Gossamer Gear Gorilla size

That is correct about the volume of the main compartment of both the Murmur and Gorilla. Both are about 28 L. The Gorilla is listed at 40 L of total volume which includes the outer pockets. The Murmur’s total volume is 36 L for the same reason. This is a standard way to list total volume for most manufacturers

They are two completely different packs though depending on your needs. The Gorilla has the same load carrying design as the Mariposa. Aluminum stay and an attached hip belt to help distribute weight.

The Murmur is a minimalist, frameless pack for very light base weights. Also, the weight belt will offer no appreciative load support. It’s basically there to keep the pack close to your body and offer some extra pockets.

I I have the Gorilla it carries about 25 lbs or less well. I’m guessing the Murmur would be comfortable up to 15-18lbs total.

Calculating from the dimensions for the main body:

Gorilla: 1914 (allowing 3″ for closure) or around 31.3L

Murmur: 1386ci (allowing 3″ for closure) or around 22.7L

Front pouch:

Gorilla: ~650ci or ~10.7L

Murmur: ~500ci or 8.2L

Side Pockets:

Gorilla: About 75ci or about 1.2L (Two 500ml Water Bottles fit easily)

Murmur: About 50ci or about .8L (Two 500ml water bottles fit about 3/4 of the way up)

Belt Pouches:

Gorilla: Two at around 50ci/.8L each

Murmur: Two at around 30ci around .5L, each(2015), none on the 2012

Lid Pouch:

Gorilla: 50ci or .8L

Murmur: none

The numbers at the Gossamer Gear site simply do not make sense for the main body unless they are filled completely into a “tube” (a very uncomfortable carry.) There is no way the main body of the Gorilla @ 23″  x 11″ x 6″ multiplies out to the 1760 ci they state, it is 1518ci. Adding the extra usable space of the extension collar, and still close it, makes it 1914ci?

Nor is the Murmur @ 22″x11″x4.5″ anywhere near the 1700 they state, it is 1089. Even adding the extension collar only adds 297ci. Where in hell did they get their numbers on the site??

Is it reasonable that the Murmur at 22″x11x4.5″ deep the same size as Gorilla at 23″x11″x6″deep?

The Gorilla is about just under third larger than the Murmur. I can get 2 food bags in the Gorilla. I can only fit 1 in the Murmur.  I can fit a UL loadout for two weeks at 23 pounds in the Murmur. I can get about three weeks out of the Gorilla at 32 pounds. Both were weighed at the trail head just before I started hiking and included a single day supply of water. I use the Gorilla for early and late season hikes. I use a 6″ stuff sack for my larger sleeping bag. I use a 5″ stuff sack for the Murmur. This is based on my experience with both packs. They are NOT about the same size.

I think the Gear Lab measures with ping pong balls. This is not the same packing your gear. I just use the actual dimensions and multiply out. This is really the only way to tell sizes and compare them between the many companies.