Upgrade Your Barra 400e with the Barrel Conversion Kit

Ever felt like your Barra 400e air rifle could pack a bit more punch? Barra Airguns has the answer with the Barrel Conversion Kits, an upgrade that boosts your muzzle velocity and tightens those groups for shots that hit harder and truer. If you've been plinking away and thinking, "How can I make this even better?" this kit is your ticket to a whole new level of fun. Available in both Standard and Precision versions, these kits let you customize your 400e to match your shooting style, whether you want the flexibility to use a broader range of ammunition or the maximum accuracy and velocity that comes with Barra's precision BBs. Stick around as Barra Airguns walks you through what this kit does, the versions available, and how to swap it in yourself. By the end, you'll be itching to install one and see the difference for yourself.

Why Upgrade to the Barrel Conversion Kit

The Barra 400e is already a beast for full-auto plinking, but the Barrel Conversion Kit takes it up a notch by increasing FPS and improving accuracy. That means your BBs fly faster and straighter, turning good sessions into great ones. Barra Airguns created this kit for shooters who want better performance without a whole new gun. It's simple to install and fully reversible if you ever want to switch back. The Standard kit allows for versatility with different BB types, while the Precision kit delivers maximum velocity and tightest groupings but requires Barra .177 Caliber / 4.5mm Zinc-Plated Steel BBs to function properly. For best results with either kit, Barra recommends using their precision BBs. Let's break it down so you can see why this upgrade is a game-changer for your 400e.

Understanding the Barrel Conversion Kit Types

Barra Airguns offers the Barrel Conversion Kit in two main types to match your shooting needs: the Standard Barrel Kit and the Precision Barrel Kit. These kits are available for both the 400e Metal and 400e Polymer models, with each designed for the specific barrel length of your rifle.

Metal vs. Polymer: Know Your Rifle

The Barrel Conversion Kit comes in two versions based on your 400e model:

400e Metal Kit: Designed for 400e Gen 1 or 2 Metal rifles with a 405mm barrel length

400e Polymer Kit: Designed for 400e Gen 2 Polymer rifles with a 357mm barrel length

Make sure you select the correct kit for your rifle model to ensure proper fit and performance.

Which Barrel Came With Your 400e?

Knowing what came stock in your rifle helps you decide which kit best fits your goals:

For 400e Gen 1 Metal (sold up until September 2024):

Your rifle came with an older version of the Precision barrel. The older design is less consistent than the current Precision barrel kits offered. Both the Standard and Precision barrel kits will provide a noticeable upgrade over the stock Gen 1 barrel.

For 400e Gen 2 Metal (launched October 2024):

If purchased between October 2024 and June 2025, your rifle came with a Precision barrel. Starting in July 2025, all 400e Gen 2 Metal rifles come with a Standard barrel.

For 400e Gen 2 Polymer (launched October 2024):

If purchased between October 2024 and June 2025, your rifle came with a Precision barrel. Starting in July 2025, all 400e Gen 2 Polymer rifles come with a Standard barrel.

Understanding when you bought your rifle will help determine which barrel you currently have, and which kit is best for your shooting style and ammunition choices.

The Standard Barrel Kit

The Standard Barrel Kit offers reliable performance and allows for greater flexibility with BB types. It's less sensitive to slight imperfections in BB shape or finish, making it a great option for casual target shooting and higher-volume use with a broader range of steel BBs. If you want the freedom to shoot with locally available ammunition without worrying about compatibility, the Standard kit is your go-to choice. It delivers solid performance increases while keeping your shooting sessions affordable and hassle-free. Whether you're running a Metal or Polymer 400e, the Standard kit gives you the versatility to experiment with different ammunition types without concerns about feeding issues. That said, for the best performance and results with the Standard kit, Barra recommends using Barra .177 Caliber / 4.5mm Zinc-Plated Steel BBs.

The Precision Barrel Kit

The Precision Barrel Kit is built to tighter tolerances and delivers improved accuracy, consistency, and the highest velocity increase. If you're looking to push the limits of the 400e's capabilities in terms of precision and power, this is your kit. However, because of its tighter internal specs, you must use Barra .177 Caliber / 4.5mm Zinc-Plated Steel BBs—the Precision barrel will not function properly with other ammunition. These BBs are precisely machined and polished to perform reliably in the Precision barrel and prevent feeding issues. For shooters who prioritize tight groups, maximum velocity, and the best accuracy, the Precision kit is worth the investment in Barra's premium ammunition. If you have a Gen 1 Metal, upgrading to the current Precision barrel kit will give you noticeably better consistency compared to the older stock barrel design.

Both kits include all the necessary components to fully replace the barrel and install it correctly within your 400e, giving your rifle a fresh boost in customization and performance.

Compatibility and Benefits of the Barrel Kit

The Barrel Kit works with all 400e rifles and magazines, whether you have a Gen 1 Metal, Gen 2 Metal, or Gen 2 Polymer model—just make sure to select the correct kit for your rifle type. For the Precision version, using Barra .177 Caliber / 4.5mm Zinc-Plated Steel BBs is essential to prevent feeding problems, while the Standard version gives you flexibility to use a wider variety of steel BBs. Both versions boost muzzle velocity for faster shots and improve grouping for better precision, making your 400e feel like a new gun. The kit is easy to remove, so you can swap between Standard and Precision barrels based on your ammunition availability or shooting goals anytime. Barra Airguns made this kit to give shooters more options—whether you're plinking in the backyard with affordable ammo or aiming for precision targets with premium BBs, the upgrade adds excitement to every session.

How to Install the Barrel Kit

Installing the Barrel Kit is straightforward and can be done at home with basic tools. Barra Airguns recommends following these steps to replace the barrel in your 400e—it's similar to basic disassembly but focused on swapping the barrel.

First, make sure the magazine is empty and removed, and unplug the battery for safety. Use a pin punch to remove the front pin and separate the receivers. Take off the dust cover plate and loosen the screw at the back of the bucking system. Remove the old barrel assembly, then insert the new Barrel Kit, ensuring it's securely in place. Reinstall the screw, dust cover plate, and line up the receivers before driving the front pin back in. Once reassembled, test with your chosen ammunition—Barra .177 Caliber / 4.5mm Zinc-Plated Steel BBs for the Precision barrel, or your preferred steel BBs for the Standard barrel—to enjoy the increased FPS and precision. This quick upgrade lets you get back to shooting faster than ever.

Why Choose Barra's Barrel Kit

Barra Airguns' Barrel Kit stands out for its easy customization and affordability. Whether you're upgrading from Standard to Precision or simply switching to match your ammo and shooting style, this kit gives your rifle a new level of performance and customization.

The Standard Barrel Kit offers reliable performance and allows for greater flexibility with BB types. It's less sensitive to slight imperfections in BB shape or finish, making it a great option for casual target shooting and higher-volume use with a broader range of steel BBs. While it accepts various ammunition, best results come with Barra .177 Caliber / 4.5mm Zinc-Plated Steel BBs.

The Precision Barrel Kit is built to tighter tolerances and delivers improved accuracy and consistency. If you're looking to push the limits of the 400e's capabilities in terms of precision, this is your kit. However, because of its tighter internal specs, you must use only Barra .177 Caliber / 4.5mm Zinc-Plated Steel BBs. These BBs are precisely machined and polished to perform reliably in the Precision barrel and prevent feeding issues.

For Gen 1 Metal owners, either kit provides a significant upgrade over the older stock barrel design. Each kit includes all the necessary components to fully replace the barrel and install it correctly within your 400e. Barra designed this kit with shooters in mind—it's compatible with all 400e models, reversible, and built to last, making your 400e even more fun for plinking or target practice. If you're looking to get more from your airgun without buying a whole new rifle, this kit is the way to go.