RWS Diana 75 10-meter target rifle – Part 2

by B.B. Pelletier

Photos and testing by Earl “Mac” McDonald

Part 1

Before we begin I have a word about my health. Next Tuesday I’m going to have my pancreas repaired. This is hopefully the final operation I will have to undergo. It will be a major operation where they open me up rather than going in laprascopically, so I’ll be in the hospital for a week or possibly longer to recover. I have written blogs to cover the time I’ll be away, plus I’ll probably have my laptop at the hospital, but I may not be as easy to reach next week. If everything goes according to plan, I should get the drain out of my side and the stent out of my pancreas by the end of this year. And, while I’m away, I’d like to ask the veteran readers to help out the new guys, as you always do.

We’re back with the big Diana 75 target rifle today, and it’s velocity-testing day. Mac was kind enough to test the rifle with quite a few pellets, so we’ll get a good picture of how powerful it is. Along those lines, I was asked this week by someone in the UK how difficult it would be to boost the 75’s power up to the UK legal limit of 12 foot-pounds. I told him it would be impossible to do because the rifle was engineered to do a certain thing, which is shoot targets. The powerplant doesn’t have the swept volume to go as high as 12 foot-pounds. But from his question, I could tell he wasn’t asking what he really wanted to know.

He actually was so impressed by the 75’s accuracy at 10 meters that he extrapolated it out to 55 yards and wondered what a wonderful field target rifle it might make. Well, a TX200 is just as accurate, and it’s already been engineered for field target.

I see that viewpoint from the field target crowd a lot. They see the stunning 10-meter accuracy of these target rifles and assume they would be perfect for field target, if only the power could somehow be boosted. Back in the 1990s, people were going crazy by turning $2,000 Olympic PCP target rifles into $3,000 field target competition rifles, when all they had to do was look around at some of the fine rifles that already existed. Just because a gun shoots a tight group at 10 meters doesn’t mean that it’s also going to be as good at long range. It probably will be pretty good, but so will a purpose-built rifle costing one-third as much.

A .45-70 revolver doesn’t have the same range and power as a .45-70 rifle, not to mention its wrist-snapping recoil! You can’t just extrapolate a certain feature out to infinity and have it remain stable all the way. Things tend to work best when all the many factors are engineered to complement each other and to work together. Okay, so now we understand that. Back to today’s report.

Mac’s rifle is still in the original styrofoam shipping container it came in back in 1979! Kevin saw it on Mac’s table at the Roanoke airgun show, and he commented how new it looked. What he didn’t see, because it wasn’t displayed, was the complete original set of tools, sight inserts, literature and parts that also came with the gun. This really is a complete set!

As complete a set of original accessories as you’ll ever see. There’s even a sighting adapter to allow you to shoot at 6 meters instead of 10!

And, the sights are a wonder to behold. Back in its day, the Diana 75 went head-to-head with Feinwerkbau, Walther and Anschutz. All four makers had beautiful target sights that helped the shooter extract all the points possible from their target rifles, and Diana did not scrimp in any way. When the rifle was resting on your shoulder, the rear sight cup came right to your eye and closed out all of the world except that little black circle 33 feet away. It worked like radar, guiding your body to keep the black circle centered inside the front sight element, which was usually an aperture of some kind. Though you looked through that huge adjustable rear sight, you had no perception of it being there. All you saw was the front sight element and the bull.

Once you had it up to your eye, you lost all sense of the huge rear sight and fully concentrated only on the front sight and target.

The front sight of the 75 is a traditional globe with a wide variety of inserts. You can see in the picture what was available back in the late ’70s when this rifle was new, but today the clear Lucite aperture has replaced all the old inserts in popularity, because it enables the shooter to see much more than just the bull he’s shooting at. Shooting at the wrong target used to be a huge problem when there were 12 bulls on a target sheet, and the clear front inserts solved it. Of course, these days, the targets are presented electronically, one bull at a time, so the possibilities of doing that are greatly diminished, as long as you don’t shoot at your neighbor’s target.

The globe front sight is typical for 10-meter rifles. Of course, it accepts many different inserts.

Velocity testing with RWS Meisterkugeln
Now, it’s time to test the rifle for velocity with several different pellets, starting with RWS Meisterkugeln. This 8.2-grain pellet is made for target rifles and averages 564 f.p.s., with a spread from 551 to 576 f.p.s. The average muzzle energy is 5.79 foot-pounds.

H&N Finale Match Rifle
H&N Finale Match Rifle pellets averaged 532 f.p.s., with a spread from 526 to 540 f.p.s. The average muzzle energy generated is 5.14 foot-pounds.

RWS Hobby
The RWS Hobby pellet is generally the lightest lead pellet available. In this rifle it averages 619 f.p.s., with a 28 foot-second spread from 607 to 635 f.p.s. The average muzzle energy is 5.96 foot-pounds.

JSB Diabolo Exact 8.4 grains
A popular round-nosed pellet is the JSB Diabolo Exact 8.4-grain dome. JSB labels this as a match pellet right on the tin, but of course you cannot shoot in a match with anything other than wadcutters, so it really isn’t a match pellet. That’s just the name they gave it, and I prefer to call it a dome to avoid confusion. It averages 566 foot-pounds, with a spread from 554 to 581 f.p.s. The average muzzle energy is 5.97 foot-pounds.

RWS Superdomes
RWS Superdome pellets are one of Mac’s standbys. He likes their performance in many guns and always falls back on them in a pinch. In the Diana 75, they average 538 f.p.s., with a spread from 524 to 544 f.p.s. At the average velocity, they generate 5.46 foot-pounds.

Mac noted that all pellets fit the rifle’s breech easily, with Hobbys being the loosest fit. And he reminded me to tell you that this gun has been resealed. If you recall, I mentioned that all RWS Diana recoilless rifles have problems with their original piston seals dry rotting, so Mac has had this one resealed with a more permanent material. Outwardly, the gun looks brand new, and with the new seal it acts as good as it looks. The 75 I owned years ago averaged 630 f.p.s. with RWS Hobbys, so this rifle is in the same ballpark.

Mac made one additional observation. It was 56 deg. F in his garage when he chronographed these shots. By the time he reached the third type of pellet, the velocities started to vary wildly. He thought the rifle was failing; but when he shot at a test soda bottle, the shot seemed as good as ever. What it boiled down to was the battery was dying and the cold weather was speeding it along. The 75 is so fast to cock and load that Mac was staying ahead of the battery’s recovery time. When he slowed down between shots, the battery caught up, and the velocities returned to normal again. With cold weather hitting us now, that’s something to keep in mind.

We’ll look at accuracy next, and I promise you, this rifle has it in spades. You’re going to be envious.

The RWS Diana 75 10-meter target rifle – Part 1

by B.B. Pelletier

I’ll be having another outpatient procedure today and will be gone most of the afternoon. I’d like to ask the regular blog readers if they’d help out answering questions from the new people. Edith will be with me in the hospital and will have her computer and also help out with answers if needed.

Photos and testing by Earl “Mac” McDonald.

Readers who have been with us for several months know that my friend Earl “Mac” McDonald has been helping me test airguns while I recover from my hospitalization. Well, Mac is an airgunner, too, and he has a nice collection of fine vintage guns that he would like to share with all of us. So, while we were on the way to the Roanoke airgun show, we discussed the possibility of his testing some of his guns that may not be well-known among airgunners today.

I asked him to test his RWS Diana model 72, which is a youth target rifle based on the Diana model 6 recoilless target pistol. But when he went to test it for velocity, he discovered that the seal had dry-rotted, a common failure of all recoilless Diana target spring-piston guns. So, that one will have to go back to Umarex USA, which is also RWS USA, for repairs. We’ll eventually test it for you, but in the meantime, I asked Mac to test his full-sized Diana 75.

The RWS Diana 75 target rifle (right) is a normal-sized target rifle. The little model 72 next to it is a youth target rifle based on the model 6 target pistol.

The 75 is the last recoilless spring-piston target rifle made by Diana. Like all the other guns, it uses the GISS system in which the primary piston is countered by another piston of similar weight that moves in the opposite direction. The second piston does not compress air, but it’s timed so the forward thrust of the true piston is cancelled.

Do you get confused between the names RWS and Diana? Diana is the German maker of the guns and RWS is a separate and very large German company that’s the exporter.

The first four target rifles made by Diana were all breakbarrels. The models 60 and 64 were conventional breakbarrels, and the model 65 and 66 were the final versions that incorporated a barrel latch. Target shooters were no different in the 1960s than they are today, and they felt uncomfortable about using a breakbarrel for competition. They reasoned that the barrel could not possibly lock up in the same place every time. Of course, it does, and those rifles are just as accurate, and breakbarrels simply had to give way.

Diana 75
The first fixed-barrel Diana target rifle was the model number 75. It was produced in several different model variations from 1977 until sometime early in the 21st century. It’s now discontinued. When it was initially introduced, I believe Beeman referred to it as their model 400 for a brief time.

What is this Original?
The rifle Mac owns is a very early model 75. He says it is dated 1979 or possibly 1978. Date stamps on Diana rifles are usually found on the left rear of the spring tube, just above the stock line. However, you can tell that Mac’s rifle is early because of the name Original stamped on the spring tube. Diana designs and tooling were acquired by the United Kingdom as war reparations for World War II, and the Milbro company in Scotland began producing Diana spring rifles soon after the war ended. To avoid the obvious confusion this engendered, the German Diana company stamped Original on their guns. That lasted as long as Milbro continued to produce Dianas, which ended in 1982. Diana repurchased their name from Milbro in 1984 and dropped the Original name from the guns they made.

German-made Diana guns had the name Original stamped on them during the 1960s and into the ’80s, when Milbro of Scotland also made Dianas.

This is a big, heavy air rifle. It weighs about 11 lbs., depending on the weight of the walnut stock, and is 43.5 inches overall. The length of pull is 14 inches, which is quite long for a target rifle. As you see in the first photo, Mac’s gun has three holes in the forearm, and there are a matching set on the other side. They don’t go all the way through the forearm and are just there for decoration, however this design was not received well by shooters and was soon replaced with a solid forearm.

Unlike many other sidelevers, the model 75 has no latch to lock the sidelever in place. Instead it uses an over-center geometry with a connecting rod that contains a short spring. Similar to the models 48/52 and 54 that followed, this is a positive way of locking the lever to the side of the rifle without any latching mechanism.

Push the sidelever toward the stock and the spring in the end of the connecting rod puts tension on the lever, holding it fast to the rifle’s side.

Like many sidelevers, the model 75 has a sliding compression chamber. However, unlike any other rifle with that feature, the 75 has a solid floor beneath the breech that prevents a dropped pellet from getting lost, the way they always do in other guns with sliding chambers. This floor moves with the sliding chamber, and it fits under the barrel when the chamber is all the way forward.

When the sliding compression chamber is pulled back to cock the rifle, there’s a solid floor beneath the breech. A dropped pellet has nowhere to go.

The stock is rather unique in a couple of ways. First, it has an accessory rail in the forearm. While those are commonplace today, they weren’t when the model 75 was new. And, the second unique feature about the stock is found at the butt. The butt has a definite cast or angle to it that situates the cheekpiece properly against the shooter’s cheek.

An accessory rail was uncommon when the model 75 was new. Today, they’re found on all 10-meter rifles.

The butt curves into the shoulder, making the cheekpiece fit the face much better. Definitely a right-hand-only model!

The 75 was no powerhouse, even in its day. Expect velocities of normal target pellets in the high 500s. In report 2, I’ll report all velocities Mac obtained. As easy as it shoots, the 75 is even easier to cock. Mac measured just 11 lbs., 7 oz. needed to pull the lever back all the way.

Mac had one more thing to say about this rifle. He had forgotten how light the trigger was set. His gauge recorded a pull weight of only 5.2 oz. (147 grams) needed to trip the sear. While even that much sounds heavy compared to what they do today (there’s no bottom pull weight for a 10-meter rifle, so some guns have triggers that only need 20 grams of pressure to fire), it’s extremely light compared to the 3 to 5 lbs. of pull we’re used to on a sporting rifle. Many shooters will set it off just getting their finger on the trigger blade, the first few times.