BSA R-10, now what?

[Racing]

I hear ya, and just nod in agreement.





Yeah. Second layer of "dark oak" dye, and does it EVAR make for a difference. D*MN this is a purdy piece of kit! 

Now..
Issues. I´ve gotten around to actually shoot the thing and using the now expanded 4,56mm pills i use for "El-cheapo" (the Chief rip off).. accuracy out of this thing is anything BUT stellar.
Fact is, we´re talking like 2" groups at 30 meters, which is far far far from acceptable.
That probe i made in turn, need to shorten the utmost front end of it. Simply push the pill to far in. That said, them 20 grain H&N´s i use on the rats in El-cheapo (where they´re friggin literally LASER accurate).. need to order more of that stuff why i´ll of course try them as is in this BSA.
In turn i´ve got some 16 grain Rabbit Magnums laying around.. what i´m saying is that i need to get some time to myself to evaluate this.
Not only that, it is an "old" R-10 and truth be told i haven´t even cleaned the barrel out yet - which of course is a must to get a base platform to work from.

None the less it was a bit disappointing to get them groups knowing all to well what this piece is made of after all.

Sound level in turn. As i´ve stated above i run the stock untouched shroud setup and atop that one of them rather thought through Finnish made Jaki LDC´s. They´re really intended for rimfire 22cal use but..
Then.
As some of you are aware i also make my own LDC´s and then always with a "soft" innard. Use steel perforated sheet metal that i dress around a 10mm mandrel, which hands me a "tube" i wrap with regular Wettex rags.
This in combination with more or less elaborate baffle designs make for a WAY WAY WAY WAY more effective LDC setup than anything store bought. Just the way it is, and LOADS of that performance advantage comes from minute control of through holes on the baffles. Thing being that as i always dial them LDC´s in on the lathe vs the barrel i get away with running way tighter tolerances than anything store bough, which sure pays off.
Now.

The idea here is for a "medium powered" R-10. Ie; i´ll be all happy having them slugs going downrange at a level of 40-50J and in doing so.. as i turned performance up today it soon enough showed that that all to silent former setup.. nah. Not as power went up. Simple as that.

Now. From a looks POW i kind of like the way that Jaki LDC just becomes an "extended arm" on the stock shroud. So what i plan to do is something, to me, new. Ie; make me an LDC carrying my innards just on a smaller outer diameter to work from a looks point of view vs the stock shroud.

Mark that when i aim to change or whatever i want to keep with the very very beautiful design of the R-10. It´d be an absolute shame to eff that up as i see it why i´ll be happy to even go to length to keep that intact.

As for if that LDC of my own design is to work off a CF tube or regular aluminium.. not decided yet. But most likely though it´ll turn somewhat longer than the Jaki offering as i want like a 5 or 6 chamber jobbie.

More imperative though, need to figure accuracy out. This just HAS to be done, and i NEED it to be "hole in hole" at 30 meters as a bare minimum.

Shot the thing over the FX brick and where i´m at right now them 20 grain pills exit at around 820-830 and from what i´ve gathered, tried playing around a tad with reg pressure, them do so @ approx 140-150 bar.
Hm.

Apart from them Rabbit Magnums i´ve also got the original 4,46mm diameter "Pile drivers" laying around and will certainly try both of them out to get an idea as far as what give here, accuracy being an absolute MUST to me.
To recap the idea here is to setup a "build" that´ll hand me the power per above to keep it as a "ratter" and 45-50J will suffice doing that and then some.

Many a night at the shop i end the day with an hr or two ratting. Tonight no exception, which rendered me three of them scaly tails - all being victims to El-cheapo.
Again. That thing tossing them 20´s out the door at like 1050fps+ does the trick no doubt, which is an entirely new experience to me (being used to using the 25s, knowing all to well we´re talking massive overkill). That being said then, which is the basic idea here, what i aim for is a VERY silent "ratter" on like say 50J which´ll let me dispatch them critters out to an easy 50-80 meters need be.

Also got the readjust the trigger and like many other owners of R-10 i came to react to how "deep" i needed to set the trigger, physically, to reach a decent let off.
Hm. That brings i might add material to one of the involved sear pieces to make the trigger stand more "straight up" in the trigger guard - thus also affecting reach of pull a tad.

Yeah well.
Tomorrow would normally bring "a day to my own" at the shop but.. as i´m a giging guitarist too.. well, tomorrow night we´ve got a gig why.. no PCP´s tomorrow.
But we´ll get there. Rest assured.

RKR.
On that note, have you given any thought what so ever to increasing plenum volume? I am NOT aiming for "balls to the wall" setups here but more so just added volume to make output more "in harmony" at like 45-50J.
What we´ve touched on before?
A larger buddy bottle with a regulator at the end of it, but as i see it the issue there is them dirt cheap spring based regs. NOT exactly my idea of a consistent setup?
You tell me.

[rkr]

Trigger, move the hammer latch pin up and you can reduce the first stage. Just grind the flat part in the pin a bit longer and move it up. I had to do that on my R10 trigger unit as the blade was angled way too much back when adjusted. While you are at it replace the springs with springs from small BIC lighters if you feel the need for lighter trigger feel 

Accuracy, you may have a bad barrel or shroud clipping. Take off the shroud and screw Jaki on the barrel directly and test, the barrel has usual 1/2"UNF threads. If that doesn't work slug the barrel, I bought one bad .177 BSA barrel where the choke was too far in and the bore actually expanded towards the muzzle. Cut a piece off so the choke is at the right place, crown and thread and you have an accurate barrel.

Noise level, that shroud is decorative and too small in diameter - ditch it. 28mm shroud with proper back venting will cut down the noise level a lot. With R10 you can make a nice big reflex silencer which will be even better, I'm not sure but 35mm unit might fit in there. You seem to know how to make proper internals and for backventing check HUMA shroud installation videos if you need ideas.

As I don't have R10 myself I can't give you the best approach for the plenum. The stock one is good enough for 45J and will probably work at 50J as well, factory guns make 40J. You could ask HUMA how much you can make with their reg, I believe it's smaller than factory unit which increases the plenum. Some people have just ditched the regulator and tuned the gun to self regulate, that option will still give you many shots at the sweet spot.

Pile drivers do not work with hollow nose probe, they feed in at an angle. Try normal JSBs or JSB heavies, they work in all my BSAs really well. H&N FTTs and Baracudas are also good and worth trying.

[Racing]

Idea of mine with a slightly increased plenum is just that i hope it´ll hand a more harmonic gun.
In other words no "oh, i need to add 50cc´s worth" but more so me thinking that every little bit helps. Ie; a mere 5 or 10cc´s will make for a more mellow life for the gun.

No. Barrel on this R-10 isn´t threaded. I´m ahead of you though, Jaki LDC got installed on the shroud using a dial indicator on the lathe so THAT part is as on the money it can be. May it still be baffle clipping? Of course, and i will most certainly look into that.

Lack of accuracy can be for a myriad of reasons, but keep in mind that the only pills i´ve used through it thus far are the expanded H&N slugs. Will try the Rabbit Magnums at 16 grains too as well as some other pills i´ve got laying around. Will shove a few pills through it on the vise and correct as needed. Actually, a good clean would be as good a start as any! 
If she still spits sub par after that, then a fresh barrel is in order. Absolutely.

Yes. Have figured many replace the stock reg with a Huma one. Before i go that route though i want to see where the stock thing comes to a halt.

Trigger in turn, thank you.
Will look into that. Mere adjusting it though made for a world of difference as i got rid of tons of creep, which is a good start at least.

[Racing]

Hm. Think i´m starting to get a grasp on this unit. Cleaned the barrel out which made for wonders. Just using 16 grain Rabbit Magnums it was now rippin one ragged hole at 30m, which is about all i can ask.
However.
As my supply of 20 grain hollow points is running low (yes, using "El-cheapo" loads) i believe i´ll order a few different pills here.. 20´s being one of them.
Honestly, i have no idea of terminal performance out of them Rabbit Magnums but i guess due their name alone they weren´t designed for plinking only. As of current exits the north side of 900, which is about right as far as i´m concerned too.

However.



The thing is spitting ´em out louder than needed, and of course this is a matter of tune.. which i essentially haven´t this far but.. RKR? I see what you´re getting at.
The stock setup is.. a tad beyond me to be honest? Might be a good idea for a 12fpe piece, what do i know, but as we up output of it.. not so much.
Indeed that shroud is on the thin side but i´m at least TRYING to keep it "as is". So i threaded the barrel 1/2"-20UNF and recut an old FX diffusor to fit. Keeping the bottom piece of the BSA setup to seal the shroud off at its end at the breech block.
Still with the Jaki LDC up front.. and i guess it works. To a degree but i know from previous that it can be had to be way more quiet so.. it is what it is.

At least i´ve had the chance to sit down with her at the bench a bit aaand... well, yes. I guess. Even with that Jaki up front she´s still not an especially big girl by any measure.
What she IS though is sorts of an air hog, and especially so seeing the performance platform we´re at. Need to adress that.

Current i´m running an FX Impact hammer spring and the stock hammer, which is of a mere 27 grams, have a guide/insert added out of brass of yet another 11 grams.
38 grams in total in other words, and that coupled with a stock FX spring with very little preload hands me the above. The stock regulator seems rather insensitive to adjustment, have to say, and what´s more there´s as noted no real provision to check reg pressure on the fly.
Giving thought to that, have to say. Q is how to go about that WITHOUT breaking into the beautiful lines of the stock gun?
You guys tell me.

In turn i´ve stared at the bare mechanics of the thing for a good while, trying to figure a way out to add a tad of plenum volume - again without breaking the lines of the piece.

She DOES sport a tad of a bark, even at the rather limited level of performance we´re talking here. I bet loads of that from an overly enthusiastic amount of air per shot vs the relatively short barrel.
In short, she´s starting to ask for a decent tune and that will of course happen.. One thing at a time tho.
In all this i´ve actually come to give thought to a slightly longer barrel. Something the north side of 500 would do well me thinks. Mainly for a more harmonic gun at said power level while also leaving a bit of room to grow, if and when the need arise.
A 530-540 would settle in fine i believe.

[rkr]

If you really want to make power in .177 then you can copy my .172 build - it shoots at 60 fpe/80J level with 26 grainers so you could get close to that in .177 as well. You would want at least 30cc plenum and my guess is that you would need to remove the regulator and run it unregulated, which is actually not that bad. Here: https://airgunforums.co.uk/threads/172-bsa-bullet-shooter.44377/

As for the shroud, it's loud even at 12fpe. UK shooters and even BSA add silencers to the shroud to make it quiet. With good 28mm shroud you can make a 12 fpe gun action noise only quiet. As I said you can fit in even bigger thing for R10 so it's not hard to make it fairly quiet even at high power level.

I know there was a .25 R10 build somewhere that made well over 40 fpe but I just can't find that info. The plenum size was increased which took some innovation but I don't recall the details.

One option could be to use BSA Ultra/Scorpion SE:s first air tube part to replace your plenum: https://www.airgunspares.com/gunspares/airgun-spares/bsa-air-rifle-models/ultra-se/multi-shot/167693bsascorpionsebodyadaptor.html
It would likely need some machining but it would be a half ready thing. It would move the bottle forward but maybe you could compensate by using a bigger bottle as they sometimes need an adapter or stock modification to fit.

BTW, your gun must be rather old as it had non threaded barrel. IIRC they were used for a short period of time for late Mk1s or early MK2s.

[Racing]

Uhu.
Figured it being rather old, which i don´t mind at all.
Threading the barrel 1/2"-20 the least of my issues 

When looking into the innards of the stock shroud setup i really fail to see the reasoning behind it. Or put another way, i just don´t get it. Be that as it may it still, IMO, lacks a decent diffusor and as such i used a 25cal such for an FX which of course is "off" too so will turn a press fit insert and install to it. Seeing the 4,5mm caliber i bet a 5,5mm through hole will work just fine, especially so seeing the rather large "windows" of the FX part.

Taming the bark i know how to do. Not an issue, and as i write above i´m with you on the rather limited diameter of the stock shroud. However, when using an effective LDC a shroud very much becomes a matter of taming the pressure spikes within the complete "package" why ANY shroud sure is better than none.

No. Utmost power still isn´t the game here, by far. If you check my post on the Beeman Chief rip-off i did just recent i got decent power out of it using H&N´s 20 grain hollows, and that with downright insane accuracy seeing what that gun after all is. Tosses them 20s through "the wall" like it was going out of style at will. That is NOT the intent in this case.
My idea this time out is a harmonic and "laid back" piece that´ll hand say 45-50 and do so all night without hesitation and do so quitely without upsetting anyone really. In short a pure "ratter" of reasonable dimensions and weight (that Accufire thing ontop there sure weighs its fair share) that is pleasing to the eye too. thinking this R-10 can check all them boxes.

The stock barrel IS rather short and that said being aware that the one on this piece seems to be the longest version of the options at hand? None the less, just a scream less than 400mm still isn´t much to write home about, no matter how we regard it. Thus the idea of mine that it MIGHT be of use with a slightly longer barrel, in essense in an effort to keep reg pressure as hammer spring down really more than anything.

I´d say for a 177cal already at 45-50 a barrel on 500+ it would make for a more balanced setup? What´s more at that length, length total for the gun wouldn´t change seeing how the stock shroud is extended way beyond the stock barrel. In short, room to grow.

If i´m off, tell me so. More a feeling than anything else on my behalf.

Ditto on the plenum.
Of course the power requirement can be met as is. That´s not the issue, having played around a bit with plenum volumes for regulated guns though learning how imperative it really is i figure as such that every little bit helps. Again with the main focus being a harmonic gun that simply feels "laid back" doing what it does. Have to say though that looking into the stock regulator.. is strikes me as a bit cumbersome? But yeah. Need to have a sit with added coffee staring at the thing a bit i believe.

[rkr]

Oh, you have 15" barrel on that one, they were only used in 12fpe/16J versions. That will certainly limit the power, export and FAC guns used 18.5" barrels and Scorpion SE 1200 had 24" barrel so there are longer options out there.

Stop staring at the stock regulator, they are &^^& really. They typically produce a power curve and stop working after few years, especially on those old guns. They are poorly manufactured with poor material choices and the design is not that great either. Huma is a proven option for R10 and will save you from wasting time with something that's not going to work in the long run.

Do you really need 45 joules for ratting? UK shooters drop them by thousands at guns running under 12 fpe. That extra energy will give you some 10M extra range but that comes with much reduced shot count and more noise + harsher shot cycle. I have all my .177 airguns tuned at around 12fpe/16J power as it just seems to work so well.

[Racing]

Need n need...
I just feel more comfortable with it. Shot count is a non issue to me as i do my ratting at the shop where i keep scubas and compressors both. So..

As for barrel length. Uhu. Thing is..
I got it shooting using the 20´s too. Handing at least "minute of rat" accuracy why i took the thing ratting tonight for the first time. Outcome of that, one very dead rat. At approx 20m, so fairly short range work. Dropped like a ton of bricks on impact.
Have them 20´s running approx 910 at the moment, which brings that the 16 Rabbits are running around 960 approx.
The short barrel showing that the heavier pill is put to good use i guess.

On a regulator. I hear you, and i guess.. it isn´t working all that well in this piece. Will pick it apart and take a closer look no matter but.. uhu. Yes. Message both received and understood.
As i basically got this gun for free (a barter) i don´t mind spending a few on it.
That however brings a different note and that IS the use of a different regulator. That the Huma offering is a prime candidate we can agree on but..
If i´m to replace the bottle at the same time and have the option to do so installing a regulator of the "cheaper" variety (most of these are simply spring loaded from what i´ve understood?) that bolts directly to the bottle thereby also handing me that there added plenum volume i´ve been ranting about..

There IS another option, of course, and that is to fab me an "add on" piece piece of housing to hold say a Huma reg while at the same time placing it closer to the bottle. Of course then spacing the new bottle further forward, vs the muzzle end of it.

A replacement bottle is due. The thing on there carries a date stamp from november of 2011 and that says.. you´re outta here. As much as i adore the sleek lines of this R-10 the truth of the matter is first up that they WERE delivered with slightly larger bottles than the 177cal was and second of all.. evolution. I guess.
However.
I have no intention what so ever going overboard with this. In short a 300-350cc bottle will suffice just fine, and then some, in my opinion. CF or aluminium.. again more a matter of looks than anything else as i don´t carry this or any other PCP around exactly. Difference in hang tag isn´t overly large either right so..
At least not for a CF bottle of the capacity we´re talking here.

But the main Q to settle me thinks is the matter of WHICH regulator and WHERE to install it. I´m starting to give thought to a replacement barrel as stated, a longer one seeing the power goal i´ve got in mind. At that.. sure wouldn´t hurt with a few cc´s for the gun to "draw" from as far as regulated volume.

Btw.
Made me a can to install up front in a jiffy, a 6 chamber jobbie, and it indeed makes for a rather silent piece in operation. Sounds kind of like an elongated silent fart.. so very very quiet in operation.
However.
Same thing again.. that LDC (or any other for that matter) registers on the shroud.. that registers on a couple of plastic bungs that registers on o-rings.. before hitting the barrel.
Like friggin INVITING trouble why i´d feel a TON more at ease with a slightly longer barrel that the actual LDC bolts directly to. Due that i´m able to keep through hole diameter down, and due that the thing will be more quiet in operation still.. Win/win in my book.

[Racing]

Oh! Btw!
As it turns out you were equally correct on the bolt jumping around upon firing.
This, as i regard it, is just a matter of poor design cause a spring loaded steel ball lock should suffice all needed and then some.
What i don´t get is why the crevis on the probe wasn´t done with a ball mill?
By just careful use of a ball mill and then just as careful a cutback on the "opening" side.. that would render a setup that stays locked until further notice. From what i´ve measured it seems there´s a 6mm diameter steel ball on a 7mm drilled cutout?
As i see it the basic idea and concept is sound it´s just poorly executed.

In turn a heavier bolt handle would sure help too, massive even. As it IS a rather elegant and simple solution i need to figure this out as i want it to work both for this R-10 and the "El-cheapo" Beeman Chief rip off.
Gonna pick a numer of such ball bearing balls up already tomorrow and take it from there.

[rkr]

Oh! Btw!
As it turns out you were equally correct on the bolt jumping around upon firing.
This, as i regard it, is just a matter of poor design cause a spring loaded steel ball lock should suffice all needed and then some.
What i don´t get is why the crevis on the probe wasn´t done with a ball mill?
By just careful use of a ball mill and then just as careful a cutback on the "opening" side.. that would render a setup that stays locked until further notice. From what i´ve measured it seems there´s a 6mm diameter steel ball on a 7mm drilled cutout?
As i see it the basic idea and concept is sound it´s just poorly executed.

In turn a heavier bolt handle would sure help too, massive even. As it IS a rather elegant and simple solution i need to figure this out as i want it to work both for this R-10 and the "El-cheapo" Beeman Chief rip off.
Gonna pick a numer of such ball bearing balls up already tomorrow and take it from there.

It's not just the ball bearing that's the problem, the bolt jumps up because the banjo is just at the edge of the probe bearing and starts moving to open position when pushed back. Add some 5-10 degrees more turning angle to the bolt and it stops moving. Big bolt knob helps a bit but it doesn't solve the problem. In the long run the bearing nose edge starts galling the banjo and gets rounded in use causing the bolt to pop open even more easily. Take off some material from the banjo nose as shown, grind the breech a bit to allow a bit more turning and re-ground the indent for ball bearing.
banjo by abbababbaccc, on Flickr
Since you have removable probe nose you can just turn it to correct position or widen the hole a bit. I've been working with these BSAs for up to 100 fpe level and I have a pretty good idea of what works with them and what not.

[rkr]

Need n need...
I just feel more comfortable with it. Shot count is a non issue to me as i do my ratting at the shop where i keep scubas and compressors both. So..

As for barrel length. Uhu. Thing is..
I got it shooting using the 20´s too. Handing at least "minute of rat" accuracy why i took the thing ratting tonight for the first time. Outcome of that, one very dead rat. At approx 20m, so fairly short range work. Dropped like a ton of bricks on impact.
Have them 20´s running approx 910 at the moment, which brings that the 16 Rabbits are running around 960 approx.
The short barrel showing that the heavier pill is put to good use i guess.

On a regulator. I hear you, and i guess.. it isn´t working all that well in this piece. Will pick it apart and take a closer look no matter but.. uhu. Yes. Message both received and understood.
As i basically got this gun for free (a barter) i don´t mind spending a few on it.
That however brings a different note and that IS the use of a different regulator. That the Huma offering is a prime candidate we can agree on but..
If i´m to replace the bottle at the same time and have the option to do so installing a regulator of the "cheaper" variety (most of these are simply spring loaded from what i´ve understood?) that bolts directly to the bottle thereby also handing me that there added plenum volume i´ve been ranting about..

There IS another option, of course, and that is to fab me an "add on" piece piece of housing to hold say a Huma reg while at the same time placing it closer to the bottle. Of course then spacing the new bottle further forward, vs the muzzle end of it.

A replacement bottle is due. The thing on there carries a date stamp from november of 2011 and that says.. you´re outta here. As much as i adore the sleek lines of this R-10 the truth of the matter is first up that they WERE delivered with slightly larger bottles than the 177cal was and second of all.. evolution. I guess.
However.
I have no intention what so ever going overboard with this. In short a 300-350cc bottle will suffice just fine, and then some, in my opinion. CF or aluminium.. again more a matter of looks than anything else as i don´t carry this or any other PCP around exactly. Difference in hang tag isn´t overly large either right so..
At least not for a CF bottle of the capacity we´re talking here.

But the main Q to settle me thinks is the matter of WHICH regulator and WHERE to install it. I´m starting to give thought to a replacement barrel as stated, a longer one seeing the power goal i´ve got in mind. At that.. sure wouldn´t hurt with a few cc´s for the gun to "draw" from as far as regulated volume.

Btw.
Made me a can to install up front in a jiffy, a 6 chamber jobbie, and it indeed makes for a rather silent piece in operation. Sounds kind of like an elongated silent fart.. so very very quiet in operation.
However.
Same thing again.. that LDC (or any other for that matter) registers on the shroud.. that registers on a couple of plastic bungs that registers on o-rings.. before hitting the barrel.
Like friggin INVITING trouble why i´d feel a TON more at ease with a slightly longer barrel that the actual LDC bolts directly to. Due that i´m able to keep through hole diameter down, and due that the thing will be more quiet in operation still.. Win/win in my book.

The BSA regulator design is unnecessarily long so you can indeed use smaller regulator and get more plenum space. If you decide on paintball type of a regulator you need to figure out where to put the gauge and fill nipple, I don't think it will look good on a R10. The belleville washer stack is used on most paintball regs and also in HUMA regs so I don't see that as a problem. On best fittings site they sell bigger bottles for BSAs and also extended valves to fit them (https://www.bestfittings.co.uk/product-brands/bsa/), that means you should be able move the reg forward with bigger bottle - perhaps by using the Scorpion air tube piece I linked. Check the HUMA offering, they have lots of different options for BSAs from internal to external regs.

As for the silencer I've been using a modified A&M Marksman in my higher power small caliber PCPs and it's pretty good unit for the money. Even with stock internals it does good job for up to 100fpe level (I broke the stock internals at 150fpe).

I just remembered, here's some notes from the time I was testing HUMA's Lonestar regulator in one of me BSAs with 15" barrel: https://www.gatewaytoairguns.org/GTA/index.php/topic,168044.0.html

[Racing]

Very interesting read, thank you.

I´ll be tearing this piece down anyways so what i´ll do is have a stare at what can be had cause i still feel that added plenum volume would be a good thing here.
As for if Huma or other regulator.. same same to me to be honest.

Gun is shootable as is, that´s not the issue. I will however replace the barrel for a longer one seeing what we´ve arrived on. See no reason not to, and in doing so will use one that´ll take slugs just as well as pellets a´la some of the Kral and what not offerings.
Doesn´t have to be extreme bench rest accuracy to me, but accuracy enough that i find 100% confidence in the piece all said and done.
Funny thing is, reading up on that post of yours.. On that stock 390 barrel i get absolutely reasonable accuracy out of it using the "bumped up" 20 grain H&N´s. Not stacking them, like would it pellets, but say a total dia of maybe 10-15mm at 30 meters, which to me is acceptable seeing the use of it.
But.
To refrain best i can from keeping this an airhog i need to adress a few things. The regulator and barrel length are certainly two such. Then that "blast master" of yours too i´d say..

[Racing]

FWIW a couple of decisions has been arrived on here.

Picked the gun apart half ways and took the regulator apart to look into how it was doing.
Truth of the matter is that RKR here was on the money, again.
In short a different reg is called for and there i weighed back n forth on either the Huma unit that fits in the stock location or a "universal" bottle mounted one.
The latter handing me direly needed added plenum volume.
So.
As these are dirt cheap like..everywhere i'm going to pick one up that sports a gauge for bottle pressure ONLY.
This as the stock BSA gauge will still be in place, which will hand me a good reference for regulated pressure. Btw. As it turns out that stock BSA gauge reference quite well vs actual pressure.

The basic idea is to use one of the 350cc bottles i've got laying around for trials and if that pans out replace said bottle with a CF one up the road. Both for weight n looks.
Now.
This will, for trials, hand me more plenum volume which i will of course measure to get a fair idea of what i'm dealing with here.
If the install turns out to be what i wish for i'll go after the stock regulator block with end mills on my Bridgeport to hopefully find even more volume, reasoning as such that seeing the limited capacity every cc arrived on helps.
If i've read up correctly the stock unit hands us 13cc's so If I can double that and then some i'll be a happy camper. 30cc's would support the power level goal with ease.

For now i removed the innards of the stock reg and run the piece on direct bottle pressure which of course brought need of way less hammer spring too, for the time being.
On a 230 fill, for now, this hands me the 20s used exiting @ approx 900 which is perfectly usable for task at hand.

Next up then the barrel and as i've got a few 177 ones laying around i thought i'd cut one of them to fit and then set length to "fill" the stock shroud, in contrast to the stock setup.
Yes.
I will thus keep the stock bracketry for the shroud at the receiver end but cut away the front end sporting the 1/2"-20 UNF.
Instead work it up "as intended" meaning a diffusor that sports the thread for the LDC and an o-ring groove cut to handle sealing vs the shroud.
Thus handing me a WAY more true reference point for the LDC to work off and thereby making way closer tolerance through holes on the baffles a reality, in the end making for a more quiet gun.

In this manner i hope to keep most of the original looks of the little carbine although now sporting a 1:16 twist barrel on 500mm+ length and at that one that will work well with them 20 grain H&N hollow point slugs.

Why so hellbent on them slugs?
Well first off as it turns out they actually shoot well in the stock barrel too and I know they perform well in the to come longer barrel as well. So in contrast to RKR here i have had great success using them in the basically stock rifle already as is.
I ordered yet a couple of tins as late as today and doing so i ordered some 16s as well - wanting to check them out too seeing how well the 20s work.
Main reason for 20s to me is to buck wind really as lighter pills, this is a mere 177cal after all, doesn't have what it takes to be laser accurate even with a slight mild breeze going on even.
20s sure ain't perfect from that regard either but beats the living &^^& out of the 8.4s and what have you the little i've tried.

As target distance varies from like 10 to 75 meters in my case the 177 also brings the added benefit of being way more flat shooting than the larger calibers, especially so seeing the limited power levels we're talking here.

Again.
I want to stress that this "build" is NOT about going balls to the wall for power but more so about a tool, cause that's what it is to me, in harmony and balance.
Hopefully, due added plenum volume, at reasonable regulated pressure

[Racing]

I´ll keep pushing.
Again me just thinking out loud here RKR, in this case as far as bolt lock - or in stock form the lack thereof.

The OEM setup, to me, is more of an "auto shut" than lock really. Or, at least it works that way in practice on my gun.

Upon firing the probe sees the full grunt of the mass of the aircharge and this forces the probe rearwards. Sir Isaac Newton and all of that. He would have loved it i bet.

Now. The probe sports a sorts of banjo bolt that interacts with the breech part of the receiver in as much that it turns a tad sideways running into a groove cut for the purpose on the breech.
As we fire this "lock" tries to revert and indeed both can and will open up. The stock spring loaded ball detent or no.

Sure. There´s a number of ways to handle/enhance this i guess but as i see it the stock solution isn´t all that bad. It´s just poorly executed. Or more to the point misplaced for "higher horsepower" applications if you wish. It should simply have been positioned elsewhere on the breech.

So. That probe is linear to the force at hand while the banjo bolt is not. In fact that banjo bolt presents a torq arm and this is where i propose that a cut can be made to the breech part using a standard end mill where we cut a "track" longitudal that juuuuust about clears and opens up a minor hole to the rearward side of that stock track for the banjo bolt.
This track that we cut will hold YET another spring and in turn ball which the banjo bolt has to clear completely, a detent, to pass into its "resting spot" when in battery.
As we´re talking a torq arm this brings that the force to open said "lock" will be way higher from an instantaneous perspective than that OEM setup can ever deliver.
Fact is, need be, as the force implied is very abrupt and very sudden/short the ball in case might even be a good idea to have out of rubber.? Seeing rubbers way different friction coefficient. I know that FX markets such rubber balls in various diameters, as well as steel dittos at basically a dime a dozen.

Can you visualize what i´m getting at here? In the longitudal plane of the breech just by that OEM sideways cut track for the banjo bolt, from the rear upwards vs that OEM track for the banjo bolt we mill yet another track to keep a ball n spring that juuuuuust protrudes (and thus is kept in place with the contraption installed no matter what) into the OEM track for the banjo bolt.
This brings that the banjo bolt has to clear the entire ball in the track we cut to come to a rest with the entire bolt in its "locked" position. In turn, using a regular endmill will ensure that the end of this track is perfectly round, thus fitting a ball 100%.

This also brings that upon opening there will in essence be two "spring pressures" to cope with.
1st being the one to clear that springloaded ball WE cut for and installed, and then the stock detent on the probe (the self closing feature). Sort of a "click eti clack" kind of deal.
Steel or rubber, that will really have to be decided by how the setup works IRL as i regard it. Rubber no doubt presenting more friction upon momentary force - by the actual shot being taken - while still "smooth" enough to overcome with ease as you deliberatly open the bolt.

As we´re in this case talking "over center" travel for said banjo bolt vs the ball detent (as in the banjo bolt has to clear the detent ball entirely) it MIGHT very well be that a steel ball will suffice, which will sure make wear come to a minimum vs using a rubber ball.
To the point in such a case that grease could probably be used for a minimum of wear.

All this tex about something real simple really. Using an endmill to cut a simple track in line with the breech, perpendicular to the stock "locking track" for the banjo bolt.
Say on a 5mm diameter or whatever. Then just drop a semi stiff spring and a steel ball into that track we just cut and.. letting it rip to find out if it suffices.
On a mill or a drillpress with a coordinate table a job that´s a matter of minutes.

Thoughts?

[rkr]

You could try a banjo that has rectangular arm profile instead of being round. Note that the banjo arm locks against bearing nose only, not against breech.

[Racing]

True.

On the actual lock, be aware that what i´m proposing here is a ball detent that the banjo has to overcome to "break free". In other words at idle it won´t affect anything really.
It´ll just step in as the banjo tries to move.

[rkr]

True.

On the actual lock, be aware that what i´m proposing here is a ball detent that the banjo has to overcome to "break free". In other words at idle it won´t affect anything really.
It´ll just step in as the banjo tries to move.

Yes, I understood that. There's very limited room in there so a simple solution like rectangular arm is always good if it works.

[Racing]

Yesterday i got around to picking the barrel up to be used.
A 550 jobbie on a 1:16 about non choked setup.
Making it fit another story as it´s for anything BUT a R-10
So made a sleeve on the lathe ever so slight press fit and installed with glue. Going to cut the various cuts today time permitting.

Checking this also means swap of shroud tube. Picked one out that´s on 28mm diameter and will make that fit vs the stock rear support i believe. Up front i´ll fab me a diffusor sporting the 1/2"-20 UNF thread to make install of a LDC that´s directly fitted to the end of the barrel.
No more of that " i hope it ends up linear enough to work" BS.

[rkr]

A sleeved 550mm barrel may swing quite a lot. I had 600mm unsleeved 17mm diameter .224 barrel in my BSA and it didn't group at all until I installed a barrel band.

[Racing]

Barrel is on 14,0 and i sleeved it to the 15,5 needed for the BSA receiver.