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AR-15 Parts

Whether you are assembling a new rifle, replacing worn components or upgrading an existing build, Ballistic Barn offers a growing selection of AR parts for both AR-15 and compatible large-frame AR-10 platforms. Shop upper parts, lower parts, barrels, handguards, receivers, bolt carrier groups, charging handles, muzzle devices, gas-system components, triggers, stocks, braces and buffer-system parts.

Read More About Our AR Parts & Components

The modular design of the AR platform allows shooters to configure a rifle for hunting, precision shooting, competition, recreation, defensive use or general-purpose field applications. Selecting properly matched components is essential for dependable cycling, safe operation, accuracy and long-term durability.

This category includes parts for both AR-15 and large-frame AR platforms such as AR-10, LR-308 and SR-25-pattern rifles. These platforms share some components, but many upper receivers, barrels, bolt carrier groups, handguards, charging handles, buffer systems and other parts are not interchangeable.

Use the category cards and linked parts directory below to move from the main Upper Parts and Lower Receiver Parts branches into the more focused categories for the exact components you need.

Shop AR Parts

Select a category below to view available products and options.

Upper Parts

Upper Parts

Shop Upper Parts
Lower Parts

Lower Parts

Shop Lower Parts

Build. Repair. Upgrade. Configure.

Find the Right AR Parts for Your Platform

Shop upper and lower components for AR-15 and compatible large-frame AR rifles. Start with the two main parts branches below, then use the linked directory to reach individual component categories without searching through the entire catalog.

Shop the Main AR Parts Categories

AR Upper Parts Shop receivers, handguards, barrels, bolt carrier groups, charging handles, muzzle devices and gas-system components. Shop Upper Parts → AR Lower Receiver Parts Shop buffer-system components, lower-parts kits, stocks, braces, controls and trigger upgrades. Shop Lower Parts →

Browse AR Parts by Component

These links provide direct access to the current parts categories beneath the Upper Parts and Lower Receiver Parts branches.

Upper Parts & Components

All Upper Parts Browse the complete upper-parts branch. Upper Receivers Stripped and assembled receiver options. Handguards & Rails AR-15 and compatible large-frame rail options. AR Barrels Multiple platforms, calibers, lengths and profiles. Bolt Carrier Groups Platform- and caliber-specific BCG options. Charging Handles Standard, extended and ambidextrous designs. Muzzle Devices Brakes, flash hiders, compensators and related parts. Gas Blocks Low-profile, adjustable and multiple-diameter options.

Lower Receiver Parts & Components

All Lower Receiver Parts Browse the complete lower-parts branch. Buffer Tube Parts & Kits Receiver extensions, buffers, springs and kits. Lower Parts & Kits Controls, pins, springs, detents and complete LPKs. Stocks & Pistol Braces Adjustable stocks, fixed stocks and brace options. Trigger Upgrades Performance trigger and fire-control options.

Choose Parts for the Correct AR Platform

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AR-15 Parts Small-frame components for standard AR-15-pattern rifles and pistols.
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Large-Frame AR Parts Components for compatible AR-10, LR-308 and SR-25-pattern builds.
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Check Compatibility Match receiver pattern, caliber, barrel extension, rail height and buffer system.
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Configure by Purpose Select components around hunting, precision, competition or general use.

AR-15 and Large-Frame AR Parts Are Not Universally Interchangeable

Do not select a part by appearance alone. Large-frame AR rifles can use different receiver patterns, rail heights, barrel nuts, bolt carrier groups, charging handles, buffer components and magazines. Always confirm the platform and manufacturer specifications listed on the product page.

AR Parts Buying Guide

Upper Receivers & Handguards

Match the receiver and handguard to the correct platform, receiver pattern, rail height and barrel-nut system. Large-frame dimensions vary more than standard AR-15 dimensions.

Barrels & Bolt Carrier Groups

Confirm platform, caliber, bolt-face dimensions, barrel extension, gas-system length and headspace compatibility before assembly.

Gas-System Components

Select the correct gas-block diameter and gas-tube length for the barrel. Adjustable gas blocks can help tune suppressed or specialized configurations.

Charging Handles & Controls

Charging handles are generally platform-specific. Lower controls may be more widely shared, but manufacturer compatibility should still be confirmed.

Triggers & Lower Parts

Many large-frame receivers use AR-15-pattern trigger components, but receiver-specific fitment requirements can vary. Verify the trigger and lower specifications.

Buffers, Springs & Stocks

Match the receiver extension, buffer length, buffer weight and spring to the platform and gas system. An incorrect combination can prevent reliable cycling.

AR-15 and Large-Frame AR Parts Compatibility

Component Compatibility What to Verify
Upper Receivers Platform and pattern specific Receiver pattern, takedown geometry, rail height and matching lower receiver.
Barrels Platform and caliber specific Barrel extension, caliber, bolt face, gas system and receiver compatibility.
Handguards Usually platform specific Barrel nut, rail height, receiver pattern, length and inside diameter.
Bolt Carrier Groups Platform and caliber specific Carrier size, bolt face, barrel extension and headspace.
Charging Handles Generally platform specific AR-15 versus large-frame length and upper-receiver pattern.
Gas Blocks Often cross-platform by diameter Barrel journal diameter, gas-port alignment and handguard clearance.
Triggers Often shared, not universal Receiver specifications, safety compatibility and manufacturer approval.
Buffer Systems Platform and tube-length dependent Receiver extension, buffer length and weight, spring and bolt-carrier travel.
Stocks & Braces Based on receiver extension Mil-spec versus commercial tube dimensions and applicable law.
Magazines Platform and caliber specific Lower receiver, cartridge geometry, capacity and feeding compatibility.

Why Buy AR Parts From Ballistic Barn?

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Carefully Selected Components
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Based in Fredericksburg, Texas
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AR-15 & Large-Frame Options
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Knowledgeable Customer Support

Ballistic Barn offers components for repairs, upgrades and complete custom builds. Our product pages identify important platform and configuration details so you can compare parts more confidently before ordering.

AR Parts & Components FAQs

Does this category include both AR-15 and AR-10 parts?

Yes. Ballistic Barn carries parts for AR-15 rifles and compatible large-frame AR platforms, including AR-10, LR-308 and SR-25-pattern builds. Always verify the platform listed on each product page before ordering.

Are AR-15 and AR-10 parts interchangeable?

Some small components may be shared, but many major parts are not interchangeable. Upper receivers, barrels, bolt carrier groups, charging handles, handguards, buffer components and magazines commonly differ between platforms and receiver patterns.

What parts are needed to assemble an AR upper?

A typical upper assembly requires an upper receiver, barrel, barrel nut, handguard, gas block, gas tube, muzzle device, bolt carrier group and charging handle. Requirements vary by caliber, receiver pattern and operating system.

What parts are needed to complete an AR lower?

A lower build commonly requires a compatible lower receiver, lower-parts kit, fire-control group, safety selector, grip, receiver extension or buffer tube, buffer, spring and stock or brace where lawful.

How do I know whether a handguard will fit?

Confirm the platform, upper-receiver pattern, rail height, barrel-nut design, inside diameter, length and gas-system clearance. Large-frame handguards and barrel nuts require especially careful pattern matching.

How do I choose the correct AR barrel?

Match the barrel to the platform, caliber, bolt face, barrel extension, gas-system length, intended ammunition and application. Barrel length, profile, material and twist rate also affect handling and performance.

Do bolt carrier groups work with every caliber?

No. The carrier may be shared within a platform, but the installed bolt must have the correct bolt face and must be compatible with the barrel extension and cartridge.

What is the advantage of an adjustable gas block?

An adjustable gas block allows gas flow to be tuned for a particular barrel, ammunition, suppressor and buffer setup. Correct tuning can reduce excess gas and improve how the rifle cycles.

Which buffer weight should I use?

The correct buffer depends on the platform, receiver extension, gas system, barrel length, bolt carrier group, ammunition and suppressor use. Use the component manufacturer's recommendations as a starting point.

Are AR triggers interchangeable between AR-15 and AR-10 lowers?

Many large-frame lowers accept standard AR-15-pattern fire-control groups, but compatibility is not universal. Confirm the trigger manufacturer's platform and receiver requirements.

Can I install AR parts myself?

Many owners install common AR components, but proper tools, torque procedures and compatibility checks are important. Work beyond your knowledge or equipment should be completed or inspected by a qualified gunsmith.

Why buy AR parts from Ballistic Barn?

Ballistic Barn focuses on carefully selected parts, practical configuration choices and knowledgeable support. Product listings identify important compatibility details so customers can choose components suited to their platform and application.

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