

MC-30 4wt Fly Line
This aggressive weight-forward fly line shines when conditions call for repeated short casts of 30 ft or less.
Description
This 4wt fly line has an aggressive weight forward taper. With 149 grains in the first 30 ft of line, you’ll be able to load even the stiffest of fast action fly rods for a powerful delivery. An ideal choice for creeks and other small waters where the catch of the day includes brookies, grayling, or juvenile trout. Welded loops at either end allow for simple, loop-to-loop attachment to backing and leader. Looking for a different line weight? Look at all available weights for MC-30 Fly Line.
Specifications
- Line Size: 4-Weight
- Taper: Taper Contained in First 30 ft
Physical Weight in Grains & Grams
- 4wt: 149.0 grains / 9.70 grams
- 5wt: 173.0 grains / 11.20 grams
- 6wt: 189.0 grains / 12.30 grams
- 7wt: 245.0 grains / 15.80 grams
- 8wt: 245.0 grains / 15.80 grams
- 9wt: 306.5 grains / 19.80 grams
- 10wt: 362.5 grains / 23.50 grams
![]() |
![]() |
![]() |
|
Fly Line | MC-30 Fly Line | MC-38 Fly Line | MC-40 Fly Line |
Available Sizes | 4wt - 10wt | 4wt - 9wt | 4wt - 9wt |
Taper | Taper Contained in First 30 ft | Taper Contained in First 38 ft | Taper Contained in First 40 ft |
Physical Weight | --- | --- | --- |
4wt | 149.0 grains / 9.70 grams | 130.0 grains / 8.39 grams | 120 grains / 9.00 grams |
5wt | 173.0 grains / 11.20 grams | 150.0 grains / 10.0 grams | 140.0 grains / 9.0 grams |
6wt | 189.0 grains / 12.30 grams | 171.0 grains / 11.10 grams | 163.0 grains / 10.5 grams |
7wt | 224.0 grains / 14.50 grams | 188.0 grains / 12.2 grams | 182.0 grains / 11.8 grams |
8wt | 245.0 grains / 15.80 grams | 222.0 grains / 14.4 grams | 204.0 grains / 13.2 grams |
9wt | 306.5 grains / 19.80 grams | 306.5 grains / 19.8 grams | 235.5 grains / 15.2 grams |
10wt | 362.5 grains / 23.50 grams | Not available in 10wt | Not Available in 10wt |
Our Favorite Uses | Large nymphs & roll casting | Light nymphs or dry flies; Long casts in med/big waters | Long distance casting, windy conditions |

Montana Casting Co. Fly Lines
Each Montana Casting Company fly fishing line is designed to company founder Scott Joyner’s specifications to take full advantage of your rod’s dynamic power curve. Wind, rain, snow or shine, these lines are precision-engineered and Montana-tested for accurate casting with minimal effort.

Useful Fly Fishing Knots for Attaching Your Fly Line
How to Tie a Perfection Loop
Scott shows you how to tie one of the easier fly fishing knots, the perfection loop. This knot can be used to attach a leader to the end of a fly line that has a welded loop on it. Watch a video demonstrating the Perfection Loop.
How to Tie a Nail Knot
Scott demonstrates using a nail knot tool to attach a length of butt section to a fly line. Watch our Nail Knot Video on YouTube.