Why worry about neck turning cartridge cases before reloading them? After all, I had been successfully reloading cartridges for 25 years without going to the trouble to neck turn.
Neck turned .30-'06 handloaded rounds.
Well, I was reading through Varmint Al's web page (www.varmintal.com), an interesting and (as he admits) eclectic gathering of all sorts of information. (If you are at all interested in varmint shooting or reloading, you should take some time to peruse his website.) As you may know, most varmint hunters such as Al are very interested in achieving great accuracy with their guns and ammunition. I have a similar bent, which I suppose started when I was a member of the intercollegiate pistol team at the Air Force Academy, and it has continued through my subsequent years as a plinker and a competitor.
According to Al, because neck turning creates a cartridge case with uniform wall thickness, it helps to center the bullet on the bore axis and reduces split necks. He claimed that he didn't start to "get true accuracy" until he neck-turned his cases. He pointed-out an added benefit -- neck turning also clearly identifies cases with large variations in wall thickness, so the handloader can put them aside for plinking ammo.
So, I decided to run a test to see how my results compared to Al's success, and to see if any gains were worth the added trouble (and expense) of neck turning.
After doing a web search and survey, and looking through my printed reloading catalogs, I noticed that neck turning tools fell into two basic categories: hand-held, hand-powered tools and motorized tools. The operation of each type was similar to that of a lathe -- the cartridge case is held in a chuck while a piloted cutter is rotated around the case neck, trimming the high spots. I chose a Forster Products outside neck turner, a hand-powered device that featured a carbide cutter and a micrometer adjustment knob. Forster has a good reputation for making accurate tools, and I figured the micrometer adjustment would help me keep track of how much I trimmed from each type and lot of cases.
I chose a bunch of new, unfired .30-06 R-P cases that I had acquired recently, and set aside 100 for an experiment. I reamed the primer pockets with a Lyman primer pocket uniformer tool for large primers, and de-burred the primer flash holes with a Lyman flash hole uniformer tool. Then, after full-length sizing the cases so they would fit into my test rifle, a target rifle built on an Enfield M1917 receiver, I trimmed them each to the correct length with a Lee hand-held case trimmer. After de-burring the case mouths, I neck turned half of the cases to a uniform thickness, according to the instructions included with the turning tool. None of them were so far out of spec that they required much turning, but some were definitely worse than others. I left the other 50 cases with "as received" neck thickness.
Neck tools: Forster neck turner, RCBS Burring Tool, RCBS Rock Chucker Press.
I loaded each cartridge with 46 grains of IMR 4895, an old standby for .30-06 loads, topped by a Sierra MatchKing 168 grain hollow-point boattail bullet. Even though I "threw" each powder charge with a powder measure, I weighed each load since this was an accuracy test and I wanted to remove each variable, except for neck turning. The primers were CCI 200 standard large rifle primers.
Next came the part I enjoy even more than reloading -- heading to the range to try the new handloads! I took 100 of my handloaded .30-06 cartridges to the range and ran about half of them through my old Enfield M1917 target rifle. The accuracy and chronograph results from that afternoon's shooting were a bit surprising to me, but my surprise was due to factors having nothing to do (I think) with neck turning.
Shooting directly into a breeze, which varied from a baby's breath to about 10 knots throughout the afternoon, did not affect the accuracy of my shots. The concrete bench I used for my shooting perch was in a shady spot in the middle of the firing line. It was sunny and mild, with the temperature starting out at 60oF and decreasing a couple of degrees by the time I finished. What better way for a gun nut to spend an afternoon?
I started by shooting a 10-shot string of unturned cartridges, followed by a 10-shot string of neck turned cartridges, then back to unturned, etc. until I had fired 40 rounds. Since I was shooting over a chronograph, I had to shoot from sandbags on the bench (wouldn't want to put a round through the equipment). I was shooting 10-shot strings because my chronograph works on 10-shot averages, and I followed my groups through a spotting scope. So, I measured 10-shot group sizes for my test, instead of the typical three-shot groups.
As I stated earlier, Varmint Al claimed that he did not start to "get true accuracy" until he neck-turned his cases. Also, recall that I loaded each cartridge with 46 grains of IMR 4895, thrown and weighed for each cartridge and topped by a Sierra MatchKing 168 grain hollow-point boattail bullet. I wanted to see if I could equal Al's accuracy improvements.
The table, below, contains data from the four 10-shot groups I fired that afternoon. I was a bit disturbed when I first looked at the data:
|Average velocity (feet per second)
|Extreme spread (feet per second)
|Standard deviation (feet per second)
|Group size @ range (inches @ yards)
||1.25 @ 50
||1.38 @ 50
||3.5 @ 100
||2.5 @ 100
The strings fall into two distinct groups, but not the two I expected to see (neck turned versus not). Instead, the strings were separated by shooting order, with data for the first two strings showing lower average velocities, lower extreme velocity spreads and better standard deviations. As far as this data was concerned, neck turning made no difference. What caused the distinct groups of data if neck turning was not a factor? Why would the shooting order make a difference?
I believe that heat was the culprit; I took ammunition and my shooting iron from a cool basement out into a cool day, and as I shot the rifle, it warmed-up significantly. I moved the target downrange during the interval between strings two and three, allowing the rifle more time to distribute firing heat. I can think of no other reason for the difference, since I took great care to make each cartridge identical (aside from intentional neck turning differences). Anyway, differences among cartridges should have shown-up as scatter in the data, rather than as consistent change.
The bottom line -- I could find no reason for going to the trouble to neck turn this cartridge for this rifle. Other rifle-cartridge combinations may benefit, but the only way to tell is by taking them out and shooting them in a head-to-head comparison. Gee, another good excuse to head to the range!
Warning: The loads developed for this column are safe only in the gun(s) for which they were developed. Neither the author nor Bass Pro Shops assumes any liability for accidents or injury resulting from the use or misuse of the data.
Interested in Handloading?
If you are not a handloader and the aforementioned experiment has piqued your interest, there might be a handloader inside you just trying to rear his ugly head. For most of us handloaders, reloading ammunition is a serious hobby, not a vocation. Since it's a hobby, the key is to enjoy yourself while doing it. The fact that you may save some money, that you can produce better ammunition than the cartridges you buy at your local retailer, and that you will be able to shoot twice as much for your money should not get in the way of the enjoyment and stress relief that results from handloading.
What do you need to get started? Well, this is one of the fun parts of handloading because we all like to buy new toys for ourselves. Your first purchase must be at least one, if not several, reloading manual(s). Do this before buying any equipment. Manuals published by major reloading component manufacturers such as Speer, Lyman and Sierra contain the basic information that you won't see in handloading articles such as this one. The knowledge you obtain by reading these basic "how-to" guides is essential if you are to reload safely and effectively. So, get yourself a good manual, grab a comfortable chair and your favorite beverage, and settle down for a couple of hours of enjoyable reading.
After you understand handloading basics, you'll want to try different loads with different powder charges, powder types and bullets. If you wish, you may make some low recoil, accurate target loads that are cheap to make and difficult to find commercially. Or, you may choose to work up a load that matches the characteristics of your favorite factory ammo self-defense round. You might want to "tune" a rifle round -- it's proven that each rifle has a specific load that it shoots more accurately than others.
Just be sure you follow the reloading basic safety rules (akin to our "Always and Never" rules in explosives handling and blasting):
- Never mix or substitute components
- Always wear eye protection
- Never eat or smoke while reloading
- Never reload while under the influence of alcohol or other drugs that affect motor skills and brain functions
- Always work where you are free of distractions
- Always keep your workbench free of clutter
- Always keep reloading components in their intended containers, and stored properly
- Always keep good records
- Always keep ammunition and ammunition components out of the reach of unsupervised children
- Never guess; stop and find-out for sure that what you are doing is correct
- Always establish a good loading routine, and follow it exactly
- Always check for over- or under-pressure signs in ammunition while shooting
- Always use common sense and good judgment