strange pressure signs

[Neil S.]

Hello everyone. This is my first post, but I have been around the forum for a while now. The information that I have learned here has convinced me that a 204 is right for me, and a week ago I picked up a new savage 12fv! I broke in the barrel with the recommended routine. I have shot 53 rounds of factory 32 v-max and 20 rounds of factory 40 v-max and have gotten impressive results (for me). I have shot several half inch groups with the 32's, and put 3 into .25" with the 40's, no pressure signs or keyholing. Two days ago, I loaded and shot 18 rounds of 34 dogtown reloads in a ladder test (hornady cases, BL-C(2) powder, Magtech 7 1/2 primers) and got mediocre accuracy, but had no pressure signs. Today I shot some more reloads (39 Bk, BL-C(2) powder, Magtech 7 1/2 primers, hornady cases, COL 2.316"). Here is the problem, my first group of 3 was at 28.4 grains, they showed some cratering. The second group was 28.6 grains and went as follows: first round keyholed, second and third didn't, fourth round resulted in a sticky bolt and a pierced primer. All were cratered. At that point I stopped. All charges were measured, and I checked the digital scale i used against a lyman balance type and it was dead on. The barrel was cleaned rigorously for powder and copper fouling last night, and 3 factory 32 v-maxes were used as foulers before todays testing. Any help would be appreciated. Are my primers junk maybe?

-Neil

[Neil S.]

guess no one has any input? well I did some looking and others have said that the magtech primers are pretty soft. I also looked at the batch of dogtowns that i had fired previously and they too had cratered primers. I will be getting new primers ASAP, possibly remington 7 1/2, as They are supposed to be tougher. If anyone has any load suggestions for my savage 12fv and BL-C(2) I would love to try them.

-Neil

[futuretrades]

From what I've seen posted at different times here on the forum, BLC2 powder seems to be very sensitive to heat. You did not mention what temps were. Or maybe if your ammo was sitting out in the sun and heat. This is just guessing on my part. I have not used any other primers than Win small rifle in my 204 and my 223. But I did have a problem w/ 223 and H335 powder. Very hot, around 90-92 degrees that day. Loads testing were almost 2 full grs. under max charge. Had some pierced primers and bad cratering, and hard opening of the bolt. I was keeping my ammo in the shade of my truck, but still had bad problems. Now when its hot, I keep my ammo in the ice chest until ready to do some shooting.

A little more info would be very helpful trying to diagnose your problem.

[jo191145]

Welcome to the forum Neal

Yes, if your Magtechs are anything like my Magtechs they're worthless. Crater and pop is what they do best.
Does'nt explain keyholing but the primers are not worth using in anything heavier than a 22 Hornet.


Just my opinion. BLC2 is the one suitable powder for the 204 I respect book max data for. Pressure seamed to ramp up dangerously fast going higher. I could be wrong, been a lot of years but thats the impression that stuck

[Neil S.]

hey thanks guys. lets see, I know it was in the 80's yesterday and fairly sunny. I did try to keep the ammo in the shade until I loaded it. I had a feeling that the primers are not made for higher pressures, as even light 204 loads are showing pressure signs. I will definitely stop using them. I am now more concerned about the 39 BK that keyholed, as from what I have read here If your gun shoots the 40's then it shouldn't have a problems with them. it did shoot 6 of them without keyholing so maybe it was a fluke? Also, should I be looking at using a different powder? If BL-C(2) is that heat sensitive I would just as soon use a safer powder.

-Neil

[OldTurtle]

When I first got my .204 severa; years ago, I had a friend reload some 40gr and 39gr bullets using BL-C2 and wasn't real impressed with how they shot...I started reloading my own the next year and started using W-748 and found that magnum class primers provided better accuracy with the .204, as well as my .223s...The magnum level primers are slightly thicker....Just my $.02...

[Neil S.]

hey thanks for the input OldTurtle. A box of Remington 7 1/2 bench rest primers just arrived in the mail. I have heard that these primers are tougher than most so I am hoping this solves my problems. I'm still not sure why I had a 39 BK keyhole, but hopefully it was a fluke, as this is the bullet I want to shoot.

-Neil

[bow shot]

Welcome Neil! It may sound off the trail, but I've noticed odd things happen to the primer witness depending on the tighntess of the pocket... or so it seems. For example (using fed 205M primers all the way):

Primers seat easily in my Nosler and Federal brass, but even lower charges make them flatten, and as I work up in charge, they begin to crater.

but...

Primer pockes in my Hornady brass are so tight that I can't get a (possum hollow/sincliar type) reamer in there, and I have to be quite careful not to mis-seat. No matter how high I go in charge though, I get no flattening or cratering with the Hornady brass.

I believe that in my case however, that the cratering is actually the witness left from the bolt's firing pin hole as the primer backs hard against the bolt face.

...ummm I think I made sense...

[Neil S.]

Thanks bow shot, that makes sense. I am using hornady brass only, so maybe I should try a different kind.