Understanding the Internal Bore of a 12 Bore ShotgunEver wondered why the internal bore dimensions of 12 bore shotguns vary? These differences are not random—they play a significant role in how your shotgun performs and even how it feels to shoot.The internal bore diameter refers to the size of the barrel’s inner wall. Some manufacturers prefer smaller bores, while others use larger or “back-bored” designs. So, what’s the difference and how does it affect your shooting experience?Standard Bore: Most traditional shotguns have a bore diameter of around 18.4mm to 18.5mm. These provide tighter shot patterns and are great for high accuracy at shorter ranges.Back Boring: Some shotguns, like the Beretta DT Series, feature back-bored barrels. Back boring involves slightly increasing the bore diameter beyond the standard size for a section of the barrel, often around 18.6mm to 18.7mm. This has a couple of key benefits:Reduced Felt Recoil: By allowing the shot and gases more room to expand, back-bored barrels reduce pressure buildup, leading to a noticeable reduction in recoil.Improved Shot Patterns: Back boring can result in more consistent, dense shot patterns, which can make a big difference in your accuracy, especially at longer ranges.Beretta, for instance, uses multiple bore dimensions across its models to tailor the shooting experience for different needs. The Beretta DT Series shotguns, known for their superior handling, use back-bored barrels for a smoother, more comfortable shooting experience.How Bore Size Affects Felt Recoil:A smaller bore typically leads to increased pressure inside the barrel, which can result in more felt recoil.A back-bored or larger bore gives the shot more room to expand, reducing recoil, and making the gun easier and more comfortable to shoot.Choosing the right bore size is all about finding the balance between recoil reduction, accuracy, and shot pattern for your specific shooting style.At Midlands Gun Services, we can help you understand the perfect bore configuration for your needs! Whether you’re looking for precision shooting or reduced recoil, we’ve got you covered.
How Bore Dimensions Affect Plastic and Fibre Wads in Shotgun CartridgesWhen it comes to shotgun performance, the relationship between bore dimensions and the type of wad used in cartridges—plastic or fibre—is crucial. The bore of your shotgun can significantly influence how these wads perform, affecting the shot pattern, pressure, and ultimately the shooter’s experience.Plastic WadsPlastic wads are designed to create a perfect seal in the barrel, allowing for optimal gas pressure to build up behind the shot. This pressure propels the shot forward with maximum efficiency.In Standard Bores: With typical bore sizes of 18.4mm to 18.5mm, plastic wads form a tight seal. This ensures that the gas pressure builds properly behind the wad, leading to consistent and dense shot patterns.In Back-Bored Barrels: With larger bore diameters, such as in back-bored barrels (18.6mm or larger), plastic wads still maintain a good seal, but the increased space reduces gas pressure slightly. This can lower felt recoil, but the wad still ensures tight, efficient shot patterns because of the material’s ability to expand and adapt to the wider bore.Fibre WadsFibre wads are eco-friendly and typically used in areas where plastic is restricted or for shooters preferring traditional loads. However, fibre wads do not create as tight a seal as plastic, which affects performance differently depending on bore size.In Standard Bores: Fibre wads can struggle to form the same tight seal as plastic wads in a narrower bore. This may lead to a slight loss of pressure and slightly less dense shot patterns. However, this also reduces muzzle velocity slightly, which can soften recoil.In Back-Bored Barrels: In larger bore diameters, fibre wads have even more room to move within the barrel, leading to a less efficient gas seal. This could result in a wider spread and less consistent shot pattern. However, because the pressure is distributed more evenly, felt recoil is reduced, making fibre wads feel smoother to shoot in back-bored barrels.Key ConsiderationsShot Pattern: Plastic wads generally produce tighter, more consistent patterns, regardless of the bore size. Fibre wads, while more environmentally friendly, can lead to inconsistent shot spreads with reduced muzzle velocity, especially in back-bored barrels.Eco-Friendliness: Fibre wads are the more sustainable choice and are becoming increasingly popular in areas that prioritize environmental impact.Ultimately, choosing between plastic and fibre wads, and selecting the appropriate bore size, depends on your priorities—whether you prefer tighter shot patterns or reduced recoil, and whether environmental factors play a role in your decision.
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