April 20th, 2017

Wicked Accurate Low-Cost Rimfire Ammo — Norma Tac 22

Norma Tac22 Tac-22 .22 LR rimfire 22LR ammunition ammo
Photo from Champion Shooters Supply. Groups shot with Anschutz 1913 match rifle at 50 yards.

Check out that group. That’s impressive accuracy at 50 yards. You’d expect to pay $10.00 or more per box for rimfire ammo that can shoot this well. But get this — you can now get the Norma Tac-22 for just $3.99 per box. That’s right, this is some of the lowest-priced “Big Name” rimfire ammo you can buy, yet it offers top-tier accuracy. Low cost with high performance — that’s hard to beat.

Norma Tac22 Tac-22 .22 LR rimfire 22LR ammunition ammo

The target photos above come from Champion Shooters Supply, which may have gotten an exceptional lot. This vendor tells us: “We have found this to run very well in Ruger rifles, handguns, and target pistols. These are 5-shot groups at 50 yards with an Anschutz 1913 rifle. This is an incredible value.”

We agree. We just ordered some Norma Tac-22 ourselves. Grab it while you can at these rock-bottom prices. The best deal we found on Norma Tac-22 ammo was $3.99 per box at Midsouth (Click below).

Norma Tac22 Tac-22 .22 LR rimfire 22LR ammunition ammo

Other vendors with this Norma Tac-22 .22 LR rimfire ammo:

Bullets.com, $5.25/box | Champion Shooters Supply, $4.80/box | Grafs.com, $6.29/box

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April 20th, 2017

New Spin on BC — How Barrel Twist Rates Affect Bullet Drag

Bryan Litz bullet rpm BC Drag ballistics coefficient twist rate

You may not realize it… but to get the optimum BC from your bullets (i.e. the lowest aerodynamic drag), you must spin the bullets fast enough. Bullet drag increases (as expressed by lower BC) if the bullet spins too slowly. Bryan Litz of Applied Ballistics explains how BC changes with twist rates…

More Spin, Less Drag
In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance.

Any test that’s designed to study BC effects has to be carefully controlled in the sense that the variables are isolated. To this end, barrels were ordered from a single barrel smith, chambered and headspaced to the same rifle, with the only difference being the twist rate of the barrels. In this test, 3 pairs of barrels were used. In .224 caliber, 1:9” and 1:7” twist. In .243 caliber it was 1:10” and 1:8”, and in .30 caliber it was 1:12” and 1:10”. Other than the twist rates, each pair of barrels was identical in length, contour, and had similar round counts. Here is a barrel rack at the Applied Ballistics Lab:

Applied Ballistics used multiple barrels to study how twist rate affects BC.

stability gyroscopic ballistics coefficient drag twist rate

“The Modern Advancements series is basically a journal of the ongoing R&D efforts of the Applied Ballistics Laboratory. The goal of the series is to share what we’re learning about ballistics so others can benefit.” –Bryan Litz

Barrel twist rate along with velocity, atmospherics, and bullet design all combine to result in a Gyroscopic Stability Factor (SG). It’s the SG that actually correlates to BC. The testing revealed that if you get SG above 1.5, the BC may improve slightly with faster twist (higher SG), but it’s very difficult to see. However, BC drops off very quickly for SGs below 1.5. This can be seen in the figure below from Modern Advancements in Long Range Shooting.

The chart shows that when the Gyroscopic Stability Factor (SG) is above 1.5, BC is mostly constant. But if SG falls below 1.5, BC drops off dramatically.
stability gyroscopic ballistics coefficient drag twist rate

Note that the BC drops by about 3% for every 0.1 that SG falls below 1.5. The data supports a correlation coefficient of 0.87 for this relationship. That means the 3% per 0.1 unit of SG is an accurate trend, but isn’t necessarily exact for every scenario.

It’s a common assumption that if a shooter is seeing great groups and round holes, that he’s seeing the full potential BC of the bullets. These tests did not support that assumption. It’s quite common to shoot very tight groups and have round bullet holes while your BC is compromised by as much as 10% or more. This is probably the most practical and important take-away from this test.

To calculate the SG of your bullets in your rifle, visit the Berger Bullets online stability calculator. This FREE calculator will show you the SG of your bullets, as well as indicate if your BC will be compromised (and by how much) if the SG is below 1.5. With the stated twist rate of your barrel, if your selected bullet shows an SG of 1.5 (or less), the calculator will suggest alternate bullets that will fully stabilize in your rifle. This valuable online resource is based directly on live fire testing. You can use the SG Calculator for free on the web — you don’t need to download software.

Learn More About SG and BC
Barrel Twist Rate Velocity Modern Advancements Book Bryan Litz Applied BallisticsThis article is just a brief overview of the interrelated subjects of twist rate, Gyroscopic Stability, and BC. The coverage of twist rates in Modern Advancements in Long-Range Shooting is more detailed, with multiple live fire tests.

Other chapters in the book’s twist rate section include:
· Stability and Drag – Supersonic
· Stability and Drag – Transonic
· Spin Rate Decay
· Effect of Twist rate on Precision

Other sections of the book include: Modern Rifles, Scopes, and Bullets as well as Advancements in Predictive Modeling. This book is sold through the Applied Ballistics online store. Modern Advancements in Long Range Shooting is also available in eBook format in the Amazon Kindle store.

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April 20th, 2017

Try NO-LEAD Cleaner for Barrels after Shooting Lead-Alloy Bullets

Suhl Rimfire Benchrest indoor cleaning
We have used NO-LEAD Cleaner in rimfire benchrest rifles similar to this modified Suhl 150-1. It helped restore accuracy with minimal brushing.

NO-lead brushless lead remover Wipe-out Sharp Shoot-rMade by the same folks that created Wipe-Out™, and Carb-Out™, the NO-LEAD Brushless Lead Remover™ really works. Honest. If you are an active rimfire shooter, or if you shoot cast lead-alloy bullets in centerfire rifles and pistols, you should try this product. We now use NO-LEAD in our rimfire benchrest rifles, and in some centerfire guns that receive a steady diet of soft-alloy cast bullets (90%+ lead). (With rimfire guns, you don’t need to use NO-LEAD very often — maybe every 300-400 rounds unless you have a real fouler of a barrel.)

If you’ve got stubborn lead fouling in a rimfire barrel, or on a pistol’s muzzle brake/compensator, you should definitely give this stuff a try. We don’t know how but it does soften lead deposits. The manufacturer says you don’t need brushes, but we found that a bit of brushing (after NO-LEAD application) can help remove more serious lead build-up.

Frankly we were surprised to find a lead solvent that really works. We have tried a half-dozen or more other lead “cleaners” that promise to dissolve lead and most of them, we discovered, are nearly useless. There’s a reason for that, as the lead alloys used in bullets don’t react to typical petrochemical-based solvents. It took the Wipe-Out chemists over five years to perfect a new water-based solution that really does dissolve lead.

NO-LEAD Cleaning Procedure — Read Carefully
NO-LEAD Lead Remover is a clear, red gel that is easy to apply. Just swab it in your bore (or on muzzle brakes) with wet patches or bore mop and let it sit for a few minutes. (The manufacturer says you can leave the NO-LEAD for up to 20 minutes, but that long of a dwell time does not seem necessary with our rimfire barrels.) When it contacts lead it will start to foam and you’ll see that the NO-LEAD solvent turns a pastel pink when it dissolves lead. The pink comes from the formation of lead oxide. After the recommended dwell time, simply patch out the dissolved lead deposits (you can also use a nylon brush for stubborn lead build-up).

NOTE: After cleaning, it is very important that you get all the NO-LEAD out of your barrel, and neutralize it. We recommend following the application of NO-Lead with Wipe-out or Patch-Out to neutralize the NO-LEAD, clear the bore, and remove residual carbon and copper fouling. If you don’t have Wipe-Out or Patch-out, flush the barrel thoroughly with Rubbing Alcohol or even a solution of Dawn dish detergent — then re-oil the bore.

Be Sure to Neutralize NO-LEAD After Use
Remember that N0-LEAD is a strong, slightly acidic chemical that needs to be neutralized after use. If you leave it on a nice, blued barrel for too long, it can harm the bluing. NO-LEAD will remove all the surface oils from the barrel bore. For this reason it is recommended that you neutralize NO-LEAD with Wipe-Out, or Patch-Out, which both contain effective corrosion inhibitors. If you don’t have those products, once you’ve flushed the NO-LEAD with something like rubbing alcohol, then follow with a gun oil. Caution: A petroleum-based gun oil will NOT, by itself, neutralize NO-LEAD. You need to neutralize first, then apply the corrosion inhibitor (or do it all in one step with Wipe-Out or Patch-Out).

Where to Buy NO-LEAD Lead Remover
NO-LEAD Lead Remover costs $15.99 for an 8 oz. squeeze bottle with a flip-top spout. This product is sold directly by Sharp Shoot R Precision Products, www.Sharpshootr.com, or you can purchase NO-LEAD through many other online vendors. For more information, send an email via the Sharp Shoot-R Contact Form or or contact Sharp Shoot-R at (785) 883-4444. You can ask for Terry Paul, Sharp Shoot-R’s owner and the master chemist who developed the NO-LEAD formula.

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