Product Tips & Troubleshooting — Dies
Neck Bushings — Finding the Right Size
Selecting the correct neck bushing for your Matchmaster dies is essential for consistent neck tension and accurate, reliable ammunition. There are two ways to determine the right bushing size depending on what components you have on hand — use whichever method applies to your situation.
Method A
With a Loaded Cartridge
-
1
Measure the Neck
Using a caliper or micrometer, measure the outside neck dimension of the loaded cartridge.
Example
.295"
-
2
Subtract for Neck Tension
Subtract .002"–.003" depending on your desired neck tension.
Example
.295" − .002" = .293" Bushing
- 3 Order Your Bushing Add the correct bushing size to your cart. This method allows approximately .001" of spring-back for proper neck tension.
Method B
With Unloaded Components
-
1
Measure Neck Thickness
Using a Vernier ball micrometer or caliper, measure the neck wall thickness and multiply by 2.
Example
.015" × 2 = .030"
-
2
Add Bullet Diameter & Subtract
Add your bullet diameter to that figure, then subtract .001" for the bushing size.
Example
.264" + .030" = .294" − .001" = .293" Bushing
- 3 Order Your Bushing Add the correct bushing size to your cart. This method also allows for .001" of spring-back for proper neck tension.
Both Methods Yield the Same Result
Notice that both example calculations arrive at the same bushing size — .293". Whichever method you use, the goal is the same: enough neck tension to hold the bullet securely without over-working the brass.
Measuring Loaded
Measuring Unloaded
Need More Help?
Contact RCBS Customer Service at 1-800-533-5000 (US or Canada) or 530-538-2699, or email rcbs.tech@rcbs.com.
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