How light is too light for pellets for a 20fpe .22 springer?

[slag]

Would a 12 grain .22 pellet be too light for use in a ~20fpe rifle, something like a Diana 54 or a Weihrauch HW90?

[Wayne52]

I've heard that Diablo style pellets will start to spiral when they're being shot too fast, I'm presently shooting the JSB Monsters redesigned in .177 at 40 yards for an excellent group doing in the low to mid 900fps range but from what I've heard that's pushing it.

[A.K.A. Tommy Boy]

Hi Chris.       I have a 22cal Benjamin Trail NPXL that I hunt with.  It shoots the following list of pellets out to 40 yards, with good accuracy.  These are my primary hunting pellets with this particular rifle.   If I shoot 12 grain and lighter pellets in this gun, they tend to not group well.       
Best Wishes - Tom




#1   15.89 gr. Predator Polly Mags  ( Best )

#2   14.5 gr.  Gamo Red Fire  ( Better + )

#3   14.3 gr. Crosman Piranha. ( Better )

#4   16.36 gr H&N Terminator  ( Good + )

#5   14.3 gr Crosman Destroyers  ( Good )

[subscriber]

At 20 ft.lb, it would seem that any lead .22 pellet would not shoot "too fast".  11 grain .22 Hobby are probably the lightest lead pellets available.  These carry 20 ft.lb at 905 FPS.

Spiraling is more likely if you are shooting well over 950 FPS; or your barrel has an unusually fast twist rate. 

That is not to say that wadcutters are a good choice for long range.    Common 14 or 15 round nose pellets would be traveling near 800 FPS at 20 ft.lb.  They are probably the better choice.

Ultimately, you need to try a few different pellets to which your airgun prefers.  It might be a "lighter" or "heavier" one...

[ranchibi]

Chris, I have D48 .22 and the best lighter pellet it prefers is the JSB RS 13.43gr. I tried the Predator GTO 11.75gr but they did not group as well for me...could just be me!

[rsterne]

Only the pellet can tell you if you are shooting it too fast to be accurate.... However, Springers can have a harsh shot cycle if the pellets are too light, because the piston may hit the end of the compression chamber instead of bouncing off the air cushion just before the pellet moves away from the breech like it is supposed to.... Usually if you check the velocity of a variety of pellet weights, and calculate the FPE, you will find a sweet spot where the FPE peaks, with lighter and heavier pellets not delivering as much energy.... I try and use the most accurate pellet, but if I have a choice I pick one in that sweet spot....

Bob

[slag]

Background info...

I purchased a RWS-Diana 350 rifle in .177 a number of years back with the intent to hunt. California then enacted its lead-free hunting laws state-wide. I've been looking for heavy lead-free pellets off and on ever since.

The heaviest pellets I've found to date are Skenco Golden Type 3 Long Range 8.5 grain pellets. The 350 initially propelled these things to 1073fps. The rifle's power level has since gone up about by about 1 fpe since I last measured velocity with this pellet. This rifle needs something heavier.

I've encountered references to 9.5 grain Promethius Dynamic TM-1 / Dynamic Terminator 1 pellets, but I haven't been able to find any. Even if I did find some, the 350 would still shoot them too fast.

I have a recently-acquired RWS-Diana 36 in .177 I could use instead. It is presently tuned to about 12fpe. I'm concerned that the low sectional density of the lead-free pellets available to me will very quickly bleed off the little energy the pellet starts with, so I'm reviewing what's available in .22. My calculations indicate I'd need to use 11.75 grain Predator GTO pellets, or something heaver, to get a worthwhile improvement in sectional density over light 6.48 grain .177 Barracuda Green pellets. A 20fpe rifle should get the velocity up there without going too fast.


To summarize, the options being considered are:
RWS-Diana 36 .177 12fpe, shooting H&N Barracuda Green 6.48 grain or something heavier
A .22 20fpe rifle, shooting Predator GTO 11.75 grain or something heavier

Any input is appreciated, and thanks for everything provided so far.

[subscriber]

Well, Chris; this may not help, but I have a RWS 350 in both .177 and .22.  They seem like totally different animals:

The .177 sounds harsh, as if all that air is battling to pass through the "tiny barrel".  While the .22 has a shot cycle as sweet as my HW50 in .177.

It could be that the lower pellet velocity of the .22 is a large part of the lower sound; while the barrel volume and muzzle pressure may make up the rest.  Even the spring twang of the .22 seems much less than the .177, although I don't know if that is just luck of the draw.

Anyway; I wonder if you can find a .22 barrel for your 350 and try that.  Otherwise, you should try .177 pellets over 10 grains in weight...  May have to cast them yourself from bismuth or tin.

[LAalex]

Chris, I have D48 .22 and the best lighter pellet it prefers is the JSB RS 13.43gr. I tried the Predator GTO 11.75gr but they did not group as well for me...could just be me!

Same for me these are most accurate in my 48 and are lethal on squirrel. Don't think I would go any lighter

[gendoc]

Chris, I have D48 .22 and the best lighter pellet it prefers is the JSB RS 13.43gr. I tried the Predator GTO 11.75gr but they did not group as well for me...could just be me!

Same for me these are most accurate in my 48 and are lethal on squirrel. Don't think I would go any lighter

i did witness a person shooting his 48 with a new to him tin of rws hobbies
11.9gr.
he shot it about 4 times and the spring broke....
its entire life, the 48 shot 15 and 18gr jsb pellets with authority.
so what Bob said earlier about.....

"the piston may hit the end of the compression chamber instead of bouncing off the air cushion just before the pellet moves away from the breech like it is supposed to"

is true and i seen it happen.

[Horatio]

Pretty sure the lead ammo restrictions are specific to firearms, not air guns.

[mpbby]

Pretty sure the lead ammo restrictions are specific to firearms, not air guns.

This would be the salvation!

Otherwise, you could detune the 350.  Maybe cut some coils from the spring?

[screwwork]

Pretty sure the lead ammo restrictions are specific to firearms, not air guns.

Chris,
California is lead free for firearms only.. Air Guns don't fall under lead free ammo.

https://www.wildlife.ca.gov/Hunting/Nonlead-Ammunition#25046244-when-does-the-nonlead-ammunition-regulation-take-effect-
Are pellet rifles included in the nonlead ammunition ban?
Since pellet rifles are not firearms, the use of lead projectiles in pellet rifles is not prohibited

[slag]

I've learned some valuable things . Thanks to everybody who responded. I truly appreciate all the information provided. And special thanks to screwwork for going the extra mile to provide a link to information directly addressing my legal misconception.

[subscriber]

Does that mean you will be shooting 10.5 grain lead .177 pellets, at 20 ft.lb, then? 

[Bryan Heimann]

I think at 12 grains your gun should be fine.  I think 11.9 grain hobbies would be the bare minimum, but I doubt the accuracy woukd justify their usage over other ammo.  I think you'd be fine with the 12.65 barracuda green as well, and they might be accurate in your gun.