Diana Diana 48 .22 (2006) shooting slow?

[Racer-X]

RWS Super-H Point Field Line
14.2g @710-716 fps, 16.16 fpe

Beeman Crow Magnum (my tin does not state grams, info taken from Pyramid Air)
18.21g @608-613 fps, 15 fpe

The extreme spread was 6 fps consistently.

173 fps slower with the RWS Super-H Point Field Line and 134 fps Beeman Crow Magnum.


https://web.archive.org/web/2020022...aightshooters.com/rws-model-48-.22-beech.html
Straight Shooters.com velocities
.22 Caliber Pellets

Pellet Name	Pellet Weight (grains)	Ratings at the Muzzle	Ratings at 10 Yards	Ratings at 25 Yards	Ratings at 50 Yards	Ballistic Coefficient
Name	Advertised	Tested	Velocity (fps)	Energy (ft lbs)	Velocity (fps)	Energy (ft lbs)	Velocity (fps)	Energy (ft lbs)	Velocity (fps)	Energy (ft lbs)	Average Energy
Meisterkugeln​	13.90	14.20​	884​	25​	775​	19​	648​	13​	482​	7​	.010​
Super H Point​	13.90	14.40​	889​	22​	779​	19​	651​	14​	484​	8​	.010​
Crosman Premier​	14.30	14.30​	866​	24​	810​	21​	739​	17​	637​	13​	.020​
JSB Express​	14.30​	14.40​	818​	21​	774​	19​	715​	16​	629​	13​	.023​
SuperDome​	14.50	14.50​	884​	25​	765​	19​	627​	13​	451​	7​	.009​
SuperPoint​	14.50	14.40​	863​	24​	749​	18​	615​	12​	441​	6​	.009​
FTS​	14.60	14.80​	856​	24​	793​	21​	712​	17​	599​	12​	.017​
FTS Double Gold​	14.72​	14.80​	840​	23​	779​	20​	700​	16​	589​	11​	.017​
Napier ProHunter​	15.40​	15.20​	834​	23​	780​	21​	709​	17​	607​	12​	.019​
Silver Sting​	15.74	16.00​	817​	24​	737​	19​	635​	14​	497​	9​	.012​
JSB Exact​	15.90	16.00​	767​	21​	731​	19​	680​	16​	605​	13​	.025​
JSB Predator​	16.10​	16.30​	811​	24​	762​	21​	696​	8​	601​	13​	.020​
Silver Arrow​	17.10	17.70​	779​	24​	698​	19​	595​	14​	453​	8​	.011​
JSB Exact Heavy​	18.00​	18.20​	762​	23​	729​	21​	682​	19​	612​	15​	.027​
Crow Magnum​	18.20	18.10​	747​	22​	690​	19​	613​	15​	504​	10​	.015​
Kodiak​	21.10	21.30​	659​	21​	629​	19​	586​	16​	521​	13​	.025​
Kodiak Double Gold​	21.12​	21.40​	648​	20​	618​	18​	576​	16​	512​	12​	.025​
JSB Exact Monster​	25.40​	25.40​	597​	20​	572​	18​	537​	16​	483​	13​	.028​

I haven't had a chance to see the condition of the spring and piston seal. Breech seal looks good. I'm in the process of making a spring clamp.

 

[Sqwirl57]

If its shooting well don't worry about it. With an extreme spread of 6fps its probably just a worn 17yr old spring. If it does bother you or it isn't shooting well tear it down and inspect the seals and spring. Personally I'd just replace it all while I was in there and call it a decade.

Fyi, you don't really need a compressor for that gun unless you really want one. Just drill a hole in a block of wood for the safety to sit in and then press the gun down onto the block while you remove and reinstall the pins and then let up slowly. There is a little bit of preload but nothing crazy.

 

[Sc0-]

Not sure what your build is or experience with springers are but, without stating the normal disclaimer:

The Diana sidelever was my first serious airgun, never used a spring compressor. Simple two push pin arrangement and hand pressure. I doubt I could install an OEM spring back in with my hand but removing a tired OEM and installing a ARH spring was pretty easy. Now these HW's are getting on my nerves and I might finally need to use one...

 

[SteveV]

Those numbers are fine - 886 with Crosman 14.3 with a 6 fps spread? Are you kidding me? Quit worrying about the numbers and enjoy your 48!!

 

[Sqwirl57]

Those numbers are fine - 886 with Crosman 14.3 with a 6 fps spread? Are you kidding me? Quit worrying about the numbers and enjoy your 48!!

I think the numbers in the table were factory numbers pulled from Straight Shooters. I think he's closer to 710fps with 14gr pellets which still isn't too hateful in my books. The gun probably shoots pretty nicely.

 

[cjtamu]

That gun in new condition should make 20+ FPE with just about any pellet. Could be tired spring, but my first guess would be breech seal. If you’re worried about it get either an ARH breech seal or one of the “new” blue Diana ones. You have to take it apart to do that so you‘ll be able to inspect everything.

 

[DesertSilver]

What is your elevation? Elevation affects springer power due to thinner air.

 

[SteveV]

I think the numbers in the table were factory numbers pulled from Straight Shooters. I think he's closer to 710fps with 14gr pellets which still isn't too hateful in my books. The gun probably shoots pretty nicely.

My bad, first cup of coffee,, should have not skimmed, but read!

 

[Sqwirl57]

My bad, first cup of coffee,, should have not skimmed, but read!

I did the same thing first read through lol. I thought to myself "wow this guy sure does efficient pellet testing!" before seeing the link he had there

 

[Racer-X]

That gun in new condition should make 20+ FPE with just about any pellet. Could be tired spring, but my first guess would be breech seal. If you’re worried about it get either an ARH breech seal or one of the “new” blue Diana ones. You have to take it apart to do that so you‘ll be able to inspect everything.

I have a new Vortek breech seal from AOA. They now only stock the Vortek breech seal.

 

[Racer-X]

That gun in new condition should make 20+ FPE with just about any pellet. Could be tired spring, but my first guess would be breech seal. If you’re worried about it get either an ARH breech seal or one of the “new” blue Diana ones. You have to take it apart to do that so you‘ll be able to inspect everything.

Got a good pic of the breech seal, looks like damage at 6 and 8 o'clock

 

[cjtamu]

Link below to an old and very good tutorial on disassembly/reassembly of Diana side lever. 2006 is still a T05 gun I think? T05 or T06 trigger you want to use the dummy pins.

The Dianawerk Collective-Detailed Step-by-Step 48-52-54 Tuning Instructions

RWS 48-52-54 - Disassembly/Reassembly, Replacing Springs, Guides & Seals - Step by Step How to Do It (this is very long!) I first wrote this sever

www.tapatalk.com

 

[PEP3]

Link below to an old and very good tutorial on disassembly/reassembly of Diana side lever. 2006 is still a T05 gun I think? T05 or T06 trigger you want to use the dummy pins.

The Dianawerk Collective-Detailed Step-by-Step 48-52-54 Tuning Instructions

RWS 48-52-54 - Disassembly/Reassembly, Replacing Springs, Guides & Seals - Step by Step How to Do It (this is very long!) I first wrote this sever

www.tapatalk.com

That “dummy pin” video on YouTube is the reason I started working on all my guns myself. No one is going to beat on my guns with a hammer like that. I can change out the spring in my 48 in less than 10 minutes and never needed any dummy pins.

 

[crosman2016]

Those numbers are fine - 886 with Crosman 14.3 with a 6 fps spread? Are you kidding me? Quit worrying about the numbers and enjoy your 48!!

Yeah, I was thinking the same thing.

 

[Frogy]

Yeah, I was thinking the same thing.

That’s not what he said reread it

 

[cjtamu]

That “dummy pin” video on YouTube is the reason I started working on all my guns myself. No one is going to beat on my guns with a hammer like that. I can change out the spring in my 48 in less than 10 minutes and never needed any dummy pins.

No idea what you’re talking about. Can’t imagine why anyone would beat on an airgun with a hammer. Then I remember that 50% of the world is below average. But, when it comes to Diana rifles I’ll take Hector’s suggestions over yours. Every. Freaking. Time.

 

[PEP3]

No idea what you’re talking about. Can’t imagine why anyone would beat on an airgun with a hammer. Then I remember that 50% of the world is below average. But, when it comes to Diana rifles I’ll take Hector’s suggestions over yours. Every. Freaking. Time.

Not trying to offend, just trying to help out. The 48 is a really easy gun to service, I only offer help for jobs I have done, not read about. Here is the video, enjoy.

 

[cjtamu]

Not trying to offend, just trying to help out. The 48 is a really easy gun to service, I only offer help for jobs I have done, not read about. Here is the video, enjoy.

Same here. If you have to hit it that hard, you’re doing it wrong. I can start my pins with a finger. Push them out with the dummy pin. And then opposite to reassemble. If people have trouble getting the dummy pins back through the trigger assembly is probably rotated slightly. They’re not a necessity, have done it without. But, after seeing Hector explain why to use them and having him post a link to the pins he uses, I went that route.

 

[PEP3]

Same here. If you have to hit it that hard, you’re doing it wrong. I can start my pins with a finger. Push them out with the dummy pin. And then opposite to reassemble. If people have trouble getting the dummy pins back through the trigger assembly is probably rotated slightly. They’re not a necessity, have done it without. But, after seeing Hector explain why to use them and having him post a link to the pins he uses, I went that route.

Exactly, I always cringe when I see people hammering pins home.

 

[Toxylon]

"Just go shoot the gun" is a curious bit of advice for a gun shooting around 25 % under the KE it is supposed to, with way curvier trajectories.

Diana mainsprings last around 3500 shots - any old-ish gun is suspect for mainspring fatigue / breakage. Aftermarket options are way more durable and readily available.

Piston seal fit is critical for performance: a piston seal just a hair too tight robs a couple hundred fps just like that. Vortek seals in particular need hundreds of shots to start shooting like they're supposed to.

The sidelever Dianas are sensitive to both breech seal condition and pressure. Adjusting the sidelever for proper tension giving the breech seal proper pressure against the breech is critical, and mandatory after replacing the breech seal.