Why you SHOULDN’T clamp your airgun in a vise!
by B.B. Pelletier
First let me share the inspiration for this blog. Pyramyd Air received a negative review about an air rifle from a customer. He said the air rifle he received was unable to group closer than three shots in several inches at 35 feet. He also said he was shooting the gun from a shooting vise. He was extremely unhappy with the gun and ended up returning it.
Okay, an angry customer. And also one who just shot himself in the foot and doesn’t even know it. He doesn’t know that he was most likely the cause of the lousy accuracy he got. It probably came from the very technique he used to supposedly make the gun accurate. It was proven a century ago that a vise is no guarantee of accurate shooting and can actually rob accuracy. I refer to the work of Dr. F.W. Mann and his extensive work shooting target guns mounted on his massive “Shooting Gibraltar” concrete pedestal with a massive vise bolted to its top.
Then on Saturday, reader Mike asked a similar question. Isn’t there a way of shooting an air rifle in which the shooter doesn’t have to hold it? He wanted to take himself out of the equation, because he believes his technique isn’t as good as it should be. I told him I would address this topic today.
What about using the artillery hold? The first person who complained about the inaccurate rifle makes no mention of it in his message, so we can assume that he isn’t aware of it and how it tightens airgun groups — especially with spring-piston rifles. He’s like a lead-foot driver on ice, spinning his tires and wondering why his car is sliding sideways instead of going where he wants.
When Feinwerkbau (FWB) tests a target rifle, they don’t put it in a vise. They shoot it from a rested position. Those tight groups that come with each rifle and pistol are from hand-held guns.
Don’t shoot airguns from a vise unless you know what you’re doing. The complaining customer doesn’t give enough information for us to know whether he does or doesn’t know, but since the majority of shooters do not know how to use a vise with an airgun, I’ll assume the customer didn’t know either.
I addressed this topic three years ago in this report: What about shooting from a vise? (Although I misspelled vise throughout the blog.)
But it appears that the topic needs to be discussed some more. Vise shooters are convinced that they’ve removed the last bit of human error, when that isn’t true at all.
The irate customer mentions using a bench gun vise. Well, that would be just about the worst kind of vise to use for many air rifles. A spring rifle would move that kind of vise every time it’s cocked, destroying any hope of repeatability. When Dr. Mann shot from his Shooting Gibraltar, he used a special cylindrical action he had made that allowed him to load the gun without taking it out of the fully machined V-block vise or moving the vise when he reloaded. Each custom barrel made for testing had machined concentric rings to interface with the vise, so it was also made especially for vise shooting. Famous barrel maker Harry Pope made most of the test barrels for Mann.
Since Mann’s vise weighed over 1,000 lbs., was sunk 40 inches into the ground and rose 28 inches above ground, there was no way to move it anyway. The vise was fastened to the concrete pier by 5/8″ bolts that were sunk 14 inches into the cement. And, yet, with all this careful preparation, Dr. Mann found that getting repeatable results from a gun held in a vise was extremely challenging.
In sharp contrast, what kind of flimsy bench did our irate customer shoot from? We’ll never know, but consider any movement as the enemy of repeatability in a vise test.
What kind of powerplant is he shooting? No spring-piston air rifle is suited to bench gun vise use. But let’s hypothecate that he’s using an RWS Diana 48 and clamping just the barrel in the vise. That leaves the sidelever free for cocking. And let’s also assume that he fastidiously ensures by some method (laser mounted on the action and pointed at a registration point on the target?) that the gun didn’t move during cocking. With all that precaution, he’s still spitting into the wind.
The RWS Diana 48 has a barrel jacket surrounding a thin inner barrel. It’s possible for the inner barrel, the real barrel, to move even when the outer barrel remains stationary. Sidelever owners eventually discover this fact when their barrel jackets loosen enough to rattle. What’s the solution? Shoot using the artillery hold so the true barrel and the sights always have the same relationship.
Two gun powerplants that do lend themselves to vise shooting are CO2 and PCP. Both allow the guns to remain stationary, as long as they don’t require a lot of cocking effort and the vise is really stable.
When I tested the AirForce Edge for 10-meter accuracy, I had the gun clamped in a vise, but not for accuracy. I did it so I could load and shoot fast without having to aim. I can hold a group off a rest just as small as a vise can deliver at 10 meters. But I have to aim the rifle each time following loading, while with the vise I don’t. So, a lot of time is saved.
And that’s the point of today’s blog. You don’t need a vise for most accuracy testing. It can help if the powerplant you’re testing lends itself to use with a vise’ but if it doesn’t, you’re courting disaster. And stop thinking that a vise make the gun more accurate. Generally speaking, you’re just as accurate shooting with a good artillery hold off a rest as you will be with a vise; and, with spring guns, that’s the only technique that works.