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Diana 34 Easy Modular System (EMS) Synthetic: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Diana 34 EMS
Diana 34 EMS with synthetic stock.

Part 1
Part 2

This report covers:

  • The test
  • RWS Hobby
  • Norma Golden Trophy
  • JSB Exact Heavy
  • The trigger
  • Firing behavior
  • RWS Superdome
  • Impressions so far

Today we begin looking at the accuracy of the new Diana 34 Easy Modular System (EMS). It’s a breakbarrel with a conventional coil-wound steel mainspring that will, at some time in the future, be convertible to the N-TEC gas piston system. It will also be able to exchange the barrel at some point in the future, which means the user can change calibers.

We have already seen that this rifle has some power without being ridiculous. The trigger is light and vague, and today we will find out how that affects things downrange.

The test

I decided to just get used to the rifle today by shooting at 10 meters and using the open sights. I got rid of the fiberoptic rear sight and replaced it with the black notch Diana included with the rifle. The target was lit brightly, which canceled out the fiberoptic front bead, allowing me to aim precisely at each bull. The front sight post is rounded, but I was able to balance the black bull on the rounded center of the post.

I shot 10-shot groups off a rest, using the artillery hold. The rifle was held as lightly as possible, but the thumbhole stock makes it hard to use a true artillery hold. Still when you see the results I think you’ll see I did okay.

RWS Hobby

Because this is a Diana rifle, I figured RWS pellets would be good. I started with 7-grain Hobby wadcutters. Sight-in took 4 shots and then I moved to a clean bull for the first group. Ten pellets went into a scattered group measuring 1.019-inches between the centers of the two widest shots. That rules out Hobbys for this rifle.

Diana EMS Hobby group
The Diana 34 EMS put ten RWS Hobbys into a 1.019-inch group at 10 meters.

Norma Golden Trophy

Next I tried ten Norma Golden Trophy domes. They gave me a second scattered group that measures 1.54-inches between centers. One pellet that hit below and to the left of the main group was not a called pull.

Diana EMS Norma Golden Trophy group
Ten Norma Golden Trophy domes went into 1.54-inches at 10 meters. The pellet that’s low and left was not a called pull.

JSB Exact Heavy

The next pellet to be tested was the 10.34-grain JSB Exact Heavy dome. People have reported doing well with this pellet in the EMS.

Ten made a tight 0.392-inch group at 10 meters. Now, we are talking! This is the sort of performance I expected from a Diana 34.

0Diana EMS JSB Exact Heavy group
Ten JSB Exact Heavys went into 0.392-inches at 10 meters. The Diana 34 EMS can shoot!

The trigger

By this point in the test I had fired 34 rounds and had gotten accustomed to the trigger. Although it is a two-stage unit and although I can feel when stage two begins, it acts much more like a single stage trigger. It moves smoothly through stage two and releases at an unknown point that I was able to get used to. There is no creep in the trigger — just a smooth travel of the blade through stage two. If you like a single stage trigger you will love this one!

Find a Hawke Scope

Firing behavior

The firing cycle is quick and solid. I don’t see how a gas piston could do any better. Maybe because the piston would be lighter there would be less of an impulse at firing, but that’s about it.

Now I know for certain what the Diana 34 EMS reminds me of. It reminds me of a Diana 34 that has been tuned with a Vortek PG3 HO kit. I have tuned a number of different rifles with that kit and this EMS shoots exactly like one of them. The action is quick and there is no residual vibration. Diana, you did an excellent job in designing this one!

RWS Superdome

The last pellet I tried in the Diana 34 EMS was the RWS Superdome. Just before shooting these I dialed the rear sight down several clicks. Ten Superdomes went into 0.562-inches at 10 meters. I now know two pellets I will try when I scope this rifle!

Diana EMS Superdome group
The Diana 34 EMS put 10 RWS Superdomes into a 0.562-inch group at ten meters.

Impressions so far

Diana did this one right. It’s accurate, powerful and free from vibration. The trigger acts like a smooth, light single stage. The open sights adjust well. I’m looking forward to trying the rifle with a scope.

57 thoughts on “Diana 34 Easy Modular System (EMS) Synthetic: Part 3”

    • Oh no! A pellet snob! I hate to be the one to tell you this, but JSB 10.34’s cannot shoot.

      It has been my experience that JSB pellets are some of the best in the world, though that is heavier than I have used in a .177 sproinger. I have to say that my .177 sproingers are not uber magnums either.

    • Gunfun,

      Thanks for the loading tip on the Diana 54! Haven’t had any pellets fall out! And I can attest to the efficacy of the JSB or AA 10.34 pellets. They seem to shoot the best in my SIG P320 pistol of any pellets I’ve tried yet.

      Brent

      • Brent
        No problem and good to hear it worked for you. And yep what always gets me about the JSB 10.34’s is how flat they shoot for a heavy pellet. Plus are good in the wind.

  1. BB-

    Errata-
    Top picture caption- EMO instead of EMS
    Section- The Test, second paragraph, second sentence-
    ….the thumbhole stock make (makes) it hard to use
    Section- The Trigger, second sentence-
    ….a two-stage unit and I although (although I) can….

  2. BB.

    I do not know if I would like this trigger or not. What happened to the T06? It is my understanding that the newer Dianas have had decent triggers up until this contraption came along. Is it not Yogi who has a 340 N-Tec Luxus? Hey Yogi, what is that trigger like?

    Almost all of these old gals around here have single stage triggers, but only the Predom Lucznik has a “I wonder when this thing is going to go off” trigger. The others do not move until you apply the right amount of force, and then they break. I do not notice any travel beforehand.

    I have pulled a long single stage trigger on one of those new Henry .22 rifles. It was real creepy also. Yuck. Fortunately for it, you could tell when it was about to go off. Once you were used to the trigger, it shot pretty good. A little work and that would have been a nice rifle.

    Speaking of triggers:

    The trigger
    By this point in the test I had fired 34 rounds and had gotten accustomed to the trigger. Although it is a two-stage unit and I (although) can feel when stage two begins,…

      • Geo,

        I think the trigger issue has to do with the gas sproing. Likely the true T06 will not work with it. Diana just claims it is. You know. Marketeers. Liars. They have figured out that if they claim it has the T06 trigger, it will sell. They will say anything to get your money. Hey, did you know that ALL of those Chinese airguns with the Diana name on them are absolutely awesome?! Just ask their marketeers, they will tell you.

        • RR,
          I will stay away from any Chinese airguns, Diana or otherwise. It’s a crap shoot if you get a good one. Then when it requires repair, even just new seals, good luck. Unless there is a US facility to do the repairs or buy parts from, you might as well throw the airgun away and buy a new one. Shipping charges are cost prohibitive. The Chinese knockoffs are cheap for a reason, and sometimes you do get what you pay for.
          Geo

  3. B B,
    The 34EMS trigger is listed as T06 n-tec in the latest catalogue, which I find a bit strange considering the spring power plant. The EMS is very scare to non-existant in the UK so far. Diana still need a huge shot in the arm here so hopefully it starts here.
    As far as pellets go, I would try H&N FTT and RWS Superfield to the list. Sometimes H&N Spitzkugel go well in 34’s but their pointed noses make very irregular shaped holes in target cards.

    Regards,
    Drew

  4. BB

    Glad you included the JSB 10.34 grain pellet as it is the favorite in my Diana 34. AA 10.34 grain pellets are a very close second.

    I just don’t get it with the hype over air or gas piston springers unless somebody wants to leave a cocked and loaded gun at permanent ready for some reason unknown to me. I get it with hunting but do metal springs really get weak in a few hours? Cold weather is not an issue either is it? I shoot both types but prefer metal because I can tune it down with TIAT offsetting any vibration disadvantage. Maybe a magnum springer can be smoother and easier to hit what you’re aiming at with air or gas spring pistons. I’m wandering all over the place and don’t expect you to reply.

    Hoping you get to convert this rifle’s piston so we can see the differences especially with the trigger pull if any.

    Good series!

    Deck

    • Deck,

      Yes, coiled steel; spring-piston rifles do get weaker after a few houirs in the cold. I subjected a coiled steel spring gun and a gas spring gun to 0 degrees, F to a couple hours and the steel spring lost about 40 f.p.s. as I remember. The gas spring lost about half that.

      I think it is due to the hardening of the lubricants.

      BB

          • BB
            True.

            But the end result is what matters.

            Why even worry about it then if your not thinking about the end result.

            How’s it go? Oh yeah the big picture.

            And as you said the nitro piston lost velocity too. About half of what the coil spring did. So they both lost velocity.

          • B.B.,

            I suspect you are correct on the increase in lubricant viscosity being the major factor in the loss of power in the case of the coiled steel spring. The gas spring drop in velocity would be mostly caused by a drop in absolute pressure in the closed gas system. That is why PCP typically loose (a little pressure) power after the heat of the fill process is lost to the surroundings.
            Obviously your answer was anecdotally based and not a scientific method comparison; that would require controled conditions. So…what were the conditions when the higher velocities were recorded? Was there perhaps a change in density altitude, relative humidity or other significant variable? Without that control of test conditions it is pure anecdotal information.

            shootski

  5. BB,

    A briliant review. You mentioned all the subjects I would ask about. It was pure joy to look at what those domes had achieved at ten meters. I was suprised with the poor accuracy results of Norma Golden Trophy though; I know nothing about those pellets, but I bet they are light. How about trying a heavier version of them, if it exists, at the 25 yrd test? I think it’d be correct to assume this rifle likes heavy domes.

    I though Diana hadn’t included the non-fiberoptic front sight in the package. If it comes with the rifle, it’s a big deal, because I was worried that it might be expensive to add later on. I would love to see a photo of the rifle with those sights on. It might possibly end up being the only one on the Internet with synthetic stock these days. Is the non-fiberoptic front globe sight plastic or iron?

    Do you think you can adjust the trigger to make it more ‘two stagey?’

    If diana sends you a gas powerplant and a 22 barrel, it will be awesome. I cannot wait to read the next one.

    • Fish,

      I think the Golden Domes have heads that are too small for good accuracy in this rifle.

      It is the REAR non-fiber sight that Diana gives you. The front remains fiber. But the way I lit the target cancelled it.

      I have adjusted the trigger as much as I know how to do. IOt is easy to detect stage two, but then stage two moves like a single stage trigger with no knowing where it will break.

      BB

      • Ah, the rear sight – of course!

        I have a feeling Diana will eventually send you a globe front sight, a 22 barrel, and a gas piston.

        Still, very interesting and exciting air rifle.

      • A friend of mine with an old FX T12 with a Lother Walter barrel is getting groups the same size as with JSB Exacts Jumbo. His rifle is less than 30 ft lbs. The Hatsan 135 generates 30 ft lbs. If that Hatsan does well with slugs Inmay consider it over the EMS Diana (provided all promised accessories are supplied and work) lol!

        • Ton,

          You are using a PCP FX T12’s MV shooting a bullet (slug of unknown to us grain weight) at a reported muzzle < 30 FPE to decide if a gas piston Hatsan 135 with a reported muzzle 30 FPE can therefore be expected to shoot that same bullet (slug) just as well as the PCP FX T12? The PCP has an entirely different internal ballistic profile.
          You can't make the comparison on the simple 30 FPE at the muzzle. You will be disappointed.

          shootski

            • Ton,

              I hope the bullets (slugs) he has designed somehow avoid the nut of the internal ballistic issue! I have been shooting solid, cup based, boat tail, flat based, hollow point, spitzers, wad cutters, bullets (slugs) out of powerful PCPs from .25-.58 caliber since the early 1990’s. Since you have been reading this Blog of B.B.s for your airgun knowledge then you know this. The PCP has the capability to provide a continuing high pressure push, if desired, right to the muzzle. The spring piston on the other hand has a very brief high impulse followed by a very sharp decline in bore pressure as the projectile travels down the bore driven only by the inertia of that initial impulse. Drag is the cause of the problem for the spring piston powerplant and shooting bullets (slugs) well. The friction load of the bearing surface of a bullet (slug) is many times that of a diabolo pellet. Without the PCP’s continued high pressure push in the bore to some point short of the muzzle the bullet (slug) in the spring piston starts to slow down, due to friction, even before it is one-third the way down the bore. There is way more to internal ballistics but frictional drag is the biggest factor in the comparison we are digging into.

              As I said at first I hope he has found something that a bunch of us have missed!

              shootski

              • Shootski,
                I appreciate your understanding of the issue and thanks for sharing. I wish I had an uber powerful springer to find out if he has.
                PS Does not as well the build up of pressure from friction in the barrel of a PCP affect the length of time the valve remain open?

                • Ton,

                  Yes!
                  To a small degree the back pressure in the chamber/bore does help hold a Pop Off style valve open for a slightly longer Dwell time compared to just the Return Spring close input in that type of PCP valve. The Return Spring force along with the physical design of the valve seat and valve head are at the core of the balanced Pop Off Valve. There are a number of other design approaches to the PCP air metering system that are not influenced by back pressure. More on back pressure:
                  https://www.google.com/search?q=back pressure. It isn’t what most folks think it is!

                  shootski

    • I just picked up some Nielsen slugs in .17, .22, and .25 with the intention of trying them in my Condor (.22, 25) and my Flashpup (.17). I have dabbled with slugs a bit to no great result, but all of my rifles are choked and it seems common concensus is that choked barrels and slugs don’t work. I am curious however to try the .17 slugs in my 1st generation Umarex Octane, which is a true powerhouse. It is also the least pellet picky of any air rifle I have ever shot. It is 3/4″ accurate at 30 yds even with super weird and inaccurate pellets (Gamo, plastic, etc.) I will keep you guys updated.

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