by B.B. Pelletier
Today’s report is the result of a lot of research I’ve been doing for a large article that will be coming out in Shotgun News in May. Having examined the powerplants of spring rifles of the 1970s, when the 800 f.p.s. barrier had just been broken, I’ve uncovered some interesting things I’d like to pass along. I was alive during the period when the biggest news in the airgun world was which rifles were capable of 800 f.p.s., the first so-called “magnum” velocity threshold, so this stuff probably impacts me more than most of you.
I don’t want to get into which guns were in that category, because that’s the subject of the SGN article, but a couple that weren’t in that category came to the forefront while I was studying. The first was the Diana model 27.
The Diana 27 is a fine vintage breakbarrel
I reported on the Diana 27 back in 2005, but I didn’t give much technical information then. I just told you how much I liked all three of the guns I had owned – especially the one I own now. It’s a .22 and as far as performance goes, this one will put most of you to sleep. It averages 450 f.p.s. with .22 caliber Crosman Premiers.
The trigger is somewhat tricky to adjust until you know the secret, then it adjusts as easily as a Rekord, if not as crisp. But, it’s a long sight better than the triggers on today’s crop of breakbarrels, for the most part.
Cocking is only 14 lbs. and firing is dead-calm with a small forward jump. In short, the Diana 27, when properly tuned and adjusted, is about as nice an airgun as you’ll ever find. It’s very similar to a tuned R7.
Back in those days, I knew Diana made a more powerful rifle known as the model 35. I never came across one while they were new. When Diana changed their lineup, the 35 became the 34. After years of looking at airgun shows, I finally snagged a 35 for myself. The years of wanting one had caused me to project all the wonderful attributes of the model 27 onto the gun, in addition to its extreme power. Remember, I’m coming from the time when 800 f.p.s. was considered a magnum air rifle. To me, a 35 that shot 725 f.p.s., as advertised for the 35, was simply a rifle that hadn’t yet benefitted from my expert tuning!
Well, owning is a lot different than imagining! First, the 35 was a larger rifle in all dimensions. The stock was thicker and deeper and the whole rifle was heavier. While the little 27 is a joy to hold, the 35 is about as sculpted as a floor joist. And, it vibrates like crazy when fired! I used to say that shooting a S&W model 29 revolver with full-house .44 Magnum rounds is like hitting a fastball with a cracked bat. The 35 feels that way when it shoots. For those of you who haven’t played baseball, the vibration stings your hands.
So, being the “guru” of spring guns that I was, I tuned the 35. The cocking effort went down but so did the power! I couldn’t get it to shoot .22 Crosman Premiers faster than 542 f.p.s.! Before my tune, it shot them 7 f.p.s. faster. I thought I was incapable of tuning this great rifle up to even its advertised velocity, to say nothing of making it a magnum.
That was back in 1998. Ten years later, I’ve discovered in my research that the Diana 35 never did live up to its advertised potential. In .177, it topped out at 675 f.p.s. instead of the 725 advertised. The much lighter and easier-to-use 27 went 650 in .177. In my earlier post, I said they would be around 600, but that was based on the .177 I owned, and I guess it must have been tired. At any rate, a difference of 25 f.p.s. is nothing, so why bother the larger rifle with the harsher firing characteristics?
The difference between the two rifles was the stroke of the piston. The 27 was just about maxed out for the stroke of its piston. When Diana made the piston fatter but didn’t stubstantially lengthen the stroke, the rifle didn’t increase in power. A heavier mainspring added after the 35 was in production only made cocking harder; it did nothing for the velocity. Which brings me to the point of today’s report.
Knowing that there’s a relationship between the piston bore and stroke helps explain the performance of certain spring rifles. For example…why the Gamo Whisper is such a little sweetie in .177 and why Gamo doesn’t even bother bringing it out in .22. And, why the Gamo CFX gets 950 f.s. with a light .177 pellet and only 600 f.p.s. with a light .22.
Look at it from a different perspective. The Webley Patriot is a smasher in .25 caliber but a pussycat in .177. It cannot use its power in the smaller caliber. I once owned a handmade spring rifle made by a hobbyist who spent thousands of dollars to create the world’s most powerful spring rifle. He took a Beeman R1 and supersized it by 25 percent – building an 11 lb. spring rifle that took 75 lbs. of force to cock. When all was said and done, his monster was slightly less powerful than a tuned Beeman R1. I see that I haven’t reported that one yet, so I’ll add it to the list.
The bottom line is that there are balanced spring rifles and there are rifles that are not balanced. A TX200 is balanced, as is an R7. The Gamo Whisper in .177 is very balanced, but a CFX in .22 is not balanced as well. While it’s a fine airgun with respect to handling and accuracy, it doesn’t have the power potential for .22 caliber.
41 thoughts on “Some thoughts on the Diana 27, the Diana 35 and what makes a good spring airgun”
Back in the early seventies, I had a WInchester model 425 air rifle in .22 cal. I remember that it was made by Diana and looked very much like the model 27 that you show here. As you describe, it had a remarkably smooth trigger. For a while, Winchester had several models of air rifles, all made by Diana. Do you know what their Diana model numbers would have been?
– Jim in KS
They are the 416- Diana 16, the 423-Diana 23, the 425-Diana 25 (improved model with ball bearing trigger), the 427- Diana 27, the 435- Diana 35 and the 450- Diana 50. In pistols they had the Winchester 353 and the 363, which were the Diana model 5 and 6 pistols, respectively.
Hello Tom. Have you ever done a write up of the Beeman RX-1? If so, please point me in that direction. If not would you consider it? Also my RX-1 is in .177 cal. Do you think i’d benefit from sending it to Marksman to have a .22 cal. barrel installed on it or is the .22 cal. an entirely different power plant? From SAVAGESAM
So, the elements that are balanced are piston bore size and stroke length of the piston? And the last one means how far the mainspring moves? You would think that makers would have figured out the optimum relationship. I suppose the TX200 is it.
I never did ask your method for sharpening knives so that they will cut a hair that is dropped on them. This sounds like it will beat the 12000 Japanese water stone.
BB, what is the point of a .22 cal 450fps rifle? Seems too low for hunting, and I’d think that 650fps in .177 would be better for medium to longer range plinking, especially since good ammo is so much cheaper.
The .22 cal Fast Deer I had (briefly) would only do about 450, and I couldn’t get the stupid thing to ping a circular saw blade at 50 yards. My .177 was almost 200fps faster, and had no trouble with it at all.
I have never written about the RX-1 or -2. Beeman might be able to convert the caliber for you. Why not ask them?
I had to switch to frog hair when I ran out of my own. It’s real fine, and perfect for testing knives..
The stroke refers to how far the piston travels. The mainspring goes with it, of course, but the piston is the important thing.
Until you shoot one it’s hard to explain, but I’d take a 27 in either caliber.
i use a strop and green compound to finish my knives. This is a plus because other methods wont sustain (bench stones flatten them out) a convex edge. It’s .5 micron grit, as fine if not finer than a 12000 water stone heres a link…
a cheap way to get a knife sharp is micro abrasives. The 15,5, and .5 micron grits are wonderful. I always finish it off with a strop. Heres a link to micro abrasives…
with a 15 degree bevel angle and a strop finish the hairs will “pop” off your arm as the edge approaches. BEYOND razor sharp. Its mad science sharp!
Food for thought… An 8000 grit norton has abrasives of just more than one micron. A 10,000 IS exactly one micron. To put this in perspective, the smallest you can see is 50 microns, thats 1/16 of a human hair from your noggin. The micro abrasives and strop compound are as small as advertised. The “8000, 10000, 12000” are not really 8, 10, and 12 thousand grit, its only in perspective to the other stones they make.
In all honesty, a norton 8000 is a 6000!
Does anybody know what would be the equivalent .177 pellet to the Daystate domed pellet which weighs 8.4-8.6 grains? That is, what other company makes/sells the same pellet? It looks very similar to the RWS Superdome, but is not as polished compared to RWS and weighs about .3 grains more. I have found this pellet at 10 yards in my air pistol to produce 8-shot groups at least 1/4″ better than 12 other brands/types that I have tried, and even slightly better (1/8 “) than the RWS Superdomes. Thank you for helping. – Dr. G.
It looks a lot like a JSB Exact light. I’ll bet it is, because the Brits are ga-ga over JSBs, as they should be.
The Air Arms dome is also by JSB and it looks similar. The weight’s the same, too.
one thing i forgot to mention is that the .5 micron micro abrasive is actually .3!
Thanx, I think that you are correct, it it the Air Arms Dome (they look exactly like the .22 Air Arms Dome) that is the Daystate Field Target Pellets – same 8.44 grains. They have narrow waists and smooth sides. Is the JSB Exact “light” that you write the same as the “Express,” which is about 7.8 grains? The Express has a wider waist than the Air Arms/Daystate pellet. Thanx again. – Dr. G.
I meant to ask how you get the knives sharp enough to cut a frog hair.
How do you come up with this stuff?! This looks good. Is there any special technique to use with the .5 micron grit? For my fine stone, I use a kind of slicing motion of the blade across the stone at a sharp angle going from hilt to point with each stroke and using very light pressure–basically just the weight of the knife. Do you use an edge guide? I tried one but it didn’t work for evenly slightly curved edges.
I have extended my knife sharpener collection since we last talked! Yes, you do the same slicing motion you use with your current stone with the micro abrasives. I actually think the strop and green compound is best because the leather gives some room for human error (molds the the blade, thats a BIG +). The green compound is finer than a 12k waterstone.
I saved the best for last! Your not even half way there with a 12k waterstone! There is a .1 (thats not a misprint) micro abrasive. A $30 piece of sandpaper. I promise you, this is the finest abrasive I know of. Not keeping any secrets now. Heres a link to the .1 micron paper.
In comparison to a waterstone, .1 micron is like 150,000!!! Now wr talkin, but please buy a strop and the green compound before anything. With a .1 micron edge, you can cut the whole frog! LOL
This is intense. I’ve been stropping with a piece of cardboard, and I think it’s time to move up in the world. A strop is a leather belt, right? I believe I can track that down. But what is “green compound”? Is that a brand name? Thanks a lot. I’d given up on shaving the hair off my arm, but maybe too soon. And my boss has expressed interest in my knife-sharpening…
My 1954 Diana 27 in .177 is for sale on a gun auction website,sadly must go i will buy a new diana 24 to replace her.
The JSB Exact lite that I write about weighs 8.4 grains. The JSB Jumbo Express weighs 7.6 grains. They are two different pellets, shown next to each other on the Pyramyd .177 pellet page.
this is the green compound…
I suppose you could use a leather belt although strops are only $20 ($30 with the compound).
It isn’t sharpening the knives that’s the trick. It’s finding hairy frogs!
This past weekend I purchased my first springer. On a visit to a local camping/sporting goods store to just look at rifles I ended up walking out with a Benjamin Legacy 1000. As far as I know this is a sweet rifle. Thanks to your blog I was forewarned and expecting the dieseling at first and the twangyness of the firing action so I wasn’t alarmed by either. I have nothing else to compare it to as the only other rifle I have is a Daisy 880 that I purchased to see if I would even be interested in a rifle.
I did read your earlier blog on this rifle and I believe you were favorably impressed. I do like shooting this gun and I also like the Daisy 880. My shooting currently is limited to my little 25 ft. range in my basement.
That being said I was wondering where this rifle fell in with your blog today of being balanced or not. To my inexperience it seems to be. From a lot of comments out here I am sure the rifle would benefit from a tune by charliedatuna but would a $150 tune (including the GRT III trigger if it would fit) on a $150 rifle be worth it to a new to springers person like myself?
First, I wouldn’t say the Quest is balanced. More that it isn’t badly unbalanced. When you experience a balanced spring rifle you’ll understand exactly what I’m saying.
Now, is it worth the trigger and tune? Well, the trigger you do yourself and the cost is low. Also, you can move it to many other models. So yes to the trigger.
As for the tune, I would wait until you fall in love with the gun before having it tuned. I once spent a bundle on a TX 200 getting it tuned and there was no discernable difference. The Quest won’t be like that because there is a lot to improve, but I would wait until I knew that this is the gun for me.
BB. Thanks very much. I knew I couldn’t go wrong with asking you.
I’ll look more into the trigger for now then.
To show my ignorance. The Benjamin Legacy 1000 is the same rifle as the Quest? I presume you meant the Crosman Quest 1000? I did think that this was a Crosman based on the instruction sheet and things that have been mentioned out here before about Crosman owning the Benjamin name now.
You have no idea how much I appreciate all that you put into this blog and how much I appreciate the other people who comment out here about their guns. I would never have even been tempted to get this rifle if not for the info found out here.
My mistake. I was answering a lot of messages and got my wires crossed. However, the Legacy is also Chinese and a copy of the Gamo, so the same advice applies.
Crosman owns Benjamin, which is why the documentation looks so similar.
Ah. Ok, thanks BB.
You say the Legacy is Chinese. Pardon me if I seem to be a pest. The gun is stamped Made in USA (unless I am greatly mistaken) and one of the selling points was it was made in the US, does this mean made in the US from Chinese parts or that the stamp is of no use? I’m not arguing with you, just trying to understand.
I stand corrected. Both the rifle and the box say Made in the USA.
I would still bet against it, based on the design.
BB, I understand. I’ll look at doing the trigger first and see how the rest goes.
Thanks so much for your input. As I said I knew I couldn’t go wrong by asking you.
I just checked Charlie da Tuna’s website and the Benjamin Legacy isn’t listed in the list of guns that accept the GRT III trigger.
I would email him if I were you, because the trigger really looks like it will fit.
Thanks BB. I was going to do that before I ordered one as I didn’t see it listed either.
The only thing I currently have with a really nice trigger is the Gamo Compact. Knowing you like that trigger I’m guessing the GRT III is comparable if not better.
Will the Diana 27 in .177 roll a hairy frog?
I swore i would never again kill a toad as i did when i was a kid when i pumped about 50 rounds of bb’s from my crosman air-17 into one massive toad i came across.
However i am wondering how a hairy frog would go down and what the legs taste like once shaven.
Honestly, your Gamo Compact trigger is much nicer than a GRT III. The Compact trigger is target-class, while the GRT is just a good sporter pull. There is a world of difference.
But compared to a standard Gamo trigger pull, the GRT III is a huge improvement.
Thanks BB. That description does help one who is not that familiar with different triggers see how two might compare.
Based on that I will probably shoot a few hundred more shots through it and go from there. Right now I am not finding the Legacy trigger to be excessively stiff or sloppy or hard to control. Seems to feel and work pretty well for me right now but at a later date I may change it out.
Off topic but I just had to comment after reading your blog religiously for months. I picked up airgunning as a hobby after quitting smoking, or perhaps I only traded one habit for another! Anyway, I just wanted to thank you and all of the other people on this blog for the wealth and accuracy of information presented here.
And with this habit, you have something to show for your money. Glad you like the blog.
just wondering if there are any other sources for inexpensive muzzle brakes that fit a variety of barrel diameters. PA carries the Beeman, and they’re decent – but a bit pricey. I’ve even made them before, but they can get complicated, and you certainly don’t want one with slop. I vaguely remember your article on barrel shrouds, but did you address this already? On these great-shooting blasts from the past – when you get a chance, try the Baikal 512m. I paid very little for my .22, and while it’s not a true magnum in velocity – it shoots accurately, points extremely well, very easy to cock, and tears up cans with authority. I purchased a cheap 2X red dot with unlimited eye relief and mounted it on the long dovetail at the barrel break. There’s even a stop! Throws the balance off, but I got my “scout” rifle. I’m still waiting on that Leaper’s pistol scope you mentioned from the SHOT Show, but this got the ball rolling. Keep the nostalgic airgun reviews rolling, it’s possible that you’ll be able to “educate” a whole new crop of airgunners to the joys of sub-sonic shooting. It’s a perfect counter to the increasingly annoying velocity race headed by Gamo.
Universal muzzle brakes come and go. Pyramyd Air has three at present. Look under Shooting Needs and Accessories.
I haven’t looked at the 512 yet, but it’s a little too powerful for my needs. Tomorrow I’ll show you what I’m talking about.
I am very happy to inform you that we have got ourselves a Diana 27 in .177 cal. It has the rail for the peep sight. Its probably manufactured in 87 (the markings are not very clear). Not in a good condition, some pitting, rust and with Indian made stock and rear sight. But its mechanically sound. Happy to own it. Looking forward to a mini restoration project with your fantastic blog here for reference.
Just remember the big secret for assembly after the job is done. Use sticky grease to hold the trigger parts together until they are inside the spring tube.
Do that and the rest of the job should be easy.
Nice to hear from you. Enjoy fixing up your Diana 27. If you get stuck, please let us know on the current blog and someone here will give you some help.
Better yet, stuck or not let us know how your project comes out.
Vince asked "what is the point of a 450 fps .22 caliber gun"?
Back in the late '70's, I had a Model 27 in .22 cliber. I shot it a lot and i can say without a doubt that it was extremely accurate, easy to cock and a pleasure to fire. I thought all airguns were like my 27. I was surprised to find that they were not.
Crows and pigeons were a huge nuisance where we lived and I can attest to just a single shot being required to dispatch them. It was very rare that I required more than one shot to finish a crow. Usually that was just poor shot placement on my part.