Mechanical Rests

Q. What groups can I expect from one of your custom guns through a Ransom Rest?”

This is one of the most commonly asked questions we receive regarding the gauging of pistol accuracy and there are a number of issues that need to be addressed, so I decided to answer it here. To bottom line it, I’m going to suggest that you don’t use a machine rest at all to test accuracy of a locked breech pistol. Chances are it will frustrate you and place unnecessary doubts in your mind regarding the accuracy potential of your handgun. The machine rest is a good tool and has a number of legitimate uses, but it has limitations, and testing the accuracy of a custom 1911 is one of them; especially when the difference between a 'good' custom 1911 and a 'great' one could be as little as a quarter to a half an inch on a target at 25 yds. Unlike a revolver, the sight and barrel axis of these pistols is independent of the frame and this produces variances that make mechanical rests a risky tool for testing accuracy in my opinion. I can’t argue the fact that there are some 1911’s that will perform well through a mechanical rest; usually newly built custom guns with a hand full of rounds through them. But I’ve never seen a rest that can’t be outshot over a bag by a good shooter and because of that I've never been able to justify using one.

The value of a machine rest in my opinion (other than certain safety advantages in proofing procedures) is in testing ammunition against a known benchmark through your own gun. In other words, lets assume that 185 Wadcutter delivers the kind of performance you’re looking for in a hand-load. It doesn’t matter what group the gun prints out of the rest with the wadcutter because theoretically, the relationship of the loads you are building will always be a percentage of the performance of that benchmark regardless of whether your loads are better or worse. I use the word ‘theoretically’ because there are a number of factors that determine if the pistol will repeat to position after each shot and if in fact if you can actuate the trigger without upsetting the pistol in the inserts. Remember that a well built 1911 will have the barrel precision fit to the slide, bushing and slide-stop to eliminate as much of the variance between the barrel lock-up and the sight plane as possible. It doesn’t matter if there’s a controlled amount of horizontal and vertical 'play' between the slide and frame in battery when you’re holding the gun because you’re always compensating for that as you align the sights. But even secured correctly in a mechanical rest, the pistol can actually produce unrepresentative groups because of those operating tolerances in the slide and frame fit. Further, mechanical rests are seldom secured to a solid enough base. Most rests are not adequately anchored and often move on the base under recoil.

It’s also unreasonable to assume that the rest is always good when in fact the sum of potential mechanical variances in the machine rest itself (to say nothing of the ammunition) substantially outnumbers those in a well-built pistol. I’ve seen way too many good guns get ‘sold down the river’ because of a machine rest. I’m not just talking out of a hole in my head on this one. My opinion is based on years of experience at Pachmayr Gun Works attempting to attain the mandated 1.250” group out of a rest with our painstakingly built Pachmayr Combat Specials. Frank insisted that we use the rest for targeting and we battled to get the groups without cheating; literally chasing accuracy ghosts in the guns that didn’t exist. The groups always seemed to hover just outside the mark. It was only after we started shooting the guns over a bag that the acceptance rate climbed.

As with all things, there are exceptions to the rule. The wide-link and ground pin used in some of our target pistols enhances the stability of the barrel and because of the width of contact and precision between the pin, slide stop and link; the barrel and slide unit may tend to repeat better when anchored in a rest by the frame. But the system is not totally impervious to the accumulated tolerances that could be magnified by the machine. There are also a couple of people I know who are experts in getting guns to perform out of a rest. They’re almost ritualistic in the way they load the gun and reset it between shots. They sometimes back off the weight of the triggers and use a string through the trigger guard in place of the trigger actuator to get an even backward pressure on the trigger face. They have an uncanny knack of being able to get guns to perform acceptably in these machines. I just don’t have the skill, time or patience for that.

In final answer to the question that prompted this essay I can honestly tell you that I don’t know what groups my guns will produce through a rest. Chances are that the result would be different from machine to machine. I’ve never owned a rest and I’ve never personally fired a Pistol Dynamics custom gun in one and I cringe when people do, because I know that no matter what the result, it's not a true representation of the performance of the piece. I can tell you how the gun will perform in my hands, on a bag, with my benchmark ammo. The targets that are supplied with my custom guns are not faked and are also not the best of the bunch. I fire five groups of five rounds each at 25 yds and ship the group that best represents the average. If the gun doesn’t produce my expected level of performance then I find out why and either adjust the handgun or wake the next morning, get out of the right side of bed, and do it again. The target is included so that you can rest assured that the performance of the handgun is commensurate with your investment. I value my customers greatly and your peace of mind is of the utmost importance to me. Relying on a machine to do that which under every other circumstance is performed manually is the wrong way to test accuracy. That's why I take the time to personally target every custom gun that leaves my shop.

Paul Liebenberg