Can pellets be too heavy for a springer?

[HectorMedina]

So if there's bounce back, that attempts to create a vacuum and slow down heavier pellets, wouldn't a gun with a shorter barrel, like the RWS compact models, be beneficial to those who like to shoot heavier pellets?
I've always had a theory like this in pb's, that a light bullet needs a longer barrel than a heavy bullet for complete powder burn due to the difference in acceleration and time spent in the barrel.

I believe this line of thinking could lead to more barrel chopping in springers.
I had often thought of taking a chainsaw to my AirHawk to slenderize, lighten, and shorten the stock. Now I'm sure a hacksaw should've been a part of the master plan also.

Interesting point of view!
Of course you know what the real answer is: Get a compact and do some research.

There have been worthwhile experiments cutting the barrel progressively and analyzing the performance, but not in rifles with decent sized compression chambers.
And comparing two different guns always leaves the researcher with the idea that perhaps the guns were not identical to start with, something that happens a LOT in breakbarrel, long transfer port rifles.

The PB's analogy is not as good as it sounds because modern coated powders have an inversely related burn rate. If the bullet is too heavy, peak pressure will be achieved earlier into the bullet's travel through the barrel, which means that most of the acceleration will be gained in the first ¼, but light bullets will keep the pressure rising up to about ½ the barrel length. In the end, the AREA UNDER THE CURVE Pressure vs. barrel travel will be almost identical. Blast and Flash will be different, of course, as anyone that has fired a short barreled magnum knows.

So, get a hacksaw or get a compact and let us know.

 

Keep well and shoot straight!





Héctor

[39M]

39

Thanks-great picture
but YIKES tore the skirt off-blew the head down the barrel-left the skirt?

Apparently, that picture came from this article,
https://www.pyramydair.com/article/How_to_load_pellets_in_airguns_Part_1_spring_piston_guns_November_2010/80
explaining how to load a pellet. I never dreamed that there would be a whole article written on how to load a pellet. But there it is.

[39M]

So if there's bounce back, that attempts to create a vacuum and slow down heavier pellets, wouldn't a gun with a shorter barrel, like the RWS compact models, be beneficial to those who like to shoot heavier pellets?
I've always had a theory like this in pb's, that a light bullet needs a longer barrel than a heavy bullet for complete powder burn due to the difference in acceleration and time spent in the barrel.

I believe this line of thinking could lead to more barrel chopping in springers.
I had often thought of taking a chainsaw to my AirHawk to slenderize, lighten, and shorten the stock. Now I'm sure a hacksaw should've been a part of the master plan also.

Interesting point of view!
Of course you know what the real answer is: Get a compact and do some research.

There have been worthwhile experiments cutting the barrel progressively and analyzing the performance, but not in rifles with decent sized compression chambers.
And comparing two different guns always leaves the researcher with the idea that perhaps the guns were not identical to start with, something that happens a LOT in breakbarrel, long transfer port rifles.

The PB's analogy is not as good as it sounds because modern coated powders have an inversely related burn rate. If the bullet is too heavy, peak pressure will be achieved earlier into the bullet's travel through the barrel, which means that most of the acceleration will be gained in the first ¼, but light bullets will keep the pressure rising up to about ½ the barrel length. In the end, the AREA UNDER THE CURVE Pressure vs. barrel travel will be almost identical. Blast and Flash will be different, of course, as anyone that has fired a short barreled magnum knows.

So, get a hacksaw or get a compact and let us know.

 

Keep well and shoot straight!





Héctor

I'm really not into proving theory. But having ideas about how things work helps me with my choices.
Mainly I just like to shoot.

[DOKF]

So if there's bounce back, that attempts to create a vacuum and slow down heavier pellets, wouldn't a gun with a shorter barrel, like the RWS compact models, be beneficial to those who like to shoot heavier pellets?
I've always had a theory like this in pb's, that a light bullet needs a longer barrel than a heavy bullet for complete powder burn due to the difference in acceleration and time spent in the barrel.

I believe this line of thinking could lead to more barrel chopping in springers.
I had often thought of taking a chainsaw to my AirHawk to slenderize, lighten, and shorten the stock. Now I'm sure a hacksaw should've been a part of the master plan also.

Interesting point of view!
Of course you know what the real answer is: Get a compact and do some research.

There have been worthwhile experiments cutting the barrel progressively and analyzing the performance, but not in rifles with decent sized compression chambers.
And comparing two different guns always leaves the researcher with the idea that perhaps the guns were not identical to start with, something that happens a LOT in breakbarrel, long transfer port rifles.

The PB's analogy is not as good as it sounds because modern coated powders have an inversely related burn rate. If the bullet is too heavy, peak pressure will be achieved earlier into the bullet's travel through the barrel, which means that most of the acceleration will be gained in the first ¼, but light bullets will keep the pressure rising up to about ½ the barrel length. In the end, the AREA UNDER THE CURVE Pressure vs. barrel travel will be almost identical. Blast and Flash will be different, of course, as anyone that has fired a short barreled magnum knows.

So, get a hacksaw or get a compact and let us know.

 

Keep well and shoot straight!


Héctor

Another perspective is to look at the pressure chamber.  I noticed when I tuned my 350 and 460 that they had very different length springs, but apparently similar swept volumes (I could be wrong there).  So if they have similar volumes, producing similar muzzle energies, then the shorter spring could have compressed the volume faster.  Tuning the rate of compression (spring expansion) to the pellet chamber compression and pellet travel would be of interest.

Of course many shooters do just that in de-tuning their springers to get a more manageable shooter (less recoil and bump at a lower relative power).




.

[Buldawg76]

Yep all in that never ending quest for the perfect spring gun its amazing what changes do to help or hurt the guns character and shootability or improve it to near perfection.

I know I am never satisfied and always think it can be better and have always been that way with my hot rod cars and bikes as well. Just don't know how to leave well enough alone I guess.

Mike 

[phoebeisis]

39M
Right-never would have figured there was THAT much to loading a pellet
But it was a very good article
Frankly-not wanting to pick a fight
BUT-why would anyone choose a break barrel over an under lever
granted ease of loading and perhaps 4-8 ounces in weight-well those are important-my 460 sure as heck isn't light

DOKF-such a cute little pup-spaniel of some sort?

Buldawg76-  know  what you mean-In 1998 I sent a head from my SR500(28 hp 1980 yamaha  500 cc street single) TO FRANCE- Krautergershiem France-sure sounded germanic,but france-paid $1000 to have the intake port raised 55 degree turn instead of 71 degree turn(carb. to chamber angle) and a second plug pumbed in-
allowed it to make MAYBE 40 hp when combined with $1200 more hot rod stuff-
and it was STILL the slowest 500cc motorcycle in the WORLD-my late wife was very tolerant!
I know I probably can't beat the OEM engineers-(now I'm a mpg nut) but I still try

[capnru]

My head is spinning from the amount of info here. It now brings me to question the purchase of a dual caliber air rifle. Is it wise to subject a spring to such wide variations in pellet weight?

[Lskywalker]

so I'm trying to load pics but my camera's smallest pic size is 2mb....hmm.

i think my seater is probably too long, and it's beginning to explain why i've lost some accuracy....just goes to show 'it's you not the gun'...

Capnru, there is definitely the ocean's worth of info here...

[Back_Roads]

My head is spinning from the amount of info here. It now brings me to question the purchase of a dual caliber air rifle. Is it wise to subject a spring to such wide variations in pellet weight?

 With my Beeman dual caliber rifle i use the 10.5 gr. crosmans to slow it down , and it shoots them very accurately. With the .22 barrel I use the CHP 14.4 gr. with good accuracy and still plenty of power.

[capnru]

Good to know Back Roads. I'm guessing then that a four grain difference will be tolerable in the long haul. STILL too much to know here, I feel like I'll never know enough.
I just want to have fun, not hurt my head.

[DOKF]

DOKF-such a cute little pup-spaniel of some sort?

American Cocker Spaniel.  Very loyal, very friendly, loves to chase tennis balls and squirrels.

[DOKF]

My head is spinning from the amount of info here. It now brings me to question the purchase of a dual caliber air rifle. Is it wise to subject a spring to such wide variations in pellet weight?

Springers are all designed for an optimum muzzle energy, which dictates a range in pellet weights.  There is usually a broader range of pellet weights than pellet designs that work well in any given air gun.

I try to select pellets on the heavier side of optimum to retain higher down field momentum in hunting applications.

[Bulsaye]

well, they can be, kind of. The thing is, its a little more complicated than most folks realize. What I'm saying here is based on both my experience and Jim Maccari's. The real answer depends on the wire your spring is made from. In the case of the R-9/HW95, wire diameter has been .122". The rule of thumb for .177 cal was not to go above 9.5 gr if steadily using them, because springs of .126" wire and above handle heavier pellets better. For .22 springers, the pellet weight was 16.5 gr or less for .122' wire or thinner. Again, wire .126" or thicker can reliably handle the heavier lead. OK, what happens if I exceed these recommendations? Well, nothing initially. Constant use of heavy pellets with light springs eventually shortens spring life. Most often, this translates into spring fracture. There are times when a gun will still shoot with a busted spring and the owner will not know it, except for a possible slight loss in power. Other times the spring shatters into several pieces and all of a sudden you can't get the gun to cock fully.

 In the end, you have to consider the mainspring as a consumable item. They will not last forever; especially if you are a heavy user. If you're trying to stretch the life of your R-9 spring, then keep pellet weight between 7.9 and 9.5 grains for .177. In .22, stay between 11 and 16.5 gr. .20 cal? Keep them between 11 and 14.3 gr.
  Bigger guns like the R-1/HW80; Beeman Kodiak/Patriot, Webley Tomahawk (UK) have much heavier springs and can handle heavier lead easily.
I once published a list of guns with their wire diameters on another forum, but can't find that info anymore, although it has to be out there somewhere.

[DOKF]

It all seems pretty simple at first; point and shoot.

But the more you delve into it, the more complicated it can get.  Springs, seals, lubes, pellet weight, pellet design ... 

Optimize what you can, then point and shoot.

[Bryan Heimann]

My head is spinning from the amount of info here. It now brings me to question the purchase of a dual caliber air rifle. Is it wise to subject a spring to such wide variations in pellet weight?

It will be fine.  Most models have the same spring specifications in different cals.  Stick with ammo in the ballpark of 8 grains in .177, plus or minus a grain, and 14 grains in .22, plus or minus two grains.  Your gun will be fine.
I feel like we have you worried for nothing.  Just pick the most accurate off the shelf pellet in your gun and you should have zero issues.  Is the extra tin or two you get out of a spring worth it, if you miss things you woukd have hit with another more accurate pellet?  Not to me.  A spring swap is a fifteen minute ordeal.

[nced]

When I first got into airguns, one of the first things I read was over on CharlieDaTuna's website about using pellets no larger than about 8 grains because it can damage your spring.

Is this true?
I've just ordered a HW95 from AoA, with a box of 10.65 grain Baracuda Match H&N pellets. Maybe I should have stayed below 8 grains?

What do you think?

Kinda late to this party but I have some first hand info concerning CP heavies (10.5 grain) in an R9. When I first introduced my brother to airguns decades ago by selling him one of my home tunes .177 R9s he shot only CP heavies since they were very accurate and they would drive 3/4 way through a grey squirrel LONG WAYS after busting some larger bones. Because of this he had the skill to angle a CP heavy through the vitals of a squirrel from any angle! LOL....when cleaning squirrels with my brother there was one grey squirrel that was hit at the right hip and the CP heavy drove longways through and we found the mangled pellet lodged in the spine at the neck. Here are two 50 yard 3 shot groups (was shooting typical powder burner groups) he shot "back to back" with the R9 I sold him and CP heavies.......
Uploaded at Snapagogo.com

Shooting "heavies" I used to replace his good Maccari aftermarket spring about every two years shooting about a box of CPs a month. After shooting heavies for several years he found that the flatter trajectory of the 7.9 grain CP light trumped the slightly better wind resistance and deep driving CP heavy. After switching to CP lights I only replace one Maccari spring in several years and that spring spent half of it's "life" shooting CP heavies. After replacing that spring with a new Maccari Tarantula spring (my favorite variety no longer being sold) he never replaced it after several years of shooting when I moved to North Carolina.

Anywhoo........I've never shot pellets heavier than 8.6 grains from my R9 and heavier than 8.4 grains with my HW95 because I also believe that the flatter trajectory of the "light" pellet as more useful than the "heavy" pellet. One thing to consider is that mainsprings are indeed considered "consumables" to be replaced on occasion and with the R9/HW95 a simple spring swap can be done in less than 1/2 hour for about $20 (if you opt for the really good Maccari springs) and you're good for several years more frequent shooting! IMHO....if you don't mind replacing a spring every couple years simply shoot the "heavy pellets" IF they are indeed more accurate for you under field conditions!

[HectorMedina]

Another perspective is to look at the pressure chamber.  I noticed when I tuned my 350 and 460 that they had very different length springs, but apparently similar swept volumes (I could be wrong there).  So if they have similar volumes, producing similar muzzle energies, then the shorter spring could have compressed the volume faster.  Tuning the rate of compression (spring expansion) to the pellet chamber compression and pellet travel would be of interest.

Of course many shooters do just that in de-tuning their springers to get a more manageable shooter (less recoil and bump at a lower relative power).




.

You are quite right in that the 460 is the fixed barrel version of the 350, but the MAIN difference between them is not what is used as a cocking lever, the REAL difference is that between the front end of the piston at the end of its travel and the pellet's base in the 460 you have a short transfer port and in the 350 you have a long transfer port.

If you look into the papers we are discussing you can see that the "dead space" that the long transfer port creates creates a large difference between how the two guns need to operate to obtain the best performance.

On the "de-tuning", what is funny, Kim, is that sometimes "De-tuning" can yield the SAME results of a "Full Power" rifle.

Springers are EXTREMELY sophisticated machines and by making a number of small changes you can get all that is needed and leave behind everything  that is not.

Please read the blog entry:  http://www.ctcustomairguns.com/hectors-airgun-blog/the-wide-and-wonderful-range-of-a-short-stroked-d-54

Where I show that the combination of a good piston (to reduce piston re-bound), a reduced stroke (to reduce coil clash and inverse pressure spikes), a proper breech seal (to position the pellet EXACTLY where the cycle needs it), and proper inside/outside guides, plus a moved fulcrum point in the cocking lever, can give you full 15½ ft-lbs of muzzle energy with barely 23 lbs cocking effort.

You get power, smoothness, accuracy, reliability and consistency and you leave behind harshness, buzz, sore shoulders, broken springs and burnt seals.

Sometimes, less IS more.

 

Keep well and shoot straight!





Héctor Medina

[Buldawg76]

39M
Right-never would have figured there was THAT much to loading a pellet
But it was a very good article
Frankly-not wanting to pick a fight
BUT-why would anyone choose a break barrel over an under lever
granted ease of loading and perhaps 4-8 ounces in weight-well those are important-my 460 sure as heck isn't light

DOKF-such a cute little pup-spaniel of some sort?

Buldawg76-  know  what you mean-In 1998 I sent a head from my SR500(28 hp 1980 yamaha  500 cc street single) TO FRANCE- Krautergershiem France-sure sounded germanic,but france-paid $1000 to have the intake port raised 55 degree turn instead of 71 degree turn(carb. to chamber angle) and a second plug pumbed in-
allowed it to make MAYBE 40 hp when combined with $1200 more hot rod stuff-
and it was STILL the slowest 500cc motorcycle in the WORLD-my late wife was very tolerant!
I know I probably can't beat the OEM engineers-(now I'm a mpg nut) but I still try

Charles
Yep know exactly what you mean but back in the seventies and eighties I was a two stroke man and rode Yamahas exclusively starting with a 175 endure and ending up with a 74 SC500 single cylinder 500cc two stroke that weighed 210 pounds and made 45 HP at the rear tire to the ground with 4 gears and factory sprockets would do 105 mph in less than an 1/8 mile. It was only built 1 1/2 years by them from half of 73 and all of 74 and was designed to run the Baja 1000. I still have that bike but due to age and health cannot even consider riding it anymore but just cant make myself get rid of it as it just about killed me more time than I can count since it would accelerate far faster than it would stop on the skimpy drum brakes of the day.

My current scoots now are a 77 model KZ 1000 built to run quarter miles in 9.5 seconds with the slick and wheelie bar but its been converted to street use to play with the new crotch rockets from stop light to stop light and a 76 shovelhead that makes Evos and Twin Cammers mad when I walk away from them on the highway since they top out at around 110 mph and my shovel is just getting up on the cam at 120 mph and is only at 5300 rpm and pulling hard to a 6000 rpm redline. 

But still not done with either one as far as more upgrades are in the works for both of them.

I am just stuck in the 70s as far as vehicle go.

Mike

[phoebeisis]

Ha,ha

In one of those australian "MAD MAX" movies
which had LOTS of great bikes-safe bet some version of the Kawasaki 900-1000 was featured I think
Well there was an old HOT ROD saying posted in a hot rod garage
It said something to the effect
"Tell me how much money you have and I'll tell you how fast you can go" 
something like your 2 stroke 500 Yamaha "enduro"-that vintage with anything like the stock drums-and with the suspension frame limitations of that time-well it would have been an example of that saying
But the 9.5 SECOND kawasaki-even MORE $$-much more!
Ha!
You are LUCKY to still be alive!!
That 500 YAMAHA would have been a KILLER BIKE -in EVERY WAY!!
The Kawasaki 1000--real brakes and lower CG-much "safer" if a 9.5 second bike is "safer"

About 5 years ago-finances- age-cell phones texting-late wife's illness-I sold that SR500- over the years I owned 11 different ones-and some of them-literally the same bike-I bought re-bought -more than ONCE-
Yeah crazy for  cars-trucks-SUV-motorcycles-bicycles too-guns too-
dogs and cats too I guess\

It is a disease-no cure-

[T-Higgs]

When I first got into airguns, one of the first things I read was over on CharlieDaTuna's website about using pellets no larger than about 8 grains because it can damage your spring.

Is this true?
I've just ordered a HW95 from AoA, with a box of 10.65 grain Baracuda Match H&N pellets. Maybe I should have stayed below 8 grains?

What do you think?

Kinda late to this party but I have some first hand info concerning CP heavies (10.5 grain) in an R9. When I first introduced my brother to airguns decades ago by selling him one of my home tunes .177 R9s he shot only CP heavies since they were very accurate and they would drive 3/4 way through a grey squirrel LONG WAYS after busting some larger bones. Because of this he had the skill to angle a CP heavy through the vitals of a squirrel from any angle! LOL....when cleaning squirrels with my brother there was one grey squirrel that was hit at the right hip and the CP heavy drove longways through and we found the mangled pellet lodged in the spine at the neck. Here are two 50 yard 3 shot groups (was shooting typical powder burner groups) he shot "back to back" with the R9 I sold him and CP heavies.......
Uploaded at Snapagogo.com

Shooting "heavies" I used to replace his good Maccari aftermarket spring about every two years shooting about a box of CPs a month. After shooting heavies for several years he found that the flatter trajectory of the 7.9 grain CP light trumped the slightly better wind resistance and deep driving CP heavy. After switching to CP lights I only replace one Maccari spring in several years and that spring spent half of it's "life" shooting CP heavies. After replacing that spring with a new Maccari Tarantula spring (my favorite variety no longer being sold) he never replaced it after several years of shooting when I moved to North Carolina.

Anywhoo........I've never shot pellets heavier than 8.6 grains from my R9 and heavier than 8.4 grains with my HW95 because I also believe that the flatter trajectory of the "light" pellet as more useful than the "heavy" pellet. One thing to consider is that mainsprings are indeed considered "consumables" to be replaced on occasion and with the R9/HW95 a simple spring swap can be done in less than 1/2 hour for about $20 (if you opt for the really good Maccari springs) and you're good for several years more frequent shooting! IMHO....if you don't mind replacing a spring every couple years simply shoot the "heavy pellets" IF they are indeed more accurate for you under field conditions!

Ed, is this the tarantula spring you liked? This is still available.
http://www.airrifleheadquarters.com/catalog/item/251488/43410.htm