204Ruger

I shot some other ammo, Hornady 32gr and Winchester 40gr Ballistic tips, and no problems with either those two, and after talking to a couple of experienced/knowledgeable reloaders at my gun range, I've come to the conclusion it's probably the ammo. Possibly loose primer pockets, maybe the loads are a bit hot, or my gun just don't like that brand.

I'm probably going to work up some hand loads and see how that goes before doing anything else.

I think it's low-pressure ammo, and cases sized too short (from the factory).

ALL primers back out like that in high-pressure bottleneck rifle cartridges. That's what happens when the primer explodes; not all the gas can get through the flash hole fast enough, so the pressure pushes the primer out of its pocket. As the main powder charge lights and chamber pressure goes up, the case walls are expanded out but the case head is also pushed back, re-seating the primer. When primers are high like that from fired ammo, you know you have quite a lot of headspace (which can just as easily come from the brass being too short as from the chamber being too long), and/or your chamber pressures are low. The fact that the other ammo lots exhibit the issue to a much lesser degree or not at all reinforces my hypothesis.

And I'll be the second to say it is the ammo. I also fired some of the 32 gr. Fiocchi in a couple of my 204 Ruger rifles. Before I fired them, I checked the distance from the datum on the shoulder to the case head, and found them to be seriously short. Like 10 to 15 thousandths. You know when you fire a sized case that has the shoulder set back too far, the primer backs out of the pocket until the pressure drives the case head into the bolt face. This makes lots of things look funny. Primers can look very flat and there is no pressure issue.

On mine even after firing, some are still over 10 thousandths short of my chamber length.

The mild primer cratering is very common on Savage's. It is caused caused by a loose fit between the bolt head and firing pin. It will very unlikely cause a problem but if it bothers you it can be fixed by swapping the bolt head for one from Pacific Tool & Guage (PT&G), about $65. I've seen many cases where the cratering was much more severe and never caused a problem.

i have shot a few hundred rounds of fiocchi ammo and have never had an issue with it. the first five rounds i had were given to me by another shooter and said to try these as they were extremely accurate. i put the first three into one small hole and returned the last two as i told him i already knew where they were going. as a little side note i weighed a bunch of .204 brass--lake city, federal, remington,winchester and fiocchi. most of them weighed about 92 grains but all of the fiocchi weighed in at 100 grains. the head stamp on the fiocchi brass is GFL and it is the most consistent brass i have come across.

Just to update this thread, the factory ammo in question had a couple QC issues such as short headspace on the brand new brass, several pieces of the brass are still "short" per SAAMI specs although they shoot fine for fouler loads and light powder charges. The brass did "grow" some with subsequent firings, enough to where the raised primers are not an issue now, even tho I do inspect each case pretty close immediately after firing it and during the cleaning/prep process.

Another issue I had with this same box of ammo was I had grown tired/concerned about the raised primers, etc., so I decided to just pull the bullets and start over thinking the loads might be hot, or whatever. I tried pulling the bullets with an inertia hammer style puller, and after 75, yes I counted, 75 solid strikes with the hammer puller, none of the bullets had moved on the 2 or 3 I tried. Too much neck tension or a crimp on the factory ammo. I ordered a RCBS collet bullet puller, and it could not get a "bite" on the bullet due to the seating depth of the bullets. I then reverted to the old trick of using "sidecutter" style wire cutters. Ruined the bullets but got the #$%@ things pulled. LOL I measured the powder charge in several of the loads and there were 0.5g variances in the powder charge weights on those I tested.

I then measured the unfired cases for HS using the Hornady HS comparator tool, and will see what happens with the growth. Several of them are well short in terms of HS, so... I realize most factory ammo is made to "fit" any gun, I guess the ammo I got was made on Monday morning or after a 3 day holiday weekend. LOL

I will say the ammo shot well in terms of accuracy but the inconsistencies in the factory ammo just tells me not to buy any more of that brand of ammo.