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The "Ranging Shot" Is A Regular Column In The IHMSA News
Published in The IHMSA News, the Official Publication of The International Handgun Metallic Silhouette Association
Published monthly except November/December - January/February
IHMSA on the web at http://www.ihmsa.org
Volume 15, Issue 1 Jan/Feb
 
  The Ranging Shot Email Todd:  TSPOTTI@worldnet.att.net
  With ( Comments or questions? )
Todd Spotti
 

     If you remember, I discussed the long range efficiency of Lapuaís Scoremax 22 ammunition a couple of months back. Basically I said that because of the combination of its subsonic velocity and greater ballistic coefficient (due to the longer length of its 48 grain bullet) it was able to hit the 100 meter rams at higher velocity and with more weight than a standard subsonic 22 bullet. Well, that leads us to the next logical question "How does a standard 40 grain subsonic bulletís hitting power compare to a standard 40 grain supersonic bulletís hitting power at 100 yards?"

     Thereís a fair number of silhouette shooters that like to shoot the supersonic stuff figuring that thereís going to be more impact on the rams at 100 yards. Intuitively, it makes sense. Often the differences in velocity between a subsonic and supersonic 22 bullet can be substantial. However, we also know that a supersonic bullet will have to deal with the turbulence of breaking through the sound barrier, but thatís an accuracy issue. What about velocity?

     Well, we also know that because of the increased air flow over the supersonic bullet that drag will be increased as well. The question now becomes "In spite of the much greater drag, will the substantially greater initial velocity of a 40 grain supersonic bullet allow it to hit the ram at 100 yards with more velocity than a subsonic 40 grain bullet?" To tell the truth, I wasnít really sure. Even though the subsonic bullet is subjected to less drag and will lose less speed as a percentage of its muzzle velocity, is that enough to overcome the supersonic bulletís substantially higher speed? I decided to check it out.

     What I would do is compare the performance of high quality supersonic 40 grain ammunition (Eley Scorpion) against the numbers of the 40 grain subsonic ammo that I used in the Scoremax evaluation (PMC Rifle Match).

  Muzzle Vel 100 Yd Vel Vel Drop
Scorpion 1248 fps 1012 fps 236 fps
Rifle Match 1036 fps 936 fps 100 fps

     Both brands would be chronographed at the muzzle and at 100 yards with my Oehler 35P chronograph. Here are the subsequent numbers:

     The numbers are kind of interesting. We see that Eley Scorpion lost far more speed i.e. just about 19% of its muzzle velocity at 100 yards. On the other hand, the PMC Rifle Match lost less than 10% of its initial velocity. So, we see that because the subsonic bullet doesnít have to overcome as much drag, itís going to lose less velocity.

     Never the less, horsepower does make a difference. Because itís starting off much, much faster, the Eley Scorpion will definitely put more hurt on the 100 yard targets (76 fps more to be precise) in spite of the fact that itís going to be losing more velocity overall.

     This little experiment shows that the supersonic route in silhouette does have value, but also be aware that supersonic bullets are more sensitive to the wind. Additionally, in general, most supersonic ammunition has not demonstrated the degree of accuracy that subsonic ammunition delivers.

     Remember I said "in general". There are always exceptions. Consequently, if you want or need to use supersonic ammo because of sticky rams at your club, use high quality products like Eley Scorpion. When the wind is calm, this stuff will shoot an inch or better at 100 yards. (Note: Eley Scorpion is no longer available but Eley High Velocity is a good substitute.)

The Idea

     Quite often ideas will come to me when Iím laying in bed at night. You know, itís that period just after youíve turned off the light, fluffed up your pillow, and closed your eyes. Many people (the lucky ones) will instantly fall fast asleep. Not me. Iíll just lay there and start thinking, and thinking, etc. My thoughts will wander all over the place and then ideas will start coming out of no where - ideas that often have no connection what so ever with what I was thinking about just the second before. Iím sure there are those that would say I was being delusional or perhaps that I was hallucinating. They could be right.

     Anyway, I was in one of those states, when it suddenly occurred to me that primers are absolutely huge in comparison to the size of the flash hole that theyíre sitting on. Think about it. A flash hole canít be more than 20% of the size of a primer. So thatís around 80% of the primer material thatís probably not making down the hole into the powder. Why is that? Why doesnít someone just either make smaller primers or larger flash holes?

     Upon some reflection, I thought that it probably makes sense to have oversized primers to accommodate mechanical tolerances regarding firing pins, chamber size, etc. After all, not all firing pins are located exactly in line with every cartridgeís primer flash hole.

     Nope, it seemed that having larger flash holes would make more sense. It then occurred to me that if the flash holes were larger, more of the flaming primer material would hit the powder and more complete ignition should result. If ignition is more complete, it should result in better velocities and accuracy. Gosh, what a great idea.

     So, how could I go about testing this theory? Well, Iíd load up ten regular 357 mag cases and then fire them over my chronograph and check the velocity, standard deviation of velocity, and accuracy. Iíd also drill out the flash holes of ten additional cases using a 1/8th inch drill. This resulted in a huge flash hole in the case head with just a little narrow rim for the primer to be seated against. Iíd then fire the modified cases using the same load and compare the results. Theoretically, the modified cases should deliver greater velocities, lower SDís, and greater accuracy.

     My test gun would be a Contender equipped with a 14 inch SSK barrel. A Leupold 2.5 X 8 nestled in a set of Weaver 4X4 scope rings provided the optics.

     My test load would be a pretty standard silhouette combination consisting of 16.5 grains of H110, Sierraís excellent 180 grain silhouette bullet, Starline brass, and CCIís small pistol mag primer. The bullets were seated with Reddingís competition die and the profile crimp was also provided by a Redding die.

     After reflecting a little more on the subject, I began to wonder if the increase in primer flash would boost ignition too much, too fast, and result in out of control pressures. In fact, I got worried enough about it that I called a very good friend of mine who works for one of the primer manufacturers. He kind of scratched his head for a while and then admitted he didnít have a clue what would happen. He just advised that I go slow. Well the ammo was already made up and I wasnít going to tear it all down in order to reduce the load. I figured the Contender should be able to handle the situation.

     Well I got everything set up at the range and fired off the ten cartridges with the standard flash holes. The chronograph numbers were actually pretty good and accuracy was around 2 inches at 100 yards. (I should explain that this barrel is over 20 years old and is for all practical purposes shot out. I plan to re-chamber it one day in 357 Max or maybe even 35 Remington and use it for a pig gun.)

     I have to admit I was a little nervous when I loaded the first case with the oversized flash hole. I had no idea what to expect. I slowly squeezed the trigger, the gun fired, and everything ---- was absolutely normal. No blinding flash, no loud thunder clap, no punishing recoil, no pieces of shrapnel flying. Everything just seemed ---- ok.

     A glance at the chrono showed the velocity of that first shot to be right in the same range as the average for the first group of ten shots. Well, that must have been a fluke. I should be getting more velocity. I then fired off the remaining nine cartridges. Hereís the results.

  Normal Hole Oversized Hole
Velocity 1620 fps 1610 fps
Std Dev 7 fps 10 fps
Group 2.2" 2.1"

     Results? There was no practical difference between the performance of the loads from a statistical or accuracy point of reference. Heck. I guess Iím not a genius after all - what a surprise. Well, it was an interesting idea and Iím glad I tried it out. As they say "Even negative information has value."

Brownells Screwdriver Kit #1

     Any silhouette shooter that has ever owned a Thompson Contender with more than one barrel knows about the necessity of having a screwdriver kit in your shooting bag. For instance, in order to change barrels, we need a blade type screwdriver to take off the forend. If we want to remove the grip, we now need an Allen wrench or hex head driver.

     If we should want to put on a scope or switch scopes, we first have to remove the open rear sight which requires one size blade to take out the elevation screw and another size blade for the smaller attachment screws underneath. Then we have to put on the base and rings, again with two different size blades or perhaps a hex head. Quite often the ring straps will use the new torx screws and require special screwdrivers.

     The same situation applies to other guns used in silhouette shooting as well. The point is that the serious silhouette shooter is constantly making adjustments, changes, or even repairs on their guns, and quite often those changes are occurring out at the range without the benefit of the full breadth of tools that we have at home.

     This kind of activity demands that we have the basic tools we need on hand to do the job. Subsequently, the shooter oriented screwdriver kits that we take to range must meet at least four criteria.

     1. They should be very versatile and contain as many items as possible so they can meet almost every expected and unexpected situation.

     2. Kits should be the best quality available. I donít know about you, but when Iím working on a silhouette gun that cost me big bucks, Iím not going to use some cheap, no name tool that was made in a Chinese sweat shop.

     3. Kits should be compact in order to take up as little space as possible in our shooting bag. Heavens only know Iíve already got everything but the kitchen sink in there already without adding a bunch of screwdrivers, allen wrenches, etc. Obviously, this criteria is in direct conflict with the first criteria as the more items you place in the kit, the less compact it will be. Of course you can go overboard in the opposite direction as well and have a very compact kit with hardly anything in it. We also need to keep in mind that there is one set of requirements for making adjustments/repairs at the range and then there there is a very different set of requirements for doing the same out in the field on a hunt. The field kit we carry in a backpack on a hunt obviously should be extremely compact and light weight. Naturally it will contain fewer items than a range kit. A range kit will usually be larger because weíll only be carrying it from the car to the shooting bench. My remarks here are geared primarily at range use.

     4. The individual pieces of the kit should be easily replaceable. Losing something out of the kit is almost inevitable over a long enough period of time and it shouldnít take an act of Congress to get another one.

     Iíve used a number of these shooters kits over the years and I have to say that the Brownells #1 Magna-Tip is probably the Cadillac of the bunch as it comes the closest to perfectly meeting the four criteria. Letís compare it to our requirements one at a time.

  Versatility - The kit contains the following:

  • 7 - inch and a half long hollow ground bits for slotted screws (for extra reach)
  • 4 - one inch hollow ground bits for slotted screws
  • 4 - inch and a half hex bits
  • 6 - one inch hex bits
  • 3 - Phillips bits
  • 1- 8" Magna-Tip screwdriver handle
  • 1 - bench tray to hold the above materials
  • 1 - plastic field case to carry all of the above

     I wanted even more versatility for my kit and so added a 2.5" stubby screwdriver handle for close in work and two torx screwdriver bits for scope ring screws. The fact that I was able to easily add items to the standard kit and configure it to my needs is a plus. To be honest, I canít think of gun adjustment or maintenance situation that calls for a screwdriver that this kit couldnít handle. It doesnít get more versatile than that.

     Quality - First, the kits are American made. This goes a long way in my book. The magnetic tipped handle is particularly nice and itís the primary item that makes this kit different. Thatís because itís not the little, wimpy, under sized type thatís usually found in most shooting kits, but rather itís a big, hand filling eight inches long with a beefy inch and a quarter wide handle for lots and lots of grip and torque. Itís also virtually unbreakable, and like the rest of the kit, comes with a lifetime warrantee. One nice feature is the fact that the steel shaft is hex shaped to allow the attachment of a small wrench to put even more torque on really tough jobs like rusted screws. Canít do that with a round shaft.

     The big advantage of a magnetic handle is that the bits can be rapidly changed in and out very, very easily. The magnet in the handle is no slouch either. Itís strong enough to make it seem like the bits are literally being sucked down into the receptacle on the end of the shaft. The bits almost seem to leap out of your fingers when you put them on. Once theyíre in place, theyíre not going to move either. To test the magnetís holding power, I put on the heaviest bit in the kit and whipped the handle as hard as I could in a downward motion several times. The bit didnít move at all.

     Another advantage of a magnetic handle is the fact that when the bits are attached, they become magnetized as well. This is very handy because small screws wonít fall off the end of the screwdriver which makes screwing them on much easier.

     The bits themselves are hardened tool steel and are industrial grade quality. This is not just a name. This means that they are actually made by a supplier that also furnishes them to several manufacturers who run large, high volume assembly lines. These bits are used in impact type power screwdrivers day in and day out. Strength and durability are critical. Tool failure in high speed assembly operations is not tolerated. Iíve got bits from another brand of kit that get thoroughly messed up on a regular basis in high torque situations because they were made from fairly soft steel. That hasnít happened with the Brownells bits, and I doubt if it ever could. However, if a bit somehow did break or get buggered up, itís backed by a no hassle life time warrantee. Just call and theyíll send you a new one.

     The Brownells bits for slotted screws are also perfectly hollow ground for an exact true and square fit. As you know a standard, tapered screwdriver is the absolute worst tool to use in a slotted screw. Why they still make them that way is beyond me. In tough situations, theyíll cam out of the slot, and damage to the screw head is the inevitable result. Even cheap, imported "hollow ground" bits from third word countries can cause damage. Brownells points out that inexpensive "hollow ground" bits are often off square and will put uneven force on the screw which can result in damage or even breakage of the screw head. Breaking off a screw head on your gun - now THAT would really ruin your day.

     Compactness - The kit comes in a hard ABS plastic case that measures 4" X 8.5" which is held together with a snap type lid. Almost all of the discount store bit assortments come on a large, open tray-like affair that is good for displaying the wares but totally unsuitable for being packed up in a range bag or backpack. The Brownellís kit is somewhat bigger than other similar kits but thatís because of the big, full sized eight inch screwdriver handle. Slightly bigger in this case is not necessarily bad as thereís room inside for a little bin to store spare hammer springs, scope screws, etc. The plastic tray on the inside that holds everything in place can even be removed if you want to keep the tools on your work bench. Thereís also some extra recesses in the tray for additional optional bits and for a stubby handle if you want to customize your kit even further as I did.

     In an impromptu experiment I dropped the closed case on the concrete floor of my garage to see if the case would be damaged and if the lid would stay closed. The case was dropped from a distance of about 5í on the front and side edges of the case. The lid stayed tight and there was no damage other than a little minor scuffing. The reason I did this is because some time back, I happened to knock a kit that I previously used off a shooting bench at the range. The lip popped open and bits flew out all over the place. After a lot of searching, I eventually found all but two of them - which brings us to our next criteria.

     Replacement Parts - Things, especially small things, have a bad habit of disappearing from time to time. Unlike the cheap tool kits in the discount stores, if you lose a bit, you donít have to buy an entire new kit just to get that one part. Brownells can easily replace anything in the kit. There are also specialty bits available in metric sizes, extra thin blades for really fine screws, anti cam out Phillips types, extra long Phillips, and even a bit for Millet rear sight elevation screws, etc. There are also additional handles available like the stubby I choose, a collet type, or maybe youíd like one with a hollow handle to hold even more bits on the inside.

     All in all, I really like this kit. It comes very, very close to my concept of an ideal set. I only have one suggestion, and that is that they throw in a # 15 torx bit that fits scope ring screws for Leupold, Burris, Weaver, and others as part of the standard package. If they really wanted to get crazy, they could also throw in the stubby handle previously mentioned as itís ideal for either close in work or for jobs not requiring any amount of force like adjusting elevation screws on open rear sights. Even without the extras, this is a four star product worthy of a place in every serious shooterís range bag.

     One last thought. If youíre into amateur gunsmithing, definitely take a look at Brownells Super Kits. There are more bits in there than I thought existed. What ever you do, call them at 800-741-0015 and order one of their catalogs. Itís fascinatingly huge and only costs five bucks, which is refundable with your first order. Thatís a heck of a good deal.

Good luck and good shooting. Todd

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Warning: All technical data mentioned, especially handloading and bullet casting, reflect the limited experience of individuals using specific tools, products, equipment and components under specific conditions and circumstances not necessarily reported in the article or on this web site and over which IHMSA, The Los Angeles Silhouette Club (LASC), this web site or the author has no control. The above has no control over the condition of your firearms or your methods, components, tools, techniques or circumstances and disclaims all and any responsibility for any person using any data mentioned. Always consult recognized reloading manuals.