This illustration shows headspace measurement for the popular .308 Winchester cartridge, which headspaces on the shoulder. Image copyright 2015 Ultimate Reloader.
In this Brownells Tech Tip Video, Brownells gun tech Steve Ostrem explains what headspace is and why it’s one of the most critical measurements for nearly all firearms. Even if you’re an experienced rifle shooter, it’s worth watching this video to refresh your understanding of headspace measurements, and the correct use of “GO” and “NO-GO” gauges.
Headspace Definition
In firearms, headspace is the distance measured from the part of the chamber that stops forward motion of the cartridge (the datum reference) to the face of the bolt. Different cartridges have their datum lines in different positions in relation to the cartridge. For example, 5.56x45mm NATO ammunition headspaces off the shoulder of the cartridge, whereas .303 British headspaces off the forward rim of the cartridge. If the headspace is too short, ammunition that is in specification may not chamber correctly. If headspace is too large, the ammunition may not fit as intended or designed and the cartridge case may rupture, possibly damaging the firearm and injuring the shooter. (Source: Wikipedia)
Problems Caused by Too Much Headspace
Excessive headspace issues can include: light primer strikes, failure to fire, bulged/blown cases, case separations, split shoulders, or unseated primers after firing. Case ruptures caused by excessive headspace can lead to catastrophic failures causing serious injury. That is why headspace is such an important measurement.
Problems Cause by Too Little Headspace
Insufficent (or excessively tight) headspace can prevent the firearm from going into battery, resulting in failure to fire or deformation of the cartridge case. Various feeding and functioning problems can be caused by cases with too little headspace, even if a round can be chambered (with effort).
Headspace Gauges
Headspace is measured with a set of two headspace gauges: a “Go” gauge, and a “No-Go” gauge. Headspace gauges resemble the cartridges for the chambers they are designed to headspace, and are typically made of heat-treated tool steel. Both a “Go” and a “No-Go” gauge are required for a gunsmith to headspace a firearm properly. A third gauge, the “Field” gauge, is used (as the name implies) in the field to indicate the absolute maximum safe headspace. This gauge is used because, over time, the bolt and receiver will wear, the bolt and lugs compress, and the receiver may stretch, all causing the headspace to gradually increase from the “factory specs” measured by the “Go” and “No-Go” gauges. A bolt that closes on “No-Go” but not on “Field” is close to being unsafe to fire, and may malfunction on cartridges that are slightly out of spec. (Source: Wikipedia)
To learn more, read Brownell’s article Headspace Gauges and How to Use Them. Among other things, this explains the relative lengths of “Go”, “No-Go”, and “Field” gauges. The “Field” is actually the longest: “The GO gauge corresponds to the SAAMI minimum chamber length, while the FIELD gauge usually matches the maximum chamber depth, or slightly less. NO-GO gauges are an intermediate length between minimum and maximum, that, technically, is a voluntary dimension. A firearm that closes on a NO-GO gauge and does not close on a FIELD gauge may not give good accuracy and may have very short cartridge case life from the ammunition re-loader’s standpoint.”
While AccurateShooter.com focuses on rifles, we know that a large percentage of our readers own handguns, with 1911-style pistols being particular favorites. For you 1911 owners, here are six short videos from Brownells showing how to customize a 1911-style pistol with after-market upgrades.
How to Accessorize Your 1911
This six-part series by Brownells provides step-by-step instruction on how to accessorize your 1911. The videos cover changing out the mainspring housing, magazine release, slide release, hammer, guide rod, and installing a group gripper. If you want to upgrade your 1911, these videos are worth watching.
Model 1911 Components and Cycling — Cut-Away Animation Video
If you’re not familiar with M1911 type single-action pistols, this video animation provides an inside look at the M1911’s components and shows how the M1911 cycles:
If you’ve been thinking about a big purchase at Brownells, here are some money-saving codes. Brownells is currently offering $40 Off a $450+ purchase, $20 Off a $250+ purchase, $15 Off a $150+ purchase, and $10 Off a $100+ purchase. It’s simple to get these discounts — there are no buyers’ clubs to join, no forms to fill out. Just use the appropriate Discount Code during online check-out.
Listed below are the Codes to use. Simply use the appropriate Code for your purchase at Brownells.com. As these Codes may be deactivated without notice, if one Code doesn’t work, try a different Code and you can still save some buck$. Also if the highest value code no longer works, try a lesser value CODE.
Coupon Code: VST — $40 Off $450 or more
Expiration date: Unknown
Coupon Code: VSJ — $20 Off $250 or more
Expiration date: Unknown
Coupon Code: SAE — $15 off $150 or more
Expiration date: Unknown
Coupon Code: TAG — $15 off $150 or more
Expiration date: Unknown
Coupon Code: PTT — $10 Off $100 or more
Expiration date: Unknown
Coupon Code: RSA — $10 Off $100 or more
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Coupon Code: RTA — $10 Off $100 or more
Expiration date: Unknown
NOTE: All these codes have no listed expiration date, so Brownells could terminate them at any time. Accordingly, we recommend you do your shopping soon.
Brownells’ Do-It-Yourself (DIY) video series provides logical, step-by-step installation help for triggers, stocks, and springs. Nine separate videos cover Brownells various DIY Kits. Not sure if you’re up to the project? Just watch each video to see what’s involved. The nine DIY kits are:
This video shows Remington 700 after-market trigger installation:
In the Do-It-Yourself videos, Brownells’ Gun Techs proceed step-by-step, showing you exactly how to install the parts on your gun. Each kit also comes with complete, illustrated instructions you can take to the bench. To learn more, click the links above, or CLICK HERE to visit Brownells’ DIY Kit online page.
Many Remington 700 rifle owners swap out the factory trigger. This is not a difficult task, but you need to follow the proper procedure so you don’t damage any important parts during installation, and so that you don’t interfere with the operation of the bolt and safety. This Do-It-Yourself video from Brownells leads you through step by step how to safely and correctly replace your Remington 700 trigger. This installation video covers the common methods used to install most of the popular after-market Rem 700 triggers. Importantly, the video also shows how to function test after installation, and how to make sure your safety is working properly.
Many Rem 700 owners fit Timney triggers to their rifles.
Video find by EdLongrange. We welcome reader submissions.
Brownells is once again offering fans the chance to win a barrel full of freedom with its Super Barrel III contest. In connection with Super Bowl on Sunday February 7, 2021, Brownells will give away one huge red barrel full of 14,000 rounds of Winchester 55-grain FMJ 5.56x45mm M193 NATO ammunition. Right now through 11:59 pm CST on 2/7/2021, you can sign up online for a chance to win the big barrel of ammo.
One lucky Brownells fan will bring home the championship-worthy trophy of a barrel full of 14,000 rounds of ammo. With current prices of about $1.00 per round for Winchester 55gr 5.56x45mm (.223 Rem) ammo, that big read Winchester barrel could be worth $14,000.00!
The contest concludes at 11:59 PM on Sunday, February 7, 2021. To enter you must provide your email. Be aware that you will be added to Brownells’ email lists and will then receive messages from Brownells until such time as you unsubscribe. Is it worth being put on an email list for a very small chance of winning a very big prize? Only you can decide that. As Dirty Harry famously said: “Are you feelin’ lucky?”
If you want a chance to win, you can sign up at the Brownells Super Barrel III webpage. One lucky winner, name drawn at random, will win the big red barrel full of Winchester ammo.
Those 14,000 Rounds Could Stretch 870 Yards
Containing enough ammo to fill 70 standard-length belts for an M249, the Winchester barrel weighs more than even an NFL football lineman. If all 14,000 cartridges contained inside were laid to end-to-end, they would stretch over 870 yards — almost twice as far as the most passing yards ever in a modern pro football championship game.
About Brownells — 82 years in Business
Founded in 1939 by Bob Brownell, the Brownells enterprise has, for 82 years, been a leading source for guns, gun parts and accessories, ammunition, reloading supplies, gunsmithing tools, and outdoors gear. With a large selection of both common and hard-to-find items, and an extensive collection of videos, articles, and gun schematics, Brownells is a good source for everything shooting-related. For more information or to place an order, call 800-741-0015 or visit Brownells.com.
There is no SHOT Show in Las Vegas this year, but in its stead Brownells is presenting a NOT-Show featuring products from major manufacturers. In addition, on every day from January 18 through 22, 2021, Brownells has offered a PRIZE Giveaway.
Today, the final day of Brownells NOT-Show, Brownells features Stag Arms products. Along with .223 Rem ARs, Stag Arms offers AR-platform rifles in 6.5 Creedmoor (Stag 10 Marksman) and 6mm ARC (Stag 15 Covenant). Stag is one of the first manufacturers to offer complete 6mm ARC rifles.
In addition, Brownells’ tech team looks at the impressive new Area 419 Zero Turret Press (photo right). This press sets new standards for precision repeatability in a turret press.
A major unveiling today was the all-new, illuminated 1-8x24mm Match Precision Optic (MPO) from Brownells. This could become very popular with hunters because this compact scope offers a true 1-power for wide field of view, plus max 8 power to spot details at long range. This Japanese-made optic is on sale today for $799.99 complete with cantilevered AR mounting bracket.
On Thursday, January 21, 2021 the Brownells NOT-Show covered Hornady’s new line of RFID safes. These offer some very sophisticated features with fast-open technology.
Reloading components are in short supply these days, particularly powder and primers. But primers may be the biggest challenge these days — finding them may seem like a Quest for the Holy Grail. That’s a big problem for handloaders. You may be able to find substitutes for your favorite powder and bullets, but if you don’t have primers, you can’t even get started.
To locate primers these days, you must consider ALL possible sources: local gunshops, local private sales, sale tables at shooting club meetings, gun/hunting forum classifieds, large outdoor stores, and mail-order vendors. Then yes, worst case scenario, look at the auction sites such as GunBroker.
You need to be looking at multiple places — local vendors, gun clubs, big retailers such as Cabela’s and Sportsman’s Warehouse. And get creative — talk to shooting buddies, check for estate sales.
Consider all Possible Sources — Not Just Online Vendors
The guys who are scoring primers these days are resorting to old-fashioned methods — visiting small, mom-and-pop gunstores, checking local estate sales, and “networking” with local shooting club members. First, if you are not a member of a local shooting club, you should join for a multitude of reasons. We recently acquired some powder at a local shooting club meeting, exchanging some H4198 for Hodgdon Varget straight across. A Forum member recently scored both powders and primers at the estate sale of a shooting club member.
For the best chance of success, regularly check 6-10 brick-and-mortar locations in your region. One good way to do this is by combining forces with shooting buddies. Get together with 3 or 4 guys and collectively scout ALL the local gunshops and outdoor stores with shooting supplies. You CAN get lucky. For example, we regularly check a small gunstore in a nearby mall. Just last week we were able to find CCI pistol primers! Yes, deliveries are happening, you just need to check. And check often.
How to Find Primers — SEVEN STRATEGIES
1. Make a list of ALL local gunshops and outdoor supply stores within a 70-mile radius. Call them on a regular basis.
2. Join a local shooting club. Attend meetings where you can sell/exchange products. (We recently exchanged pistol primers for rifle primers we needed).
3. Join local/regional gun forums. You may find listings for “face-to-face” transactions where you can buy/exchange primers. Our AccurateShooter Forum also has a thread on Where to Find Primers.
4. Bookmark multiple vendor websites and check daily (we provide a list below).
5. Combine resources with some shooting buddies. Get together with 3 or 4 guys and collectively scout ALL the local gunshops and outdoor stores with shooting supplies. Assign each guy a different “territory” (perhaps close to his work locations).
6. Search your garage and storage areas. This Editor recently found 5000 Winchester Small Pistol Primers in an unopened box. These were left over from his IDPA and 3-gun days, years ago.
7. Consider APS Primers. CCI sells APS primers pre-loaded in plastic strips. These can still be found gathering dust in some shops. You can remove the primers from the strips, or simply buy an APS priming tool and use them as intended.
Online Vendors for Primers
Here are leading online retailers that sell primers (along with other reloading components). NOTE: Most of these vendors are sold out of most primers most of the time (as of 1/21/21). However, you should check regularly. Persistence will pay off, eventually. Primer shipments DO arrive, they just sell out fast.
Best Strategy for Online Primer Purchasing (Not Auctions)
With these (and other) online vendors, you need to check “early and often”. Primers may arrive and sell out in a matter of minutes. You should bookmark multiple sources and check them multiple times each week.
The primer shortage has been worsened by dramatically reduced imports of Russian primers.
Last Word — About Online Auctions for Primers
We are seeing persons selling primers at crazy high prices ($200/1000!) via online auctions at Gunbroker and elsewhere. Be careful… very careful. Primers are a HAZMAT product. They may ONLY be shipped legally by Hazmat-certified businesses. Some of the Auction sellers are not HAZMAT-certified. If your primer shipment is seized or not delivered because the seller was not properly certified, don’t expect to get your money back.
There is a new Gundies Award program for gun-centric social media content creators. Modeled after the Oscars or Emmys, the Gundies Awards focus on the world of guns, shooting, and hunting. Nominees include those who write about guns on Facebook, who post photos on Instagram, and who make videos for YouTube. The annual community-voted Gundies awards spotlight notable firearms-centric content creators. You can register on Gundies.com and then vote for your favorite “influencers” and video-makers. The last day to vote is 12/31/2020.
Mixed Bag of Nominees — Some Good, Some Laughable
To be honest, some of the female “influencers” are just narcissistic social media queens who trade on their looks. They get dolled up in revealing outfits and lots of make-up for posed shots with guns. And on the male side there are plenty of tattooed tactical poseurs with almost no technical knowledge. But there ARE some solid nominees, especially in the Best Shooter and Best Gun Reviewer categories. We showcase videos from five Gundies candidates below. NOTE: These are NOT the category winners — the actual winners will be decided by popular voting which closes December 31, 2020 (better vote soon).
There are 15 Gundies Categories:
YouTuber of the Year
Best Gun Reviewer
Best Shooter
Best Cross-over Creator
Breakout Creator of the Year
Influencer of the Year
Influencer Turned Entrepreneur
Best Outdoorsman
Most Innovative Content of the Year
Most Influential Female of the Year
Most Influential Male of the Year
Most Creative Content of the Year
Most Entertaining Content Creator
Most Likely to Survive an Apocalypse
Best Gun Store/Shooting Range
1. Gundies Nominee — Mrgunsngear
YouTuber of the Year Category
The Mrrgunsngear Channel has nearly 550,000 subscribers and we know why. This YouTube channel offers a combination of gun-centric content and complimentary reviews of outdoor gear (such as generators, lamps, backpacks, body armor). The host is articulate and a pretty good shooter. He also comments on recent gun law developments, such as the ATF Pistol Brace controversy. Here are four videos that showcase the variety of content from this capable Gundies nominee:
2. Gundies Nominee — Dustin Ellermann
Best Shooter Category
Our friend Dustin Ellermann is a past Top Shot TV Show Champion. He is a very capable shooter who also runs a Christian-focused Camp for kids. Dustin produces multiple videos every month for his Top Shot Dustin YouTube Channel. Here we feature Dustin’s review of the the Volquartsen Summit rimfire rifle. This is a straight-pull bolt rifle available in .22 LR, .17 Mach2 and .17 WSM. Dustin reports: “[The Summit] is extremely accurate as well as a perfect suppressor host.”
3. Gundies Nominee — Caleb Savant (Brownells)
Breakout Creator of the Year Category
While many Gundies nominees have very little technical knowledge of firearms, Brownells Firearm Support Technician Caleb Savant is the exception. Caleb’s Brownells videos cover a variety of technical topics — including sight installation, cartridge terminology, dry-firing, gun maintenance, tool selection, and much more. Honestly, you can really learn a lot from Caleb’s videos for Brownells. In this video Caleb Savant shows how to install a pre-fit barrel on a Savage bolt action. Pre-fits come with the chambers pre-cut, and they have a simple barrel nut that makes installation extremely easy.
Pew Pew Tactical (PPT) has a good website with useful content, such as a very thorough Review of Nine Long-Range Scopes. Along with its Blog articles, PPT offers dozens of videos on the PPT YouTube Channel. You’ll find many reviews of ARs, military-style rifles, and pistols. But in addition, PPT offers many good product reviews that are honest about product pros AND cons — that’s pretty rare these days. Here is one of PPT’s most informative videos, a 7-minute guide to cleaning and lubricating AR-platform rifles. This shows important details for the bolt and bolt carrier group.
5. Gundies Nominee — MrBigKid
Best Cross-Over Category
MrBigKid is not a typical gun-centric YouTube creator. That’s because his videos focus on two main topics — GUNS and BBQ. Since both those topics — shooting and eating — appeal to a broad audience, MrBigKid’s YouTube channel is growing quickly. When you get tired of the “bang and clang” of guns shooting steel, you can switch to pro-level barbecue methodology shared by a talented cook. Here are TWO of MrBigKid’s recent videos, one featuring a .50 BMG rifle and the other serving up delicious smoked Beef Ribs. Be honest… which video did you click first?
Times are tough right now for hand-loaders. It is hard to find reloading components, particularly powder and primers. Thankfully, Brownells has made it easier for folks to find available powders without going through hundreds of searches resulting in “0ut of Stock” results. Just visit Brownell’s IN-STOCK Powder Page to see all reloading propellants currently available. This can save you much time and effort.
Brownells has two dozen major-brand powders IN STOCK today, including excellent, popular propellants from Vihtavuori, Hodgdon, and Winchester. Vihtavuori propellants such as N140 and N550 have a proven track record in competition and are popular with benchrest and F-Class shooter. As of today, 12/16/2020, here are 16 powders IN STOCK and available at Brownells.com. There are at least eight more powders in stock. But act quickly — these may sell out very soon. CLICK HERE for ALL in-stock powders.
Headspace Gauges
Today, the final day of Brownells NOT-Show, Brownells features Stag Arms products. Along with .223 Rem ARs, Stag Arms offers AR-platform rifles in 
