Peterson Brass

[AKBman]

I recently purchased 250 pieces of Peterson 300 WM Long Brass, I have been searching for more Norma Brass, but looking at the reviews I thought I'd take the plunge. It seems to be softer than my Norma Brass, and it certainly has less capacity. I loaded up 20 of them with 208gr AMax bullets over IMR4955, lit by CCI250s. Accuracy was as good or better than loads with the Norma brass, but I started seeing the ejector imprint 3 grains under the max load. I am shooting these in a factory Sendero, and so expect a little more velocity than some of the book loads using 24" barrels. At 2 grains under max, my velocities were 50fps over the expected velocity for the max book charge. I didn't notice the ejector imprints until I got home, very faint, and almost identical across a 1.5 grain increase in powder charge, the primers showed some cratering in the last rounds fired. I know that 4955, which is in the same ballpark as 4350 in burn rate, but it is the powder that was available to buy. I am going to try some RL 26, as I have a pound of it, and I have a bunch of Magpro left in a Jug I got a smoking deal on, I just don't like shooting it in hot weather. I also have a little RL22 on hand. Anyone else using this 300 WM Long brass seeing the same thing, am I over thinking this? Bolt lift and extraction were perfectly normal.

 

[ButterBean]

It's not softer and it has less capacity because it's thicker in all areas hence the higher velocities with out pressure, Peterson Brass is the best IMO

 

[lancetkenyon]

You are 2 gr under max charge weight, but 50fps over max velocity, and more accurate than with other brass.....and you are not satisfied with those results?
Talk about looking a gift horse in the mouth...

It is because Peterson's brass is thicker, meaning reduced case capacity, meaning higher pressures with like charge weights. Back it down until you see no ejector mark and enjoy.

 

[Veteran]

I'd be interested to know both your measured case capacities on average for virgin and once fired brass, by vol. water weight and
your velocities from your shooting.

This would give us some better basis for comment.

 

[Jud96]

Sometimes virgin brass will have ejector marks when fired. I have seen it myself and when I test with the same brass when it's once fired, there's no more ejector marks at the same load or above it for 0.5gr or more. I believe it's something to do with the brass having to grow so much during the initial firing. Peterson brass has been excellent for me in everything I have tried it in. Most of their cases are smaller capacity and heavier than Norma, Winchester, Hornady, etc.

 

[ButterBean]

Sometimes virgin brass will have ejector marks when fired. I have seen it myself and when I test with the same brass when it's once fired, there's no more ejector marks at the same load or above it for 0.5gr or more. I believe it's something to do with the brass having to grow so much during the initial firing. Peterson brass has been excellent for me in everything I have tried it in. Most of their cases are smaller capacity and heavier than Norma, Winchester, Hornady, etc.

Norma Brass is way softer than Peterson is his only issue

 

[AKBman]

I knew the Peterson brass had less capacity, it weighs 30 grains more than the Norma brass. This is why I went back to the starting loads, I was merely surprised to see pressure signs 3 grains off max, and 2.5 grains lower than where I have been loading the same bullet in my Norma brass. I really like the Peterson brass, and I am not going to be looking for any Norma brass at this time. I have gotten excellent case life from the Norma cases, and have little doubt that I will get the same from the Peterson. When I shot these, I was at 5300 feet of elevation, temp was 84 degrees F, humidity was 17%, starting loads gave me 2824fps, the top charges I had loaded gave me 2917 fps. Top load in Norma brass nets me 2825, same box of bullets, same box of primers, and same bottle of powder. Seating depth was 3.420. I know that the chamber in my Sendero is on the tight side. I care more about the accuracy and case life than I do top velocity, 180 degrees out from 30 years ago.

 

[Veteran]

My fired Peterson 300 WM brass
regular, not long averages about 91.3 g water weight capacity

It has more volume than other brands I measured at more like 88

I have some 300 WM long but have not loaded or fired them yet.

But I have had good experiences w Peterson Brass. I pretty much stay w Peterson and Lapua brass.

 

[AKBman]

I am happy with the brass, it is consistent in all dimensions straight from the box. I will move forward with trying a different powder.

 

[mike06]

I am happy with the brass, it is consistent in all dimensions straight from the box. I will move forward with trying a different powder.

Best brass I have used in my 25 plus years of reloading. Got 50 reloads before my first neck split in my 308. I do anneal every firing.

 

[highdrum]

As Jud said, upon first firing faint ejector marks can form from bolt slap. The long brass is supposed to be closer to proper headspace to shoulder. Deprime the fired brass, measure the shoulder datum line with your bump gauge, then measure the new unfired peterson, if there is a difference of more than 3 thou I'd bet your ejector shadows are coming from the initial forming to your chamber.

 

[AKBman]

Quick measurement shows .0015" expansion just ahead of the belt between virgin and the once fired.

 

[Mike D Texas]

Quick measurement shows .0015" expansion just ahead of the belt between virgin and the once fired.

Which is typical for most 300 WM brass. That's why they came out with the long brass. It's .010-.012 longer than regular brass.

 

[erikblank]

Peterson brass is right up there with Lapua brass. Both hold less powder than other brass. I have some of both in non magnum rounds that are going on 15 times reloaded and still looking good. I do prefer Peterson, if for no other reason than how carefully it's packed when you get it. Norma brass is good, but it's not in the same league.