Brass cases Peterson .308 Winchester

Peterson .308 Winchester LRP is premium rifle brass developed for shooters who demand consistent parameters and long service life. The LRP version features a standard Large Rifle Primer pocket and a 0.080" flash hole, equivalent to approximately 2.03 mm.

The cases are manufactured in the United States from high-quality C260 cartridge brass. Every case passes through a multi-stage, closely monitored manufacturing process. The neck and shoulder are factory annealed to improve brass ductility and resistance to repeated firing and resizing cycles.

Peterson leaves the annealing discolouration visible. These marks are not a defect or a sign that the brass has previously been fired. They are a natural result of the factory heat-treatment process.

The .308 Winchester is widely used in long-range shooting, F-Class, target competition, tactical disciplines and hunting. Peterson Match-Grade cases may be used in both bolt-action and semi-automatic rifles, provided they are compatible with the chamber of the individual firearm.

Key advantages

• Match-Grade quality for precision ammunition
• Standard Large Rifle Primer pockets
• 0.080" / approximately 2.03 mm flash hole
• Reliable ignition with a wide range of powders
• Dependable ignition in low temperatures
• Tight and consistent primer pockets
• Uniform internal capacity
• Consistent neck-wall thickness
• Precisely formed flash holes
• Excellent neck concentricity
• Long service life with proper use and maintenance
• Factory-annealed neck and shoulder
• Premium C260 cartridge brass
• Manufactured and quality-controlled in the USA
• Protective packaging containing 50 cases

Technical specifications

• Manufacturer: Peterson Cartridge
• Calibre: .308 Winchester
• Product type: new, unprimed rifle brass cases
• Primer pocket: Large Rifle Primer – LRP
• Flash-hole diameter: 0.080" / approximately 2.03 mm
• Case type: rimless, bottleneck
• Material: C260 cartridge brass
• Neck and shoulder: factory annealed
• Quantity: 50 cases
• Manufacturer’s product code: 40017-R / 40017R
• UPC: 859449006018
• Country of manufacture: USA
• Quality class: Match-Grade

Peterson’s tight primer pockets

Peterson intentionally manufactures its Large Rifle primer pockets slightly tighter than the lower limit of the SAAMI range:

• New Peterson primer-pocket diameter: 0.2075–0.2078" / approximately 5.271–5.278 mm
• SAAMI Large Rifle primer-pocket range: 0.2085–0.2100" / approximately 5.296–5.334 mm
• Typical increase after the first firing: approximately 0.0007" / 0.018 mm

According to Peterson, the greatest increase in primer-pocket diameter normally occurs during the first firing. The initially tighter dimension is designed to place the pocket near the lower end of the SAAMI range after the first use. This may help primers continue to seat with suitable resistance over more firing cycles.

A primer-pocket uniforming tool may not fit an unfired Peterson case. The manufacturer states that the factory pockets are already highly uniform and do not require this operation before the first firing.

SAAMI cartridge and case dimensions

• Maximum case length: 2.015" / 51.18 mm
• Cartridge overall length: 2.490–2.810" / 63.25–71.37 mm
• Maximum case-head diameter: 0.473" / 12.01 mm
• Case-body diameter near the base: 0.4703" / 11.946 mm
• Shoulder diameter: 0.4553" / 11.565 mm
• Maximum outside neck diameter: 0.3435" / 8.725 mm
• Maximum bullet diameter: 0.309" / 7.85 mm
• Maximum rim thickness: 0.054" / 1.37 mm
• Shoulder angle: 20°
• SAAMI maximum average cartridge pressure: 62,000 psi / approximately 427 MPa

The pressure figure is a cartridge-standard parameter and not recommended reloading data.

Peterson reference data – LRP lot N082

The following values were published by Peterson for production lot N082, inspected on 6 December 2023:

• Average empty case weight: 175.8 grains / approximately 11.39 g
• Average internal capacity: 53.9 grains of water / approximately 3.49 cm³
• Shoulder diameter: 0.451" / approximately 11.46 mm
• Base diameter: 0.469" / approximately 11.91 mm
• Neck-wall thickness: approximately 0.0146" / 0.371 mm
• Loaded neck diameter: 0.338" / approximately 8.59 mm
• AMP Aztec annealing code: 0152
• AMP pilot: No. 11
• Testing equipment: AMP Mark II

These values apply to the tested production lot and should be treated as reference data. Measurements and internal capacity may vary slightly between production lots.

Peterson durability test – 32 firing cycles

During Peterson’s durability test, five .308 Winchester cases were fired 31 times using loads reaching the SAAMI maximum average pressure. A lighter load was used for the 32nd firing.

After 32 cycles:

• no case cracks were detected,
• no signs of case-head separation were observed,
• primer pockets had increased by approximately 0.002",
• the pockets still retained primers with suitable resistance,
• the cases remained suitable for further use.

This was a controlled test involving a small number of cases and does not guarantee 32 firing cycles from every case. Actual service life depends on pressure, chamber dimensions, resizing method, annealing frequency and other operating conditions.

What do users say about Peterson .308 Winchester LRP brass?

The advantages most frequently mentioned by shooters and reloaders include:

• exceptionally tight primer pockets,
• small variations in internal capacity,
• consistent new-case length,
• uniform neck-wall thickness,
• clean flash holes without significant burrs,
• minimal preparation before first use,
• durability through repeated resizing cycles,
• quality frequently compared with Lapua,
• good value when service life is considered.

In one detailed inspection of a 50-case box, the user measured case lengths between 2.004" and 2.007", while most cases weighed between 175.0 and 175.5 grains. Measured water capacity ranged from 53.42 to 54.30 grains. The user also found no visible burrs inside the flash holes.

These results relate to one particular box and are not guaranteed tolerances for every production lot.

Why choose the LRP version?

Large Rifle Primer is the conventional primer system for the .308 Winchester. It provides energetic ignition and broad compatibility with powders and published reloading data.

The LRP version is particularly suitable for:

• hunting ammunition,
• shooting in low temperatures,
• rifles with standard factory firing-pin systems,
• configurations using slower-burning powders,
• reloaders who prefer conventional .308 Winchester components.

Unlike the SRP version, LRP cases do not require an undersized decapping pin for a 1.52 mm flash hole. The standard 2.03 mm flash hole is compatible with typical decapping pins.

Preparing new cases

Peterson does not recommend extensive preparation of new cases. According to the manufacturer, lightly chamfering and deburring the case mouth is normally sufficient before the first use.

Sizing new brass is generally unnecessary because all cases from a production lot are manufactured using the same tooling. Peterson specifies factory neck tension of approximately 0.003–0.004" and high neck concentricity.

Every case should nevertheless be inspected and measured before use. With semi-automatic rifles, it is especially important to verify unrestricted chamber fit and reliable operation.

Important reloading information

Peterson cases may have a different weight, wall thickness and internal capacity from Lapua, Norma, Winchester, Hornady or other manufacturers. Lower internal capacity may produce higher pressure when the same powder charge is used.

After changing the case manufacturer, production lot or SRP/LRP version, begin load development again using safe starting data from a current reloading manual or powder manufacturer.

The package contains empty, unprimed cartridge cases only. Primers, powder, bullets and loaded ammunition are not included.

Frequently asked questions

Are primers included?

No. These are new, unprimed cartridge cases. Large Rifle primers must be purchased separately.

What does LRP mean?

LRP stands for Large Rifle Primer. These cases have primer pockets designed for standard Large Rifle primers.

What is the flash-hole diameter?

The flash hole measures 0.080", equivalent to approximately 2.03 mm.

Why are the primer pockets so tight?

Peterson intentionally manufactures new primer pockets slightly tighter. Their diameter increases after the first firing and approaches the lower part of the SAAMI range, which is intended to promote longer case life.

Do new cases need to be sized?

Peterson generally does not recommend it. Lightly chamfering and deburring the case mouth is normally sufficient. Chamber fit should always be verified before use.

Are the marks around the case neck a defect?

No. They are natural signs of the factory annealing process applied to the neck and shoulder.

Can I use a load developed with another brand of brass?

It should not be transferred without new load development. Differences in internal capacity can affect pressure and muzzle velocity.

Are .308 Winchester and 7.62×51 NATO cases identical?

They are not identical standards. This product is manufactured and marked as .308 Winchester. Before using it in a firearm marked exclusively for 7.62×51 NATO, consult the firearm manual and manufacturer’s recommendations.