.22 LW barrel vs .22 Discovery barrel for .22 jsb beast 33.96gr

[gabi.nechita]

 Hi.
I need a new barrel for a new project, and I intend to use .22 jsb beast or bbt bullets.
It is really true what I heard about 15.5 inch twist for Discovery  .22 barrel ?
Seems to be a good candidate after a hand lapping for shooting heavy projectile.
What do you think guys ? 

[Prouzy]

Funny you posted this, I just got in my .22 JSB Beast last night for a project using QB78 HPA converted.  I realize that they are different and not the barrels you have listed, but there are some similarities.  With a 2000psi fill, I was getting 679, 682, 680, 679, 678, 672, 669 fps for 7 shots.  They volume is also similar to the Discovery.  What is of great interest is the accuracy coming out of this set-up/barrel.  These are all 5 shot groups, shooting off a tripod while sitting on a stool, so not the most supported position.  It was just below 0 degrees C.

25yd


40yd


40yd


So I would shoot whatever set up you have, assuming stock barrel, as it may just be adequate for these. 

[gabi.nechita]

Very nice shooting.
Do you have any idea about yours barrel twist rate?

[Prouzy]

Sorry for the delay,  I've been  searching. I even contacted a distributor that specializes and they say they don't know. All I've come across is, "it's fast," whatever that may mean.

[rsterne]

LW barrels are typically 17.7" twist.... I have "heard" that Crosman are 16", but have no idea if that is correct or not.... I recently checked a Crosman barrel I have here, and one of my 0.219" BBTs fell right through it.... so I can tell you they MAY be quite large in ID.... or not....

Bob

[gabi.nechita]

I have another option for heavier pellet or bullet.
It is 22 Hornet barrel from LW site. 15.4 inch twist, .217 land and .222 groove or .22 lr barrel.

[rsterne]

I don't think you need to worry about the twist rate being too slow for even a long pellet like the 34 gr. Beast.... Diabolo pellets (those with a waist and skirt) are drag stabilized, and Tom is using extremely slow twists in his EVOL Carbines.... 19" in .22 cal, 32" in .25 cal and 42" in .30 cal.... My guess is that if he could get one, he would go even slower on the .22 cal, something down about 26" would be in keeping with his other choices.... He has found that the slower twist rates eliminate the spiralling at long ranges common to fast twist barrels with waisted pellets....

Bullets are a completely different situation.... My 30 gr. BBT was designed for a 16" twist, although would likely work OK in an LW at 17.7".... It is available in 0.217/0.219" or 0.220/0.222" diameters.... I have some of the 34 gr. Beasts here, and they measure 0.217" at the head and 0.224" at the skirt....

Bob

[gabi.nechita]

Very interesting, Bob.
I must digest your information. For your bullet  and heavier I understand that it is better with .22 hornet barrel.

[Hobbyman2007]

Very interesting, Bob.
I must digest your information. For your bullet  and heavier I understand that it is better with .22 hornet barrel.

The 22lr barrel is too big for pellets or the 30 grain BBt. Either the crosman or LW barrel is your best bet . Keep the cost low , your gonna go through piles of lead to find out what speed your barrel likes best anyway .

[WHITEFANG]

LW twist is why on rebarrels I go 16.5" to 17" on the barrel length. Close to the  sweet spot. JMO

Thought TJ made a .22 barrel.

[rsterne]

Yep, TJ's make a .22 cal barrel that is 0.213" land and 0.217" groove with a 16" twist.... I just put one on my Regulated Disco Double.... Planned fodder is the 34 gr. JSB and my 27 & 30 gr BBTs.... http://www.gatewaytoairguns.org/GTA/index.php?topic=117625.0

Bob

[gabi.nechita]

But for this ''pellet'' it is still good LW airgun barrel ?  https://drummencustomguns.com/en/pellets/793-dab-airgun-ammunition-223-415-rn-1000.html
This is what I want to shoot in first place and JSB Beast will be in second place.
Because Bob tell me that Beast are .217 head and .224 skirt I was thinking that I could use this pellet in 22Hornet barrel. Will be something like ,,nose riding'' if I say correct.
I have all the time to made up my mind until May when I will find some money for this project.
Thank you very much for your advice.

[rsterne]

I have those bullets, they are made by RWS, and are a slightly larger diameter copy of their 22LR bullet, and weigh 41.3 gr.... I use a .22 cal centerfire TJ's liner that is 0.219" land and 0.224" groove, and those bullets measure 0.224", and won't work in anything smaller.... My barrel has a 14" twist, I understand they will work in a 15", but success in 16" has been spotty to poor.... If you ask the right question, you can get better answers....  .... LW make a 26.3" long barrel that is 1.26" OD with exactly the specs. above, and that would be my choice.... You can also purchase it in 28.0" long for a few more dollars....

I have never tried shooting pellets in a "bore riding" mode, but Tom Costin tried .30 cal pellets in his .308 Slayer (with the power dialed back) and said they shot incredibly well.... He pushed one through and said there were basically just faint scratches on the head (bore riding) but the skirt fully engaged the rifling and sealed perfectly.... I see no reason that the 34 gr. Beast should not do the same, and I will push one through (later today, if I get time) and photograph it so that you can see.... That won't guarantee it will shoot well, of course, but it will be an interesting piece of information for all of us....

The BBTs I designed for .224 cal. are heavier, starting at 37 gr., and intended for faster twists.... and the 30 gr. .217" and .220" bullets would be too small for that barrel....

Bob

[gabi.nechita]

Thank you very much for illuminating me. 

[rsterne]

Here are photos of three "pellets" chambered in my .224 cal TJ's liner....



On the left is the 41.3 gr. RWS from Drummen in Holland.... next is a 34 gr. JSB Beast.... and on the right is a 30.5 gr. bullet from North American Arms.... The chamber in my rifle is too tight, I need to do some work on it, the bullets were actually impossible to push completely into the rifling by hand (the pellet was easy).... You can see that the base on the RWS is actually expanded from the plastic tipped rod I used, and touching the rifling.... Both bullets have the typical hollow base (a shallow hemisphere) used in .22 rimfire bullets.... You can see that the rifling is quite deep in this barrel, and both bullets are deeply engraved.... The NAA bullet didn't touch the grooves, but there were a few small marks between the rifling on the RWS.... The nose of the bullets is flattened from pushing them out backwards, they required a lot of force to do so.... I wonder how much velocity I am losing from the tight fit in the bore and not enough taper in the leade?....

The JSB pellet had some very slight marks on the head, but not all the way around.... It may not be quite large enough to stay straight in the bore.... of it might work just fine.... only shooting it would tell you.... The skirt collapsed slightly, like all pellets do when chambered, but had good rifling marks, and would expand to perfectly fit the bore on firing.... one of the advantages of a hollow skirt....

I really do need to do some work on the chamber on that barrel....  .... and the bore needs polishing as well.... 

Bob

[gabi.nechita]

Your bullet is .224 or it is a little bigger?
My dream about Beast nose riding is almost ruined. Maybe I must to concentrate around a bullet shooter .

[rsterne]

The 41.3 gr. RWS measures 0.2243 - 0.2248".... The 30.6 gr. NAA measures 0.2241 - 0.2245".... Only shooting the 34 gr. pellet will tell you how accurate it will be.... You will probably use the bullets at longer range anyway.... Here is a link to the NAA bullet....

https://northamericanarms.com/shop/parts/cbb3/



They are actually very nicely swaged bullets, and very inexpensive.... close to a .22 Short/Long bullet (which are typically 29 gr.)....

Bob

[gabi.nechita]

I was thinking about
 http://noebulletmolds.com/NV/index.php?cPath=24_117  and
 http://noebulletmolds.com/NV/index.php?cPath=24_114
Maybe it is better to cast myself instead buying bullet.

[rsterne]

I have used bullets cast from a Lyman 225107, which is what the NOE 37 gr. mould is patterned after, since the Lyman is discontinued.... They cast at about 39.3 gr. in pure lead, and need sizing to fit my barrel, they are WAYYYYYYYY too tight as cast (about 0.226"), I can't even load them.... They are probably one of the best cast bullet choices for a .224 barrel, once sized to fit.... I have not tried the 45 gr. NOE, but I think it is a bit heavy for my .224 Hayabusa, and I'm not crazy about the huge Meplat (flat nose).... I also have a .225 Ranch Dog mould by Lee that was made by mistake.... There was a Group Buy for a .255 cal. 50 gr. RD, and Lee filled the order at 0.225" and had to remake all the moulds.... Some of the early "wrong" moulds were shipped (the rest returned to Lee), and I have one.... It casts at 40.7 gr. in pure lead, but as yet I have never shot any.... 

Bob

[K.O.]

Hi.
I need a new barrel for a new project, and I intend to use .22 jsb beast or bbt bullets.
It is really true what I heard about 15.5 inch twist for Discovery  .22 barrel ?
Seems to be a good candidate after a hand lapping for shooting heavy projectile.
What do you think guys ?

A very light hand lapping in the case of the Disco barrel... look at how shallow the rifling is compared to the L.W. ... I do a quick fire lap with toothpaste or auto rubbing compound or JB bore paste... loaded qtip in front of a tight fitting hard pellet(crosman) I used the cleaning rod method to check twist and get right at 1:16

You do not tell what fpe, semi floated, or full, barrel length etc...

I just sent out the .22 BBT from my MK1322 Build (830 fps @ 22 pumps with 14.3 CPHP /disco barrel chopped @22") I used the .217/.219 and will try the .220/.222  today... and maybe have time to hollow point a few and send them downrange...

My Fowler mic( B-day present in Nov) will be back home tomorrow so I will hold off measuring... even though I charted my digital verniers against my buds Mitutoyo mic I would have to put "about" in my size because .250 may be .2497-2503   and 2505 may be 2503-2507...    that is about my best estimate of what I think I can repeatedly measure...and that my be optimistic and me fooling myself...

 Honestly even with the Fowler, Brown & Sharp or Mitutoyo /etc. mics  I am not sure .250 is not .2498-.2502... just not sure of my feel and repeat ability when measuring something soft like lead... Never have put a ton of thought into just what degree of confidence I should have... the fowler is only accurate to .00016...



the Main problems that the disco barrels face is that they have very shallow rifling not a bad thing for drag stabilized pellets but I bet once you get to about 30 fpe with a BBT 30g it will start stripping thru the rifling... casting with a bit harder alloy may gain you a few fpe...

The other prob with the disco barrel is it is a 7/16 barrel (.4375") and you have about a .219"  diameter bore that leaves only  .2185 /2 =.109" of soft metal for your wall thickness...Can you say floppy and likely to have harmonic probs as the fpe goes up... I do plan on sleeving a disco .22 barrel to .5"  for my .25 Mrod test mule eventually just to see how much fpe it can stay accurate with...  why do it? well  because of the disco barrels main advantage... it is only about 20$  so yep the disco barrel under a certain fpe has its uses...

I started typing this yesterday and since have sent some BBT 29.2 out at 40-50 yards... It may be my alloy/ temp but both the .220/222 and the 217/219 are dropping small... and it is the .220 that is really dropping small but is working at what ever fpe/fps the MK1377 is sending them at... I am guessing I went past the .242 ci dump valves optimun pellet weight and lost fpe so lets say 2.5 or so... call it 19+ fpe...little lee beam scale variation is mostly 29.1g to 29.4g... so lets call it 550 fps.

the alloy well that is a bit complicated in the middle of pouring the 40g .250 I decided to see if tuning it all the way up and fluxing would get me back to softer lead... it glows at 950* kept it there for about 3-4 min and even made a couple .250s  at 900* as I let it cool back down to 825*-850*,  dial about 7.3 on the little lee pot... Lyman Ladle poured  started at about

2.8% tin from 60/40 bar
25% plumbers lead (ring)
70% mixed recovered pellets (about  66% crosman)
1/4 of 1% antimony  (from the crosman pells)

Had to use pellets for luck seeing as this is my first time casting for an air rifle( was a mold/core maker at an aluminum foundry for a bit tho ).

I am hoping that I am getting a lot of shrink with this alloy/temp... if so hoping a cooler/different alloy will let me cast closer to .220/.222  for some of my other barrels with the same  mold... Know a bit about aluminum alloys need to learn lead...

so the big one dropped at about .2175-.218 nose and .2195-220 drive band...

and is literally about a Loonie for c.t.c. accuracy at 40 yards( in honor of Bob? ) ) at about 550 fps... and the top 2 shots  are 20 pumps so I dropped to 18 and pow the dang square Bob is a goner 3 touching...

 the nose on the smaller .219/.217 lets it come out of the barrel with to much yaw...could see they did not come out of the barrel strait and  pic bellow shows why... they are shot into blankets a 5 pumps( gotta love variable power)... have pushed  both .22 sizes and the .25 thru my various .22 pellet, 22lr and .25 pellet barrels... with educational results wanna know why the .250 needs sized down... it lets you know about where you need to be size wise...(drive band finning in the .25 GM and XL 725 barrels)... the larger .22 BBT if I can get it to drop just a touch larger or even a bunch (.0007- .002) will help in some ... the Beretta Hakim and Shultz and Larson look like they will/may work as is while the Marlin Barrels (typicly loose bore tight groove) need some size....

The L.W. look like it could stand sizing even the .217 BBT down...

so yep long winded .22 BBT did alright its first time out at 40-50 yards... out of a disco barrel trundling aaaloooong at a stately  550 or so fps..