Lock-N-Load Conversion Kit: Which Presses It Fits (the 1-1/4-12 Test) and How to Install It (2026)

Last updated: November 2026 | By AltitudeCraft Team

A Hornady Lock-N-Load conversion kit lets a non-Hornady single-stage press use Lock-N-Load quick-change die bushings, but only if the press frame has a 1-1/4"-12 thread under its stock die bushing. If it does, the conversion bushing threads in where the 7/8"-14 reducer was. If it doesn't, no conversion kit will fit. This guide shows how to check your press in two minutes, which common presses pass, and how to install the bushing so it doesn't back out with the die.

Disclosure: AltitudeCraft sells a Lock-N-Load-compatible die bushing and conversion kit, and it is not cheaper than Hornady's. Prices come from retailer pages we checked on November 3, 2026. Press thread facts come from manufacturer parts listings. We did not bench-test every press listed.

What does a Lock-N-Load conversion kit actually do?

A Lock-N-Load conversion kit swaps your press's threaded die station for a twist-lock receiver. You still use standard 7/8"-14 dies, but each die lives in its own bushing and comes out with its setting intact.

On a stock RCBS Rock Chucker, dies screw straight into a steel reducer bushing. That bushing has 7/8"-14 threads inside for the die and 1-1/4"-12 threads outside where it screws into the cast frame. A conversion kit replaces that reducer with Hornady's conversion bushing. It has the same 1-1/4"-12 thread outside, with the Lock-N-Load receiver inside.

Each die is then threaded into a die bushing and set once with its lock ring. To change dies, give the bushing a short twist, lift it out with the die, and drop in the next one. Hornady's dealer copy for kit 044099 describes it plainly: insert a Hornady bushing "into a RCBS Rock Chucker or other reloading press using a 1-1/4-12 thread," and the kit "includes three Lock-N-Load bushings and one conversion bushing" (Kinsey's listing).

One retailer listing we found describes the Hornady conversion bushing as fitting "presses with common 7/8"-14 threads." That has it backwards. The 7/8"-14 thread is the die thread. The conversion bushing needs the larger frame thread.

Which presses accept Lock-N-Load bushings (RCBS, Lee Classic Cast, Redding)?

Any press with a removable bushing over a 1-1/4"-12 frame thread should accept the conversion bushing. RCBS lists four such presses, the Rock Chucker, Rock Chucker Supreme, Summit and Reloader Special-5. Lee and Redding single-stage presses with a removable 1-1/4"-12 bushing join them. Turret plates do not.

Lee sells a Breech Lock press with its own quick-change receiver. That is a separate system from a different maker, so buy bushings that match the receiver you actually have.

How do you check if your press takes Lock-N-Load bushings? (The 1-1/4-12 test)

You can settle press compatibility in two minutes with a caliper or a thread gauge. Unscrew the stock bushing, then measure what it was screwed into.

1. Remove any die. Lower the ram so nothing is under load.
2. Unscrew the stock bushing. On RCBS presses it is the large threaded ring in the top of the frame. If it is tight, grip it with padded pliers or a strap wrench so you don't scar the flats.
3. Measure the bushing's outside thread. A 1-1/4" thread measures just under 1.25 inches across the crests.
4. Count the pitch. A 12-TPI leaf on a thread gauge should sit flat in the threads with no rocking. If the 18-TPI leaf fits instead, you have the older 1-1/4"-18 pattern and the conversion bushing will not thread in.
5. Check thread engagement. Make sure your dies still leave enough thread above the die bushing for the lock ring. The bushing adds height above the press top.

If you have never used a thread gauge, our guide on how to identify any bolt thread size walks through the same caliper-and-gauge method.

How do you convert a Rock Chucker to Lock-N-Load?

Converting a Rock Chucker means installing one Lock-N-Load conversion bushing, and it takes about five minutes. The step that matters most is snugging it tight enough that it doesn't unscrew when you twist a die out.

1. Clean the frame threads with a brush. Old lube and brass dust make the bushing feel tight before it seats.
2. Thread the conversion bushing in by hand until its flange sits flat on the press top.
3. Snug it with padded channel-lock pliers or a strap wrench. It needs to be firm, not forced.
4. Thread a die into a die bushing, insert the bushing, and twist until the lugs stop.
5. Set the die the normal way with the ram up, then tighten the die's lock ring down against the die bushing.
6. Scribe or paint a witness line across the die and bushing so you can see if the setting ever moves.

One failure to prevent is the conversion bushing backing out with the die. In one Sniper's Hide thread on this problem, reloaders fixed it with padded pliers on the flange and a full seat against the press top. Some add blue thread locker, which others avoid because it makes the bushing harder to remove later. Our article on Lock-N-Load bushings that won't lock covers spinning and slop symptom by symptom.

This video from F-Class John shows the Hornady conversion kit going into an RCBS Rock Chucker and a Summit press.

What does a Hornady Lock-N-Load conversion kit cost?

Converting one press usually costs about $20 to $25, plus about $6.60 to $8.30 for each extra die bushing, depending on pack size. Hornady's own kit is the cheapest complete option we found.

Keep your stock bushing. Undoing the conversion is just unscrewing one part and screwing the other back in. The reloader behind ocabj.net, who identifies both the Rockchucker and the Redding Big Boss II as 1-1/4"-12 presses, writes that he has used the Hornady Lock-N-Load bushings on his Rockchucker "for well over ten years." He also recommends clamp-style lock rings, noting that set-screw rings press the screw directly against the die threads.

Do Lock-N-Load-compatible bushings lock as well as Hornady's?

Not always. Half of the written return comments on our own bushings (32 of 64) describe a bushing that would not lock or that spun, and 28 describe fit or thread problems. If you need a lock you never have to think about, start with Hornady's own bushings.

We pulled every Amazon return for our three die bushing kits. That came to 96 returns, 64 of them with a written comment. 32 comments mention the bushing not locking, spinning, twisting or being loose. 28 mention fit, threads or the press. Some comments fall in both groups. One buyer wrote in September 2026 that ours "do not fit in the Hornady press properly... will spin 360 degrees. Bought authentic hornady parts and they lock in." Another wrote in 2025 that "the thread size is different so it will not screw in." That comment doesn't name the press, so we can't tell whether the frame thread or our part was the problem.

We also found a mistake in our own listing. A compatibility graphic on our product page lists the Rock Chucker Supreme and Lee Classic Cast as incompatible, labelled with their 7/8"-14 die threads. Our specification graphic shows that the included conversion bushing has a 1-1/4"-12 thread, which matches those frames once their stock bushings are removed. That graphic is wrong on this point, and we have reported it internally. Measure your frame instead of trusting it. We have not test-fitted our conversion bushing in every press in the table, so measure your frame before you order from anyone.

What mistakes ruin a Lock-N-Load conversion?

Most failed conversions come from buying before measuring, or from treating the O-ring as the lock.

• Buying by brand name instead of thread. "Fits RCBS" is not enough. A Rock Chucker converts, but an older RCBS press with a reported 1-1/4"-18 bushing, such as the A2, does not.
• Confusing Lee Breech Lock with Lock-N-Load. They do the same job, but they are separate systems from different makers. Match the bushing to the receiver.
• Expecting the O-ring to hold the die setting. The O-ring is there to let the die float slightly, not to lock it. The lock ring holds the setting, and the lugs hold the bushing in the press.
• Leaving the conversion bushing finger-tight. It will back out with the first stiff die.
• Throwing away the stock bushing. You need it for large dies, for resale, or to undo the conversion.

Frequently Asked Questions About Lock-N-Load Conversion Kits

Will a Hornady Lock-N-Load conversion kit fit a Rock Chucker?

Yes. The Rock Chucker and Rock Chucker Supreme frames take a 1-1/4"-12 bushing, according to RCBS's replacement parts listing. Hornady's dealer copy names the Rock Chucker as a target press. Unscrew the stock RCBS bushing and thread the conversion bushing in its place.

Does the Lock-N-Load conversion bushing fit a Lee Classic Cast?

The standard Classic Cast should fit once its 7/8"-14 adapter is removed, because the frame underneath is 1-1/4"-12. Lee's own 1-1/4"-12 Breech Lock update kit lists the Classic Cast as compatible. The Breech Lock version of the press already has Lee's receiver, so check which model you own.

Can I use Lock-N-Load bushings on a turret press?

Usually not. Turret plates are drilled and tapped for 7/8"-14 dies, so there is no 1-1/4"-12 hole for the conversion bushing. Single-stage presses with a removable 1-1/4"-12 bushing are the realistic candidates.

Do I still need lock rings with Lock-N-Load bushings?

Yes. The die bushing locks into the press, but the die's own lock ring holds the die's height in the bushing. Clamp-style rings are preferred because they don't press a set screw into the die threads.

Is a Lock-N-Load conversion kit worth it on a single-stage press?

It pays off if you change dies often, for example sizing and seating for several calibers. If you load one cartridge with one die set, the time saved is small. The cost is about $22 to convert plus about $6.60 to $8.30 per extra die bushing.

Should you convert your press to Lock-N-Load?

Check the thread, not the brand. Here is the short version by press:

• RCBS Rock Chucker, Rock Chucker Supreme, Summit, Reloader Special-5 or Redding Big Boss II: buy a Hornady 044099 conversion kit.
• Lee Classic Cast: measure the frame thread first, then choose Lock-N-Load or Lee's Breech Lock system.
• Turret press, toolhead press, or a 1-1/4"-18 bushing: don't buy a conversion kit.

If your press has a 1-1/4"-12 frame thread under its stock bushing, a Lock-N-Load conversion kit is a cheap, reversible upgrade. If it doesn't, no conversion bushing will thread in. Hornady's 044099 kit is the lowest-cost complete setup we found. If you already run our die bushings and conversion kit, check a bushing for lock and play as soon as it arrives, and use our won't-lock checklist if anything feels loose.

Related reading

• Complete Guide to Die Bushings for Precision Reloading
• How to Set Up a Full-Length Sizing Die
• Headspace Gauge vs Headspace Comparator vs Case Gauge
• How to Measure CBTO With a Bullet Comparator