Diana 350 .177 went off like a cannon-blast and smoke!

[phoebeisis]

My Diana 350 .177 finally arrived about 7pm last night

It was well packed-Numrich knows their business-they even taped folded bubble wrap to the inner box to preven movement in the outer box

I pulled it out-eyeballed it

It was HEAVILY OILED-

Seems I remember some member mentioning that one brand-forget which-heavily oiled their guns-maybe in case it spent a  long time on shelf.

Well I cocked it-really easy to cock- put in my usual 5.2 grain lead free Flat nose Daisy pellet-

Aimed-fired

BAM-the report was like a cannon a black powder cannon-and a HUGE CLOUD of nasty black smoke erupted-filled hallway

Yeah DUMB to not have anticipated the Dieseling-but this was  much more than other new guns-much more

No my ears were not ringing-but close-

Anyway after adjusting sight-it shoots dead on at 10 meters-standing freehand

Observations

1)Pretty gun-pretty wood-points nicely -not front heavy to me-the 460-despite being shorter-feels slightly front heavy-the 350-no

2) It-and the box-only marked DIANA no RWS and no weird name like UMAREX-in 2015 my 460 arrived with all 3 names on the box-

3) 2018 manufacture date

4) very easy to cock-worlds easier than my Crosman NP Phantom .22 that has more stiction than you would believe-easier than the HW77 and the 460 and the TX200-

Really easy to cock! Easy to load of course-despite od fumbling hands and tiny .177 pellets

5) Nice sights but I will change front to green fiber optic-bad eyes

6) cuts very clean holes-must produce plenty of velocity-30 shots in still dieseling

I am very satisfied-reminds me of my 1st air rifle-1963 mail order Czech made rifle-small easy to cock-

7) it is just over 8.25 lbs-about .2 lighter than the 460 which is just under 8.5 lbs-it is long but not really front heavy to me

Thanks all

Charlie

PS Yogi suggested I wear muffs-should have read that before setting off first shot-literally like a black powder rifle -BLAST AND NASTY SMOKE-filled hallway! Did not cause ear ringing

but close-I probaly will always wear plugs with it-noisier than the .22 460-probably supersonic with those Daisy 5.2 grain pellets

PPS It is prettier than the picture shows-clean looking rifle- it does have a cheek piece that would suggest it is right handed-but I shoot left handed-and right-I didn't even notice that-

so it is ambidextrous  despite cheep piece

[Denby95]

Thanks for the update!

You might want to check out Hector's guide on how to run in your bore initially. It's a fun little process.

https://www.ctcustomairguns.com/hectors-airgun-blog/the-diana-430l-second-entry

I think we already covered in the other thread that you gotta start using some heavier pellets than those 5.2s !

[Mrblonde40]

I spent 2 days of my last vacation using Hector's run in method.  But the first real 10 ahot group I shot was under 1/4" at 18 yards so I'm not going to complain.  I would also say use heavier pellets.  I don't use anything under 8 grains in my HW95 and I'm pretty sure the 350 is a step up in power from mine.

[Cslinger]

My Diana’s have been quite literally OVERPACKED WITH PISTON LUBE. They all shot like firearms out of the box. I had to clean them up.  I have also had a recent Weihrauch with a super dirty/lubed barrel that needed a good cleaning.

Also a 5 grain pellet out of a 350 is probably breaking the time barrier.

[Toxylon]

Funny, my 2015 Diana 350 Mag was dry as bone inside. It also had a trashed piston seal.

Cocking effort is highly subjective, dependent on individual physiques and technique, but I'm surprised at your impression of the 350 Mag being easier to cock than a HW77 or a TX200. The full-power 350 Mag has a substantial cocking effort, it's deffo a magnum in that regard, too, although less demanding than some other magnums. I would think that something is amiss, by the cocking being very easy. But hey, highly subjective.

 

[35 shooter]

My understanding is Numrich bought this batch of Diana’s straight from the factory.... thus the lack of other markings such as RWS, etc. on them.
At least that’s what I was told.

[Yogi]

Glad you like it.
Check your stock screws after every shooting session.
Check to make sure your barrel pivot bolt is not to tight or too loose.
Enjoy!

-Y

[Denby95]

My understanding is Numrich bought this batch of Diana’s straight from the factory.... thus the lack of other markings such as RWS, etc. on them.
At least that’s what I was told.

Same. I personally consider that more attractive and of greater value. Who wants a middle man that did nothing besides import and bump up the price? I'd much prefer the actual manufacturer who actually created something.

[ER00z]

That's a beauty of a beast you have there, hope you enjoy.

[JNG]

Not trying to be rude. Really I'm not.  But trying such a light weight pellet in a 350mag is asking for detonation.

[subscriber]

Not trying to be rude. Really I'm not.  But trying such a light weight pellet in a 350mag is asking for detonation.

The heavier the pellet the more likely the gun will diesel because a higher peak compression pressure is reached.   Even then, it may not exceed the speed of sound, so you won't hear it dieseling, but you will see the smoke.   

The lighter the pellet the more likely the pellet will leave the muzzle at super velocity - even without dieseling.  Some people assume the crack of a light pellet is due to "detonation".  It is due to it being too light for the power of the airgun.

A .177 350 in stock US tune wants to shoot at 20 FPE.  It might not get to 20 FPE with 5 grain pellets (unless it is dieseling - which can happen with factory lube), but it almost certainly will shoot supersonic.  As amusing as the crack is, you are going to find that pellets over 9 grain in weight will do much better.  Anything less than 8 grains is really too light for the 350, and probably contributes to piston slam at the end of its forward travel.  Hard on the piston seal, stock screws and scopes.  Just say no to light pellets...

[phoebeisis]

Thanks all

Wrote a too long reply-will compress it-thanks all

Yogi-you were right-20th shot    it spit the front sight 8 or so feet down the hallway-no damage- Yeah should have checked EVERYTHING-but I wanted to shoot it soooo badly

Crude calculations indicate the rifle was traveling well over 10 fps  maybe 16fps  forward to launch the sight that far- the sight had to fall for .5 sec  -54" hold height so fell for .5 sec or so

Traveled 8 feet in 1/2 sec  means 16fps horizontally-even if it was less how in the world can a 8lb rifle get that much forward velocity??

Even if it was just 5 feet-10 fps-how in the world 8 lb rifle  10 fps forward velocity


Target-my checking what a 10.4 grain pellet would feel like- 2    5.2 grain pellets stacked-nice soft recoil   quieter too-nice clean holes-hard to see that-but clean

Yes I am going to find a way to shoot heavier pellets-

My pointed .177 SSP are not the claimed 5 grains-they are 4.2 GRAINS- the flat nosed Daisy are 5.2 grains  no wt claim on box-guessing 4.2 must hit 1250 or so-

not sure what they sould like-plugs or muffs

[Yogi]

The lighter the pellet the more likely the pellet will leave the muzzle at super velocity - even without dieseling.  Some people assume the crack of a light pellet is due to "detonation".  It is due to it being too light for the power of the airgun.

No, the crack is because the pellet created a mini sonic boom when it went faster than the speed of sound.  A heavier pellet that exceeds the speed of sound will also "crack".

-Y

[Jeff Marshall]

Quote:
The heavier the pellet the more likely the gun will diesel because a higher peak compression pressure is reached.

Subscriber, At first glance what you said would seem to be logical. But in practice, the opposite is true. Heavy pellets detonate less.

Firing a spring piston gun with
no pellet produces the most detonation.

When firing a new spring piston gun that is loaded with protective lube, it is best to
start out with a heavy pellet, or even fire two light to medium weight pellets at once until the gun burns off or blows out some of the lube.

Burning lube is very different from detonation.

I have been using 30 weight motor oil for many years in springers with leather piston seals.
After lubing I always start out by firing two light-to-medium weight pellets at once,
then heavy pellets, before switching to normal weight pellets.

If I start out by firing normal or light weight pellets, the gun will always detonate.

If you give it "a shot", you'll find that what I'm saying is true. ;-)

[subscriber]

I think what I stated implies exactly that.  With the added statement that "heavier pellets not dieseling" is bogus.  Just because they stop cracking does not mean heavier pellets are not dieseling.  If heavier pellets are supersonic, they crack to. 

So, "no" to you "no", or I might be tempted to define the word "is" to you .

The lighter the pellet the more likely the pellet will leave the muzzle at super velocity - even without dieseling.  Some people assume the crack of a light pellet is due to "detonation".  It is due to it being too light for the power of the airgun.

No, the crack is because the pellet created a mini sonic boom when it went faster than the speed of sound.  A heavier pellet that exceeds the speed of sound will also "crack".

-Y

[subscriber]

If I start out by firing normal or light weight pellets, the gun will always detonate.

Thanks Jeff, for bothering to lead me to your way of thinking:

How do you know if a given shot detonates?  If the answer is because detonation causes supersonic velocity, then my explanation above is still a good one - not disproven.  On the other hand; if dieseling is produced with only the back pressure of air flow through the TP (dry firing), then there is another mechanism at play.  If this is observed to happen, then I must be willing to consider how this is possible:

I can imagine that higher air flow velocity from an uncushioned piston (dry firing) is better able to "scrub" lube off the compression chamber, TP or barrel wall; and to atomize more of it, so it lights easier.  In that case, even with a light or no pellet, there must be enough pressure to increase the temperature above the ignition point of the oil vapor.

How does one measure the extent of dieseling in a springer?  I would use the amount of smoke and the increase in pellet energy as metrics for how much dieseling there is with a given pellet. 

Dieseling should make the sound of the shot louder, but as soon as the pellet is going supersonic it will be much louder.  A light pellet may be over or near the speed of sound anyway; so a little dieseling may put it over and make it super loud.  If a light pellet has an extra 2 FPE over what is seen after dieseling stops, but a heavier pellet has an extra 5 FPE, then I claim that the heavier pellet is dieseling with greater intensity because it gained more energy.  Even if it is not as loud because it is still subsonic.

So, my goal is to prove a statement that has been repeated "forever" about heavy pellets dieseling less, with a concrete test.  There are many explanations for observed phenomena relating to shooting that are incorrect, but repeated anyway.   Samples of such beliefs are stated at the bottom of this overly long post.

The fact that dry firing can provoke dieseling at all, is interesting.  I have not dry fired a springer in 50 years, so I have never seen evidence of this.   That does not mean it does not happen.   I definitely consider dry firing a springer more abusive that light dieseling that produces a little smoke.  Perhaps the explanation is more "air scrubbing", and that the piston "slaps" the compression chamber so violently that the air battles to get out of the gap, raising the pressure and temperature to ignition point.  Or, that the piston slam noise and vibration are mistaken for dieseling.  Ditto for light pellets - which brings me to this:

Even if it was just 5 feet-10 fps-how in the world 8 lb rifle  10 fps forward velocity

Simple.  The 350's piston is heavy.  When the piston slams into the end of the compression chamber, from shooting a pellet that is so light that it offers hardly any resistance to air flow down the barrel, the whole air rifle is slammed forward by the piston impact, at high enough speed to "throw" the front sight that far.  The sight flying off forwards is a clue to the abuse imparted by shooting light pellets (never mind dry firing).

Now, arguing about dieseling when shooting a piston slammingly light pellet, is like surgery for an ingrown toenail, where the nail is kept and the rest of the body incinerated as medical waste.  Stop shooting light pellets in magnum springers.  It is damaging to the air rifle, regardless of whether dieseling occurs or is "excessive" or not.


Amusing assumptions, based on real observations:

I was a conscript in the SADF almost 40 years ago.  My Boer shooting instructor told us that a rifle bullet reaches its highest velocity 100 meters down range.  He knew this because his grandfather told him so.  His grandfather knew this because his 7 mm Mauser would shoot through a Kudu broadside at over 100 meters, but would stop short of full penetration when shot from 50 meters.  The conclusion reached from this observation was that the bullet was travelling faster at over 100 meters than 50 meters.  Reasonable conclusion, but wrong.  If they had bothered to look at the width or more precisely, volume of the wound channel they may have concluded correctly.  If they compared the recovered bullets against the ones that made it through, they might have notified a difference in the degree of riveting.  Of course, shooting through a Kudu makes finding the bullet to look at it difficult and hardly a priority .

My own Boer grandfather told me that his 7 mm Maser shot "flat" to 200 meters.  He explained that the bullet was so fast it did not drop at all. until it had travelled 200 meters.   This was really just an observation that the point blank range was 200 meters, at the lowest sight setting.   That no compensation for the trajectory was required to 200 meters.  Not that gravity had zero effect - even if that seemed like the practical explanation.

[Jeff Marshall]

I once had a gun dealer tell me that bullets didn't expand well at close range
because they hadn't had time to heat up! 

[subscriber]

I once had a gun dealer tell me that bullets didn't expand well at close range
because they hadn't had time to heat up! 

Well, that sounds like USDA certified hooey.  That said, sometimes nonsense statements, or gross generalization do have a factual foundation.  One that is often expressed out of context. 

Do bullets heat up in flight?  My guess would have been that they cool down after leaving the barrel; until they strike the target.  Apparently I was wrong:

Here is a video about bullet BC dropping unexpectedly in flight, over long range.  Using a LabRadar helped Hornady figure out that the plastic "ballistic tips" were melting in flight, making the bullet tips blunter.  The solution was using a plastic with a higher melting point:





I would bet that all bullets don't heat significantly in flight.  That supersonic bullets, leaving the muzzle at Mach 2.5 to 3 heat up a lot at the tip, should not be a surprise.  Not, if one considers that certain stealth aircraft made from titanium grow in flight from the skin friction - even at high altitude.

SR-71 designed to leak fuel on the ground:  https://aero-space.us/2020/02/15/heres-why-the-sr-71-was-actually-designed-to-leak-fuel-all-over-the-tarmac/

When developing the aircraft, engineers accounted for the temperature fluctuations that it would experience. More specifically, they realized that the plane’s components would heat up as the aircraft gained more speed.

This friction would inevitably prompt the plane’s body to expand, so they had to fit some pieces together loosely. The fuselage panels, in particular, were purposely positioned farther apart. These loose-fitting parts are what produced the leakage, but it was a necessary design quality to prevent overexpansion. As the SR-71 reached 2,200 miles per hour, the panels enlarged as expected. Fortunately, there was enough room between them to allow for this inflation.

[Mrblonde40]

Hatcher's Notebook discusses bullet penetration related to velocity.  The bullets at closer range are still moving so fast at close range that they begin to tear apart on impact.  So this has been tested and as stated before, they aren't faster 100 yards down range.

[subscriber]

...they aren't faster 100 yards down range.

Where would the energy come from to increase the bullet velocity, after it clears the muzzle?  It has to start slowing down due to air resistance, as soon as there is no longer high pressure gas pushing on it from the rear. 

It is laughable that anyone would think otherwise.  Even more so, an instructor in any military.  Some people are good at following orders, without question.  Others, not so much