You probably know by now that David Tubb has introduced a new two-stage trigger for Remington 700 rifles, the Model T7T. Priced at $385.00, the new T7T Trigger is a true two-stage design: first and second stages are independently adjustable for both weight and feel. Overall (combined stage) trigger pull weight can be adjusted from just under 1 pound to slightly over 3.5 pounds.
If you are interested in the 7ZT, watch these two videos. The first shows how to adjust pull-weights for both stages. The second video shows how to modify your stock to provide clearance for the T7T.
This video shows how to adjust the new Tubb T7T two-stage trigger for Remington 700s:
The new T7T is a quality product. We’ve received good feedback from “early adopters” who tell us the two-stage function works well. While installation of the T7T may require minor modifications to your action, most gun owners with basic mechanical skills can install the T7T by themselves. The T7T is made using stainless steel and aluminum for maximum corrosion resistance. Note, installation of the T7T trigger (either Right-Hand or Left-Hand) also requires a companion T7T bolt release, offered by DavidTubb.com for $10.00.
This video shows how to modify your stock to fit the T7T trigger:
Are you trying to decide what components to use for your next F-Class build, or are you looking to upgrade your current rig? Wonder what the “big dogs” in the sport have selected as their hardware? Here’s what United States F-Open team members are using. The most popular chambering is the .284 Winchester, followed by the 7mm Walker (a 40° .284 Winchester Improved). Kelbly and BAT actions are the most popular, and nearly all team members are using cut-rifled barrels. A wide variety of stocks are used, with PR&T holding a slight edge over second-place McMillan.
Most shooters know Carl Bernosky as a 10-time National High Power Rifle champion. But you may not realize that Carl is also a very talented stock-maker and rifle-builder. Carl crafts a wide variety of wood and wood laminate stocks for competition as well as hunting. He also crafts many stocks for Alex Sitman of Master Class Stocks.
Master Class Low-Profile F-Open Stock
Here is a new Master Class Low-Profile F-Open Stock crafted by Carl Bernosky. It is made from a Cherry/Maple wood laminate. This design features a railed fore-end along with a flat, parallel toe for improved tracking and stability on the bags. The front section of the fore-arm has a low profile. This allows the barrel bore axis to ride lower. That helps reduce hop and helps the gun recoil straight back. For more information on this low-profile F-Open stock design, visit Carl Bernosky’s Facebook Page and MasterClassStocks.com.
Note that the stock maintains full depth under the action and quite a few inches forward of the action. This smart design feature is very important. We have seen other low-profile stock designs that can flex or “hinge” forward of the action because there’s not enough wood material there. In fact, the only part of the stock that needs a cut-down profile is the front 10″ or so, where the stock actually rides the front bag.
This particular stock features a “pop-off” magnetic cheekpiece, as well as a buttplate that adjusts for Length of Pull (LOP) via spacers. The action is by Pierce Engineering. This and other Master Class Stock designs can be customized with other features on request.
What do you get when you cut a 6.5 Creedmoor-chambered barrel down to just over 16 inches? A lot more velocity than you might think. Our friends at Rifleshooter.com recently did a barrel cut-down test with 6.5 Creedmoor test rifle, shortening the barrel from 27 to 16.1 inches in one-inch increments. Surprisingly, with a 142gr Sierra MK, the total velocity loss (as measured with a Magnetospeed) was just 158 FPS, an average of 14.4 FPS per inch of barrel length. With the lighter 120gr A-Max bullet, the total velocity loss was 233 FPS, or 21.8 FPS average loss per inch of barrel.
Test Procedure
Five (5) rounds of each type of cartridge were fired at each barrel length and the velocity data was recorded with a MagnetoSpeed V3 barrel-mounted chronograph. The rifle was then cleared and the barrel was cut back one inch at a time from 27″ to just over 16″. NOTE: During this winter test, the air temperature was a very chilly 23° F. One would expect higher velocities across the board had the outside temperature been higher.
The photo below shows how the barrel was cut down, inch-by-inch, using a rotary saw. The barrel was pre-scored at inch intervals. As the main purpose of the test was to measure velocity (not accuracy) the testers did not attempt to create perfect crowns.
6.5 Creedmoor vs. Other Mid-Sized 6.5mm Cartridges
The 6.5 Creedmoor is a very popular cartridge with the tactical and PRS crowd. This mid-size cartridge offers good ballistics, with less recoil than a .308 Winchester. There’s an excellent selection of 6.5mm bullets, and many powder choices for this cartridge. When compared to the very accurate 6.5×47 Lapua cartridge, the 6.5 Creedmoor offers similar performance with less expensive brass. For a tactical shooter who must sometimes leave brass on the ground, brass cost is a factor to consider. Here’s a selection of various 6.5 mm mid-sized cartridges. Left to right are: 6.5 Grendel, 6.5×47 Lapua, 6.5 Creedmoor with 120gr A-Max, 6.5 Creedmoor with 142gr Sierra MK, and .260 Remington.
When asked to compare the 6.5 Creedmoor to the 6.5×47 Lapua, Rifleshooter.com’s editor stated: “If you don’t hand load, or are new to precision rifle shooting, get a 6.5 Creedmoor. If you shoot a lot, reload, have more disposable income, and like more esoteric cartridges, get a 6.5×47 Lapua. I am a big fan of the 6.5×47 Lapua. In my personal experience, the 6.5×47 Lapua seems to be slightly more accurate than the 6.5 Creedmoor. I attribute this to the quality of Lapua brass.”
4140, 4150, 316, 17-4, 6061, 7075-T6 — What is the significance of these numbers? No, they’re not winning lottery numbers. These are all designations for metals commonly used in firearm and barrel construction. 4140 and 4150 are carbon steels, with 4150 often used in mil-spec AR15 barrels. 316 and 17-4 are grades of stainless steel. 316 is “marine grade” stainless, while 17-4 has 17% chromium and 4% nickel. 17-4 is a harder steel used in barrels and receivers. 6061 and 7075-T6 are aluminum alloys. 6061 is “aircraft grade” aluminum, often used for rings and trigger guards, while 7075-T6 is a much stronger, heat-treated aluminum commonly used in AR15 uppers.
You can learn about all these metals (and more) in the online archives of RifleShooter magazine.
Written by Patrick Sweeney, RifleShooter’s Guide to Gun Metal summarizes the primary types of steel and aluminum used in gun and barrel construction. Sweeney explains the nomenclature used to define metal types, and he outlines the salient properties of various steel and aluminum alloys. This is a useful resource for anyone selecting components or building rifles. We recommend you print out the page, or at least bookmark it.
Metals by the Number
The number system for steel classification came from the auto industry. Sweeney explains: “The Society of Automotive Engineers uses a simple designating system, the four numbers you see bandied about in gun articles. Numbers such as 1060, 4140 or 5150 all designate how much of what [elements are] in them. The first number is what class—carbon, nickel, chromium, and so forth. The next three numbers [list other elements in the alloy]. 4140, also known as ordnance steel, was one of the early high-alloy steels. It has about 1 percent chromium, 0.25 percent molybdenum, 0.4 percent carbon, 1 percent manganese, around 0.2 percent silicon and no more than 0.035 percent phosphorus and no more than 0.04 percent sulphur. That leaves most of it, 94.25 percent, iron.”
Aluminum Alloys
Numbers are also used to differentiate different types of aluminum alloys. Sweeny writes: “Aluminum is used in firearms in two alloys: 7075 and 6061. 6061 is commonly referred to as ‘aircraft aluminum’ and has trace amounts of silicon, copper, manganese, molybdenum and zinc. 7075 is a much stronger alloy and has markedly larger amounts of copper, manganese, chromium and zinc.” 7075 Aluminum has significantly better corrosion resistance, and that’s why it is used for AR receivers. The “T6″ you often see appended to 7075 refers to a heat-treating process.
Aluminum (or “Aluminium” in the UK) is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal. Aluminum is the third most abundant element, and the most abundant metal, in the Earth’s crust. (Wikipedia)
To learn more about the metals used in your firearms’ barrels, rings, receivers, and internal parts, read Sweeney’s article in RifleShooterMag.com. Taking the time to read the article from start to finish will expand your knowledge of metal properties and how metals are chosen by manufacturers and gunsmiths. CLICK to Read Guide to Gun Metal.
Story Tip by EdLongrange. We welcome reader submissions. Aluminum Alloy chart courtesy AluminiumDesign.net.
Last summer we published our comprehensive 6.5×47 Lapua Cartridge Guide, researched by the 6.5 Guys. In case you’ve been wondering what kind of accuracy is possible for a tactical-type rifle chambered for this mid-sized cartridge, check out this tack-driver built by gunsmith Ryan Pierce. That’s a mighty impressive 0.206″ five-shot group fired with Berger 140gr Hybrids using a Brux cut-rifled barrel. The powder was Hodgdon H4350, a very good choice for this cartridge.
Ryan reports: “Here is a 6.5×47 I built for a customer. It features a trued Rem 700 action, Brux 1:8″ Rem varmint-contour barrel, Mcmillan thumbhole stock, Surgeon bottom metal, and 3-port muzzle brake. The customer’s preferred load is the same that has worked in the last couple dozen 6.5x47s I’ve built: 41.1-41.3 grains of H4350 with 140 hybrids .050″ off the lands. This should run about 2810-2815 fps from a 26″ barrel. The 3.128″ refers to length of a loaded round from the base to ogive including the Hornady ogive comparator tool.”
Brownells recently reviewed some interesting new products including Howa Barreled Actions and a low-profile titanium gas block for AR-platform rifles. We really like the Howa Barreled Actions as the basis of a varmint or hunting rifle build. The actions are smooth and the Howa-supplied, adjustable HACT 2-stage trigger is excellent. Brownells will stock these barreled actions in a wide range of calibers and barrel profiles (including some with threaded muzzles for brakes or suppressors).
Watch Brownells NEW PRODUCT Review 3/11/2016:
Starting at $407.00, Howa Barreled Actions include hammer-forged barrel, bottom metal, magazine (internal or DBM), and the HACT 2-stage trigger. The three-position safety allows you to manipulate the bolt with the trigger blocked. These Howa barreled actions, which are drilled and tapped for scope mounts, come in Blue or Cerakote Gray finish in Short, Long, and Mini-Action sizes. The Howa Mini-Action is a great basis for a light, compact small-caliber varminter.
Low-Profile Titanium Gas Block for AR-Platform Rifles
The Battle Arms AR-15 Titanium Gas Block (#100-800-003) provides a very trick, low-profile set-up for an AR “space gun” or 3-Gun rig. Light and strong, the Battle Arms Ti gas block fits underneath almost any handguard. This slim, ultra-lightweight Titanium block helps keep an AR-15 rifle/carbine fast and maneuverable by reducing front-end mass. Brownells price is $99.95.
Planning to put together an AR-platform rifle? Or are you looking to upgrade your AR with a new barrel, stock, or trigger group? Then you should check out the AR-15 Rifle Build DVD from our friends at UltimateReloader.com. This DVD covers all the details of a custom build, using high-resolution video sequences, and helpful supporting graphics.
In this DVD, Gavin Gear guides you through the entire process including selecting components, acquiring and using the necessary tools, assembly steps and details for each component, and even mounting a scope. Building an AR-15 can be overwhelming, but with the right guidance and help it’s not difficult and is a lot of fun. With this DVD you’ll be able to build your AR-15 with confidence.
Right now, as a New Year’s promotion, the AR-15 Build DVD is on sale for just $9.90 (plus $3.80 shipping/handling). This DVD can pay for itself many times over by showing you how to do your own gunsmithing (and get quality AR components at attractive prices).
At the IWA Trade Show in Germany a few years ago, a correspondent for The Firearm Blog interviewed Woody Woodall, who runs Lothar Walther’s USA operation. While many shooters assume that Walther hammer-forges most of its barrels like some other European barrel-makers, in fact Lothar Walther USA uses the button rifling technique for most of its US-made barrels.
In the video below, created for The Firearm Blog, Woodall explains that button rifling involves some extra steps to ensure a good result: “The extra work that goes into it is that you’ve got to make rifling, stress relieve it, and have it come out the right size. And it takes a lot of skill to do that. Lothar Walther invented button rifling in 1925, if a better way of making rifling came out, we’d be glad to go to it.”
Woodall explains that hammer forging is a good method for mass production, but it is costly to set up: “Hammer forging is relatively new, it came out in 1934, but did not come into prominence until the 1950s…. But the cost of [hammer forging] in the world today is getting above what the market will bear for barrels. [Hammer forging] is more complicated. As the hammers hit the barrel the barrel gets longer, but the hammers have to hit uniformly so the barrel [stays] straight. There’s a higher failure rate in that. There’s also some surface delamination that can occur, and some other issues. So if you’re hammer forging, you really have to pay attention to the details. So, it’s like button rifling, only ten times more complicated. It’s for super-high-volume production… The large companies tend to use the hammer forging, intermediate size companies tend to use the buttoning, and craft companies tend to use the cut rifling. All three [methods] can make an equally accurate barrel.”
How well can factory .308 Win ammo perform? Amazingly well it seems. Our friends at Criterion Barrels recently tested some .308 ammo from Creedmoor Sports. This was loaded with Lapua’s 175gr Scenar HPBT bullet. The results speak for themselves. Any time factory ammo can shoot inside quarter-MOA, that’s impressive. This ammo was used in a “Rem/Age” project rifle. That term refers to a Remington action rifle that has been re-barreled with a pre-fit Criterion barrel. The new barrel is secured with a Savage-style barrel nut. Hence the term “Rem/Age” or “Rem-Age”.
Criterion posted: “I think we may have a new favorite factory match load for the nitrided Rem/Age build.” Another reader added: “[Creedmoor’s] 175 Scenar .308 ammunition is top notch.” FYI, this group was shot on our load development target, which you can download for free from our Targets Page.
Why do Criterion barrels shoot so well? One reason is that Criterion’s barrel steel is carefully stress-relieved. In the photo below, Criterion Rack 1A (aka the “Coffin”) has been loaded with barrel blanks — made ready for the stress-relieving process.
At the 
