.20 Caliber JSB 13.72 Stability -> Theory

[fwbsport]

The 98 encompasses the power and the accuracy, it is a medium to high power springer.
The D54 can put that into higher velocity.
The 80 can come close to the D54, as mine did compared to Hector's D54 .20, in velocity and accuracy.

I found this all out myself for offhand shooting. 

My conclusion after seeing these rifles work the .20 is that the .20 in the light pellets 13.73 gr will work for all models but the heavy pellets (what a few grains more?) ARE more accurate in the HW80 and equally as accurate in the HW98 .20.

Upon seeing the HW80 .20 kill a squirrel with a body hit as the HW98 .20 did the other day on the fenceline, both squirrels were immobilized in their positions and just fell over.  Never saw that happen before with any caliber except while using the Theoben .25 Eliminator.

The R7 was made in .20 and that is taking the pellet down in velocity.  I never had an R7 .20 to compare with my other .20s and Hector's D54. 

Perhaps the search for the pellet weight that works involves a range beyond just 13.73 and 15.

[Chouchin66]

Kirk, I know we are talking two different platforms but I am trying to get to a similar goal. That is using the .20 at a high FPS to get a flat and accurate trajectory over a longer distance to minimize holder over and still have a good punch down range. Any ideas from your experience what would be a good weight .20 pellet and at what speed would be a good starting point. I need all the input I can get. The only limited experience I have with .20 is with a multi pump.

Fang, thanks for the info. Don’t want to poop my pants.

Hey James , sorry to step in , but my experience is that for fast& flat( barrel willing) 11.42 FTT @ 780 - 800 in an R9/ 95 platform are divine... I'm rollin' a Vortek kit @  16 ft- lbs w/ these..
 Hit like a hammer... Sub MOA @ 50 yds, smooth cycle...YMMV...have fun !

[HectorMedina]

I'm actually in a High Speed Train (as in 220 mph) in Germany, and it has WiFi, LOL!
It's gonna take three hours to get to the other side of the country, with the stops.
Can you imagine travelling from Washington to Miami in a bit over 5 hours?
Ah, well, different strokes....

Back to airguns:

@ Scott.- Blown out pellets can STILL be exceedingly accurate. Remember that the last swage die in the life of a pellet is the barrel itself. The ONLY way to know is to capture some pellets and then measuring the "waist" where most of the deformation can be quantified. If you can't/won't that is OK, it was just an idea.

@  LastDog.- AF usually does not "chamber" their barrels, relying on the different diameters of head and skirt for the proper fit.
IMHE EunJins are not as accurate as JSB's, so if you want a long range varminter, build it around the JSB Heavy.
If you have one of the 24"L-W barrels you should be able to hit the 850-875 fps which is where most waisted pellets have the stability limit. MAYBE you can try up to 900 fps.
I had no problems reaching the "magical" 875 with an 18" barrel out of a Talon, so your Condor should do it nicely.
¿What to do with the EiunJins?  you would have to find a Career barrel for them. Maybe a SUMATRA barrel can also yield the same results. L-W barrels are NOT designed for E-J pellets. Some of them shoot exceptionally well, but they do need some chamber work. And  then you cannot use anything but E-J.
In the end, you ONLY need about 7-8 ft-lbs at impact to kill any critter up to about 35# body weight. It's a matter of precision, not energy.
Your call.

@ Kirk.- The thing about the 0.20" is that you get more penetration than with an 0.177", given the same velocity at impact. So, for slightly larger prey, they are better.
If you are not hunting, then the "Oomph" is not too relevant . . . unless you shoot at heavy spinners, or metal plates. Then the "clang" of the 0.20" is more satisfying than the "ding" of the 0.177" ;-)

@ Dave.- I am glad you are still having fun with that rifle.

@ John.- Life would be simple indeed if you only had to have 2 types of pellets. ;-)

Keep well and shoot straight!





HM

[19Sheridan57]

  All the Sheridans in my stable like the 13.73 JSB's. I only have one .20 Twanger to test different pellets with . It is the Webley VMX, [ made by Hatsan ] a few years ago. It shoots a fair bit faster than Sheridans & the heavier JSB 15.89 are the most accurate in it. If you have not tried the heavier .20's in your rifles, you may want to give them a try.

[dtdtdtdt]

"@ Dave.- I am glad you are still having fun with that rifle."  - Hector

Hector:  Yesterday, I got out the .177 and did the same routine as I did with the .20.  Not quite as good but still 1/4"minute of chipmunk at 20yds.  I'm thinking about asking you to tune it for me and to get a .22 D54 to tune too.  That way I will complete my stable of 54s and my favorite FWB300SU.

I did find a problem with the .20 this morning.  I set up on a chipmunk that was scurrying around and found that the very fine crosshairs of the Sightron scope were invisible against the tree line around my yard.  I guess I will have to find a scope in my inventory that has a visible crosshair.    I do have a brand-new Weaver T-16 16X A0 FIXED POWER (or whatever its designation really is) that has the same problem.  I bought it heavily discounted from Sharpshooters.com (now I know why!) it has a 1/8 Moa dot that shows up on a 100yd target less than 1/2 the diameter of a .22 hole!  The wires are so fine and the dot so small that I sent back to Weaver as a possible damaged scope.  NOPE!  ITS JUST MY AGE AND POOR VISION!!!!

My bench-rest friends use it and its brother the 60x !!! on their unlimited class rifles.  I guess I will have to sell it to a MUCH younger shooter.  Even my son has trouble with it.

Both the Sightron and the Weaver would be great on white background targets on bench-rest rifles but hunting - not so much!

To the point of this thread:  there are a few books that talk about air gun ballistics from a science standpoint but they are out of print.  I have electronic copies and will find them and put their titles and authors here. 

The book was written by CARDEW - The air gun from trigger to target. 

[SpiralGroove]

I'm actually in a High Speed Train (as in 220 mph) in Germany, and it has WiFi, LOL!
It's gonna take three hours to get to the other side of the country, with the stops.
Can you imagine travelling from Washington to Miami in a bit over 5 hours?

Back to airguns:
@ Kirk.- The thing about the 0.20" is that you get more penetration than with an 0.177", given the same velocity at impact. So, for slightly larger prey, they are better.
If you are not hunting, then the "Oomph" is not too relevant . . . unless you shoot at heavy spinners, or metal plates. Then the "clang" of the 0.20" is more satisfying than the "ding" of the 0.177" ;-)

HM

- If we had that good of Rail service in the States, I would much rather take it than flying.  Matter of fact, you're really flying done the rail
Is there much of a Cost advantage of High Speed Rail vs. Air tickets for consumers?

- I don't hunt anymore, but it's nice to really blast something now & then . 
Almost .22 cal. impact with almost .177 trajectory.
I mostly, just appreciate the command you retain over the pellet at 80+ yards vs. .177 caliber. 

[HectorMedina]

"@ Dave.- I am glad you are still having fun with that rifle."  - Hector
...
I did find a problem with the .20 this morning.  I set up on a chipmunk that was scurrying around and found that the very fine crosshairs of the Sightron scope were invisible against the tree line around my yard.  I guess I will have to find a scope in my inventory that has a visible crosshair.

...

Both the Sightron and the Weaver would be great on white background targets on bench-rest rifles but hunting - not so much!

To the point of this thread:  there are a few books that talk about air gun ballistics from a science standpoint but they are out of print.  I have electronic copies and will find them and put their titles and authors here. 

The book was written by CARDEW - The air gun from trigger to target.

You had me worried there! LOL! It's not the gun that is giving you problems.  Phewwww!

;-)

IMHO, the 0.20" cal pellet is the "7 mm's" of the airgun world. Yes there are bigger, heavier ones, and there are smaller, faster ones, but for all intents and purposes, it is a "good medium".
Fur or feathers, long range, or short, light loads or heavy hitters, the cal. itself is very versatile, yes there are few pellets to choose from, but those that do exist, are very good and you only need ONE good pellet anyway.
The other reason I like it a lot is that, in most spring-piston airguns, the Crow Mags and the Predators, as well as the new H&N offerings, can be driven to the required expansion impact speed. That is not so easy with the 0.22", and in the 0.177" the expansion is there but you go from 0.177" to 0.22" hole, whereas the 0.20" flies like a 0.177" and makes a 0.25" cal hole.

With PCP's and higher pressures, I am sure we will see the same ballistics out of a 0.22" than what we can get from a 0.20" at spring-piston speeds.

Pistons will also advance somewhat still. There is credible evidence that efficiency can still be improved in the last 2 mm's of travel in the forwards stroke. But that's work for the future.

Coming back to the scope: If you could find a FFP Bushnell Nitro, you would probably solve your problem. As, in these scopes, the reticle size GROWS (and so does the thickness) as the magnification grows.
The other thing you could look into (literally) is an illuminated reticle. That one will not "blend" into the background. There are a few economy scopes in which you can try the concept and then, if you find it works for you, then you can look into getting better glass.
When I get home, I'll send you a cheap scope so that you can try both concepts and decide which path to follow.

We're working with SIGHTRON on a series of reticles for different purposes on FFP scopes; and the findings, though really simple to understand and clear to see once you have come up with the idea, have not been implemented by anyone so far.

Again, more work for the future.

Thanks for the feedback, keep well and shoot straight!





HM

[HectorMedina]

- If we had that good of Rail service in the States, I would much rather take it than flying.  Matter of fact, you're really flying done the rail
Is there much of a Cost advantage of High Speed Rail vs. Air tickets for consumers?

- I don't hunt anymore, but it's nice to really blast something now & then . 
Almost .22 cal. impact with almost .177 trajectory.
I mostly, just appreciate the command you retain over the pellet at 80+ yards vs. .177 caliber.

Here Rail tickets for first class cost the same as a coach plane ticket. So, it's not that you are saving money, but you are travelling "better". More room, working faciliities, restaurant car, etc.
AND, the train takes you to the CITY CENTER straight away, no 1 hour prior arrival, no lengthy boarding process. End to end, it is shorter than flying.

Yes, "thumping" stuff is fun, LOL!

Keep well and shoot straight!





HM

[Hoosier Daddy]

Both .20's I owned liked the FTT's better than the JSB's

Same here. I do not have the numbers with me but IIRC my R10 chrono speeds were in the low to mid 700's and it prefers the H&N FTT in 11.42g over either of the JSB offerings.
 My CO2 .20 shoots everything about the same.

[Motorhead]

I'm actually in a High Speed Train (as in 220 mph) in Germany, and it has WiFi, LOL!
It's gonna take three hours to get to the other side of the country, with the stops.
Can you imagine travelling from Washington to Miami in a bit over 5 hours?
Ah, well, different strokes....

Back to airguns:

@ Scott.- Blown out pellets can STILL be exceedingly accurate. Remember that the last swage die in the life of a pellet is the barrel itself. The ONLY way to know is to capture some pellets and then measuring the "waist" where most of the deformation can be quantified. If you can't/won't that is OK, it was just an idea.

HM

Hector,
 Have no problem in doing this, just need to get the materials to make a long enough trap to stop a pellet w/o damage.  I'll work on that and report back findings with photo's.

[Nvreloader]

Scott

Here is what I am doing for a pellet trap, that leaves NO marks or deforms in the pellet,
unless you hit the sides and slide a pellet towards the back end.......

4" diameter PVC pipe, threaded cap glued to one end, fill the inside with those cheap WM shopping bags,
medium packed, shoot a couple rounds, unscrew the rear end, (removed the 1/8" steel plate, for safety,
just in case a pellet makes it to the end, I shoot in the shop and don't need a Aw S(^# problems or holes in the walls.)   

Take a 6' length of PVC pipe, and start pushing the bags out the front end,
looking for a long tit with the pellet caught in the end etc.
Remove the pellets, re stuff the bags back inside in any which way, and then keeping shooting and repeating as needed.

I am running a 14 gr @ 900-950 fps and the pellets are about halfway down the pipe. 
and keep the muzzle at least a foot from the shooting end, or you'll blow bags back out.....LOL

HTH's,

Tia,
Don

[JungleShooter]

Here is what I am doing for a pellet trap, that leaves NO marks or deforms in the pellet,
unless you hit the sides and slide a pellet towards the back end.......

4" diameter PVC pipe, threaded cap glued to one end, fill the inside with those cheap WM shopping bags,
medium packed, shoot a couple rounds, unscrew the rear end, (removed the 1/8" steel plate, for safety,
just in case a pellet makes it to the end, I shoot in the shop and don't need a Aw S(^# problems or holes in the walls.)   

Take a 6' length of PVC pipe, and start pushing the bags out the front end,
looking for a long tit with the pellet caught in the end etc.
Remove the pellets, re stuff the bags back inside in any which way, and then keeping shooting and repeating as needed.

I am running a 14 gr @ 900-950 fps and the pellets are about halfway down the pipe. 
and keep the muzzle at least a foot from the shooting end, or you'll blow bags back out.....LOL

HTH's,

Tia,
Don

Don,

thanks, I had just been wondering about how to catch a pellet without further deformation — after hitting a volunteer pigeon or other critter, whatever the hunt produced.

Your pellet catcher will help me figure out if my hollow points actually expand or not.

THANKS!

Matthias

PS:  The excellent description of your Pellet Catcher deserves a separate post, so people can find it easier.  😊

[HectorMedina]

Matthias;

My preferred method is to capture the pellets in Dacron/Pillow fill, VERY loosely packed into a cardboard tube.

Using a 4" tube makes it possible to shoot and capture pellets at short and long range. Unimportant for a single experiment, but important when you want to establish how much the sudden deceleration of the pellet upon catching will deform the pellet.

To gather the data for this post entry:

https://www.ctcustomairguns.com/hectors-airgun-blog/at-the-moment-of-firing-and-fit-of-pellet-to-the-rifling

I tested the method at 20 and 50 yards, and found that using Dacron pillow fill produced identical results, therefore if impact speeds as different as 800 fps and 580 fps produced no difference, then my conclusion was that the method was good and no further deformation due to the catching was being inflicted on the pellets.

Pellet catching is an eye opener in many guns, specially PCP's that are assumed to be "softer"shooting than spring-piston airguns.

HTH





HM

[Nvreloader]

Hector

Do you have a post on where you described your pellet catcher details etc?   

Tia,
Don

[HectorMedina]

Hector

Do you have a post on where you described your pellet catcher details etc?   

Tia,
Don

Don;

I have described the process several times in different fora, even the British STB one because there was strong contention that ANY form of catching pellets deformed them.
It's so easy, it does not really merit a blog entry:

1.- Get a 4" cardboard tube:

You can also scrounge it from the tubes that metal and plastic suppliers use to ship materials.  I usually receive several when I buy long tubes, rods, or DOM tubing.

2.- Buy some Pillow Dacron Filling:
https://www.michaels.com/the-original-poly-fil-premium-fiber-fill-bag-12oz/10509850.html

Get a long strip of the Dacron material from the "pillow", usually it comes in a sort of "roll", so you cut a long strip about 8" wide and as long as the cardboard tube you have. IMHE 24" is more than enough to catch pellets at up to 24 ft-lbs.
Use a long wooden dowel to "push" the Dacron into the tube (dowel goes to the FRONT of the Dacron, and therefore it is pulling, though you are pushing).

The Dacron should "fluff up" to fill the tube without any pressure in any sense.

Now, test with a pellet shooting at an open end of the tube from 20 yards (you should be able to hit specific spots, if not, then tape some paper over the end you will be shooting and draw 6 or 8 aiming dots).
If the Dacron catches the pellet correctly, then you can shoot the other spots.

It is OFTEN the case, that you can only shoot ONE pellet and then need to fish for it.

Get the whole roll out and you will see the pellet encased in a ball of Dacron (how that happens is very interesting in itself, but it is a different story). Unravel it and you have captured your pellet.

Re-install the Dacron and repeat.

As you get better, you can use smaller and smaller tubes and then have a bunch of "catcher tubes" that you can label as to the test you are performing, shoot them all and then recover them all. Much more time efficient.

To test if you are packing the Dacron loosely enough, shoot exactly the same setup at 20 yards and at 50 yards, if the pellets show substantially the same deformations, then you are doing it correctly.

As you can see, it is a VERY simple process, just tedious if you need to test a bunch of pellets in different rifles/powerplants.

If you find any difficulty, drop me a line, or post somewhere; telling me where, LOL!

Keep well and shoot straight!





HM

[JungleShooter]

Héctor,

muchas gracias! 😊
Great description. I'll try this soon for some post-pigeon hollow points....! 😄
Matthias

[Nvreloader]

Hector
Thank you for that info,
I give it a try along with my plastic bag pellet catcher, and compare the differences.

Thanks,
Don

[JungleShooter]

I give it a try along with my plastic bag pellet catcher, and compare the differences.

Don,
would you please report on your findings?!

I'm interested in the results, too! 😊
THANKS!
 
Matthias

[Nvreloader]

Matthias

Will do, as soon as I find the proper materials etc.

Thanks,
Don

[Gear_Junkie]

I'm actually in a High Speed Train (as in 220 mph) in Germany, and it has WiFi, LOL!
It's gonna take three hours to get to the other side of the country, with the stops.
Can you imagine travelling from Washington to Miami in a bit over 5 hours?
Ah, well, different strokes....

Back to airguns:

@ Scott.- Blown out pellets can STILL be exceedingly accurate. Remember that the last swage die in the life of a pellet is the barrel itself. The ONLY way to know is to capture some pellets and then measuring the "waist" where most of the deformation can be quantified. If you can't/won't that is OK, it was just an idea.

HM

Hector,
 Have no problem in doing this, just need to get the materials to make a long enough trap to stop a pellet w/o damage.  I'll work on that and report back findings with photo's.

Scott, I've shot into multiple gallon Ziploc bags (longways) filled with water.  IIRC it only took 2 bags to stop pellets up to 12fpe.  I've done this on several occasions to examine pellets after being shot.  This is how I found out how badly my HW57 was deforming pellets.  You can get about 10 shots off before the bags leak out enough to be useless. 

I've also shot into a spa.  The pellet stopped long before the bottom.  Which is too bad because I wanted to get rid of it at the time and was looking for an excuse   Thankfully, the pump eventually died and my spa maintenance days ended