January 21st, 2019

RifleShooter.com .308 Win Barrel Cut-Down Velocity Test

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

With barrels, one wonders “Can a little more length provide a meaningful velocity gain?” To answer that question, Rifleshooter.com performed an interesting test, cutting a .308 Win barrel from 28″ all the way down to 16.5″. The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length.

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

READ RifleShooter.com .308 Win Barrel Cut-Down Test Article.

Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. With a barrel reduction from 28″ to 16.5″, the average speed loss of the four types of .308 ammo was 261 fps total. That works out to an average loss of 22.7 fps per inch. This chart shows velocity changes for all four ammo varieties:

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

Summary of Findings: The average velocity loss per inch, for all four ammo types combined, was 22.7 FPS. By ammo type, the average loss per inch was: 24.6 (Win 147 FMJ), 22.8 (IMI 150 FMJ), 20.9 (Fed GMM 168gr), and 22.5 (Win 180PP).

Interestingly, these numbers jive pretty well with estimates found in reloading manuals. The testers observed: “The Berger Reloading manual says for the 308 Winchester, ‘muzzle velocity will increase (or decrease) by approximately 20 fps per inch from a standard 24″ barrel’.”

How the Test Was Done
The testers described their procedure as follows: “Ballistic data was gathered using a Magnetospeed barrel mounted ballistic chronograph. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. Average velocity and standard deviation were logged for each round. Since we would be gathering data on 52 different barrel length and ammunition combinations and would not be crowning the barrel after each cut, we decided to eliminate gathering data on group sizes. Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. The barrel was cut off using a cold saw. The test protocol was repeated for the next length. Temperature was 47° F.”

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and complete data sets for each type of ammo. Rifleshooter.com also offers ballistics graphs showing trajectories with different barrel lengths. All in all, this was a very thorough test by the folks at RifleShooter.com.

Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .308 barrel cut-down test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. When we cut our 6mmBR barrel down from 33″ to 28″, we only lost about 8 FPS per inch. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5″ longer than Rifleshooter.com’s .308 Win start length. Velocity loss can be more extreme with shorter barrel lengths (and bigger cartridges). Powder burn rates can also make a difference.

Permalink Bullets, Brass, Ammo, Gear Review, Gunsmithing 4 Comments »
January 21st, 2019

Bargain Finder 174: AccurateShooter’s Deals of the Week

Accurateshooter Bargain Finder Deals of Week

At the request of our readers, we provide select “Deals of the Week”. Every Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.

1. MidwayUSA — MagnetoSpeed Sporter Chronograph, $159.99

Deals of Week Magnetospeed sporter Kit

If you have been waiting to get a Magnetospeed… wait no longer. Priced at just $159.99 at MidwayUSA, the Magnetospeed Sporter model costs less than half as much as Magnetospeed’s V3 models. This chronograph attaches directly to your barrel so you don’t have to go downrange to position tripods and set up skyscreens. For most people the Sporter Model contains all the features they need. Using Magnetospeed’s XFR adapter (sold separately), data can be transferred easily from the display module to your mobile device. READ Magnetospeed Sporter Review. NOTE: You need to add the item to cart to see the $159.99 price. This sells elsewhere up to $190.00.

2. Bruno Shooters Supply — Lapua Brass Sale

Lapua Brass Sale

This isn’t the first time we’ve featured Lapua brass from Bruno Shooters Supply. But you may want to act soon because prices are going up. Bruno’s is offering very good pricing now for existing Lapua brass inventory. However, Bruno’s managers tell us that future supplies will likely cost more — this will be the last opportunity to get Lapua Brass at low, 2018 mark-down prices. So get ready for the new shooting season and stock up on brass now with Bruno’s favorable pricing.

3. Amazon — Protektor Model Rear Bags

Protektor Model Bags

When it comes to rear bags there’s really only a few brands that the pros use and Protektor is always one of them. Protektor leather rear shooting bags are well made, hold up to abuse, and do their job rain or shine. Now you can purchase these quality Protektor rear rest bags from Amazon. That means you’re getting a very competitive price with super-fast Prime Shipping available. if you need a rear bag quickly for that next match, this is a smart option.

4. EuroOptic — Vortex Viper & Razor Close-Outs, Save Hundreds

Viper Vortex scope closeout sale discount Eurooptic

Here is an awesome deal on the popular Vortex Viper scopes, a top choice for hunters and tactical shooters. EuroOptic has slashed prices on last year’s model Vipers so you can save hundreds. Get the First Focal Plane (F1) 4-16x50mm Viper PST for $499.99. That’s a whopping $400 off the original price. Or, grab the higher-magnification F1 6-24x50mm Viper PST for $649.99, a $300 savings. Both scopes have a great reputation, and the Vortex warranty is second to none. Buy with confidence.

Viper Vortex scope closeout sale discount Eurooptic

If you want a true high-end tactical optic, there are also great deals on the premium Vortex Razor HD Gen II 4.5-27x56mm scopes — save $650.00.

5. EuroOptic — FN Pistol Sale

FN Pistol Sale

Who couldn’t use a quality pistol crafted by a legendary manufacturer for up to 45% off? EuroOptic is clearing out its FN America Pistols at super-low prices. Chose from a wide variety of models in popular chamberings such as 9mm Luger and .40 S&W. There are full-size, compact pistols, and sub-compact FN pistols on sale. For example the FNS-40 Compact NMS (.40 SW) is just $339.00, hundreds less than you’d pay for a compact Glock. If you are looking for a quality semi-auto handgun for targets shooting or self-defense, check out these deals.

6. Graf & Sons — Free Sierra Ballistics Software w/ $75 purchase

Sierra Ballistic Software

Graf & Sons is running a great promotion right now for anyone who is serious about precision hand-loading and long-range shooting. Purchase $75 worth of Sierra Bullets and get the Sierra Infinity Ballistics Software for FREE. That’s a $39.95 value just for buying the bullets you love to shoot anyway. The ballistics program is very sophisticated and includes hundreds of bullet profiles.

7. Amazon — 100-ct Pack of 7″ Reactive Splatter Targets, $22

reactive splatter targets

Anyone can print out paper targets but what’s the fun in that? For only $22.00 you can grab 100 of these multi-color reactive splatter targets and know exactly where your shots are landing. A bright-colored Hi-Viz “halo” appears each shot in the black bull. These targets are made of a weather-resistant material, so you can use them in light rain without worrying about them getting soggy or falling apart (as would normal paper targets). NOTE: Reactive splatter targets typically cost much more. With this deal each target costs just twenty-two cents, less than a quarter — a real bargain.

8. CDNN — Kryptek Sound Soldier 27 db NRR EarMuffs, $8.88

ear muff earmuff 27 nrr db kryptek highlander passive deal $8.88
Note: You get one set of muffs (either gray or camo, NOT both) for $8.88 plus S/H.

Good muffs that offer 27 db Noise Reduction and won’t spoil your cheekweld — for under ten bucks? Can’t argue with that. Right now CDNN is offering a killer deal on Kryptek Sound Soldier 27 NRR muffs that sell elsewhere for around $24.00. Get these in either Highlander Camo or Typhon Grey for just $8.88. These passive muffs have low profile shells engineered to stay out of the way when shouldering your weapon. The ergonomic headband keeps the muffs aligned, in their proper position. Purchasers report the soft leatherette ear seals are surprisingly comfortable. These muffs provide a pretty high NRR considering the low profile design. And the price, just $8.88 on sale, is hard to beat! NOTE: Other vendors have a more conservative 25 NRR for these type of muffs. That’s still quite good.

9. Amazon — Boosteady Pack of 1000 Patches, $8.99 – $13.99

BOOSTEADY Pack of 1000 Professional Square Gun Cleaning Patches

A clean gun is a happy gun and since patches are the core of any cleaning regimen why not grab some great patches for a great price? Amazon sells 1000-count packs of Boosteady Professional Cleaning Patches starting at just $8.99 for 1″ square patches — a great bargain for 1000. Now you won’t feel so bad running a few extra patches every time you clean just make sure you got the last bit of crud out. Boosteady patches are very highly rated by purchasers and come in 1″ square ($8.99), 2″ square ($11.99), and 2.5″ square ($13.99) sizes, inside a convenient box.

Permalink Bullets, Brass, Ammo, Handguns, Hot Deals, Optics No Comments »
January 21st, 2019

Make Your Own Target Stand with This FREE Set of Plans

Some years ago, the folks at TargetWorkz published a a handy set of plans for a 48-inch tall self-supporting target stand. This makes a great do-it-yourself project. To create a sturdy, self-supporting target frame, all you need are some 2x4s, 1x2x48 furring strips, plus fasteners. The target holder, which supports an 18×24 inch cardboard target backer, separates from the base for easy transport.

Note: There is no cross-piece shown in the plan, but we do recommend putting wood crosspieces at the top of the target stand and about 18″ up from the bottom. This will make the frame more rigid, and will allow the frame to work even if the cardboard is badly “shot up”. Use a T-square to set the crosspieces before attaching them with screws.

CLICK HERE to Download TARGET FRAME PLANS »

Alternative Target Stand May from ABS or PVC Pipe
If you like this kind of project, but want to build a frame that is taller, yet can break down into sections, we also have an article showing you how to build a nice frame with inexpensive ABS or PVC tubing. VIEW ABS/PVC Tubing Target Frame Plans.

PVC ABS Target Stand

Permalink Tech Tip 1 Comment »