January 30th, 2018

Seven Smart Ways to Use Old Film Canisters

35mm film cannister tip bushings patches

While nearly everybody now favors digital photography over “old-fashioned” 35mm film, don’t toss those old 35mm film canisters, especially the clear Fuji-type with secure snap-in lids. Small plastic film canisters have a multitude of uses for the shooter and reloader.

Here Are Things You Can Do with Plastic Film Canisters:

1. Hold thrown powder charges. If you weigh powder charges after throwing them with a manual powder dispenser, throw the charges first into a film canister and then use that to drop the powder into the measuring pan on your scale. The canister will catch every kernel of powder. If you throw charges directly into a weighing pan, powder can sometimes bounce out. Using the film canister will help keep spilled powder off your loading bench and floor.

2. Store extra sets of foam ear-plugs in the canister. You never want to be without ear protection. This editor has four film canisters filled with plugs. Two go in the range kit, one goes in the car’s glove compartment, and a second stays in a lock box I use to transport pistols. This way I never find myself at the range without ear protection.

3. Place smaller cotton patches in film canisters, marked by caliber. If you use the water-tight Fuji-style canisters, you can even pre-soak the patches with solvent. You can have one canister for wet patches, another for dry patches. That saves time when you’re at the range, and avoids spillage. One caution–some solvents may react with plastic, so test this first before you put a solvent-filled canister in your range kit.

35mm film canister shooting gear rifle kit

4. Store your neck bushings, sorted by caliber in film canisters. With a permanent marking pen, you can mark the side or top of the canister with the bushing sizes, or caliber.

5. Store your favorite Bolt Grease (for rifles) or anti-seize compound (good for pistol slide rails), in the canister. You don’t need to fill it all the way up — a little dab will do ya. We only recommend this with the snap-top Fuji canisters.

6. Protect your muzzles with canisters, during transport. When shipping a rifle or barrel, slip the film canister over the muzzle, then secure it with electrical tape. This will protect the precious crown of a match barrel from dings or damage.

7. Protect front sights with linked film canisters. Forum member SPClark explains: “I’ve seen several shooters use film canisters to make up front match sight protection. Use some elastic cord between two canisters… that’s easy to remove once you get to the line.”

TELL US Your Tips!

There are countless other uses for 35mm film canisters. We invite readers to respond with their own tips on using these handy containers. If you don’t have some stashed in your workshop already, you can get empties for free at most film processing centers. The clear plastic Fuji canisters are the best — you can see what’s inside and the lids are watertight.

Permalink Reloading, Tech Tip 4 Comments »
August 27th, 2017

Controlling Grip on Bullet — Why Bushing Size is Only One Factor

case neck bushing reloading die tension bullet release

Many novice hand-loaders believe that neck bushing Inside Diameter (ID) size is the only important factor in neck tension. In fact, many different things will influence the grip on your bullet and its ability to release from the case neck. To learn the ins and outs of neck tension, take some time and read this article carefully.

Neck Tension (i.e. Grip on Bullets) Is a Complex Phenomenon
While we certainly have considerable control over neck tension by using tighter or looser bushings (with smaller or bigger Inside Diameters), bushing size is only one factor at work. It’s important to understand the multiple factors that can increase or decrease the resistance to bullet release. Think in terms of overall brass-on-bullet “grip” instead of just bushing size (or the internal neck diameter in non-bushing FL dies).

Bullet grip is affected by many things, such as:

1. Neck-wall thickness.
2. Amount of bullet bearing surface (shank) in the neck.
3. Surface condition inside of neck (residual carbon can act as a lubricant; ultrasonic cleaning makes necks “grabby”).
4. Length of neck (e.g. 6mmBR neck vs. 6mm Dasher).
5. Whether or not the bullets have an anti-friction coating.
6.The springiness of the brass (which is related to degree of work-hardening; number of firings etc.)
7. The bullet jacket material.
8. The outside diameter of the bullet and whether it has a pressure ridge.
9. Time duration between bullet seating and firing (necks can stiffen with time).
10. How often the brass is annealed.
11. Amount (length) of neck sized (e.g. you can size only half the neck).
12. Interior diameter of bushing, or neck section of non-bushing die.

— and there are others…

One needs to understand that bushing size isn’t the beginning and end of neck tension questions, because, even if bushing size is held constant, the amount of bullet “grip” can change dramatically as the condition of your brass changes. Bullet “grip” can also change if you alter your seating depth, and it can even change if you ultrasonically clean your cases.

Redding neck bushingsIn our Shooters’ Forum a reader recently asked: “How much neck tension should I use?” This prompted a Forum discussion in which other Forum members recommended a specific number based on their experience, such as .001″, .002″, or .003″. These numbers, as commonly used, correspond to the difference between case-neck OD after sizing and the neck OD of a loaded round, with bullet in place. In other words, the numbers refer to the nominal amount of interference fit (after sizing).

While these commonly-used “tension numbers” (of .001″, .002″ etc.) can be useful as starting points, neck tension is actually a fairly complex subject. The actual amount of “grip” on the bullet is a function of many factors, of which neck-OD reduction during sizing is just one. Understanding these many factors will help you maintain consistent neck tension as your brass “evolves” over the course of multiple reloadings.

Seating Depth Changes Can Increase or Decrease Grip on Bullet
You can do this simple experiment. Seat a boat-tail bullet in your sized neck with .150″ of bearing surface (shank) in the neck. Now remove the bullet with an impact hammer. Next, take another identical bullet and seat it with .300″ of bearing surface in another sized case (same bushing size/same nominal tension). You’ll find the deeper-seated bullet is gripped much harder.

PPC lapua brassNeck-Wall Thickness is Important Too
I have also found that thinner necks, particularly the very thin necks used by many PPC shooters, require more sizing to give equivalent “grip”. Again, do your own experiment. Seat a bullet in a case turned to .008″ neckwall thickness and sized down .003″. Now compare that to a case with .014″ neckwall thickness and sized down .0015″. You may find that the bullet in the thin necks actually pulls out easier, though it supposedly has more “neck tension”, if one were to consider bushing size alone.

In practical terms, because thick necks are less elastic than very thin necks, when you turn necks you may need to run tighter bushings to maintain the same amount of actual grip on the bullets (as compared to no-turn brass). Consequently, I suspect the guys using .0015″ “tension” on no-turn brass may be a lot closer to the guys using .003″ “tension” on turned necks than either group may realize.

Toward a Better Definition of Neck Tension
As a convenient short-cut, we tend to describe neck tension by bushing size alone. When a guy says, “I run .002 neck tension”, that normally means he is using a die/bushing that sizes the necks .002″ smaller than a loaded round. Well we know something about his post-sizing neck OD, but do we really have a reliable idea about how much force is required to release his bullets? Maybe not… This use of the term “neck tension” when we are really only describing the amount of neck diameter reduction with a die/bushing is really kind of incomplete.

My point here is that it is overly simplistic to ask, “should I load with .001 tension or .003?” In reality, an .001″ reduction (after springback) on a thick neck might provide MORE “grip” on a deep-seated bullet than an .003″ reduction on a very thin-walled neck holding a bullet with minimal bearing surface in the neck. Bushing ID is something we can easily measure and verify. We use bushing size as a descriptor of neck tension because it is convenient and because the other important factors are hard to quantify. But those factors shouldn’t be ignored if you want to maintain consistent neck tension for optimal accuracy.

Consistency and accuracy — that’s really what this all about isn’t it? We want to find the best neck tension for accuracy, and then maintain that amount of grip-on-bullet over time. To do that you need to look not only at your bushing size, but also at how your brass has changed (work-hardened) with time, and whether other variables (such as the amount of carbon in the neck) have changed. Ultimately, optimal neck tension must be ascertained experimentally. You have to go out and test empirically to see what works, in YOUR rifle, with YOUR bullets and YOUR brass. And you may have to change the nominal tension setting (i.e. bushing size) as your brass work-hardens or IF YOU CHANGE SEATING DEPTHS.

Remember that bushing size alone does not tell us all we need to know about the neck’s true “holding power” on a bullet, or the energy required for bullet release. True bullet grip is a more complicated phenomenon, one that is affected by numerous factors, some of which are very hard to quantify.

Permalink Bullets, Brass, Ammo, Reloading 5 Comments »