Palma brass?

[jsthntn247]

I just started using palma brass and am getting primer cratering. It's not bad (will catch a fingernail however) and I'm not seeing any other pressure signs as I started low and worked up. However, I am seeing cratering on all cases from the bottom of load dev to the top. It seems this is a common occurance with this brass but when should I get worried? Last thing I want is a pierced primer in the middle of a string that I drove 4 hours to shoot. Stiller predator action cci 450 primers. My ES and SD's were single digits on all loads, so I would like to be able to stick with it.

 

[mr45man]

What you describe can be a result of the firing pin hole
being to large and needing bushed.
But i would not have thought so with a Stiller predator action.
John H.

 

[jsthntn247]

What you describe can be a result of the firing pin hole
being to large and needing bushed.
But i would not have thought so with a Stiller predator action.
John H.

I didn't think it would be a problem either and actually asked the folks at stiller about it before buying the action. Might not be a problem, just would like to hear feedback from those who know to keep my mind at ease.

 

[suberjc]

What you describe can be a result of the firing pin hole
being to large and needing bushed.
But i would not have thought so with a Stiller predator action.
John H.

I didn't think it would be a problem either and actually asked the folks at stiller about it before buying the action. Might not be a problem, just would like to hear feedback from those who know to keep my mind at ease.

Interesting Brad. I ordered 100 last week then changed my mind and ordered convenvtional .308. What's the accuracy like - craters notwithstanding. BTW I use the same primer in my 6 X47 Lapua. I don't think I've ever fired a round that didn't crater a little across 3 different barrels, and I shoot a medium to low charge weight.

 

[jsthntn247]

I only shot a few at each powder charge to see if the nodes would be similar. Groups were a little larger than with regular brass but I didn't have that good of a rest either. What I really found interesting was the velocity was higher (20 fps) with the palma brass v/s equally charged loads of the lapua and wolf lr primed brass.

 

[mr45man]

Well, i load the same primers, CCI in the palma and the regular 308 lapua brass and don't get the cratering.
Even a hot load that totally flattens the primer and wreaks the brass.
In a Bat M and 8208 or Varget
John H.

 

[Scott Harris]

I've shot palma brass with defiance actions with both large and small firing pins: never had a cratering problem. On the other hand, Remington actions seem to crater until bushed by Gre-Tan. If you are getting cratering, I think is related to the firing pin hole size and firing pin geometry.

 

[jnyfeler]

I had the same cratering problem with my Model 70 when I switched to a small rifle primer cartridge (6BR) using only medium loads. +1 for Greg Tannel of Gre Tan Rifles for the solution. He'll turn your firing pin to a smaller diameter and bush the firing pin hole to a commensurately smaller diameter to resolve the problem. Turnaround is really fast, too.

Here's a great video from Greg explaining in detail his solution and the cratering phenomenon here: https://www.youtube.com/watch?v=-CDJKLp7BsI.

His website: http://www.gtrtooling.com/

Disclaimer: I have no financial interest in Gre Tan, I'm just a very satisfied customer.

Jeff

 

[jsthntn247]

The firing pin hole in my bolt measured .063. My Remington bolt was .073. I wouldn't think bushing the hole on the stiller would help. I have noticed that the firing pin spring seems stiff. It will eject brass a few feet if cycled fast. Not sure if this could be an issue.

 

[mr45man]

The firing pin spring has nothing to do with the ejection of the brass .
Hope this helps.
John H.

 

[jsthntn247]

I shot some loads again today. I didn't have any cratering and the temp was higher today than Sunday. Not sure if it being the first firing on the brass had anything to do with it? My groups are at least 2x as big with this brass over standard. The ocw at 100 I shot Sunday didn't reveal a solid node as it did with the large primer Lapua and the groups I shot today showed that, as all had more vertical over standard brass. I might try a milder primer than the 450 magnum and see if that helps, is the BR4 milder than the 450? I have seen conflicting reports on that. Thanks for all the help so far fellas.

 

[Concha]

I have had great success with BR-4's. What is your load range and what powder?

 

[jsthntn247]

I have had great success with BR-4's. What is your load range and what powder?

Varget from 41 to 43.