Not for every shooter: in our test, group size shrank for one shooter and grew for the other. In our testing, shots landed 28% closer to the bullseye with Sling Steady under the stock. Muzzle rise was about 75% lower. It also helps manage recoil.
Landing closer to the center and shooting a smaller group are two different results, so this post keeps them apart.
How we tested
Two shooters, David and DJ, shot the same AR-platform rifle at 105 yards on Birchwood Casey Big Burst targets. Each fired 10 shots without the bag and 10 shots with Sling Steady under the stock, and each target shows 10 holes.
For each target we measured how far every shot landed from the bullseye and averaged it, and we measured the size of each group.
Did the groups get smaller?
Not for both shooters. DJ's group was 11% smaller with the bag. David's group was 6% larger. So results vary, and a smaller group is not what this test shows for every shooter.
A group can sit closer to the bullseye and still spread as wide, or wider. Average distance from the bullseye measures where the shots land. Group size measures how far they spread from each other. In our test the first improved for both shooters and the second did not.
How much closer did the shots land?
Across both shooters, the average distance from the bullseye went from 0.64 to 0.46 ring diameters: 28% closer. David's hits in the center X went from 1 to 4. DJ's hits inside the inner ring went from 3 to 5.
The full write-up of the 105-yard test shows each target, the per-shooter figures and how every shot was measured. Our test is two shooters, one AR-platform rifle, one distance and 10 shots each way, and the figures describe that test.
What a rear bag takes out of the hold
Without rear support, one hand or the shoulder holds up the butt of the rifle, and small muscle movements show up in the reticle. A rear bag supports the butt on a soft base instead, so that hand has less holding to do.
That is a statement about technique. It describes what the muscles are doing, and it is the reason shooters reach for a rear bag in the first place.
What reviewers say about squeezing a rear bag
Outdoor Life's review of an adjustable bag rider (John B. Snow, updated 24 July 2023) makes a related point: squeezing a rear bag works, but it is hard to hold for long periods and less consistent than a mechanical adjuster. That is one reviewer's view, and it is about holding elevation, not about group size.
How to test it on your own rifle
You can run the same comparison. Shoot a group from your normal rest without the bag, then the same number of shots with the bag, from the same position and at the same distance with the same ammunition. Measure how far each shot lands from the bullseye as well as the group size, since the two can move in different directions. Write down the rifle, the ammunition, the distance, the position and the shot count so the numbers mean something when you compare them later.
Our post on using a rear squeeze bag on the bench and prone covers the setup.
What Sling Steady offers
Sling Steady is a rear shooting rest bag that sits under the stock. It rides on your sling or attaches directly, so it is on the rifle when you need it. The Sport 7", 7" x 2.5" and 6.3 to 6.8 oz, is for AR-platform rifles. The Pro 9", 9" x 2.5" and 9.5 oz, is for bolt-action, sport and hunting rifles. Both ship filled with SteadyFill, with hook-and-loop ports to add or remove fill, and cost $89.99. The bags are made in the USA. Sling Steady is a veteran-run company.
Run your own test: Sport 7" · Pro 9"
Related reading: The 105-yard test, in full · Range day: using a rear squeeze bag on the bench and prone · Building a stable prone position with a rear bag
Sling Steady is Ready When You Are.