Measure for measure

We put six mechanical measures through the same powder test, and come up with some surprising results.

First, the six measures we will be testing here: Lee Perfect, RCBS Uniflow, Forster Bonanza Benchrest, Hornady L-N-L Bench Rest, Redding BR-30 and Harrell’s Precision Premium BR, in ascending price order.

We tested them with four powders: Hodgdon VarGet, Vihtavuori N140, IMR-4064 and Hodgdon Hybrid 100V, a stick-type with rounded ends that is claimed to meter as well as ball powders. IMR-4064, on the other hand, has a reputation for problems, including trapped kernels causing rotors to stick and ‘bridging’ in the measure drop tube.

Design-wise, the sextet covered most types, apart from the Lyman #55 and its unique horizontal slides. The Lee, Hornady, Redding, and RCBS examples have conventional rotor designs with their screw-type metering cylinders sticking out towards the operator – all performed smoothly.

Forster’s Bonanza Bench Rest has a small body-rotor with a massive cast operating handle that contains the metering chamber, its capacity varied by moving a sliding piston.

It’s a little slower to set up and fine tune the charge adjustment, but once set it, operates very well. Thanks to the girth and weight of its handle, it has a different feel to the others.

Redding’s Competition BR-30 uses a traditional layout, optimised for 30gn charges

Finally, the Harrell exudes quality, with its brass and polished aluminium parts, a rotor spindle that rides in roller bearings giving the lightest and smoothest handle operation of the six, and, its biggest plus, a massive precision-machined adjuster drum that allows you to make small (0.1gn) changes with consistency, and whose calibrations allows a reliable return to settings. For instance, moving the knob to 53 plus one ‘click’ throws 29.7gn Hodgdon VarGet for a standard 6mmBR load.

We initially adjusted the measures to throw 50gn of N140, and left them at that setting for the other powders. A good way to do this is to start a test run with a full powder reservoir, before throwing and discarding 10 charges to settle the powder column.

The test proper saw 25 charges thrown and weighed on my Acculab VIC123 electronic scales. Measure bodies were tapped twice with a wooden kitchen spoon before throwing each charge, and their handles moved as smoothly as possible at an even pace.

The tiny, inexpensive Lee Perfect performed very well

The 35 charges thrown with each combination were returned to the maker’s bottle, not the reservoir, to replicate actual case-charging and the ensuing reduction in powder column weight.

Everyone’s a winner

It would be unlikely that any model would be outstandingly good or bad with all four powders – a prediction that was largely fulfilled.

There isn’t room here to include even summary results for the data collected, so we’ve used SD values to rank each measure for each of the four powders, and totalled those positions to produce a score that could range from 4 (four first places) to 24 (four sixth places).

The Hornady came out best overall, but remember, it’s the more expensive Bench Rest model with an improved metering chamber. It still offers good value, but on this metric, the runaway winner was the Lee Perfect, whose £26 price even includes a pressed steel bench-stand.

Harrell’s precision measure from above, with the reservoir bottle removed

The only drawback to it is that it is tiny, and being so small, it needs frequent reservoir top-ups. Whether you’d buy the Lee also depends on whether you want old-fashioned cast iron tools, or can live with an all-plastic assembly, a few aluminium or stamped metal components aside.

However, thanks to its nylon rotor and ‘elastomer wiper’, it coped well with all powders, including long-grained IMR-4064. If your handloading doesn’t involve too many combinations, it can be worth buying two or three of these little machines and leaving them permanently set up for one load, as opposed to buying a more expensive model and constantly resetting it. 

The other result shown is combinations that failed to stay within 0.2gn of the mean weight. With a 50gn charge, significantly larger deviations aren’t really acceptable if using charges ‘as thrown’.

Out of 600 charges, 106 failed this target, and only two combinations managed to avoid a single breach: RCBS Uniflow / N140 and Hornady L-N-L BR / H100V. The Forster did best on this metric, with 11 instances out of 100 charges; the RCBS worst with 22.

The Forster Bonanza Bench Rest measure is an unusual design but works well

To be fair to the latter measure, its results were thrown by the IMR-4064 – it racked up 14 breaches with this one powder, producing a massive 1.26gn ES. However, 4064 and similar powders see little use here, so it’s hardly a major issue.

Harrell’s Precision and Redding models occupy the last two places – a surprise considering they are the most expensive. There is a reason for the price, though: they’re designed for BR competitors using small cartridges with charges in the 25-35gn range.

Charges of 50gn are achievable, but outside of the measures’ optimum performance envelope. So we reran the tests for this pair with 29gn of Viht N133, the ‘standard’ 6mm PPC load for 65-70gn bullets. Table 2 shows their performance – it is transformed by the switch, but is still not as good as you might expect. 

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