Peterson Brass 300 Winchester Mag Long Unprimed Box of 50

Peterson Brass 300 Winchester Mag Long Unprimed Box of 50
Peterson Brass 300 Winchester Mag Long Unprimed Box of 50
Peterson Brass 300 Winchester Mag Long Unprimed Box of 50
Item #:PCC300WML50
Price:$79.99
$1.60 per piece
Shipping: One flat fee of $9.95 per online order.
Exclusions apply. Click for details.
Availability:In Stock
Quantity Limit:Only 3 PCC300WML50 allowed per customer. Duplicates will be canceled.
MPN:40051R-PETERSON
Due to the packaging and shipping process, case necks are often slightly dinged or bent and need to be rounded up and sized to give proper neck tension. New and/or fired cases must be full-length resized or have the expander ball of the sizing die run through the case neck prior to loading.
Read 6 Reviews

Product Information

All Peterson Cartridge casings come in one of their plastic ammo boxes.

Made in the U.S.A.

Peterson Cartridge Co. of Pittsburgh, PA announced it is producing .300 Win Mag casings in two versions. Peterson makes the traditional SAAMI spec’d version that headspaces off the belt. But it also makes a version that headspaces off the shoulder. Peterson calls that version the .300 Win Mag- Long.

Shooters that reload .300 Win Mag casings have often wished they could get more reloads from their casings. Well now you can!

Derek Peterson, president of Peterson Cartridge explains, “Traditional .300 Win Mag casings tend to show signs of case head separation after only 5 to 7 firings.

“Here’s why. The SAAMI specs for any caliber, list a minimum and a maximum tolerance for each dimension on the casing and the rifle’s chamber. With most calibers, the max dimension of the casing, for length-to-shoulder (L-T-S), has the shoulder of the casing right up against the chamber wall. With .300 Win Mag, unlike most other calibers, if your rifle’s chamber is cut to the SAAMI minimum for L-T-S, and your casing is at the max length-to-shoulder dimension, the casing shoulder is still .0095” away from the chamber wall. With the same minimum rifle chamber, a casing at nominal L-T-S is .012” away from the chamber wall. In a worst-case scenario, if the casing was produced at the SAAMI minimum L-T-S, and the chamber was cut at the maximum L-T-S dimension, the casing shoulder could be up to .026” away from the chamber wall. That might not sound like a lot, but it is.

“That large gap is what causes the casing to stretch so much when it is fired. It’s that stretching that causes premature case head separation.”

Peterson continued, “With Peterson .300 Win Mag- Long casings, we make them with a longer L-T-S dimension. All the other dimensions are SAAMI spec. But the longer L-T-S prevents the casing from stretching excessively on the 1st firing. The casing has more support, which translates to less stretching, which translates to longer case life.”

Peterson concluded, “If you are a handloader, that wants more reloads from your .300 Win Mag casings, we think you will appreciate our new .300 Win Mag - Long casings. I’d like it if you’d give them a try and let us know what you think.”

 

Warning: Only use Peterson Cartridge Co. casings in firearms in good condition, designed, marked, and chambered for this cartridge. Do not use Peterson Cartridge Co casings for “fire forming” or any other purpose other than what they were designed and tested for. Peterson retains no responsibility for the enclosed casings if they are used outside of the manufacturer’s recommendations. 

 

This is not loaded ammunition.

Read 6 Reviews - Average Rating: 5 stars

Just another 5 star review

By John M. on Aug 16, 2021
Can't add anything to the reviews above except this is the best packaging I've seen for brass and I've bought from all the big name manufacturers. Another happy customer.

300WM Long. Amazing Results

By Jason B. on Jun 10, 2021
300 WM Long brass by Peterson is showing amazing results. I found the new brass to only be .003 off instead of the average .021 thou I was finding with other high end brass. And as much as .026 thou with cheaper brass. I am getting more firings, more precise results on target, lower SD and ES. I will be buying these from now on and highly recommend them.

What a Phenomenal Idea!

By Joe L. on Dec 06, 2020
I’ve been using 300 WM brass to make (or form) 7mmRM brass that actually fit the chamber on the first firing. Very happy to get proper brass from the get go for my 300. Haven’t used the Peterson brass in 300 yet but have used it in other calibers with excellent results.

Peterson Brass - why not buy the best

By Jerry N. on Nov 11, 2020
Peterson Brass is the best brass I have ever used. The consistency is outstanding and the brass is beautifully prepared to be loaded. I just run a mandrel through the neck to make sure nothing got dinged in transit and it is ready to load. Nothing has ever gotten dinged it transit because it is superbly packaged. The Long option is the way to go - you don't have to fire form this brass to start getting great results. Not stretching the case to fit your rifles headspace has to make the brass last longer.

The brass is slightly thicker so the case capacity is a little less so back your loads down half a grain or so.

Be prepared to be pleased with Peterson's Brass - my only complaint is that they, as of yet, don't make cases for every cartridge and supply is sometimes tight.

300 winchester long peterson brass

By Vincent M. on Nov 10, 2020
Wow a company that makes the long brass to fit the chamber and avoid fire forming. As usual top quality in weight, length, and every other thing that you would ask for in a top quality products. packaging in above any standard that would cause the product to be damaged in shipping. And cost yes a somewhat higher but you are getting for once a quality product as advertised and with proper care will outlast many other so called quality products as advertised

Finally!

By Lance K. on Oct 12, 2020
A company that produces virgin brass that is not .014-.020" shorter than your cut chamber!
Very consistent in weight, OAL, headspace, and high quality fully prepped brass. I just ran it through my neck sizer and expander mandrel to ensure proper neck tension, and ready to load. No fire forming needed.
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