February 15th, 2020

Changes in Humidity Can Alter Powder Burn Rates — IMPORTANT

Tech Tip Norma Powder gunpowder moisture temperature humidity

Most shooters realize that significant changes in temperature will alter how powders perform. That’s why you want to keep your loaded ammo out of the hot sun, and keep rounds out of a hot chamber until you’re ready to fire. But there are other factors to be considered — HUMIDITY for one. This article explains why and how humidity can affect powder burn rates and performance.

We’ve all heard the old adage: “Keep your powder dry”. Well, tests by Norma have demonstrated that even normal environmental differences in humidity can affect the way powders burn, at least over the long term. In the Norma Reloading Manual, Sven-Eric Johansson, head of ballistics at Nexplo/Bofors, presents a very important discussion of water vapor absorption by powder. Johansson demonstrates that the same powder will burn at different rates depending on water content.

Powders Leave the Factory with 0.5 to 1.0% Water Content
Johansson explains that, as manufactured, most powders contain 0.5 to 1% of water by weight. (The relative humidity is “equilibrated” at 40-50% during the manufacturing process to maintain this 0.5-1% moisture content). Importantly, Johansson notes that powder exposed to moist air for a long time will absorb water, causing it to burn at a slower rate. On the other hand, long-term storage in a very dry environment reduces powder moisture content, so the powder burns at a faster rate. In addition, Johansson found that single-base powders are MORE sensitive to relative humidity than are double-base powders (which contain nitroglycerine).

Tests Show Burn Rates Vary with Water Content
In his review of the Norma Manual, Fred Barker notes: “Johansson gives twelve (eye-opening) plots of the velocities and pressures obtained on firing several popular cartridges with dehydrated, normal and hydrated Norma powders (from #200 to MRP). He also gives results on loaded .30-06 and .38 Special cartridges stored for 663 to 683 days in relative humidities of 20% and 86%. So Johansson’s advice is to keep powders tightly capped in their factory containers, and to minimize their exposure to dry or humid air.”

Confirming Johansson’s findings that storage conditions can alter burn rates, Barker observes: “I have about 10 pounds of WWII 4831 powder that has been stored in dry (about 20% RH) Colorado air for more than 60 years. It now burns about like IMR 3031.”

What does this teach us? First, all powders start out with a small, but chemically important, amount of water content. Second, a powder’s water content can change over time, depending on where and how the powder is stored. Third, the water content of your powder DOES make a difference in how it burns, particularly for single-base powders. For example, over a period of time, a powder used (and then recapped) in the hot, dry Southwest will probably behave differently than the same powder used in the humid Southeast.

Reloaders are advised to keep these things in mind. If you want to maintain your powders’ “as manufactured” burn rate, it is wise to head Johannson’s recommendation to keep your powders tightly capped when you’re not actually dispensing charges and avoid exposing your powder to very dry or very humid conditions. The Norma Reloading Manual is available from Amazon.com.

Real-World Example — “Dry” H4831sc Runs Hotter

Robert Whitley agrees that the burn rate of the powder varies with the humidity it absorbs. Robert writes: “I had an 8-lb. jug of H4831SC I kept in my detached garage (it can be humid there). 43.5-44.0 gr of this was superbly accurate with the 115 Bergers out of my 6mm Super X. I got tired of bringing it in and out of the garage to my house for reloading so I brought and kept the jug in my reloading room (a dehumidified room in my house) and after a few weeks I loaded up 43.5 gr, went to a match and it shot awful. I could not figure out what was going on until I put that load back over the chronograph and figured out it was going a good bit faster than before and the load was out of the “sweet spot” (42.5 – 43.0 gr was the max I could load and keep it accurate when it was stored in less humid air). I put the jug back in the garage for a few weeks and I now am back to loading 43.5 – 44.0 gr and it shoots great again. I have seen this with other powders too.”

If you have two jugs of the same powder, one kept in a room in your house and one somewhere else where it is drier or more humid, don’t expect the two jugs of the same lot of powder to chrono the same with the same charge weights unless and until they are both stored long enough in the same place to equalize again.

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February 15th, 2020

Great Guns: Smith & Wesson Model 617 Rimfire Revolver

Smith & Wesson 617

While Accurateshooter.com concentrates on high-accuracy rifles, we know that many of our readers enjoy handguns. We are often asked “What is your favorite handgun — Glock? HK? SIG Sauer?” The answer to that question may be surprising. This Editor’s favorite handgun, at least the one that gets shot most often, is a rimfire revolver — that’s right, a wheelgun.

This Editor’s first really accurate handgun was a .22 LR Smith & Wesson Model 617 that could easily stack ten shots in a dime at 10 yards. It remains my favorite and most-used handgun. What can we say about the Model 617? The single-action trigger pull is superb, and the accuracy surpasses most any semi-auto rimfire pistol, except for a few, very expensive target pistols. We like the 6″ version for the longer site radius, but the 4″-barrel 617 is also very accurate, and it balances better.

Smith Wesson model 617 .22 LR Revolver handgun
S&W Model 617 now has a 10-round cylinder, but early models were six-shooters.

We strongly recommend that new pistol shooters start off with a .22 LR rimfire handgun. The .22 LR cartridge is accurate but has very low recoil, less “bark” than a centerfire, and very little smoke and muzzle flash. New shooters won’t have to fight muzzle flip, and won’t develop a flinch from the sharp recoil and muzzle blast common to larger calibers. With the .22 LR, the trainee can focus on sight alignment, breathing, and trigger pull.

Smith & Wesson Model 617 Video Reviews
Here are three video reviews of the Smith & Wesson Model 617, both 4″-barrel and 6″-barrel versions. All three videos demonstrate the 617’s great accuracy. The reviewers concede that this handgun is pretty expensive, but all agree that the Model 617 will last a lifetime, and hold its value.

Hickok 45 Demos “Wonderful revolver”, a 4″ Model 617. See also Hickok 45 m617 Part 2:

Popular YouTube Host 22 Plinkster Tests Model 617 with 6″ Barrel:

22 Plinkster loves the Model 617, “one of [his] favorite revolvers in the whole entire world — a great choice”. He reports it “shoots straight [and] functions pretty much flawlessly” with nearly any .22 LR ammo. In this video, 22 Plinkster tests a wide variety of rimfire ammo types including CCI .22 LR Std Velocity, .22 Shorts, .22 LR Shotshells, .22 Stingers, .22 Super Colibri, and .22 LR tracers.

This Video Features the Smaller 4″-Barrel Model 617:

Other Rimfire Revolvers — from Ruger and S&W

If you’re considering a rimfire revolver but would like to see other options, read our Buyers Guide to Rimfire Revolvers. Along with the S&W Model 617, this covers the Ruger GP100 10-shot (5″ bbl), Ruger LCRx 8-shot (3″ bbl), Classic S&W Model 17 6-shot (blued 6″ bbl), and S&W Model 63 (3″ bbl).

TOP FIVE Reasons to Own a Rimfire Revolver:

1. Rimfire .22 LR Ammunition is once again plentiful and affordable. The revolver can shoot all kinds of rimfire ammo — even 22 Shorts.

2. A good, full-size .22 LR revolver will be MORE ACCURATE than the vast majority of semi-auto rimfire handguns. It will shoot all types of .22 rimfire ammo with no cycling issues. With no magazines to jam, a good wheelgun will also be more reliable than most self-loading rimfires.

3. A rimfire revolver can shoot tens of thousands of rounds, with just routine maintenance. The gun can last a lifetime and then be passed on to your kids.

4. On a S&W revolver, it is very easy to tune the pull weight. You can have a safe double-action pull with a very light, crisp single-action release.

5. It is easy to change grips and sights to suit your preference. You can also easily mount a scope on the top-strap.

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February 15th, 2020

Seven Ways to Save Money on Your Shooting Hobby in 2020

Money Saving Discount Codes Shooters Shopping Demo Optics

The true cost of living has risen significantly in recent years. Accordingly, it’s important to save money whenever possible. General prices are going up, health costs are rising significantly*, and the cost of components (bullets, brass, powder) continues to climb. To help you hang on to those hard-earned dollars, here are seven ways shooters can save money on gear purchases and other shooting-related expenses.

1. Watch for Our Deals of the Week. Every Monday, in our Daily Bulletin, AccurateShooter.com offers some of the best deals to be found. We search the web to find great deals on ammo, reloading components, optics, tools, firearms, gun safes, electronics and more. It’s not unusual to find savings of 20-35% through our Deals of the Week. And many of our vendors are now offering special deals just for AccurateShooter.com readers.

AccurateShooter deals of the week

2. Check Out the Forum Classifieds. There are great deals to be found every day in the AccurateShooter Shooters’ Forum. The latest deals are displayed in the right column of every Forum page. To see all the listings, browse through the Forum MarketPlace section which has four main categories:

  • Guns, Actions, Stocks, & Barrels
  • Tools, Dies, Rests, Reloading Components & Misc
  • Scopes, Optics, Sights, Rings, Bases Etc.
  • Commercial Sales by Paid Sponsors

3. Share a Ride to Matches. Fuel prices are on the rise — Mid-grade gasoline is nearly $4.00 per gallon in Southern California now and around $2.80/gallon nationwide. With many shooters living 30-100 miles from the nearest range, fuel remains a big part of a shooter’s hobby budget. We’d say 90% of shooters drive solo to matches, often in large, gas-guzzling trucks. If you drive 200 miles round-trip to attend a match in a 20-mpg vehicle, you’ll burn over $28.00 worth of gasoline on your trip. That adds up. By simply sharing the ride with one fellow shooter you cut your fuel expenditures in half. And, if you alternate vehicles with a buddy from one match to the next, you save on vehicle wear and tear. At $0.50/mile (overall operating costs) consider the savings.

4. Use Discount Codes to Save. It’s always smart to check for discount codes before you buy. In the Daily Bulletin, we feature “Deals of the Week” every Monday morning, and we provide discount Coupon Codes when available. These can reduce the price substantially or lower shipping costs. Search codes for Creedmoor Sports, Brownells, Sinclair Int’l, Cabela’s, MidwayUSA, and Precision Reloading. Check your email also — some discount codes are only announced in email newsletters. If you can’t find a Coupon Code for your preferred vendor, visit Gun.deals and/or RetailMeNot.com. Both those sites list current coupon codes, and RetailMeNot.com covers thousands of vendors.

5. Shop for “Demo” Optics. Modern high-quality optics can easily cost $1500.00 or more, often exceeding the value of the rifle on which they are mounted. However, you can often save 20-30% by purchasing demo optics. These are normally display units used at trade shows. They may have slight ringmarks, but otherwise they are “as new”, having never been carried in the field or used on a rifle that has fired live ammo. When purchasing demo scopes, you should always ask about the warranty before consummating the sale. However, most demo scopes from name-brand manufacturers come with full factory warranties. EuroOptic.com and SWFA.com are two respected vendors that offer a good selection of demo optics.

6. Train with Rimfire Rifles. The true cost of shooting a match-grade centerfire rifle, when you consider barrel wear along with bullets, powder, primers, and brass, can exceed $1.20 per round. READ Shooting Cost Article. By contrast, quality .22 LR target ammo sells for under $0.15 per round. Good rimfire barrels last a long, long time, so you don’t have to be concerned about wearing out your barrel quickly. A quality rimfire barrel can retain its accuracy for 10,000 rounds or more. If you run the ballistics, a .22 LR round at 100 yards can emulate the wind drift experienced by a centerfire cartridge at long range. This allows for effective cross-training with much less expensive ammo.

7. Take Advantage of Factory Rebates. Every year there are some attractive rebates available from quality manufacturers such as RCBS, Hornady, Savage, CCI, Federal, Nikon, and Remington. You’ll find rebates on rifles, pistols, optics, ammo, powder, bullets, reloading tools — you name it. Yes, many rebates are used to move less-popular merchandise. But some rebates apply to a very wide range of merchandise (perhaps with a dollar total minimum), so it’s hard to go wrong if you shop smart. Just make sure that, when you buy a product, you retain the sales slip and the original packaging (it’s also wise to print out online orders). To qualify for the rebate, you may need to mail in a product identification code found on the box, along with your original sales receipt.

* Since the adoption of Obamacare, there has been a huge increase in medical insurance costs for self-employed persons above a modest income level. Prior to Obamacare, this Editor was paying about $330/mo for Blue Shield insurance in California. Now my Blue Shield policy (similar coverage but with higher deductibles) is over $1350 per month — a 409% increase! And the office visit co-pay free has risen from $25.00 to $75.00, a 300% increase.

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