Case Preparation

MatchMaster Precision Case Trimmer: Where Trimming Fits in Your Reloading Process

If the pilot will not enter your case necks, the trimmer is usually not the problem. The order of your case prep steps is.

Almost every time, the pilot is correct and the trimmer is fine. What has happened is that the case reached the trimmer before its neck was opened back up. This article walks through where trimming belongs in the sequence and why that position is not negotiable.

Why the pilot will not fit

The 22 caliber pilot for the MatchMaster measures .219" to .220". A .223 Remington case that has been sized in a bushing die, without any expanding step afterward, can easily finish with an inside neck diameter around .218".

The pilot is larger than the hole. No amount of pressure changes that, and forcing it will only mar the case mouth. The neck has to be opened before the case goes near the cutter.

What the pilot is actually doing

The pilot is not a spacer. It enters the case mouth and holds the neck concentric to the cutter while the cut is made, so the trimmed mouth is square to the case rather than square to however the case happened to sit in the holder.

That is why dropping to a smaller caliber pilot to force a fit is a poor trade. A pilot that rattles inside the neck lets the mouth wander during the cut, and you lose the squareness the trimmer exists to deliver. Use the correct pilot and fix the neck diameter instead.

Check your pilot first

MatchMaster pilots ship without markings, so if you are not certain which one you have, measure it with calipers before assuming it is the wrong size. We covered the full method in How to Identify Your MatchMaster Precision Case Trimmer Pilot Size.

The correct order of operations

Case prep runs in a fixed sequence, and expanding always comes before trimming.

Clean and inspect

Get the brass clean enough that grit is not riding into your dies or your trimmer collet. Inspect for split necks, incipient case head separation, and damaged mouths, and set aside anything questionable before you spend labor on it.

Size and decap

Run the case through your sizing die. This is the step that determines everything downstream, because whether or not your die expands the neck on the way out decides if you need a separate expanding step at all.

A rifle case being run into a sizing die on a single stage press. — A conventional full length sizer die sizes the neck down and then expands it back on the upstroke, in one pass.

Expand the neck

If your sizing die did not expand the neck, do it now, before the case sees the cutter. An expander opens the inside of the neck to a consistent diameter, which is what allows the pilot to enter and seat squarely.

The RCBS Neck Expander Die handles this in a dedicated pass and is offered in .224 along with fourteen other sizes.

Trim to length

Now the pilot enters the neck without resistance and the case can be trimmed. Measure a representative sample of your brass against the trim-to length published for your cartridge before you set the cutter, and check the first few cases you trim against your calipers.

Brass being trimmed on the RCBS MatchMaster Precision Case Trimmer. — With the neck expanded, the pilot supports the case mouth through the cut.

Chamfer and deburr

Trimming leaves a burr on the inside and outside of the mouth. Break both edges so the bullet starts straight during seating and the mouth does not shave jacket material on the way in.

The mistake to avoid

Sizing, trimming, and then expanding does not work. The pilot cannot enter an unexpanded neck, so the trimming step has nowhere to happen. Expanding after trimming also works the case mouth after it has been cut square, which is the opposite of what you want.

Does your sizing setup expand the neck?

Whether you need a separate expanding step depends entirely on the dies you are running. This is where most of the confusion starts, because reloaders who have only used conventional full length dies have never had to think about it.

Common sizing setups and whether they leave the neck expanded.
Sizing setup	Expands the neck?	Separate expander needed before trimming?
Full length sizer die with expander ball	Yes	No. Sizing and expanding happen in one stroke.
Full length sizer die, expander ball removed	No	Yes.
Neck sizing bushing die	No	Yes.
Body die only	No	The neck is untouched, so it depends on the condition it was left in by the previous step.

Bushing dies have become far more common as reloaders move toward controlling neck tension directly, and that is what has made this sequencing question come up so often. If you are sizing and decapping in one step and expanding in another, the expanding step has to land before the trimmer, not after it.

See it on the bench

Setup, adjustment, and a full pass through the trimmer:

The short version

Clean, size and decap, expand, trim, then chamfer and deburr.
The 22 caliber MatchMaster pilot runs .219" to .220" and will not enter a neck sized to .218".
If your die does not expand the neck, something else has to, and it has to happen before the trimmer.
Do not substitute a smaller pilot to force a fit. You give up the squareness you bought the trimmer for.