December 28th, 2019

Case-Neck Chamfer Tools — Choosing the Right Option

Neck case chamfer tools Redding Forster Rocket model 15-p
Shown is the Redding Model 15-P Competition Piloted Inside Chamfering Tool with pilot rod that centers in the case flash hole. Also shown is a Forster 45° Rocket Tool.

There are a wide variety of reloading tools designed to cut a slight chamfer in case necks and deburr the edge of the case mouth. You don’t need to spend a lot of money for an effective tool. A basic “rocket-style” 45° chamfering tool, such as the Forster, actually does a pretty good job taking the sharp edge off case mouths, particularly if you use a little scotch-pad (or steel wool) to smooth the edge of the cut. The Forster chamfer tool, shown below, is a nicely-made product, with sharper cutting blades than you’ll find on most other 45° chamferers. It costs $20.99 at Brownells.com.

forster rocket 45 degree neck chamferer chamfer tool

Redding sells a handy piloted chamfering tool with a 15° inside cutting angle and removable accessory handle. This Redding Model 15-P chamferer works really well, so long as you have consistent case OALs. The pilot rod (which indexes in the flash hole) is adjustable for different cartridge types (from very short to very long). This ensures the concentricity of the inside neck chamfer to the case mouth. This quality tool ($35.99 at Brownells) works with cases from .22 to .45 Caliber.

Neck case chamfer tools Redding Forster Rocket model 15-p

Sinclair International offers a 28° carbide chamferer with many handy features (and sharp blades). The $29.99 Sinclair Carbide VLD Case Mouth Chamfering Tool will chamfer cases from .14 through .45 caliber. This tool features a removable 28° carbide cutter mounted in the green plastic Sinclair handle. It is on sale right now for $24.99 at Brownells. NOTE: A hex-shaft cutter head power adapter can be purchased separately for $14.99 (Sinclair item 749-002-488WS). This can be chucked in a power screwdriver or used with the Sinclair Case Prep Power Center.

Neck inside chamfer chamferer case neck tool

Many folks feel they can get smoother bullet seating by using a tool that cuts at a steeper angle. We like the 22° cutter sold by Lyman. It has a comfortable handle, and costs just $11.54 at Midsouth Shooters. The Lyman tool is an excellent value, though we’ve seen examples that needed sharpening even when new. Blade-sharpening is easily done, however.

K&M makes a depth-adjustable, inside-neck chamferer (“Controlled Depth Tapered Reaper”) with ultra-sharp cutting flutes. The latest version, which costs $51.70 at KMShooting.com, features a central pin that indexes via the flash hole to keep the cutter centered. In addition, the tool has a newly-designed handle, improved depth-stop fingers, plus a new set-screw adjustment for precise cutter depth control. We caution, even with all the depth-control features, if you are not careful, it is easy to over-cut, slicing away too much brass and basically ruining your neck. We think that most reloaders will get better results using a more conventional chamfer tool, such as the Forster or Redding 15-P.

K & M K&M neck chamferer reamer controlled depth

One last thing to note — tools like the K&M and the Sinclair chamferer are often described as VLD chamferers. That is really a misnomer, as bullets with long boat-tails actually seat easily with very minimal chamfering. In reality, these high-angle chamferers may be most valuable when preparing brass for flat-base bullets and bullets with pressure rings. Using a 22° or 28° chamferer can reduce the risk of cutting a jacket when using VLD bullets though — so long as you make a smooth cut.

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December 28th, 2019

Get FREE Data Book Scoring App for Android and iOS (Apple)

Creedmoor Sports High Power CMP Competition Scoring App Apple Android

Creedmoor Sports High Power CMP Competition Scoring App Apple AndroidTired of carrying old-fashioned paper Score Books? Well now you can go digital — Creedmoor Sports offers a full-featured Scoring Book App that lets you plot your shot locations/scores using an Android device or Apple iPhone or iPad. The price is right — FREE! Just visit the iTunes store or Google Play Store to download the App for FREE.

Record Match and Practice Data
This new App, available for free in the Apple App Store, and the Google Play Store provides all the same functions and capabilities of the traditional Creedmoor print Data Book, but with the convenience and ease of recording your match and practice information with your mobile device. With this App you can break your 20 shot slow-fire segments into either 10- or 20-shot targets, and also opt for sighting shots. All the specific event data can also be recorded, such as location, wind, light etc., along with wind and elevation adjustments.

creedmoor scoring app

Download HERE for iOS (Apple)

creedmoor scoring app

Download HERE for Android OS

creedmoor scoring app

COMMUNICATIONS Restrictions: In some matches you are not allowed to have electronic communication ability, so you may have to set your iPhone to “Airplane Mode”, or use this only with an iPod (which does not have two-way communication capability).
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December 28th, 2019

Variances in Load Data — Why Load Manuals Don’t Always Agree

load manual sierra reloading hornady data

Written by Sierra Bullets Ballistic Technician Duane Siercks
One of the first things new reloaders notice is that load data varies between reloading manuals. The Sierra Bullets Technicians frequently get inquiries asking us to explain why the load data appears to be inconsistent. This article explains five key factors that can influence published load data.

Example of load data variances for two 168 grain bullets:

Sierra Reloading Manual Hornady Load Reloading

Here are five reasons why the load data varies:

The Bullet
Basically, the similarities in the .30 caliber 168 grain Match bullets (for example) end with weight and diameter. The bullets likely have dimensional differences such as bearing surface length. Bearing surface has a large effect on pressure and velocity. There are also differences in boat tail, flat base, ogive and over-all lengths, which each help determine the cartridge over-all-length (COAL). With different COAL’s, we can expect changes in pressure and velocity also. In some calibers there are differences in bullet diameter with different bullet manufacturers.

It is also worth noting that bullet manufacturers do not all use the same copper alloy for their jackets. This produces more or less friction that results in load pressures and velocities. The solid copper bullets also vary quite a bit in comparison to a lead core and copper jacketed bullet.

The Gun
Each gun is unique, even if you are using the same make, model, and caliber. Special consideration should be used to consider that not all firearm chambers are the same either, creating more variables that need consideration. There can be drastic differences in the throat length. This controls the amount of “jump” that a bullet experiences when the cartridge is fired.

The Powder
Within normal manufacturing tolerances, you can see some variation in a given powders burn rate between different lots of the same powder. So naturally when two different Manuals are produced, it would be doubtful that the same lots would be tested.

The Cartridge Cases
New cases are almost always near minimum specs in dimension. A load fired in a new case would likely have slightly more pressure that when fired in a re-sized case. This would certainly be true if we were loading into fire-formed cases that have had minimal re-sizing done. Fired cases that are full length resized most of the time be slightly larger than the new unfired cases. This gives you differences in case capacity. The same powder charge placed within a new case and a full length resized case will produce different pressure levels and probably different velocities.

Conditions
Temperature can cause pressure increases or decreases. Hot temperatures tend to cause pressures to increase, while cold temperatures will usually do the opposite. Humidity and altitude can impact pressures and velocities likewise.

Conclusion
As you can see, an amazing number of variables effect any load combination. With the differences in the manuals, you’re just seeing firsthand examples of what took place when the data was collected with that particular set of components and firearm. Think of a reloading manual as a report. In essence, a reloading manual says, “We tried this particular component combination, and these are the results we obtained.”

Remember that you may or may not reach the same maximum load safely. There is no “one load fits all bullets.” The minimum load data offers a safe place to start. The maximum load data listed should always be regarded as a safety guideline and not necessarily a goal! Your gun should shoot accurately without breaching the maximum load data. The best advice is: always start low and work your load up!

If you have questions about variances in load data or other reloading questions, please call our ballistic technicians at 1-800-223-8799 or send us an email at sierra [at] sierrabullets.com.

Sierra Bullets Blog reloading information

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