


🔧 Trim with precision, reload with pride.
The RCBS Trim 90378 is a premium case trimming tool designed for .338 Lapua Mag and .45-70 Govt cartridges. Featuring high-speed tool steel cutters and precision primer pocket truing, it ensures consistent, professional-grade reloads. Compact, lightweight, and built from top-tier materials, this tool is a must-have for serious hunters and reloaders seeking durability and accuracy.




| Item Package Dimensions L x W x H | 5.5 x 1.8 x 0.3 inches |
| Package Weight | 1.6 ounces |
| Item Dimensions LxWxH | 1 x 2 x 6 inches |
| Item Weight | 0.06 Pounds |
| Brand Name | RCBS |
| Warranty Description | Limited Manufacturer |
| Model Name | 90378 |
| Color | Black |
| Material | Blend |
| Suggested Users | unisex-adult |
| Number of Items | 1 |
| Manufacturer | Green Supply |
| Part Number | 90378 |
| Style | Classic |
| Included Components | Primer Pocket Uniform |
| Size | Large |
| Sport Type | Hunting |
S**S
Works great
Works as expected from RCBS.
A**N
Better Than The Lyman
I bought this to use on the Lyman Case Express unit (which I REALLY like). I had been using the Lyman Primer Pocket Uniformer to process .223/5.56 and was reasonably satisfied until I saw this one. The difference is that the RCBS has two relief grooves that allow the trimmings from the pocket to fall out of the pocket as it is uniformed while the Lyman has none. So with the Lyman you must constantly watch that no debris is on the surface beside the cutter that would prevent the casing from fully seating on the cutter which would not allow the cutter to go to the full depth of the pocket which defeats the purpose of uniforming the pocket.I have not yet compared how well primers seat but I have not noticed that the RCBS fits snugger in the pockets than the Lyman uniformer which I am assuming is better but I may be wrong.The RCBS uniformer has the same threads as the Lyman so easy to mix these.I like it so much that I also ordered the RCBS Large Pocket Uniformer.
A**.
Fast delivery
Works as it should. Just what I needed.
G**R
Great piece of hardware
Great piece of hardware,at a good price. Works real nice to uniform primer pockets. One problem though, brass tends to collect on the top and needs to be cleaned often in spite of the slots to clear the brass.
R**O
RCBS Large primer pocket uniformer
Does a very good job. However, if you are going to use this on military brass I would strongly suggest using the RCBS Trim Mate Military Crimp Removal tool (large), AND slightly debur the inside of the primer pocket FIRST. Military brass will get stuck very easy on this tool causing the Trim Mate to stall/stop. Then you have to shut it off the machine, and wiggle the brass back and forth A LOT to get it off of the tool head.
Z**H
Cuts smooth and quick
Works great, just as most RCBS products do! Looks and performs as well as the one that originally came with my RCBS case prep station. Would definitely recommend!
M**.
Cuts too deep... cases are unusable!
This tool cuts to 0.128" when the SAAMI spec is 0.123" maximum for primer pocket depth...No idea whether they are all the same but his tool will ruin your cases and it cannot be adjusted to cut less.Waste of money
M**E
Three Stars
works but difficult to adjust
Trustpilot
2 months ago
2 months ago