Cratered primers in 300 wsm

[adbeck18]

I have a Savage model 16 in 300 wsm and I found a load that shoots an inch group at 300 yards. The only thing is that the primers are cratering and flattening. My load is 210 grn Berger vld hunting with 63 grn of RL-17. I use winchester brass with CCI 250 magnum large rifle primers. I don't know muzzle velocity because my chrono shorted out. I shot some federal 210 lrg rifle primers and they flattened along with federal fusion ammo. From what I have read, a lot of people are using 65 to 66 grn of RL-17 in 300 wsm and I'm only using 63. Is this from overpressure or from the firing pin and too much headspace? I would have some pics but my camera sucks and you couldn't see anything from the pics.

Thanks.

 

[Outlaw6.0]

A velocity measurement would be beneficial, the mid sixties in weight sounds a pretty HOT.gun) IIRC one of the most widely used loads for the 300 WSM & RL-17 is 68.0grns... with a bullet in the 168-180 range (can't remember which)I am shooting a Lazzeroni Patriot, which is nearly identical in capacity, i'm running 67.0 grns with a 168TTSX. It is as hot as I intend to go, with noticably sticky bolt above 67.5grns. I'd say you have to be reaching your pressure ceiling, but that is long on speculation & short on fact

Flattening primers is a good reasonable identifier of pressure... but not always. What about bolt stick? Case Measurements? Primer pocket life? Any ejector marks? Etc...

Access to a chrony would be helpful....gun)

Edit: Looking again, you stated cratering... are you seeing that too? Or just the flattening?

 

[bbutturff]

You could ask a member of this forum to run the numbers through Quickload to get an idea what pressure you may be reaching.

I had someone run the numbers for RL-17 and the 200gr Nosler Accubond a while back and max was right at 60.0 gr with an overall length of 2.86 and a 25 inch barrel.

Based on that I'd say your load could be above max.

Good luck,
Bruce

 

[adbeck18]

I will send my chrono back to get fixed... Are there any ideas about what velocity would be too fast for my load?

 

[brentc]

63.0 grains is on the upper end for sure, but it's a common load area with the 210. It's hard to say what you have going on without pictures or velocity numbers. I'm curious about your definition of flattening and whether the brass is showing ejector marks. Also, what are the air temps when you're shooting.

In many cases cratering comes from excess space between the firing pin and the pin hole in the bolt face. Many guns shows cratering with all loads.

 

[adbeck18]

I was shooting in 60 degree farenheit weather. Ill see if i can get some good pics tonight but all of the craters were exactly the same shape. Does this suggest that it is with the bolt more than pressure? Ive heard that irregular craters are a pressure sign but im not sure. The flattening wasnt too much no more than what the federals or the factory ammo flattened.

 

[adbeck18]

I finally got my chrono back. I was getting around 2850 fps. I contacted Berger about recommendations for 300 wsm. I said I used RL-17 but they never gave me any data for RL-17. Any ideas?