December 20th, 2019

USAMU Tips for Using a Progressive Reloading Press

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Each Wednesday, the U.S. Army Marksmanship Unit (USAMU) publishes a reloading “how-to” article on the USAMU Facebook page. In this article, the USAMU’s reloading gurus help you avoid potentially disastrous mistakes with a progressive — such as double powder changes. The USAMU experts caution that: “beginners would be better served by starting on a single-stage press”. That said, owning a progressive makes sense if you shoot more than 100 centerfire rounds a week. If you own a progressive press, or are thinking of buying one, you should read this article.

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For those interested in progressives, we’ll examine different key features among the types and relate them to handloading processes. The first, and simplest, type is the manually-advanced progressive. The shellplate holds the several cartridges being processed with each stroke of the handle. On these presses, the loader must manually advance the shellplate after each handle stroke.

While this obviously slows production vs. a press that cycles the shellplate automatically, this feature does have advantages though. (The disadvantages follow shortly.) No case is advanced to the next station until the operator deliberately does so – which is especially helpful for the new handloader.

Problems that arise during loading can be diagnosed and fixed without fears of some “extra” operation happening unnoticed with cartridges at the other stations. Beginners NOTE: one way to positively prevent this risk is to remove the cases from each press station when a problem emerges, before beginning diagnosis. Usually, however, experienced loaders omit this step as a time-saving measure, being confident in their understanding of the loading machine, process and the appropriate remedy.

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If all cartridge cases are left in place, the operator must monitor what’s happening at each station. For example, raising the press ram twice may result in a double-charge of powder. With rifle cartridges, this usually results in a massive powder over-flow, alerting the loader to the problem. With pistol cases or small rifle charges in large cases, such an over-flow isn’t guaranteed. [Editor — one way to be sure you don’t have an overcharge or undercharge is to use a Lock-Out Die — see below.] The manually-advanced progressive keeps all operations under the loader’s control at all times. This is intuitively easier for the beginning loader to understand and to operate with confidence.

However, this same characteristic can be problematic if the loader isn’t paying 100% attention to what they are doing during routine operation. Some new handloaders apparently aspire to load progressively while daydreaming and paying little attention to the operation. Their plan is to feed components in, like feeding potato chips to a monkey, while good ammo drops out at the other end. Unfortunately, such an approach may likely result in something other than “good” ammo dropping out at the end…

Forgetting to cycle the shellplate when appropriate will cause problems. As with all handloading, distractions MUST be kept to a minimum for safety purposes. Never watch TV, talk with friends, or have other distractions (such as a rambunctious pet or child) in the room when loading. Avoiding distractions will do much to ensure that one produces consistent, high-quality ammunition, free of defects. For example, when a case doesn’t line up correctly with the case mouth expander or powder drop tube, a difference in “feel” often alerts the loader to correct the problem without ruining a case. If one is interrupted or becomes distracted, be certain to examine ALL cases in the shellplate before resuming loading.

Better Safe Than Sorry — the RCBS Lock-Out Die
RCBS Makes a “Lock-Out Die” that senses the powder charge. This will halt the Progressive press if you have a double charge, or an undercharge. Your Editor has the Lock-Out Die on his RCBS Pro 2000. It has “saved his bacon” a half-dozen times over the years. It can be used on Dillon and Hornady progressives as well as RCBS machines.

Other advantages of the typical manually-advanced progressives are that they are usually simpler in design, with fewer moving parts to get out of adjustment. This appeals to the mechanically dis-inclined! Caliber conversion kits are usually cheaper and take less time to install. This especially benefits the enthusiast who reloads for a wide variety of calibers.

However, many popular manually-advanced progressives have fewer die stations than the higher-end, auto-advancing machines. One item that is very useful when actually dispensing powder on a progressive press is a cartridge case powder-level sensor. This warns if powder levels in each case are too high or too low; however, it does require a die station of its own.

This condition (incorrect powder charges) often results from powder (especially extruded rifle powder) “bridging” in the powder measure. That is, one charge doesn’t fully empty into its cartridge case. This leaves some extra powder hanging up in the measure to join the normal charge in the next case. With some extruded powders, this can be quite obvious without a sensor. However, the sensor can detect small variations that would not be obvious to even an experienced, attentive operator. Considering the machine’s potential to use a powder sensor in addition to one’s other customary dies is a wise idea.

Similarly, pistol shooters are best served to seat bullets and crimp cartridges in separate operations. This should be taken into account when selecting a progressive press. Whenever loading fully-progressively, choosing powders that dispense very easily, e.g., ball/spherical or very fine-grain extruded powders, can help keep charges quite uniform.

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