.25 Caliper Springers ... Are Lighter Pellets More Advised?

[aom22]

The H&N FTT 19.91/20.06 have shot quite well out of my VORTEK Tuned .25 Mod. 48.
And, the same pellets have been producing good accuracy out of my Hatsan 125 Sniper.
Currently, my H125S is sighted-in with Predator Polymags 26gr.
But, because of the cost of shooting Polymags, I practice with JSB Exact Match Kings 25.39gr.
The heavier pellets require much more concentration for good accuracy to materialize.
Moreover, the H125S becomes very hold specific when shooting heavier pellets.
More often than not, my pest control shooting opportunity ... happen all too fast.
I spot a pest, get the air rifle, load, get in position, aim quickly and shoot before the target becomes too wary.
Not, much time can be devoted to a finding comfortable firing position ... even less so to assume a very specific hold.

After reading the following thread by Chris of C.A.P. my presumption that a heavier pellet is a better match
for my H125S ... has given me pause to re-consider my thinking.
Does anyone agree or disagree with Chris's logic?
It makes a lot of sense to me.

25 caliber pellets and their use in springer's. May 5 2010 at 12:06 PM ... C.A.P

Before you had to buy a UK or German gun to get it and you had to pay good $$$ for it.
Then you were limited to a few quality pellets.
The new blast of interest has made me realize that the manufactures still are out of tune with the .25 springer.
There are several .25 caliber pellets that are 25 + grain.
Even many at over 30 grn. That is all great for PCP but springers are just not that efficient at transferring
the energy to that much weight.
 
Webley made many .25 caliber Patriots and even sold a pellet that was made for it.
The Webley "Mosquito".It was a 19 grain dome.
A Great pellet that was probably a relabeled H&N FTT as well as the Diana Dome that was also 19 grains
along with the Beeman FTS that was labeled 19.5 grains.
These were considered mid weight pellets. Beeman did make a Laser that was 17.4 grains and was heralded
as a gimmick pellet.
 
Now I have 9 .25 caliber springer's that range from 20 to 35+ ft lbs.
Every one of them shoots with more power in ft lbs and accuracy with 20 grain domes and even the Beeman lasers
that were discounted as a Garbage pellet.
The real issue with the lighter weight pellets is tuning and that is another story.
However; I have shot the Raptors, 14.7 at 1060 out of my 35 ft lb gun.
It shoots as well or better in shot cycle as the 20 grain FTT.
 
Now before you all burn me for heresy, Look at the big picture.
We all love to shoot 14.3 to 16 in .22..
WHY NOT 16 TO 18 IN .25 AND RETAIN THE ENERGY AND GET FLATTER DOWN RANGE ABILITY.
That is .014 per side larger barrel. Not near the jump like a .177 to .22.
 
Who wants to shoot 27 to 30 ft lbs with a nice flat trajectory out to 50 yards with NO hold over?
, take your smaller BSA lightning and get better trajectory with no loss of power down range.
I say Crosman and RWS and other manufactures are missing the boat on springer pellets in .25.
I reshaped it to look like a real Super H all along weighing 20 grains on my digital scale.

[rsterne]

Too light, you will get a harsh firing cycle and may damage the cup.... Too heavy, you may damage the spring, not to mention poor trajectory.... It's all a matter of compromise.... If you shoot a bunch of different weights, record the velocity, and calculate the FPE with each weight, you will likely find that the FPE peaks at a given weight pellet.... Going heavier than that pays no benefit, IMO....

Regarding his comments about large light pellets retaining velocity and energy better, he's off base.... For a given weight, a .22 cal pellet will have a better BC than a .25 cal, given a similar shape (eg. comparing round nose to round nose).... It's all a matter of sectional density and the effect that has on BC.... It's one of the prime reasons not many springers shoot better in .25 cal than in .22 cal, they simple don't have the power of a PCP to push the heavy pellets....

Bob

[aom22]

Here's some more food for thought.

The Air Rifle Hunter's Guide, by Tom Holzel

The really key point in airgun hunting is not muzzle energy, but how well energy is carried out
to the prey.
The energy/velocity table shows dramatically how heavier, larger pellets keep their energy.
The clear winner in energy retention and ballistic efficiency is .25" caliber.
Thus, trajectory drop with the bigger, heavier pellets is far less than might be expected.
The .25" Crow Magnum, sighted in for 50 yards, keeps that powerful pellet within 2 inches
of line of sight to over 55 yards!
All factors considered, .20" caliber is probably the best all around choice, with a high power .25"
being a good second, or even first, choice for the field.

>

By the way, not to disagree with you rsterne or to seem argumentive, to me Chris's observation
of a .25 caliber pellet retaining more energy down range was in comparison to a .22 pellet of the
same weight class.
Take a closer look at the Field Velocity Table - .22 14.5gr vs .25 21.6gr.
Not the best example ... but, an interesting comparison.

[Nomadic Pirate]

I like shooting 26-28gr pellets out of my .25s

[rsterne]

WHY NOT 16 TO 18 IN .25 AND RETAIN THE ENERGY AND GET FLATTER DOWN RANGE ABILITY.

That doesn't indicate a 21.6 gr. pellet to me.... A 16 gr. pellet in .25 (or even an 18 gr.) would not retain energy as well as the same weight in .22 cal (assuming similar shape).... PERIOD.... That's what I said, and I maintain that to be true....

If you want to compare a 21.6 gr. pellet in .25 cal to one with the same Sectional Density in .22 cal, you would need to compare it to one weighing 16.3 gr., not 14.5 gr.... A 25.4 gr. pellet in .25 cal should be compared to one weighing 19.1 gr. in .22 cal.... If the SD is the same, and also the shape, then the BC should also be similar.... and the way they retain their energy downrange also similar....

Bob

[fortyshooter]

I like the 20 gr. H&N pellets for my Sniper 125. Only exception are those wonderfull 25 gr. PolyMags!

[GunnerAl]

It's more than just accepted that there are groups within groups of pellets that are the most used and possibly the best all-rounders for your average spring air rifle rated as your average 1000fps in .177 cal, along with their eqivalents in the other calibres. In .177 that equals approx 7.5 - 9gr... In .22 that equals approx 14 - 17gr, and in .25 cal I'm guessing that would be approx 21 - 25gr... When you go one step further with power, up to the 1250fps bracket in .177 and its .22 and .25 equivalents, you may be able to stretch those upper limits by a bit but not by much. It has nothing to do with the power of the spring or the rifles output in fpe etc. It's more to do with the physics of the rifles design and the fact that even though these more powerful rifles are capable of higher energy output, they are still based on that standard pellet weight usage. The internals of these more powerful rifles have to be looked after every bit as much as the lesser powerful models, because their innards are still made from the same materials and even though springs and cylinder volumes may be a little scaled up to produce more power, if they are not given the due care, they can just as easily be damaged or broken. It appears to me that pellets which are too heavy can be a major source of these troubles. You shouldn't be looking at heavier pellets as just a couple of extra grains more than the standard weights, rather, what percentage of extra weight they are,,eg...

JSB Exact in .177 at 8.4gr vs the H&N Baracuda at 10.6gr. Thats only 2.2gr heavier. Hey, what's a measly 2.2gr between friends, right..!! It's 26% heavier, over one quarter more, that's what. I guess we can make those same comparisons in .22 as in - JSB Exact @ 16gr vs H&N Baracuda @ 21.1gr which is 32% heavier, and in .25 cal JSB Exact @ 25.4gr vs H&N Baracuda @ 31gr which is 24% heavier. If all this doesn't trigger some sort of alarm bells, I don't know what will. You are looking at substantial weight percentage gains here. In rifles which are made more for the normal weights, this can represent huge strains and resultant stresses on the innards of your rifle. These stresses can cause fatigue and/or breakage on springs, pistons and seals etc.

Going too light in pellet weights can also bring on some not too dissimilar results but for ever so slightly different reasons. Same ending though..!!

I can foresee the day that .177 cal spring air rifles are more purpose built to handle pellets over 10gr,, .22 cal to handle over 20gr,, and .25 to handle over 30gr safely, but for now in my opinion, it's better to stick to the more average pellets and leave the heavier ones to PCP etc...

Of course, I am talking standard out of the box rifles here, not modded or tuned and, these are my opinions only, and, I don't have any experience in .20's so I can't really comment here...

[Bryan Heimann]

Piston weight vs. swept volume is also an important variable to consider.  A heavier piston will work better against a given volume of air and a heavy pellet thN a lighter one will.  As far as bore diameter goes, most .22 airguns are .217-.218" bores, while the .25's (except BSA springers) are actually .25" bores.  They "breathe" a lot better, and require a lot more pressure to create a uncorking "pop" or "pow".   That should tell you something right there.   A .22 springer making 25 fpe gives you a nice "pow", but with the same gun in .25 the "buzz-twang" of the powerplant is the main noise you hear- or, with a gas ram, more like a "putt" than a "pow".  That is why I think the .25's are purpose built to handle the mid-to-heavy weight ammo.  Especially guns like the Hatsans which, in most reviews I've read, offer diminished muzzle energy with lighter ammo.  Probably attributed to the heavy pistons in these guns, moving a little more slowly.  Lighter pellets don't have the weight to stay seated in the chamfer against the pressure, and begin moving before the piston slams home- prevenring max pressure from being achieved and therefore less power.  The problem with overweight pellets or lighter pistons is the exact opposite- the piston bounces off the air pressure before the heavy pellet begins to budge, so the pressure is momentarily reduced and never fully exerted against a moving projectile.  I would be a lot more concerned with the ramifications of that heavy piston slamming into the front end of the tube on lighter ammo than I would be with premature spring wear.  Pistons and tubes are a little more expensive and harder to replace.  Springs are consumables and there are springs out there that fit these guns available.  Good luck finding Hatsan tubes and pistons though.

[Mark 611]

I will say this about Chris {C.A.P.} and I'm not taking up for him in anyway! but I know he has been working and developing tunes on the bigger power plant guns Like the U.K.  Webley Patriots for several years, I know he has had access to to Tom Gores {Vortek} equipment and tuning parts and all the other goodies there and has pushed the limits of the .25cal power plants, that being said I know he has generated more power in these guns then anybody else I've heard about, are his theories right? don't know for sure on my end but I will say with all the time and effort he's put into what he's done he may just know what he's talking about!

[GunnerAl]

I think there has been quite a bit of knowledge passed in this small thread, about pellet calibre vs weight vs power. Good reading and thought provoking stuff too. I personally draw my own borders with stock standard stuff - unmodified and/or untuned,, where sometimes I think the boundaries of knowledge shown by manufacturers can be, seemingly, narrow - inside the square, sticking to the known universe etc. There's nothing wrong with that as there are some truly amazing spring airguns out there, but it does make you wonder just how much further they can go if they applied some of the "outside the square" type thinking...

It's always good to have someone branching out and trying new stuff...

Just one thing I would hesitate at in the highlighted passage at the top of the page. That is the diameter vs length of such lightweight pellets. On average, a pellet of a heavy weight in a given calibre would be either built more solidly or longer than a pellet of say, half its weight in that same calibre. This is something that can't really be overcome so quickly and are referred to as "inherent factors". Either or both of these factors would detract from the pellets ability to fly through the air efficiently compared to the heavier/longer pellet, without going to more exotic materials to make them out of etc. At the end of the day, the smaller or lighter faster pellet may only have a trajectory similar to a larger heavier pellet, or, lose much of it energy on the way, or, may not have to desired impact effects due to it light construction. I've seen and tried many of these things with centrefire loads in the past. There are some inherent factors which stay constant no matter where they are applied...

Still, it's worth thinking about and I'm sure that tuned or purpose made airguns can infact be made to handle any practical weight of pellet, light or heavy. The only weak link in the chain here would be the average owner/shooter's lack of knowledge of pellets etc and ballistics,, and that's why I think many manufacturers stick to that known universe. They play the averages game...

[Bryan Heimann]

If I am not mistaken, part of a tune from C.A.P. includes reducing tge weight of the piston and installing a more powerful spring or ram.  Find the right balance and you'll not only see more power with lighter ammo, but decreased hild sensitivity.  Lighter pistons close faster, creating more pressure before the lighter pellet starts moving.  I agree with gunner al though, a mid or heavy weight pellet will typically shoot flatter at long range vs. a light pellet with lower B.C. at a given power level, despite a slower muzzle velocity.  The FTT dome seems to defy logic, hiwever, because in .25 it retains energy really well for it's weight.  I still like to use heavier domes though, and lately I really have grown to like using #3 buckshot.  BC is not the greatest, but not bad abd you can't load it backwards.  Not to mention, it has the best cross sectional density

[Mark 611]

I will agree that factory 25cal rifles have allot to be desired, I've had few 25cal springer's in the past even a tuned 30ftlb U.K. Webley Patriot, all I can say is the 25cal don't float my boat at all in a spring gun, that's due to the fact that the .22cal will out perform it with the same weight pellet, + I'm a distance shooter, PCP's are another story with the .25cal altogether and IMO that's where the .25 is best suited JMO

[Bryan Heimann]

I agree with you to a certain extent, but in the late Hatsan magnums the .25 and .22 produce about the same muzzle energy and the .25 handles the heavier ammo better.  So you choose between trajectory and penetration with .22 or momentum and energy transfer with .25.  I have been having a lot of fun with mine.  For longer range shooting I would prefer something in .22, but so far the .25 Hatsan has been keeping me happy at my 6-10 meter range indoors!

[Paul68]

WHY NOT 16 TO 18 IN .25 AND RETAIN THE ENERGY AND GET FLATTER DOWN RANGE ABILITY.

That doesn't indicate a 21.6 gr. pellet to me.... A 16 gr. pellet in .25 (or even an 18 gr.) would not retain energy as well as the same weight in .22 cal (assuming similar shape).... PERIOD.... That's what I said, and I maintain that to be true....

If you want to compare a 21.6 gr. pellet in .25 cal to one with the same Sectional Density in .22 cal, you would need to compare it to one weighing 16.3 gr., not 14.5 gr.... A 25.4 gr. pellet in .25 cal should be compared to one weighing 19.1 gr. in .22 cal.... If the SD is the same, and also the shape, then the BC should also be similar.... and the way they retain their energy downrange also similar....

Bob

Agree with Bob. More at work then just weight, and a greater surface area is not proportional to weight as you can change one or the other without affecting the other, which is what you are doing with a larger caliber of less weight. The larger surface area of the 25 will mean increased drag and instability. IMO, the typically heavier weight of the 25's usually used helps to retain stability that would be lost to poorer BC. Plus, less mass, you just wont retain the same energy at distance. We all already know how a lighter pellet can have higher initial energy than a heavier pellet, but after 30 yards, it will have lost so much that the heavier pellet with now have more energy.

Increase the caliber without increasing the mass and imo you are creating a less stable pellet that loses energy faster.

[aom22]

When I purchased my Hatsan 125 Sniper, I also purchased a Straight Shooters Full Pellet Sampler .25 .
Had I bought a .25 caliber BSA Lightning XL ... I would have bought the same pellet sampler.
I own a .25 caliber Diana Mod. 48 and I used the same set of pellets from the sampler as well.

Logically, the range of pellet weight that would be suitable for a Lightning XL would not be the same
for a Hatsan 135 or Webley Patriot.
All considered, what would be the realistic pellet weight range for a low-power .25 caliber springer, a mid-power springer,
a magnum-power springer, a super-magnum springer.

These are the .25 caliber spring and piston air rifles that come to mind: BSA Lightning XL, HW77/97k, HW90,
Diana Mod. 48/52 with a VORTEK kit, Diana 470TH with VORTEK kit, Hatsan 125, Hatsan, Hatsan 135.