Author / Justin Helvik, Avid Outdoorsman
Today’s hunter has a huge selection of apparel to choose from, and it can be overwhelming trying to figure out which pieces will add value to their system. Our approach to hunting apparel is to create intentional, straightforward, high-performing products that will cover hunters in every condition they’ll encounter—and no unnecessary bells and whistles. We continue to push the boundaries of ultralight hunting gear without sacrificing functionality in the field, and this is definitely true of our insulation offerings.
When it comes to insulation, there are primarily two means of staying warm: down and synthetic. Deciding which insulation is right for your hunt really comes down to what you plan on doing in the field. Down and synthetic insulation each excel in different scenarios, and we created two primary insulation layers for hunters to choose from: the Grumman Down Jacket and the synthetic Cirque Jacket.
The Grumman Down Jacket comes equipped with 5.3 ounces of 90/10 goose down fill. This equates to 850+ fill power. Fill power is a number that indicates the relative quality of down that is derived from lab testing that measures how many cubic inches of loft one ounce of down fill produces. The higher the number, the more loft the down has. It is worth noting that just because a down product has a higher fill number does not mean it is warmer than a product with a lower fill number. For example, a 900-fill power down jacket with only an ounce of fill will not be warmer than a 450-fill power jacket with 3.5 ounces of fill. In theory, two ounces of 900-fill power down would provide the same warmth as four ounces of 450-fill power down. In addition, the higher loft piece would compress to about half the space.
In a nutshell, the higher fill power gives you more warmth and more packability (compressibility). This makes the Grumman Down Jacket an extremely warm jacket that can virtually live in your pack because it takes up so little space. The Grumman, when compressed, is about the size of a one-liter Nalgene bottle and weighs only 11.8 oz. (large size).
One potential pitfall of down insulation is that it loses its warming power if it becomes wet. This is where treated down comes into play. The Grumman Down Jacket is treated with HyperDRY™ DWR (durable water repellent). This treatment adds a fluorocarbon-free compound that adheres to the down cluster, allowing the down to retain its superior warmth-to-weight ratio even when it gets wet. The down we use is also covered by a Pertex® Quantum fabric using Y Fuse fabrics, creating a tightly interlocking weave that improves down-proof and water-beading properties.
That is a lot of technology bundled into one jacket. With its superior packability and low weight penalty, packing the Grumman Down Jacket is a no-brainer. However, this jacket is not really built to be worn as an outer layer for active pursuits. It is designed for stationary activities (think glassing or lounging around at base camp) or layering underneath a shell like the De Havilland, M5, or M7 jackets). While the Grumman’s outer fabric is effective for holding the down in and repelling moisture, it is not ironclad. It is susceptible to punctures or tears if you are traversing rocky terrain or beating down brush. In addition, down products do not breathe as well as synthetic insulation products. If you are trying to stay warm in cold conditions while in active pursuit, the Cirque Jacket is going to be your go-to.
This Cirque Jacket was designed for high-exertion activities. First, the synthetic Primaloft® fill has superior breathability compared to down insulation. We utilize Primaloft® Gold insulation for its superior technical performance. It is engineered to provide warmth without bulk, resulting in freedom of movement for your activity while allowing sweat vapors to escape. We also designed the Cirque Jacket with integrated pit zips so you can immediately dump heat from those hot spots. All of this allows you to keep your jacket on for core warmth without getting soaked in sweat when you’re raging up the mountain in pursuit of prey.
Synthetic jackets are far more suited to be worn as an outer layer when busting brush or climbing crags. The Cirque Jacket can handle a lot of abuse. Even if you rip the outer fabric of a synthetic jacket, the insulation will typically stay intact. If you spring a leak on a down puffy jacket, you’re likely to watch those precious down feathers drift away into the ether. Further, if you are hunting in precipitous climates for an extended time, synthetic pieces will serve you better. While down has superior loft when dry, its loft depreciates when wet. As mentioned, many down products are treated with some type of DWR. However, if you’re exposing your down jacket to moisture for an extended time, it will eventually lose its loft and insulating prowess. On the other hand, synthetics will continue to provide critical insulation even in extremely wet circumstances.
At the end of the day, down and synthetic jackets are two different animals. We designed the Cirque Jacket to be a versatile workhorse, melding heat and moisture management in an insulating garment that can be worn on the move. On the other hand, the Grumman Down Jacket is designed to provide the ultimate warmth-to-weight ratio, making it an essential tool for the ounce-counting backcountry hunter. Our down apparel line also includes the Grumman Down Vest, the Grumman LITE Down Jacket, and the Grumman Down Pant. As always, feel free to reach out to us directly if you have any questions.
About the Author: Justin Helvik is a high school principal, avid outdoorsman, mountaineer, and trail runner. Justin live in Bozeman, MT with his family.