by Tom Gaylord
Writing as B.B. Pelletier

Diana Mauser
Diana Mauser K98 PCP.

Part 1
Part 2

This report covers:

  • Trigger adjustment
  • Sight-in
  • JSB Hades
  • Beeman Kodiak
  • JSB Jumbo Heavy
  • RWS Hobbys
  • H&N Hollowpoint
  • RWS Superdome
  • Discussion
  • Summary

Today is the first day I test the accuracy of the new Diana K98 Mauser PCP.

The test

I shot the rifle with open sights off a sandbag rest from 10 meters. I shot 5-shot groups so I could test more pellets.

Trigger adjustment

I said in Part 2 that I would adjust the trigger today, so let’s get to it. There is just one screw to turn and clockwise decreases the sear engagement. I turned the 2mm screw clockwise as far as it would go and then tested the trigger by hand. It felt lighter and had less creep than it had before the adjustment. My trigger pull gauge records the 2-stage pull as still breaking at over 12 pounds. It is still creepy, though not as much as before. And that’s that.


I didn’t bother with a sight-in because I was shooting with the open sights that came on the rifle. They should be pretty close to right on — except they are not! My first pellet hit the target a quarter-inch high and a full inch to the right. Since this rifle has no provision for lateral adjustment I guess I’m out of luck with this pellet! And what a shame — it is the most accurate pellet that was tested today!

JSB Hades

The sight-in pellet was a JSB Hades and three of the five pellets landed in a tight group. Then I got careless and messed up a good group. But that was my fault so I pulled out all the stops and did my level best to shoot a good second group. This time five .22-caliber Hades pellets landed in 0.302-inches at 10 meters. For open sights that’s darn good. It’s three-tenths of an inch to the left and a half-inch high but it is a group I can work with — AS LONG AS THE SIGHTS ARE ADJUSTABLE! But of course they aren’t

Diana Mauser Hades group
The Diana Mauser PCP put 5 JSB Hades pellets in 0.302-inches at 10 meters.

The rear sight does adjust up and down on a stepped ramp, but I have it set as low as it will go. The front sight does screw up and down if you have the right tool, but Diana included no sight adjustment tool with this rifle I’m testing. Can I make do? Sure but it doesn’t cure the left and right problem.

Now, the rifle can be scoped and I do plan to test it with a scope. But this is a replica airgun, — a replica of a military rifle. It’s not supposed to need or have a scope. If you want an accurate PCP there are plenty around. This is a replica, and it misses the mark by not having sights that are regulated to hit the target. That is a serious shortcoming in my book.

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Beeman Kodiak

Okay, let’s try again. Maybe we’ll find the pellet that goes right to the point of aim. Well — it isn’t the Beeman Kodiak! That pellet hit the target 1.7 inches above the aim point and three tenths to the left. I am aiming at 6-o’clock on the bullseye, so really the pellet is landing 2.3-inches high at 10 meters. The group measures 0.4-inches between centers — another decent  group for open sights at 10 meters, but it’s in the wrong place and I can’t do anything about it.

Diana Mauser Kodiak group
The Mauser PCP put five Beeman Kodiaks in 0.4 inches at 10 meters, but look where they are!

JSB Jumbo Heavy

Next I tried so 18.13-grain JSB Jumbo Heavy pellets. Since the Hades pellets did so well I thought these might also. And they did, sort of. I can’t say for certain how large this group of five is because I had also shot one Beeman Kodiak at the same target by mistake. Who knew that the JSBs would group in the same place? Oh well, the total size of this 6-shot two pellet group is 0.507-inches between centers.

Diana Mauser Jumbo group
Five JSB Jumbo Heavys and one Beeman Kodiak went into 0.507-inches at 10 meters.

RWS Hobbys

Next I tried 5 RWS Hobby pellets. This is a Diana air rifle, after all, and Dianas like RWS pellets. Or, that is to say German Dianas like RWS pellets. This rifle was made in China, so all bets are off.

Five Hobbys made a 1.07-inch group at 10 meters. After what we have seen, this is not the right pellet for the rifle. The center of the group is 1.7-inches above the intended target and 0.33-inches to the left. This left and high placement is an ongoing thing with this rifle, no matter what pellet is tried.

Diana Mauser Hobby group
Hobbys are not the pellet for the Diana Mauser PCP. Five went intro 1.07-inches at 10 meters.

H&N Hollowpoint

Next I tried five H&N Hollowpoint pellets — mostly because I was grasping at straws. Five made a very horizontal group that measured 1.1-inches between centers. It’s the largest group of this test.

Diana Mauser H&N Hollowpoint
Five H&N Hollowpoints made this horizontal group at 10 meters that measures 1.1-inches between centers.

RWS Superdome

The last pellet I tested was the RWS Superdome. Five of them went into 0.698-inches between centers at 10 meters. Three are tighter, indicating that this might be a pellet to try again.

Diana Mauser Superdome group
Five RWS Superdomes made a 0.698-inch group at 10 meters.


Today’s test results disappoint me. The Mauser PCP appears to be a very accurate air rifle, and that trigger that everybody thinks is way too heavy is no problem at all. But to have sights that don’t work as they should — shame on you, Diana! You had best learn how to make sights that work — or get your Chinese factory to do it, because this is an unforgivable error on an accurate rifle. And tell your marketeers that if the front sight is on a screw post — WE NEED THE TOOL TO ADJUST IT! Especially on this rifle that shoots so high.


What do we have in this Mauser? It’s quiet, but short on breath. It has decent power. It’s very realistic but the sights don’t work. It’s quite accurate, but not as a replica. You have to mount a scope on it.

This air rifle is a conundrum. They got it 80 percent right but that other 20 percent is aggravating!