by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Cocking effort
- RWS Hobby pellets
- H&N Baracuda Match pellets, 4.50mm head
- RWS Superdome pellets
- Why the slow shots?
- Evaluation so far
Today, we’ll look at the velocity of the Diana 340 N-TEC Classic air rifle. I said in part 1 that cocking this rifle is a chore for 2 hands, but I’ve learned something about the gun in this test. The gas spring isn’t the only thing I’m fighting to cock the rifle. The barrel pivot joint is also a bit too tight. The cocking effort is about 35 lbs, which isn’t that bad, but the pivot joint boosts that up to 42 lbs. It made the rifle difficult to measure, but I soon learned to rapidly pull down the barrel and bypass the pivot joint tension. Then, it is a one-handed operation.
RWS Hobby pellets
Let’s get right into the velocity testing. We’ll begin with RWS Hobby pellets. The first shot out of the rifle went through the chronograph at 1070 f.p.s. I mention that because some airguns need a shot or 2 to “wake up” the powerplant. Not the 340 N-TEC. It averaged 1084 f.p.s. with Hobbys, and the spread went from 1069 to 1121 f.p.s. That’s 52 f.p.s. — a little high for a spring gun.
At the average velocity, Hobbys produced 18.27 foot-pounds of energy at the muzzle. That’s a lot for a .177 and too much for this lightweight pellet when long-range accuracy is concerned.
H&N Baracuda Match pellets, 4.50mm head
Next up was the H&N Baracuda Match pellet with the 4.50mm head. This may not be the most accurate pellet because of the head size, but it should give a close approximation of all similar pellets of any head size. This domed pellet averaged 835 f.p.s. for a 10-shot string, but there was an anomalous shot that went only 686 f.p.s. Throw out that one shot, and the next slowest shot went 818 f.p.s. The high was 869 f.p.s. At the average velocity (835 f.p.s.) this pellet produced 16.49 foot-pounds of energy. The spread for 10 shots was 183 f.p.s.
If I average the 9 fastest shots the average climbs to 852 f.p.s. At that speed, the energy jumps to 17.17 foot-pounds. The spread for the top 9 shots was 51 f.p.s. I think that’s more representative of what the rifle can do.
RWS Superdome pellets
The last pellet I tested was the 8.3-grain RWS Superdome. I’d tested a light pellet (Hobby) and a heavy pellet (Baracuda Match), so the Superdome represents a medium-weight pellet.
The 10-shot string also had one anomalous shot at 811 f.p.s., but the other 9 ranged from 922 to 960 f.p.s. For the 10 shots the average was 924 f.p.s., with a muzzle energy of 15.74 foot-pounds. But the 9 fastest shots averaged 937 f.p.s., for an energy of 16.19 foot-pounds, which I think is more representative. The spread for 10 shots was 149 f.p.s., but the spread for 9 shots was 38 f.p.s.
Why the slow shots?
If you recall, I had some slow shots last month when I tested the Diana 45 (see Part 8). I thought that had to do with the start screen of the chronograph triggering too soon from the muzzle blast, but this time I held the muzzle back from the start screen about 12 inches. I don’t think it was that, though I still need to do more testing.
I didn’t like the trigger during this test. It feels like a single stage that goes off whenever it’s ready. It is entirely unpredictable as it came from the box. The manual says stage 1 is reduced to the minimum at the factory — so that had to be corrected.
I adjusted stage one to be longer — hoping that stage two would become more positive. That didn’t happen.
Then, I adjusted what the manual calls the pull-off. I was hoping this would make stage two more positive, and it did just a little — but not as much as I’d hoped.
I finally adjusted the trigger-pull weight to the maximum, which is 500 grams. I’d hoped this would make the trigger crisper. It did clarify a little where stage two is, but the let-off is still very vague. This will be a trigger the shooter must learn, rather than one that can be set to break crisply.
It isn’t a heavy trigger, nor does it have any creep. It’s just vague. But the way I have it adjusted now, I’m sure it’s good enough for some target work.
The trigger now breaks at 1 lb., 11 oz. It’s positive enough that I’ll be able to shoot to the rifle’s maximum capability. But make no mistake, this isn’t a T06 trigger. It may be an adaptation, but it isn’t as positive as the T06 or T05.
Evaluation so far
Trigger aside, I really like the 340 N-TEC. It is, perhaps, better in .22, but it’s a powerhouse in .177. If the rifle is accurate, I think it’ll become a best buy — even considering the price. We shall see!