March 4th, 2021

Shoulder Bump — Five Cool Tools to Measure Your Bump

shoulder bump headspace gauge comparator tool whidden manson

The Tactical Rifle Shooters Facebook Group recently showcased tools used to measure case headspace before and after “bumping” the shoulder. After a case is fired, hand-loaders who full-length size their cases will typically bump the shoulders back anywhere from .001″ to .0035″, depending on the rifle and application. With our 6mmBR and Dasher cases we like about .0015″ bump.

You want the amount of case sizing and bump to be the same for all your brass. To ensure uniformity, it makes sense to measure your cases before and after the FL sizing process. When we have time, we check every case. Other folks will simply check the first 3-4 cases coming out of the FL sizing die to ensure the FL die setting is correct and delivering desired headspace/bump.

1. Whidden Gunworks Shoulder Bump Gauge

shoulder bump headspace gauge comparator tool whidden manson

There are a variety of tools that can be used to measure shoulder bump. Our favorite is a special cartridge-specific bushing made by Whidden Gunworks. The Whidden Shoulder Bump Gauge enables you to adjust your sizing die to the desired measurement. The bump gauge is attached to your calipers with a set screw and determines the measurement from the base to the shoulder of the case. The photo below, from Tactical Rifle Shooters, shows the Whidden Bump Gauge for the .375 CheyTac cartridge.

2. Dave Manson Vertical Comparator with Dial Read-Out

shoulder bump headspace gauge comparator tool whidden manson
Background image courtesy Tactical Rifle Shooters; inset photo from Manson Precison Reamers.

Dave Manson states: “This tool was designed to make life easier for the advanced shooter and re-loader by allowing precise measurement of ammunition, case, and chamber headspace. With this information, the re-loader will be able to fine-tune clearances and fits between his ammunition and chamber, with resultant improvements in accuracy and case life.” The functions of the Manson Comparator are:

1. Measure headspace of factory or reloaded ammunition
2. Quantify chamber headspace by measuring headspace of a fired case
3. Ensure minimal shoulder set-back when setting up re-loading dies
4. Compare base-to-ogive length to ensure consistent bullet-to-rifling relationship.

In addition to the Dial Indicator and Stand, the $130.00 Vertical Comparator is supplied with multiple Datum Blocks of precise length and inside diameter (.3300″/.3750″/.4000″/.4375″). MORE INFO HERE — Catalog page 20.

3. Hornady L-N-L Headspace Comparator System

shoulder bump headspace gauge comparator tool whidden manson

Hornady’s Lock-N-Load Headspace Comparator system is easy-to-use and handy. You can get a kit with Red bushing-holder body and 5 bushings for $40.12. Hornady explains: “The Lock-N-Load® Headspace Comparator… gauge measures variations in brass before and after firing or re-sizing. It allows for headspace comparison between fire-formed brass and re-sized brass.” IMPORTANT: Hornady states: “To determine the proper bushing diameter for your cartridge, simply add the neck diameter and the shoulder diameter and divide that number by two. Use the bushing closest to that number.” Hornady offers five: .330″, .350″, .375″, .400″, and .420″.

One tip — We have found the Hornady gauges may vary a little from unit to unit even with the same nominal size. If you have more than one gauge for the same cartridge, test each on your brass — you may then note a slight difference in your bump measurements. There is also an Anvil Base Kit that mounts to the opposite blade on the caliper. This provides a more stable surface for the base of your case.

4. L.E. Wilson Case Gage Depth Micrometer

shoulder bump headspace gauge comparator tool whidden manson

If you are looking for precise “bump” measurements without having to mess with calipers and clamp-on gauge blocks, you may want to consider the L.E. Wilson Case Gage Depth Micrometer. This takes very precise, repeatable measurements, but you need to know your starting point. The manufacturer explains: “Every reloader should know exactly how much your Full Length Sizing Die is pushing back the shoulder. With the NEW Case Gage Depth Micrometer you can do just that! It has never been easier to measure you cases headspace before and after sizing. The Depth Mic allows you to slip the micrometer perfectly over the top of the Gage with your case inserted into the Gage and take a measurement. Micrometer has graduations of .001″. The Case Gage Depth Micrometer is set to a zero of .100″ on the scale at our factory. Because of differences in ‘feel’ and temperature, we include a the Gage Block for you to test Zero and to adjust if necessary.”

5. Pistol Brass Case DIY Bump Gauge

Last is a “field expedient” set-up if you do not have any of the comparator tools shown above. A sized .45 ACP case (or other suitable pistol case) can be used to measure shoulder bump. The mouth of the pistol case sits on the shoulder of your rifle cartridge brass.

Make sure the .45 ACP case is trimmed square and that it is round. We recommend you first run it through an expander, then size it, trim it and chamfer. Next, take the .45 ACP case and slip it over the neck of a fired, unsized rifle case with the primer removed. Align the two cases between the jaws of your calipers and note the length from rim to rim (See left photo below).

OK, now you have the length for a fired rifle case BEFORE sizing. Next, take a full-length sized rifle case (without primer) and do the same thing, placing the .45 ACP case over the neck of the FL-sized case (Right Photo). The difference between the two numbers is the amount of “bump” or set-back you are applying to the shoulder. Here the difference is .0015″. The amount of bump you need varies with your chamber and your load, but .0015-.002″ is a good initial setting.

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March 4th, 2021

New Vortex Edge Indoor/Outdoor Training Facility in Wisconsin

Vortex Edge Training facility Wisconsin

Good news for folks in the middle of the country — Vortex, the optics-maker, has built a very impressive new training facility in Wisconsin. This new 55,000 square-foot Vortex EDGE facility boasts indoor and outdoor ranges, with shooting outdoors to 1000 yards. The modern EDGE 100-yard range is one of only a few 100-yard indoor ranges in the country, and the only one in the Midwest. The impressive new Vortex EDGE training center is part of the Vortex campus located in Barneveld, Wisconsin. The EDGE buildings are “just across the parking lot from the Vortex HQ” in Barneveld.

VIEW Vortex EDGE Training Facilities | GET Travel Information

Vortex Edge Training facility Wisconsin

Vortex has just released a video “sneak preview” showing the new EDGE facility, with the multiple indoor ranges, “shoot rooms”, and simulator training center. Check it out below:

VIDEO – Behind the Scenes of Vortex EDGE – First Look!

Vortex posted: “If you can’t travel to our campus, you can still experience Vortex EDGE. We’ll be regularly releasing videos and content, and we’ll be active on social media celebrating all things firearms training.”

Vortex Edge Training facility Wisconsin

Vortex Edge Training facility WisconsinVortex Edge Training facility Wisconsin

The 100-yard Indoor Range is ideal for load development and accuracy testing. Three-time F-TR National Champion Ian Klemm, who works for Vortex, told us: “If someone asked me to describe my dream job, I’d probably depict some magical place where I could do serious 100-yard indoor load development and rifle tuning whenever I wanted. Well, for the last three years while the Vortex EDGE facility was being completed, that’s exactly what it’s been like and we’re all excited to finally be able to share it with the rest of the Vortex Nation. I’m extremely grateful to work for the kind of company that would want to build this facility in order to share it with our customers. Come visit us and I bet you’ll at least leave with the best ‘no wind zero’ you’ve ever had on your rifle!”

There is a 1000-yard outdoor range, plus multiple indoor facilities including a 100-yard range, 50-yard indoor “tactical” range, 25-yard tactical range, a LEO/Military “Shoot House”, and even a simulator room with VirTra 300® interactive video.

Vortex Edge Training facility Wisconsin

Along with the training areas, the EDGE center includes a classroom, cleaning/locker area, and a commercial showroom. Go to VortexEdge.com to learn more about the facility and class offerings. On that website, you’ll also find EDGE Instructor Bios.

Vortex Edge Training facility Wisconsin

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March 4th, 2021

MagnetoSpeed Sporter — Great Chronograph Value

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

If you have been waiting to purchase a chronograph… now is a great time to buy. You can get the affordable MagnetoSpeed Sporter for under $180.00 from Brownells. You can set up this device in a few minutes, and you never have to go downrange to fiddle with a tripod or fuss with wires. The MagnetoSpeed Sporter is simple and effective — a no-hassle solution. Be aware, however, that the placement of the Sporter Chrono ON the barrel can affect barrel harmonics. Therefore you should do your final load testing without the Sporter attached.

See MagnetoSpeed Sporter Chronograph Features Reviewed in Video

We’re impressed by the Sporter chrono, as are other shooters — this unit is very popular. Like the MagnetoSpeed V3, the Sporter faithfully records shots, even in complete darkness. Shot strings are recorded digitally and can be transferred to a smart phone via MagnetoSpeed’s XFR accessory (and Apps).

The MagnetoSpeed Sporter chrono is less than half the price of previous MagnetoSpeed models. This is great for shooters who always wanted a MagnetoSpeed but found the higher-end V3 Model too pricey at $380.00. The Sporter Chronograph costs just $179.00 at Brownells and $178.99 at Amazon.

The Magnetospeed Sporter offers most of the features of the more expensive models (see chart below for details) and has a updated sensor. MagnetoSpeed says the Sporter is “Ideal for contoured rifle barrels (sporter barrels) and long-barreled revolvers.” The Sporter Chronograph Kit (shown above) includes: Bayonet Sensor, 3.5 foot Data Cable, Remote Display (with Battery), Strap with thumb nut, Two V-block spacers, and compact storage box.

Available NOW: MagnetoSpeed Sporter $179.00 at Brownells and $178.99 at Amazon.

Q: Will the Sporter Chrono work with thicker barrel (i.e. greater than 1″ diameter)?

A: The manufacturer recommends the $399.00 V3 model for thicker barrels. But, wink-wink, if you have a 1.25″ barrel you can get this to work, based on what we’ve seen. If you have a really fat barrel (up to 2.0″ diameter), get the V3. Magnetospeed also says the V3 is needed for airguns, shotguns, and muzzleloaders.

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magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

The Sporter Chrono attaches quickly and easily. It has a 3.5-foot-long cord, and will work with Muzzle Brakes and Flash-hiders up to 2.7″ long.

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

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