyman gives me a max charge of 45.0g. I pulled back this time due to getting flattened primers at 43.4 which I thought was on the moderate end of the spectrum.

FGGM have a COAL of 2.8. Did the normal once fired case then put a bullet in to get where the bullet contacted that lands. The COAL of that round is 2.808 (roughly). I do most of my measurement from the ogive and just took 0.020 off of that. If I seat any longer than 2.808 (or from the ogive of 2.239) my guess is I'll have trouble chambering a round as the bullet is coming in contact with that lands and being forced into the cartridge giving it the same COAL, correct?

The brass from the other two days was on shots 4-5. Only neck sized due to being only fired from that gun. Brass I used today was once fired and full length sized.

Haven't looked at the shoulder bump, thought this would be more of a sign of the round not wanting to chamber but will look into it.

 

[sib1948]

Your charge doesn't sound too high. I use 43.9 gr IMR 4064 with my 185 gr Berger VLDs with COAL 2.85-2.86. I had hard bolt lifts frequently, which stopped after I started FLS all previously fired cases. Lee collet dies for neck tension when I deprime, then FLS die, then into the stainless tumbler for 1.5-2 hours. Let dry, then prime and load and off to the range!

 

[shoot4fun]

I just looked at your pic of the brass. I do not see anything there that makes me think you have a flattened primer problem. There is one thing that bothers me though. maybe it is just the angle or shadows or something going on with the pic but it appears there are several primers that are seated way too deep. I am especially looking at the one in the third row across at the end. It has clearly been struck by a firing pin but appears to still have a bullet in it. Was that one that did not go off?
Did you uniform the primer pockets on that brass at one time?