SDB’s SPORT – An All-Weather Sporter

[sagar 12345]

today breach seal of my sport shows same behaviour likes you showed in your article .i have precihole o ring can it withstand at its place in front of this monster . sir if you find any remedy please tell us also so that we can use it on our rifle.precihole o ring is played good role on other rifles.

[prashantjha19]

I think you should first try what Basu da has suggested in this regard.....
Gently take the breech seal out ...clean the seat and groove, and wrap a couple rounds of cottin thread (or teflon tape...one that plumbers use at pipe joints, etc.). And then securely slide the seal in. Just see that it sits in tighter than it was earlier.
I am told this quick and simple remedy works well. Worth trying!

For the Precihole o-ring, you will need to shim /pad the seat of the seal groove well. Can use properly sized cut-outs (leather, plastic, metal...or even thin o-rings).
Good luck!
Do tell us what worked in your case...
regards,
Prashant

[snIPer]

Excellent write up. Enjoyed reading it.
/S

Thanks to some of you here on this forum, I got myself a SDB Sport recently. This was after a fair bit of deliberation though.

Decently Accurate, Powerhouse of a shooter…..yet light to lug around!
A light one at 3.2kgs.jpg
Well, that’s what I was looking for… and that’s what it is!...., if you do not intend to go through the full text below! A reasonably priced gun, with traditional look and balance, shoots accurate, is really powerful (old habits die hard, you see!) and is so easy to carry around! Too-many-into-one…aren’t they? Honestly, I am only smiling away ….as I write this short review with the Sport by my side. And here’s why…
First shots straight from the factory-A powerhorse.jpg


Best regards,
Prashant

[sagar 12345]

prashantjha sir as per your suggestion i used one small size o ring for bedding & one precihole o ring on that as a breach seal it worked fine let us see what happen after 100 shots.the breach seal from sdb seems uneven in thickness so i tried o ring option.

[prashantjha19]

Dear Sagar,

An O-ring breech seal needs a visible protrusion on top. That is, you should be able to see a section of the ring standing proud of the breech face when you break the barrel. Plus, the protrusion should ideally be even in height. I hope you have ensured these.

As for the SDB seal, it is not uneven. It has a taper. And so does the groove for the breech seal in the barrel base block. Please look at the seal and the breech groove /slot closely. There's a 01mm difference between the depth on top and that at the bottom of the groove.
The unevenness you mention in the seal is on purpose....so, when fitted in, the seal's bottom has full contact in the groove , and yet it has an even protrusion on top (where it contacts the TP on barrel closure).

Good luck with the new set up.
Regards,

[greenrifle]

Sent from my MotoG3 using Tapatalk

[sagar 12345]

prashantjha sir i am very much impressed with your knowledge about air rifles .i am 45 years old & i started air rifle shooting with club elite few months before.sdb rifles attract me due to their classic wooden stock & their power.i own sdb artemis gennex & now sport .in artemis i replace stock spring by precihole 40 coil spring .today when i am trying to open sport i cant open the barrel screw.then i read your review again there you mention about solvent i cant find this solvent in market so please help me to open the barrel screw. in other rifles i didnot face any problem why in sport this problem occurs i cant under stand i just want to clean the intenals as you said & remove extra lube & assemble it please reply.also sir the o ring in sport after 15 shots is also showing same behaviour as neoprene breach seal so i want to try teflon tape suggested by basu sir but i am cofused how to use this teflon tape.please make picture reviwe if possible because i think every person having sport must facing such problem.

[Basu]

Barrel screw ??
Hinge one ??
Why you want to open a new AR immediately after receipt ??
Run it for 1000 shots at least.
It seems that you are bitten by a bug of exploration.

Basu

[sagar 12345]

no basu sir i just want to disassemble & wipeout extra lube & again assemble it.because after every shot i smell burning oil but not smoke from barrel.i got succsed in opening barrel but after that i did not dare to go further so i assemble it again.

[Basu]

Please do not sniff unnecessarily.
Every time you will get something or other foul smell.
Just watch the barrel smoke.
Only open when it fumes like steam locomotive regularly.
The lubes tend to move forward with every shot you fire.
So there will be occasional fume time to time.

Basu

[prashantjha19]

no basu sir i just want to disassemble & wipeout extra lube & again assemble it.because after every shot i smell burning oil but not smoke from barrel.i got succsed in opening barrel but after that i did not dare to go further so i assemble it again.

Hi Sagar,
Basu da's suggestion is worth considering.
But, .....if you insist on opening the chamber piece screw (barrel screw), (which I assume you may already have, by now)...... just use a bighandle- screw driver which has a good tip. Grip the action in a vice or something so there's no wobble, when you apply pressure. You could call a good local mechanic home to do this for you (their hands are trained, and can feel the torque and feedback from tight screws better than you and I).

Also, use thinner (used to dilute wall paints) or kerosene oil on the screw. Hammer very lightly. Leave for a while. Put more drops, hammer lightly again. Then try to unscrew. It is only the first time you will face problem. Afterwards, it will sit loose, and the grub screw will lock it nice and proper.

The solvent I used (shown in the photo in the thread) is WD40. It is good to keep a can at home as you can use it for various applications. You should get it at any decent hardware or tools store. I order from Amazon directly.

All the best.
Regards,
Prashant

[sagar 12345]

prashantjha sir, one of my friend used sport for last 7 days.today he returned it to me.i observed o ring is intact after approx 500 shots. cocking effort remains same.precihole o ring is very good for breach seal as you said.

[Basu]

Dear Prashant,
Hope it is quite a few months since you bought Sport.
Factually that is my most favoured AR among SDBs.
Wish to hear a general assessment after some use.

Basu

[sagar 12345]

still date sport hold nicely, breach o ring hold nicely. power wise sport deliver same power like new out of box.i enjoyed it lot.now since i am using club elite & genex more but when ever i want to take long shot for plikling i prefer sport.i still not found any suitable pellet for sport so i am searching somewhat heavy pellet like 9 to 10 grain round head from gsmith for both sport & huricaine air riffles.

[prashantjha19]

Dear Prashant,
Hope it is quite a few months since you bought Sport.
Factually that is my most favoured AR among SDBs.
Wish to hear a general assessment after some use.

Basu

Dear Basu Da,
Thank you for nudging me on to take on Sport yet again!
First things first….It now seems to me that you were absolutely right when you had advised me during the last tune up to settle with a spring length of round 245mm (I had gone for 255mm, if you recall!). We will soon see why!
Second, ….I had noted somewhere in the original post in this thread that the SDB folks seem to have kind of finally arrived (that is, in terms of getting the knack of designing fine shooting air rifles….). And my new experience with Sport ….and the fact that the new spring SDB has installed in Sport is a softer and longer spring only testifies to that!
For the benefit of our readers, here’s a little update on the last tune of my Sport. I persisted with the old stock spring (My gun had the old 3.16mm wire spring). With the new seal, in a freshly setup new action, it gave one of the snuggest and solid shot cycles…dishing out 10.3 to 12.8 fpe of ME with various pellets. Almost all Precipell pellets and the lighter GECO were among the most accurate, too. The energy efficiency ranged between 30 to 38%. Noting it all on a public forum here, I feel relieved that one of our well-received members had personally tested the gun at a local shooting range in this tune and had given it full marks!
And now the climax! …….
For the last several weeks (by when the gun would have shot some 300 pellets or so…), I noticed some erratic behaviour, in that its accuracy sometimes ended to get whimsical. I first attributed it to myself –it could be anything…a shaky pair of hands, tentative state of mind, and what not! Nonetheless, But I was becoming suspicious. Got buy with projects on other rifles, and Sport took a back seat. Your query got me back to it. And when most folks were busy with Holi, I got busy with my trademark accuracy testing (old-fashioned style, some would say…but it is spot on!)….and here is proof of its whimsical accuracy behaviour. Put simply, the gun in this stiff tune has become highly hold sensitive!

IMG_20190321_141129-A.jpg

Watch the groups carefully! I use three grips to conclusively ascertain the exact state of hold sensitivity of a rifle in any given state of tune – Rested-Unrestrained, Rested-Guided and Rested-Restrained (which is akin to the field shooting hold)! In this case, only two grips got the writings clear on the wall.
In the current tune, the gun is accurate …ONLY IF YOU CAN RESTRAIN ITS RECOIL…AND IN EXACTLY THE SAME MANNER EVERYTIME! In a typical unrestrained state (which is somewhat akin to what we know as the Artillery hold), it is going nuts!
My experience is that it is only due to the seal setting in nicely! Of course, that is the sign of a good quality seal! No questions about that. To add to it, SDB cylinders have always had a fine hone inside…so all I hear during cocking is just the hiss of the seal…no gurgle, whistle or anything ever! Now, the reduction of friction between the seal and the cylinder wall during the bedding-in increased the piston velocity significantly….leading to very high initial recoil acceleration. The resultant significantly high peak pressure did not all convert to pellet driving pulse (because ME didn’t go up!). So where was all that extra pressure going? ….In driving the piston bounce! Most of it is getting used to both advance and accelerate the piston bounce….leading to a very high secondary recoil, the surge. That is something, an average shooter like me can not handle…and hence the high hold sensitivity! The fact that it has to generate this high ME with just 78mm of stroke only compounds the problem.

IMG_20190321_141208-A.jpg

Now look at this other photo…. Grouping by a Sport stable mate, again from SDB……same distance, same pellet, same holds. A sweet shooting rifle must be the least sensitive to hold. Look at how the POI drops in the restrained hold!
Let’s look at the Sport’s current behaviour from another perspective ….this 3.2 kg full rifle has a 299 gms piston assembly (piston and part spring weights) hurtling inside to generate recoil. At 10.6:1, the ratio is maddening for any break barrel, let alone for a light springer like the Sport! For comparison, look at the TX200 – A similar weight piston (actually 5 grams less) and a much lighter spring (than this 114 grams resized spring I currently have in my Sport) does the job is a whopping 4.5kg rifle….taking the ratio up to over 16:1. Nominal recoil displacement on Sport is 7.5mm (the TX has it in the 4mm range). How’s that for a spin!
No wonder, I have already readied up a lighter piston to test. But this is another project. Also, this will be set up at 85-86mm stroke….my lowest stroke of my taste personally. I would also request SDB to try this stroke length out in Sport …to give similar ME but with a softer shot cycle!

IMG_20190320_175911-A.jpg

IMG_20190320_180208-A.jpg

And you were always right, Basu da, in advising me to keep this light Sport in the 10.5-11FPE range. That is where it shoots at its powerful and sweet best!
For now, I will first go by your advice….i.e. either cut or collapse two coils of this spring, or use the new 2.9mm Sport spring that SDB is using currently. Will report back again!
The gun remains as sweet as ever. Final words….A stiffly set up light springer is a must have for all those who love shooting…..because shooting it every now and then will keep you disciplined and your technique intact, and not let you become complacent about correct hold, grip, trigger action, follow through, and all! And I love my Sport for that the most….of course, its trademark “punch” is inescapable!
Happy Holi and Happy shooting!
Prashant

Added in 6 minutes 31 seconds:

still date sport hold nicely, breach o ring hold nicely. power wise sport deliver same power like new out of box.i enjoyed it lot.now since i am using club elite & genex more but when ever i want to take long shot for plikling i prefer sport.i still not found any suitable pellet for sport so i am searching somewhat heavy pellet like 9 to 10 grain round head from gsmith for both sport & huricaine air riffles.

Dear Sagar Ji,

I have found that the Precipells (all of them) shoot terrifically accurate in my Sport. You may already have tried those out by now though. if not, it would be worth. Second, I always found the G Smith ones way too oversized for the SDB breech.
I would also suggest you try the Marvellous Shot pellets. The round head lot I ordered shoots reasonably accurate in both Precihole and SDB barrels. They do not match the Precipells but are a good cheaper option for daily plinking.
Regards,
Prashant