August 25th, 2020

Rule Out “Driver Error” — Test Accuracy with Multiple Shooters

When a rifle isn’t shooting up to it’s potential, we need to ask: “Is it the gun or the shooter?” Having multiple shooters test the same rifle in the same conditions with the same load can be very revealing…

When developing a load for a new rifle, one can easily get consumed by all the potential variables — charge weight, seating depth, neck tension, primer options, neck lube, and so on. When you’re fully focused on loading variables, and the results on the target are disappointing, you may quickly assume you need to change your load. But we learned that sometimes the load is just fine — the problem is the trigger puller, or the set-up on the bench.

Here’s an example. A while back we tested two new Savage F-Class rifles, both chambered in 6mmBR. Initial results were promising, but not great — one gun’s owner was getting round groups with shots distributed at 10 o’clock, 2 o’clock, 5 o’clock, 8 o’clock, and none were touching. We could have concluded that the load was no good. But then another shooter sat down behind the rifle and put the next two shots, identical load, through the same hole. Shooter #2 eventually produced a 6-shot group that was a vertical line, with 2 shots in each hole but at three different points of impact. OK, now we can conclude the load needs to be tuned to get rid of the vertical. Right? Wrong. Shooter #3 sat down behind the gun and produced a group that strung horizontally but had almost no vertical.

Hmmm… what gives?

Shooting Styles Created Vertical or Horizontal Dispersion
What was the problem? Well, each of the three shooters had a different way of holding the gun and adjusting the rear bag. Shooter #1, the gun’s owner, used a wrap-around hold with hand and cheek pressure, and he was squeezing the bag. All that contact was moving the shot up, down, left and right. The wrap-around hold produced erratic results.

Shooter #2 was using no cheek pressure, and very slight thumb pressure behind the tang, but he was experimenting with different amounts of bag “squeeze”. His hold eliminated the side push, but variances in squeeze technique and down pressure caused the vertical string. When he kept things constant, the gun put successive shots through the same hole.

Shooter #3 was using heavy cheek pressure. This settled the gun down vertically, but it also side-loaded the rifle. The result was almost no vertical, but this shooting style produced too much horizontal.

A “Second Opinion” Is Always Useful
Conclusion? Before you spend all day fiddling with a load, you might want to adjust your shooting style and see if that affects the group size and shape on the target. Additionally, it is nearly always useful to have another experienced shooter try your rifle. In our test session, each time we changed “drivers”, the way the shots grouped on the target changed significantly. We went from a big round group, to vertical string, to horizontal string.

Interestingly, all three shooters were able to diagnose problems in their shooting styles, and then refine their gun-handling. As a result, in a second session, we all shot that gun better, and the average group size dropped from 0.5-0.6 inches into the threes — with NO changes to the load.

That’s right, we cut group size in half, and we didn’t alter the load one bit. Switching shooters demonstrated that the load was good and the gun was good. The skill of the trigger-puller(s) proved to be the limiting factor in terms of group size.

Permalink - Articles, Shooting Skills, Tech Tip No Comments »
August 25th, 2020

Smart Advice on Powder Storage — What You Need to Know

Western Powders Blog SAAMI Storage

SUMMARY: Powder can have a very long shelf life. You need to watch for changes in smell and color. A reddish tinge, almost like rust on the powder, is a bad sign, as is a foul odor, not to be confused with a normal chemical smell. Either of these signs indicate it is time to dispose of your powder by means other than shooting.

Ever wondered about the stability of the propellants in your reloading room? There are some important things you should know about powder storage, to ensure consistent powder performance and safety. On its website, Western Powders (vendors of Accurate, Norma, and Ramshot powders) published an informative Q & A series entitled Dear Labby: Questions for our Ballistics Lab. Here are some excerpts that pertain to powder storage and shelf life. Worried that your powder may be too old? Western’s experts explain how to check your propellants for warning signs.

Proper Powder Storage

Q: I live in southern Arizona where it is very hot. I am told powders will become unstable if stored in an area not air-conditioned. My wife says no powder or primers in the house. Can powder be stored in a refrigerator? What about using a fireproof safe? I would appreciate your ideas. — M.C.

Lab Answer: SAAMI guidelines are pretty clear on issues of storage. They recommend storing smokeless powder in containers that will not allow pressure to build if the powder is ignited — ruling out gun safes and refrigerators.

CLICK HERE to Read SAAMI Guidelines for Powder Storage (PDF)

In their original containers smokeless powder’s lifespan is quite long, even in your hot, arid climate, typically longer than the average handloader would need to store them. Stored safely in a garage or outbuilding, your powder should last years. If you see the powder developing a reddish tint, or giving off a foul odor, it is time to discard it.

Clumps in Powder Container

Q: I ordered some of your Accurate 1680 powder back about in December. I just now opened it … and it is full of clumps. My knowledge tells me that means moisture. Am I wrong? I just now broke the seal and it has been stored in a ammo can with desiccant packs around it and a dehumidifier running 14-16 hours a day. I can’t imagine this being my fault, if this does indicate moisture. I don’t know if the pink part on the label is suppose to be red or not, but it is definitely pink, so if it was red I am wondering if I was shipped an old container? I hope that this isn’t bad and I am stuck with it…

Lab Answer: All powder contains a certain amount of moisture. When the powder is stored or during shipping, it can go through temperature cycles. During the cycling, the moisture can be pulled to the surface and cause clumping. Clumping can also be caused by static electricity if too dry or the powder has limited graphite content. You can break up the clumps before metering and they shouldn’t be a problem. This will not affect the powder performance, so your product is fine. Accurate 1680 labels are designed in Pink. As a side note, specification for testing powder is at 70° F and 60% humidity.

Shelf Life and Packaging Dates

Q: Does powder ever get to old to use and what identifying marks does your company put on the canister for when it is made, You have helped me out a while ago when I asked about keeping my cowboy shooting under 950 fps and it works great less stress on the hand and the recoil is very minimum. — R.B.

Lab Answer: On one pound bottles, the number is on the corner in a silver box. If the powder was poured today, it would read 012815 followed by a lot number. The whole number would look something like 012815749. Eight pound bottles have a sticker on the bottom with an obvious date code. The lot number appears above the date.

Western Powders Blog SAAMI Storage

Permalink - Articles, Bullets, Brass, Ammo, Reloading, Tech Tip 1 Comment »
August 25th, 2020

How to Clear-Coat Laminated Wood Stocks

Laminated wood stocks offer an excellent combination of price and performance, and they can be obtained in a myriad of styles to suit your discipline — hunting, benchrest, tactical, silhouette, or high power. Laminated stocks can be a little trickier to finish compared to a hardwood such as walnut, as laminates are often delivered in bright or highly contrasting colors. Traditional wood finishes can alter the colors. Also, filling the pores in laminated stocks is an issue.

Automotive clear-coat products have become popular for finishing laminated wood stocks because they won’t alter the stock’s colors, and the clear-coat provides a durable weather-resistant finish. Clear-coat is also easy to “touch up” and it fills pores better than some other alternatives. Mike Ricklefs has written a comprehensive article on stock painting that includes a special section on clear-coating over laminated woods. If you want to clear-coat a stock, Mike’s article is a must-read!

In that Stock Painting Article, Mike offers these tips:

1. When finishing laminated stocks with clear-coat, you need to prepare the wood carefully, and build up quite a few thin layers one at a time. Begin by sanding, with progressively finer paper, all the way to 400 grit. Certain laminated stocks are so rough when they come from the stock-maker, that you may have to be very aggressive at first. But be careful with angles and the edges of flats. You don’t want to round these off as you sand.

2. After sanding, use compressed air to blow out all dust from the pores of the wood. This is very important to avoid a “muddy” looking finish. If you don’t blow the dust out with air before spraying the clear it will migrate out as you apply the clear. Also, after each sanding session, clean your painting area to remove excess dust. I also wet down the floor of my spray booth to keep the dust down.

3. Some painters recommended using a filler to close the pores. That’s one technique, but the filler can detract from the clarity of the final finish. Rather than use a pore-filling sealer, I use a high solids or “build” clear for the initial applications. This is slightly thicker than “finish” clear and does a good job of sealing the pores. Three (3) fairly heavy coats of “build” clear are applied. If you get a thick spot or a run in the finish at this point, it is not the end of the world but this does create more sanding work.”

There is a helpful thread in our Shooters’ Forum that discusses the use of clear-coating on laminated stocks. Member BHoges offered this advice: “Stick with Diamont, Glassurit, and Spies. If anyone has questions, I painted cars for a long time.”

Clear-coat Laminated woodForum member Preacher, whose bolt-action pistol is shown at right, states: “I buy my two-part clear-coat from the local NAPA dealer. They recommended Crossfire mixed 4:1. I really like the end results. There are six coats on that stock that were sanded down to bare wood for the first two, and then 600 wet-sanded for the other four coats. Two to three coats would be sufficient if the pores were filled first, but I would rather fill ‘em with the clear as it seems to make it appear deeper and I have the time to devote to it. I have PPG’s Deltron DC 3000 clear-coat on a few stocks of mine, but I like the NAPA better price wise, and it seems to hold up just as good as the Deltron.”

Permalink Gunsmithing, Tech Tip 2 Comments »