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Airgun Pellet Accuracy Testing

When it comes to choosing and customising ammunition for accuracy, the airgunner loses out hands down to the firearms user for a number of reasons.The latter’s components can be individually loaded and customised to give the optimum performance from a given rifle.

Things like bullet weight, shape, and velocity can be adjusted to suit the barrel of a specific rifle. The cartridge case can be re-sized and adjusted to its exact specifications and the various types of powder and primer can come together to produce the ultimate reload. To put it simply - the power supply and the projectile are all in one package and the rifle is basically a launch platform.

A little piece of shaped lead

The air rifle is far more complicated. Virtually all the power and velocity metering is contained inside the rifle. The projectile (the pellet), is just an inert piece of lead and restricted in design due to the method of power delivery. It has to have some sort of hollow tail (skirt) to allow it to expand from the blast of air behind it as it travels up the bore. It also needs some sort of waist, which helps to reduce friction, the head and the skirt being the only points of contact with the barrel. This is called a ‘diablo’ shape and it gives stability in flight, much like a shuttlecock.

Throughout this article we are talking about a power output of just under 12ft/lbs of muzzle energy as that is the current legal limit allowed and also the limit set for all Field Target (FT) and Hunter Field Target (HFT) competitions and with that in mind, power would be realistically set around 11.5ft/lbs. The following information will be relevant whichever of the two most popular calibres the shooter uses, those being .177 and .22. There is no difference in inherent accuracy between the two, but there is a pronounced difference in trajectory.

With all this taken into account it means that the shooter’s choices can be narrowed down to just three variables when selecting ammunition.

Pulling shapes

1. Shape of pellet
In reality there is only one particular shape that offers accuracy and stability while still retaining decent terminal velocity and that is the diablo (described above) with a dome shaped head. As can be seen in the photographs, although various styles and types are available, the dome is time proven for accuracy out to 55yds and this is reflected in all of the pellets shown.

The choice comes down to the manufacturers who tend to produce the same basic shapes. One may have a thicker skirt than another, or the head may vary in roundness or have a `seam` (sometimes called a ‘driving band’) around the circumference. Some will be longer or shorter too.

Some pellets may have a hollow nose (hollow point) which is designed to help stop over penetration and transfer more energy into quarry when hunting. It does this job well at short/medium ranges but lacks long range accuracy. Other are flat headed (Wadcutters) designed to punch neat holes in paper at relatively close range, and ‘pointed’ pellets that claim better penetration for hunting – a problem that really doesn’t exist at sensible airgun distances.

What this series of articles is aimed at is pure and simple accuracy, and with that in mind only pellets with a proven record will be used in testing. Presently it appears that a well-made, diablo-shaped pellet that is completely smooth on the outside with a slim skirt and reasonably deep cavity in the rear does the job as well as it has ever done.


Pellet weight

This variation is the one with the most choice. Talking specifically about .177 cal. domehead pellets, the weight range extends from 7.6 to 10.5-grains, although in practice, due to the relatively low power available, most target shooters now avoid the heavier pellets due to their pronounced trajectory problems. This wasn’t always the case.

When FT was in its infancy, shooters used Superdome pellets, mainly because they were the only half decent design available that shot well in their spring-powered rifles. Weighing in at around 8.6-grains, and reasonably well made, these were the choice for some time until pre-charged pneumatics (PCPs) started to appear.

It was then discovered that PCPs could handle heavier pellets with better results and everybody started using 10.5-grain Bisley Magnums. They were extremely accurate but the downside was the more pronounced trajectory. What was needed was something with the same accuracy potential but a lighter weight. Enter the Crossman Premier! At 7.9-grains they were 2.5-grains lighter than the Magnums and could be fired at 820fps and remain legal on muzzle energy. This extra speed meant a much flatter trajectory. The Bisley Magnum, being a heavier pellet, was limited to 715fps to remain within the law.

It was felt by some that the small 7.9-grain Premiers were a bit too light at long range, losing energy and, more importantly, being more affected by crosswinds.  The next stage of development saw the appearance of the super consistent 8.4-grain from JSB. Not a million miles away from the original 8.6-grain Superdomes! The biggest difference was the quality of production and the complete lack of lines or grooves along the outside of the pellet skirt.

This new weight pellet is now used by 80% of target shooters and is available in a number of different guises, being badged by a number of rifle manufacturers. The only difference is in the quality of the dies (that shape the pellets) at the time of production. You pays yer money and yer makes yer choice!

Oh,by the way, what are the other 20% using I hear you ask! Crosman Premiers, Accupells, and Mosquitos. All are 7.9-grains and they all look the same!


Tight or slack
A comparatively recent trend has been to offer the top grade pellets in three different head diameters. Depending on the barrel used, a tighter or slacker fit may provide improvement in accuracy. It can also alter the ballistic co-efficient and, in turn, the trajectory.

From all this we can assume that from a target shooting point of view, the average FT and HFT shooter uses 8.4-grain pellets fired at around 11.5ft/lb of muzzle energy from a PCP. Other than choosing a good batch, weighing them and perhaps even running them through a sizer, there is not a great deal that can be done to improve things.

Experiments in accuracy and consistency

Taking all these variables, a few questions come to mind. Does weighing individual pellets make that much difference or is it a psychological thing?  To what extent does the head size affect accuracy and/or trajectory?

I must admit that I weigh all my match pellets for peace of mind but there are an awful lot of left-overs. What becomes of them? If they are that far off the mark it would be foolish to use them for practice. On the other hand, if they are that close to being accurate, why not use them for competition?

The head size is a bit more of a mystery. I had a strange experience recently when using a different size than normal, and it is that which has led me to once again start investigating my pellets.

It is these areas that I am going to look at in the next few articles and hopefully come to some solid conclusions.

All Prices Are Guides Due to the Changes in US & European Exchange Rates

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User Comments
  • best pellet for hw100 carbine using air arms they are awful

    Comment by: william park     Posted on: 14 Jan 2013 at 07:49 AM

  • Air Arms Diablos should work fine, but if not, try Weihrauch's own F&T pellets, Crosman Premier, Accupel, and H&N Field and Target Trophy which all seem to work well in the HW100.

    If none of these work, get back to us.

    Comment by: Pat Farey     Posted on: 14 Jan 2013 at 01:19 PM

  • I enjoy using an HW99s springer in. 177 and I find all varieties of JSB Exacts to be very accurate and consistent. However when I tried using Accupells just to see what they would be like, I found the accurate but very prone to dieseling. Can you suggest why one pellet might cause this more than another?

    Comment by: michael ledger     Posted on: 19 Mar 2013 at 11:56 AM

  • Pellet trajectory over water.
    I shoot about 1000 177 pellets a month either indoor 10 meters or 25 meters out doors at a target board across my small lake ( hoping to be there when a water rat shows) I have come to realise how much the air/water temp can affect the accuracy..Depending on wind direction and tempreature changes there can be strong invisible air currents (vertically upwards ) that will affect my otherwise verry accurate rifle. errors of up to 5cms typically 3-4cms will cause my pellets to climb as the warm humid air rises from the water.. Worse is with light wind (cross wind can be dialed out) actually disturbes these vertical currents and mixes them with downward currents that are normally not in the line of fire. Ok so im shooting at high accuracy with a diablo pellet. and getting errors that i don't expect. To confirm my suspisions I quickly set up another target at the same distance (a breeze block at 25m ) but over dry 9grass and shielded by trees. Now i get the same accuracy as indoors. in fact my second pellet hit the first and welded it's self on top. The pellets are going bang on target with amazing accuracy. So what do i conclude from this..

    Usually shooting over water has little affect you can't dial out but if the conditions are such that invisible water vapour is rising from the water at a high rate ( it had been verry hot for two days) your pellets that go high and off to one side are being affected by this and it is not you or the scope that has gone mad.. You have to be getting good groups of under 2 cms at 25 meters to notice the change, But the fact is there...WATER VAPOUR WILL AFFECT THE TRAJECTORY..FACT.
    shoot safely and have fun
    Colin.

    Comment by: colin martin     Posted on: 09 Sep 2014 at 10:08 AM

  • Just to answer the post before...pellets dieseling..!!! Any pellet will diesel if you have oil on them or over lubricate the gun.
    You are at fault.not the pellet. stop adding oil..Dieseling will damage seals and in pump up rifles can destroy the one way valve seal if it diesels on the pumping up of the rifle..This will require a total strip down to repair the internal seal.IS IT WORTH IT??? If you want to have more power then buy a bigger gun..

    Comment by: colin     Posted on: 09 Sep 2014 at 10:19 AM

  • Hi just brought walther rotex r8 . Does any one no the best pellet to suit rifle . Its a 22. Many thanks

    Comment by: lisa drayton     Posted on: 11 Sep 2014 at 09:21 AM

  • Hi To be honnest Lisa no.. Every rifle is slightly different and when sampling a type of pellet, it can take quite a few shots for the barrel to "lead in" and start giving constant results.. I reccomend you try a tin of 250 at a time and make notes of the results.Try and do all your testing indoors at 10 meters and at the same power level..around 650 fps should give you a more constant result to judge your rifles preference.
    Go for a quality pellet and use a diablo shape (waisted) to get a clean hole in the target for accurate test results. Try a tin at a time, never buy three different ones and start doing test groupes from different ones, Your results will be false.
    Also see what your local has a good stock of..It's annoying when you get settled in to a certain pellet then have problems getting them.

    Yes annyone can say buy gamo match or h&n diablo's for example and they are an excellent starting point..but you have to search out the ones your rifle performs best with..And clean the barrel when changing pellets and fire at least 10 pellets before you start to record the results or re-zero the scope as the barrel will need to lead in from the new profile/weight/type of lead used.
    Hope this helps Lisa, and you take the time to get the best from the rifle.
    Colin

    Comment by: colin martin     Posted on: 11 Sep 2014 at 10:35 AM

  • I own a walther lgu 2.2 I'm having trouble finding a pellet that is a snug fit I've tried Wembley accu pell bisley hn field they were all very tight the only ones that were a snug fit and very accurate was crosmans accu pell but you can no longer buy them can you help many thanks

    Comment by: Martin Groundsell     Posted on: 17 Nov 2014 at 11:07 AM

  • One of our reviewers - Pete Wadeson - has recently tested the Walther LGU and he found that Air Arms Field Diablo Heavy pellets gave good results right out to 40yds.

    Comment by: Pat Farey     Posted on: 17 Nov 2014 at 11:16 AM

  • Im having problems with my walther lgu 22 and wonder if any one else is having same problems the cocking lever keeps sticking in the closed position,I took it back to the gun smith where I bought it from and he agreed there was definite problem and sent it back to the supplier who said they would look into it , but said they were having problems with early lgu.The gun is less than two months old and has fired less than a tin of pellets

    Comment by: Martin Groundsell     Posted on: 07 Dec 2014 at 11:36 AM

  • Recently purchased the Shockley signature Benjamin 1200 fps pellet rifle in 17 caliber. Nothing in the manual talked about cleaning but I have fired about 150 pellets and cleaned it 3 times with a great deal of lead coming out of the barrel. After reading your letters and responses.....I have come to the conclusion that maybe I want that lead left in the barrel. I have also learned that shooting numerous types of pellets will give false readings...and I have had a lot of those after changing pellets after every 5 shot group. I can also concur with the writer who has trouble with groups shot over water.....I do too with this rifle....and it is only magnified by changing between 5 shot groups.

    Bottom line is that come Spring, I have a number of Wood Chucks at 55 yards that do a lot of damage in my yard that I want to eradicate....and firing a 22 isn't permitted.....though I found that shooting high velocity pellets still make a lot of noise when they brake the sound barrier....regardless of the silencer at the end of my rifle.

    What pellet or pellets should I settle down to .....for the target I am after. Russ

    Comment by: Russ Jones     Posted on: 17 Dec 2014 at 07:59 PM

  • Hi Russ, a woodchuck is a pretty large animal compared to the rabbits, rats and squirrels I shoot with air rifles. I appreciate you have more power than I do but I must admit I wouldn't be shooting a woodchuck with any sort of air rifle.

    What weight pellets are you using and are you actually getting the advertised 1,200 FPS? With this info we can work out exactly how much energy you r rifle has at the muzzle and how much power it will have at 55 yards.

    Comment by: Troll Hunter     Posted on: 17 Dec 2014 at 11:35 PM

  • Thank you for your quick response. I have 12 different pellets that I have been trying and this is what I have learned so far.

    1.) The light weight (4+ gram) pellets which advertise more velocity are the least reliable in my gun. I have several types from Gamo and Crosman that are not made of lead and have a variety of plastic tips or in one case a red plastic sleeve. I've come to the conclusion that they may be just the thing for 800 fps guns....bringing them up to 1000 fps.....but in my 1200 fps rifle they quickly break the sound barrier....provide a loud crack like a 22 rim fire rifle which is sound I want to avoid. They can then go crazy and miss a 12 x 14 paper target entirely at 30 yards.
    2.) Reliability returns once I return to the standard Crosman Premier round nose pellet that weighs 5.7 grams. A little less accuracy is achieved with the same 5.7 gram pellet with a sharp nose.
    3.) I eliminate some of those wild pellets by firing the gun 10 times first before I try to punch a tight group on paper. The gun seems to have warmed up and settled down to a consistent shooter.
    4.) I noticed that Bass Pro has some Crossman that I believe were 8+ grams that I may try next.
    5.) I also sprayed some pellets with a very light oil and I believed that added speed....but also added to the disruption of their trajectory indicated above in #1.
    6.) If as you say.....I maybe attempting the impossible at killing a Wood Chuck at 55 yards....I have a number of 22 cal rim fire that I can resort to but will have to resort to sub sonic to keep the noise down and I thought that would just put me back into the ballistics of a pellet rifle.

    In conclusion, I haven't found that magic pellet yet and I should share with you that I am former military who ranked expert in the service with pistols up to an M-60 machine gun. I have also placed 6th in Michigan at Second Chance matches sweeping bowling pin shoots and I've dropped an antelope at 454 yards......so trust me when I say that I have my breathing and trigger pull skill sets down well.

    Lastly, I realized this air gun shooting was not in the rim or center fire category when I noticed that some pellets slipped in easily and some required a hard push to get them into the breach....even though they came from the same tin.....So I need to lower my expectations. Any help you can bring to the table will be appreciated. Russ

    Comment by: Russ Jones     Posted on: 18 Dec 2014 at 04:32 PM

  • Hi Russ, most airgun companies use very light pellets to be a able state that their air rifles provide really high velocities for their sales blurb; this is all well and good but accuracy is king with any shooting sport and light projectiles lose velocity and energy very quickly.

    If I were you I'd try the heavy Crosman pellets, they are usually very accurate in a decent barrel and retain energy well. To get clean kills get as close as you can to your quarry.

    I still don't know how much power you'll need to cleanly kill a woodchuck though, it's a shame you can't use a subsonic .22 rimfire though, as that would be plenty powerful.

    Do you have access to a chrono? If you can, you'll know exactly what you're dealing with.

    One final thing I've noticed whilst typing, are you sure about the weights of the pellets, as they are usually in grains not grams. A lightweight .177 is usually around 8 grains and a heavy one is 10.5 grains.

    Let us know how you get on.

    Comment by: Troll Hunter     Posted on: 18 Dec 2014 at 06:38 PM

  • You seriously need to read my posts Russ..Oiling pellets so that they diesel will destroy your gun...
    You don't need anything like 1000 fps for hunting or target shooting and certainly not if you are trying to hit a target (paper) with precision at 10 meters...Plastic pellets wont be accurate either..thats why they aren't used in competition shooting...7 grains is a good weight for a target pellet, light enough to be fast 650 pfs is plenty for accuracy even at 25 meters. If you are elephant hunting get a bigger gun...0.177 is for plinking / target shooting ( with high precision) and killing vermin..only a high power 0.177 shooting a much heavier pellet should be used for small game hunting. OR A 0.22 cal air rifle...and stay below 950 fps. or the sonic crack or a 1000 fps pellet will scare away all the other moving targets that aren't nailed down...and use a silencer if you are shooting vermin or small game.
    I get a easy group of 1-2 cm at 25 meters outdoors with light wind..using a good quality pellet that weights 7 grains. 0.45G

    Comment by: colin     Posted on: 18 Dec 2014 at 08:00 PM

  • Actually I have a rectification or amendment to add...As i have just looked up to see what a WOODCHUCK actually is...not called the same where i live..
    ANY FUR COVERED ANIMAL ( other than rats that are vermin) should not be hunted with a small caliber like a 177, it does not have the knock down power for fur. Your talk of plastic pellets and 5.7 grain pellets must be referring to 0.177 cal...You need much heavier pellets and at least 20ft lbs..for a clean kill. So stop wasting time will oily under sized pellets trying to get 1200 fps risking damaging your rifle...get a high power 0.22 air rifle and a proper pointed heavy hunting pellet in the 14 - 20 grains region..there is even a very heavy hunting pellet called "EunJin .22 Cal, 28.4 Grains, Domed, " but these will require a very powerful rifle but not by adding a propellant like oil.. I use the same brand or design of pump up rifle in both 177 and 22 cal. they are all accurate rifles and scoped. I use the 177 for targets and small vermin, 7grains is ample with just 656 ft p sec. for very tight groups.
    Both my .22 air rifles have over 25 ft lbs and shoot a heavy hunting pellet that gives me knockdown power up to 50 yards that i can guarantee a clean kill. I have a type of water rat that burrows holes in my lake banks they are a nuisance, but i would never waste a 177 on them..but have a standby tin of gamo ts-22 pellets at the ready for when one appears. These weigh 22 grains...a long way from your 5.7 grains...
    You also mentioned using a low velocity 22 rimfire, well i have also got a german 22 rimfire rifle and although its only iron sighted with no scope rail its fine to take out a coypu at 75 - 150 meters it would be useless with the lower power quiet bullets at more than 25 meters...I've yet to fine a constant velocity from these low power rimfire slugs..but i have little experience with them so have no real information on any good rounds that might be available...all i can say is that for a water rat at 50 meters i would either shoot with the air rifle .22 at 20ft lbs min and a 22 grain pellet or a live 22 round. both would assure a clean and effective kill.

    Comment by: colin     Posted on: 18 Dec 2014 at 11:30 PM

  • Thank you Colin for your response. Yes, my air gun is 177 caliber and the dozen different pellets I have been using range from 5.2 gr.(RWS Hyper Max to a Crosman Premier Hollow Point at 7.9 gr. My rifle is advertised at 1200 fps with high velocity pellets.....I can assure everyone that my Benjamin has no consistent accuracy with those light high velocity rounds.

    Today, I purchased Crosman Premier Ultra Mag at 10.5 gr. and finally achieved the consistent accuracy I have been looking for from 10 meters to a 55 meter target placed just about the place my back yard wetlands finds a Wood Chuck on sunny days. As a hunter with rim and centerfire cartridges ...I know the value of high velocity. It not only provides a flat trajectory....but "Speed Kills"....particularly when it passes thru game providing 2 exit holes for blood loss. It is for this reason that I initially focused on 5.2 gr. pellets believing high velocity with a 177 pellet was my only hope with an air gun. No consistency quickly evaporated my plan. However, todays purchase of a Premier pellet weighing 10.5 gr. gives me new hope come Spring when the snow melts and the Wood Chucks return.

    Your comment about oil can do damage to my gun. Is this true of all air guns. My Benjamin is some type of new design called a Nitro Piston versus a Spring design. Secondly, I noticed on the Crosman Premier pellets that they are not only heavier, but more consistent in their fit into the breech....and they seem to have some coating of lube on them versus the other "dry pellets" that I have used. I believe a lube or oil coating helps seal the pellet to the inside of the barrel ....much like STP helps increase the compression of an old engine to run better. I would think that the lube would increase compression and maybe even the consistency of that compression.

    It maybe a mute point, because now that I have found the ammo that falls into my rifles "sweet spot" and it appears to have a lube on it.....then I won't be considering putting an additional spray of fogging oil on my pellets to begin with.

    I have already begun a search for a 22 cal air rifle to up the ante with heavier pellets now that I know super high velocity light pellets are just not preactical.....at least for my gun..... Your comments are appreciated.. Russ

    Comment by: Russ Jones     Posted on: 19 Dec 2014 at 07:30 PM

  • My pleasure Russ, yes oil can damage seals and in pump up rifles the seals that get damages are deep inside the rifle..
    I was oiling one of my pump up's and foolishly pumped twice...i felt a kick against the pump lever and that was that..loss of compression..i had to strip the rifle to remove the compression storage cylinder and open it up to remove the inner one way valve to fit a new seal..even had to make an extractor tool to do the job...took me about two hours...so be warned ok springers only have two seals, one on the barrel join and one on the piston...but if that one goes...then it's a replacement part you will have to order...I made my seal as i have many in my workshop but a piston seal for a springer is a bit special, same as the pump seal on a pump rifle it's a special shape...i was lucky it was just the ball valve seal...

    Another point, i use a full tin to evaluate pellets...never go back and forth as the results will be false.. Each new type of pellet has its own fit and shape..it will bed in to the rifling in your barrel. and each shot will leave a deposit that will get scraped by the next pellet. The barrel needs to bed in to each shape of pellet..dependent on the power, weight of the pellet and the temperature the resulting group will be affected by this.so a constant weight and shape plus power setting is required for the rifle to settle down and start grouping like you want it too...
    It does not matter if a pellet is a tight fit or a bit looser to feed into the chamber on a springer as the different brand / type of pellets have a different head size...the skirt will provide the seal..not the head. but there has to be a point where you decide what loads easily and what does not for your rifle..on a rifle where the pellets are pre loaded this will no longer be an issue..
    again in a single feed like my pump rifles the length of the pellet denotes what loads easier and as i often shoot late in the day at falling light it's hard to FEEL some pellets and know that they are loaded the correct way round at night in low light conditions...A worthy note for those that hunt rabbits at dusk..a pellet shot backwards will never be on line as it tries to flip over in flight.

    Most modern springers are good rifles though I only have a Chinese one ( reserved for friends ) and the modern power levels are fine, but you cant beat a pump up if you need to change the pressure at will. I target shoot at 3 pumps with the 177 and get very accurate shots..more than if i shoot at higher pressures, and they are more constant. measures with a chrono the variation with my shots is typically +- 3 fps..at 656 fps now thats very good..how many of the springers or pre charged rifles can do that all the time, every shot for a whole tin of 500 pellets....fired in one session...

    Comment by: colin     Posted on: 20 Dec 2014 at 12:45 AM

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Airgun Pellet Accuracy Testing
Airgun Pellet Accuracy Testing
Airgun Pellet Accuracy Testing
Airgun Pellet Accuracy Testing
Airgun Pellet Accuracy Testing
Airgun Pellet Accuracy Testing
Airgun Pellet Accuracy Testing
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