RidgeRunner’s Diana 34.
This report covers:
- Nice one
- Breech lockup
- Crosman Premier 10.5-grains
- JSB Exact RS
- Rear sight
- Overall condition
- Final observation
Today we begin the project to improve the shooting characteristics of reader RidgeRunner’s Diana 34. That’s the actual rifle shown above.
There is a surprise in today’s report. It comes at the point when I tested the velocity. Until then I had one opinion and it changed at that time.
I received this rifle last week and saw it for the first time last Saturday. I cocked it, just to see what I was up against, and I also shot it twice. In my opinion, this is a nice old-style Diana 34. The ball-bearing breech breaks open easily, the T05 trigger is adjusted perfectly and the rifle fires smoothly. I was surprised because I had never seen one shoot this smooth. That doesn’t mean there isn’t room for improvement in the firing cycle, because there always is.
When I say old style I mean that the Diana 34 went through a number of changes over the years and the rifle they made at the end of production wasn’t the same as the one they started with. This one has the T05 trigger that is the finest in the Diana trigger line. The T06 that everybody likes is also very nice but Diana simplified it slightly from the T05 — probably to lower production costs. This trigger is set to 1 pounds 4 ounces in stage one and the glass-crisp stage two breaks at 3 pounds 6 ounces.
This rifle was produced in December of 1995. It was made toward the end of the production run. The production date stamped into the spring tube reads 12-95.
RidgeRunner’s Diana 34 was made in December of 1995.
There are a couple keys to this rifle being an older version of the 34. For starters, it has no rubber buttpad. These early ones are just crosscut at the butt.
This wooden butt is the first style the Diana 34 used for many years.
Another clue to the age is the safety. All Diana 34 safeties are located at the rear of the spring tube and above the pistol grip. They come on at cocking, but only the early ones have a flat steel release that’s curled up at the end. Later versions have an angled black plastic release.
This flat steel safety release is the first style of Diana 34 safety. The rifle is cocked in this image.
The Diana 34 has a ball bearing breech lock that rides over a steel inclined ramp, until the spring pushes the ball over the steel ramp to lock the breech. It is not a chisel detent, which means it can be lighter, yet still positive.
I found the barrel to break open easily. I bump the muzzle out of habit, but I don’t need to. That’s a good thing because the spring-loaded ball is held in place by two deep swages. I think removing the ball is a major exercise that involves machining. It won’t be anything that I tackle.
This view of the breech shows the two swaged dents (at three and nine o’clock) that hold the ball bearing breech lock in place.
This is where my opinion about RidgeRunner’s rifle changed. When the rifle was cocked for the third shot in the velocity test the barrel stopped in mid-stroke. It feels very much like a section of mainspring has broken off and is tying up the gun. I was able to complete the cocking stroke, but from that point on I felt the same resistance with each cocking effort. Could this be what RidgeRunner experienced? If so he meant that the rifle was impossible to cock, not to break open. Or understand that when I say break open I mean just opening the breech prior to cocking.
Crosman Premier 10.5-grains
The average velocity with 10.5-grain Crosman Premiers is 709 f.p.s. The low was 704 f.p.s. and the high was 719 f.p.s. That’s a 15 f.p.s. difference. At that velocity this pellet generates 11.72 foot pounds of energy. That’s on the low side for a 34, which supports my broken mainspring theory.
JSB Exact RS
JSB Exact pellets averaged 857 f.p.s. from this 34. The low was 847 and the high was 867 f.p.s. — a 20 f.p.s. difference. At the average velocity this pellet generates 12.84 foot pounds of energy. That’s also on the low side for a 34. I expected 14+ foot pounds at least. The broken mainspring theory is fleshing out! Diana mainsprings have a well-deserved reputation for breaking. Usually it’s one inch broken on both ends, though I have seen several springs with just one end broken.
The rear sight is missing its elevation screw. It looks like somebody may have removed it to mount a scope or peep sight and forgot to put it back. The rear scope base has very light wear on the sides of the base, which is typical of a new rifle only. It’s an aluminum part that gets scratched and dented pretty quickly.
The rifle has 100 percent of its bluing and 98 percent of its stock finish. There are a couple handling nicks on the wood and that’s all. The mainspring appears dry and devoid of lubricant.
The mainspring appears pretty dry.
After looking at this rifle and handling it for this report I have come to the conclusion that this rifle is in almost-new condition. I’ll bet the mainspring broke early and the first owner put the rifle away for a few decades. Maybe he even forgot about it. Then he dug it out, tried to cock it, found that it locked up and sold it.
The groove in the inclined plane that the breech ball bearing rides on still has most of its bluing. I saw a report on the Airgun Nation forum where the owner thought that the groove had been worn in the steel by the ball bearing, but what he actually saw was the inclined plane with no bluing remaining.
What I will do next is disassemble the rifle to examine the powerplant parts. From the way it cocks and shoots I expect to find a broken mainspring and a like-new piston seal. After I see the insides I can order parts to get it going again. I need to measure that mainspring and also the space in which it fits so I can get a lighter mainspring that will fit well.
We have a neat new project open and underway. This one is a little different as we are trying to create a super-soft tune that cocks easily and works well. We are going after a smooth shooter — not a magnum breakbarrel. I am excited to see what can be done.