Peterson Brass - 300WM - Long Version

[Muddyboots]

Just received shipment today so no loads yet but I wanted to share what I have seen so far. The annealing looks darn good and appears to be consistent depth on the case. I weighed 10 random cases and the SD was 0.433 gr across the 10 cases. I measured a fired cased case from my Sendero 300WM and the Peterson Long brass was within 0.003 of the fired case shoulder measurement length so there will be literally no drastic stretch and pretty much like I bumped the shoulder back 0.003 anyway. Liking that for sure! The average weight of the Peterson brass was exactly 11.0 gr heavier than the average weight of Remington brass I have on hand. A new Remington brass was 0.014 shorter than the fired brass and 0.011 shorter than the new Peterson Long brass.

I haven't done a capacity test yet but will do so shortly.

 

[Muddyboots]

Just found this on Peterson Brass website that provides all the detail you may want on their brass including capacity for the brass they make. I highlighted the 300WM Long line for easier find. The published capacity is 88.9 gr of H2O which gives me a number to confirm when I get a chance. Pretty solid info across the board.

 

[Muddyboots]

Interesting note that ADG 300WM brass weight average is 249.5 and case capacity is 88.6 H2O so Peterson brass apears to be quite similar in in weight average of 247.2 and H2O is 88.9 gr. Now to load up and see how it performs, primer pockets, stretch etc. But at least can get Peterson brass for now.

 

[Muddyboots]

Finally got to range to try this brass. Impressed! The fired brass is ONLY 0.002 longer than the new brass measurement so the Long concept appears to be exactly what they stated and definitely should lengthen brass life. This was also a stout load of 76.5 gr of RL26 so it was good test for stretch. Will post up further info once I resize and reprime for primer pocket integrity.

 

[MagnumManiac]

What stretch exactly are you referencing?
I gots to know, am confused.

Cheers.

 

[Muddyboots]

MM: here is a good description.
Link: https://www.longrangehunting.com/threads/peterson-brass-300-win-mag-long-brass.248878/

 

[Muddyboots]

Referring to how "normal" 300WM brass is headspaced on belt and stretches like dickens in first firing whereas the Peterson 300 WM LONG version is manufactured such it is headspaced off shoulder thus closer to SAAMI chamber resulting in less case stretch. Huge increase in case life potential. The first firing on the brass showed zero distress to me. Heck still looked like new! As you are MM I know you know this better than most

 

[Calvin45]

This is welcome information! To the best of my knowledge I cannot obtain ADG brass where I live (Canada) but Peterson is intermittently available through at least one retailer here.

 

[Muddyboots]

IMO this could be a real gamechanger to how belted mag brass is manufactured then again why would other brass manufacturers change if the old way uses up brass faster?

 

[can1010]

let us know how this brass holds up over time. I have been fireforming my belted cases with a false shoulder like other wildcats and it has increased case life quite a bit as long as I don't blow the primer pockets. twenty or more reloads on the Lapua cases and fifteen on older Winchester both in 300 win mag