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Ammo Air Arms S400 MPR FT: Part 2

Air Arms S400 MPR FT: Part 2

by B.B. Pelletier

Part 1

The Air Arms S400 MPR FT is a beautiful international-class field target rifle.

Today, we’ll look at the velocity of the Air Arms S400 MPR FT rifle. I’m testing the gun just as it was sent from the factory, which is how I would use it for field target. By looking at the large reservoir tube and knowing that this is a 12 foot-pound rifle, I knew it would get a lot of shots per fill, so today I concentrated on what the gun could do in factory trim.

Blog reader Coax has asked me to try to increase the power, to see what the potential of the rifle is. I’ll do that in a separate report because I don’t want to shortchange today’s lesson. And, a lesson it will be, because the unregulated MPR FT has the classic inverted bathtub curve of power as the air charge bleeds down. I want to talk about that, because it illustrates a couple of important points that new PCP owners need to understand.

Fill the rifle
So, the first thing I did was charge the rifle up to its 190 bar fill point. I used the gauge on my carbon fiber tank, because I’ve learned that it’s usually very accurate. Once the rifle was filled, however, the onboard manometer read less than 180 bar, so be aware that gauges seldom agree.

The Air Arms fill coupling, which I showed back in part 1, requires the rifle to be held in a certain position for the keyed coupler to stay attached. This almost always places the rifle at a most awkward angle during filling and this time was no exception. I wish Air Arms would change to the Foster quick-disconnect that Crosman, Daystate and Quackenbush now use, because that type of coupling allows for maximum positioning flexibility. However, I have to say that once it’s connected there’s no problem filling the rifle.

Velocity test
I want to accomplish several thing when performing the velocity test, and our newer PCP owners would do well to copy what I’m about to do. There are several things we want to learn from this test. First, we want to know the average velocity of several representative pellets. At this point, we don’t know what the most accurate pellet will be in the rifle, but that doesn’t matter. The way I’m doing the test, we’ll still learn everything we need to know; and all that can be transferred to the best pellet, once it’s discovered.

The first step is to fill the rifle to the recommended maximum fill. We’ll soon know whether that pressure, as indicated on our gauges, is correct, or if there are adjustments to be made.

The next thing we want to learn is how many shots there are on a fill. The way I run the test, we’ll be able to select a number of shots from a larger body of data after the test is complete. In other words, we don’t need to know anything going into the test. No preconceptions.

We’ll also note the ending pressure when the rifle falls off the performance curve. If this were a regulated rifle, we’d determine the reservoir pressure at the point when the rifle falls off the reg. That way you can grab the gun and look at the manometer to determine at any time if there are any good shots left in it. That’s handy when you just want to grab the gun for a few quick shots, like a squirrel in the bird feeder.

Crosman Premier 7.9-grain domes
I’ll use the 7.9-grain Crosman Premier domed pellet in the cardboard box as my test pellet for most of this test. I use the lite 7.9-grain pellet instead of the heavy 10.5-grain Crosman Premier because this is a 12 foot-pound rifle. I know that, legally, it has to shoot slower than 825 f.p.s. with this pellet. In fact, it has to shoot a lot slower than that, because the law in the UK says the rifle cannot produce over 12 foot-pounds with any pellet. And, PCPs are always more efficient with heavier pellets. Since the 7.9 is a light pellet, I know the velocity with this pellet has to stay well away from the maximum or risk going over the limit when a heavier pellet is loaded.

Crosman Premier lites averaged 764 f.p.s. in the rifle. Shot one was at 755 f.p.s., but the other nine were at or above 761 f.p.s., which demonstrates the need to “wake up” the valve in a PCP. Whenever I competed in field target, I always shot a couple valve wakeup rounds before starting the match. And, that was a regulated gun! This gun is unregulated, which makes the wake-up call even more important.

The range of the shots was from 755 to 771. That’s pretty broad and perhaps points to the gun being overfilled, but I’m getting ahead of myself. The average velocity produces 10.24 foot-pounds.

JSB Exact heavy domes
The next pellet I tried were JSB Exact domes that weigh 10.2 grains. They averaged 740 f.p.s. and had a much tighter range — 736 to 742 f.p.s. That tells me the rifle is becoming more stable as far as velocity is concerned. That fact will be important in a moment. At the average velocity, the muzzle energy is 12.41 foot-pounds. In the UK, that would be over the legal limit. You see what happens when a heavier pellet is used? That’s why PCPs shoot so slow with light pellets. Of course, they shoot even slower with heavy pellets, so pellet selection is a tricky thing. Of course, you want accuracy over everything else.

Air Arms Falcon
The Air Arms Falcon pellet weighs 7.33 grains, making it the lightest pellet in this test. It averaged 834 f.p.s., with a tight spread from 831 to 836. That’s just 5 f.p.s. — a solid indication that we’re on the power curve. At the average velocity, the muzzle energy is 11.32 foot-pounds, making this a very efficient lightweight pellet that’s certainly in contention as a best pellet for this rifle at this power level.

The next test
After testing these three pellets, I wanted to establish the maximum number of shots I can expect from a single fill. To learn that, I started shooting Premier lites at shot 31. Let me show you the remainder of the shots in this fill

36……..790 (manometer reads 150 bar)

At this point, I’m obviously at the top of the power curve and also at a very flat spot. I wanted to see how the other two pellets would do at this point in the fill/curve. Next, I shot two JSB Exact 10.2-grain domes.


Okay, they’re going even faster than the average we saw before. The string I shot with them was not on the optimum power curve. So, 190 bar indicated on my carbon fiber tank gauge is too high a fill for this rifle. I’ll try 185 bar next fill. Now, I’ll try some Air Arms falcon pellets.


Okay, the Falcons are exactly where they were when I shot the first string of them. For the total useful number of shots per fill, I’ll begin counting with the first string of falcon pellets. I’ll disregard the first two strings, because I now know the rifle was overfilled when I shot them. But the string of Falcons was right on the power curve. Do you see that? Let’s return to the Premier lites to establish the end of the power curve.

76……..771 (manometer reads 125 bar)

I stopped the test here. As a field target competitor, I feel good about the shots from 21 (the first of the Air Arms Falcon string) and shot 75. That gives me a useful string of 54 shots. If I use Crosman Premier lites, I’ll get 54 shots that range between 784 and 794 f.p.s. That’s a 10 foot-second velocity spread for 54 shots. What I would do is mark the place in the match when 50 shots had been fired and fill after that point when it’s convenient. If I were to use Air Arms Falcon pellets, my average velocity would be about 834 f.p.s. for the same 54 shots. My total spread might be well below 10 f.p.s.

Do you see where I’m getting this? All this I’ve learned from just one string of shots. And, that, my friends is why owning a chronograph is so important for a PCP shooter. Not to see how fast you can go, but to learn useful things about your airgun.

Next, I’ll attempt to adjust the power and give you the results of that.

author avatar
Tom Gaylord (B.B. Pelletier)
Tom Gaylord, also known as B.B. Pelletier, provides expert insights to airgunners all over the world on behalf of Pyramyd AIR. He has earned the title The Godfather of Airguns™ for his contributions to the industry, spending many years with AirForce Airguns and starting magazines dedicated to the sport such as Airgun Illustrated.

45 thoughts on “Air Arms S400 MPR FT: Part 2”

  1. Morning B.B.,

    Every time you write about a PCP and its shot string I find myself trying to figure out where you are going to pick your starting and ending point. I was reading before coffee and sure missed this one.


  2. Mr. B

    Let me take a stab at this, and if I get it wrong then Tom can kick my butt.

    This is a modestly powered rifle, so keeping the velocity range tighter is necessary to keep the POI tight at distance. A few fps more or less makes more difference than it does with a fast rifle.

    Also, this is intended as a FT rifle and would be used at quite a variety of distances with a very tight POI requirement. Again, you need to keep the velocity variation tightly limited.

    A hunting rifle used at moderate ranges could be OK with a 30 fps spread, but a moderate powered FT rifle needs to be better.
    Also, look at where the curve starts to fall on it’s face. It is happening pretty fast when it goes.


  3. Hi, BB
    I’ve a question irrelivant to the topic; it is said that the quality of those Diana air rifles that have their logos “engraved” on the receiver is better than those with “imprinted” logos. The latter ones have been produced since, I think, 3-4 years ago and are sold in Asia without the “RWS” mark. Ofcourse, the ” made-in-Germany engravement” and all the other Diana specifications are present on the rifle. what is your idea if one can rely on such guns?


  4. BB,

    Of all the reports you have done over the years on the subject max fill/power curve, etc…, this one is best. It can’t get any simpler or clearer than that! Heck even I can understand it.


  5. Great Good Morning Air Gunners,

    Sorry it’s been so long… It’s a very busy time of year for our raised garden bed business and I got asked to be on the AAFTA Pistol Field Target rules committee. Pistol field target has been gaining popularity in a lot of the clubs across the nation.. so AAFTA is trying to come up with a set of classes and rules for all the different air pistols folks are shooting and the different games some clubs have come up with.

    If there are any of you out there that would like to give feed back on pistol field target.. I’d sure like to hear it! .. you can email me directly or make comments here… wayne.burns@naturalyards.com

    here is what were working on now..

    > Open Pistol- liberal equipment, sighting, and accessory rules, to allow and encourage equipment innovation and experimentation
    > Hunter Pistol- practical sporting-type equipment, sighting and accessories.

    > Target Pistol- a five F/P power limit. (Probably calls for shortened maximum target ranges)
    > Limited Pistol- a gateway for beginners, no PCP’s allowed. (Probably calls for shortened maximum target ranges).

    > Offhand Pistol*- all shots to be taken from the standing offhand position. (Probably calls for shortened maximum target ranges)
    > Iron Sight Pistol*- would require specific sighting equipment definitions.
    > Offhand and Iron Sight Sub-Classes*- an alternative to stand-alone Offhand and Iron Sight classes. This would allow any venue to apply Offhand or Iron Sight pre-fixes to any class as participation warrants. (Yes to iron sight sub-class.) No need for offhand sub-class if we create an offhand Division

    > Risk Reward Scoring**- Any shooter in any class may take any shot from the offhand position. Any targets felled from offhand score double points.
    > *To reduce the number of classes, Offhand and Iron Sight options could be sub-classes of any of the (then fewer) primary classes, and offered as options as participation warrants.
    > **Another option is to have no Offhand class or sub-class; rather, a Risk Reward system that doubles the score of any target felled from the offhand position.

    Thanks in advance for your feed back..

    Wacky Wayne
    Match Director,
    Ashland Air Rifle Range

      • Hi Matt,
        Looks to be a great year.. were getting a lot of school gardens now too… 🙂
        Were also busy moving into a larger building!
        Plus I still love to make some of the deliveries north to Washington and south to LA. when they match up with events and I can shoot with the other clubs… I be a hoppin:-)

        Wacky Wayne

    • Wayne, is all of this .177 only?

      I think that you would gain a lot of interest from many of the 2240 pistol owners out there if .22 is allowed? It is a very popular and accurate pistol, even out of the box. It may beat your targets a little hard though?

      Also, will 1X red-dot type sights be allowed?

      • Hi Brian,

        OH YES.. the .22 cal is for sure included and encouraged! The kill zones are larger in general (3/4″ to 1-1/2″).. for the pistol courses, and closer.. 10-35 yards.. so .22 cal is not even a disadvantage.. like it can be slightly in the rifle FT game with some 3/8″ kill zones.

        The 2240 is a great intro FT pistol.. I have one I had converted to HPA with some customized Disco parts.. and now the Marauder pistol is out.. and that one should be real popular with the pistol FT folks.

        Looks like at the national level the fpe limit will most likely end up at 12fpe and under for all classes including open class..

        Wacky Wayne,
        Match Director,
        Ashland Air Rifle Range

  6. BB,

    Perfect post for me, having spent much of yesterday continuing to explore and learn the ways of my .22 Marauder. I have been working with shot curves trying to get the balance of power and shot count worked out. Yesterday I put over 200 rounds across my Chrony, and I’m filling with a hand pump – no wonder everyone loves tanks!

    Your line “so pellet selection is a tricky thing” really resonated for me, as the Baracuda and H&N FTT both did best in my accuracy tests (10 shot groups of about 0.35″ ctc benched at 20 yards), and I’m struggling on which to fine tune it for – right now I’m leaning to the FTT as it is flatter through my usual shooting range of about 45 yards or less, but the energy in the Baracuda’s sure is enticing (as currently tuned FTTs range 850-880 fps, Baracudas 750 – 790, both for 30 shots).

    I’m loving the accuracy – I did six ten shot groups with the FTTs at 20 yards, testing differences in head size (5.50 vs. 5.55) and 10 shot group order (1st ten, 2nd ten, 3rd ten), and found no appreciable difference in accuracy or POI (I know results will be different at longer distances, and am looking forward to the thaw to try it out). The most amazing thing was that when I superimposed all 6 groups relative to POA, I was still able to cover all 60 shots with a dime! That blew me away I still have much to learn, but am getting it pretty much where I can live with it for now. Either a little more velocity or working at a lower fill pressure would be perfect, but this is darn close.

    I do have a question for you – the settings I am at deliver a good string starting right at the 3000 psi limit of the gun. I like to recharge when I’m done shooting so that it is ready to go next time. I know keeping a good charge is in the gun is important, but is it OK to store it on an almost continual basis at a full charge level? Or would it be better to keep it at around 2500 or so, leaving me the ability to shoot off several good quick shots if needed, but then fully charge it before most shooting sessions? I would appreciate your thoughts.

    Alan in MI

  7. B.B., I wonder if there is a way to come up with an interesting and creative graph of the velocity data with the sweet spot and optimal power range indicated. It’s said that in mathematics from the most foundational level to the most advanced there is a persistent dichotomy between the algebraic and the geometric or the discrete and continuous. Some people are very good at holding raw numbers in their head, and some of us are really not but it doesn’t mean we are incapable of appreciation. One example would be the military theorist John Boyd who was trying to demonstrate the shortcomings of the F-111 relative to its Communist counterparts. He knew that strings of numbers would have no meaning for the generals who made the decision, and combining their authority with their cluelessness and predisposition towards the existing programs, they would brush aside his arguments. So, he sought for a form of representation that was “simple enough for even a general to understand.” What he come up with is I believe still the standard tool. It is a graphical representation of the an airplane’s flight envelope with our planes represented in blue and the enemy’s in red. This way it was crushingly obvious that our planes were totally overmatched in just about every way. I have somewhat of a professional interest in this field which has been called “information visualization.” Anyway, I see a curve rising and falling with the range of the sweet spot indicated and little arrows pointing at the spot where the curve changes…

    Lloyd, I believe that physicists are not entirely sure how a bicycle works or the medieval catapult the trebuchet, and an airgun is of vastly greater complexity. On the other hand, some research tools can simply generate more data without advancing you. Einstein claimed that the key to the good scientist was being able to distinguish the important from the unimportant, and John Browning didn’t need high tech for his guns, many of which (1911 and M2) are still the standards. One wonders if there are any great discoveries left in the realm of springers.

    Victor, yes Mikhail Ryabko, Russian commando, has noted that when one tries to make a “nice” martial art for commercial consumption, you will inevitably lose out on the effectiveness. You’re not going to get a lot of customers willing to be punched out like he was from an early age. But perhaps brutality is not even the key ingredient. Having seen many aspects of our educational system, I am convinced that group education with classes is a necessary evil for economic reasons and is highly inefficient. I’m with Richard Feynman who said that the best form of education is individualized attention with a tutor.

    I’m curious what your technique is for follow-through. This is vital and it is arguably more difficult than the initial hold which takes place amid stillness while the follow-through takes place amidst recoil. I see it like the medieval knights jousting. Perched on the top of a horse at the end of their lance, they must have been very skillful in managing the lance at the moment of impact. Too rigid and they would get pitched off their own horse; too light and the lance would have no power. It must have been a critical balancing act. David Tubb says that if you just try to call your shots, you will automatically follow-through. I can’t say that has worked with me, and I’ve evolved another method. What has helped you?

    Moly for accuracy is another one of those areas for disagreement at the highest level. David Tubb swears by it and markets a line of moly-coated bullets. You fire the bullets in the sequence he recommends to improve your accuracy. One account claims that these bullets took an M1A from a 2 minute rifle to sub-minute. And then there are Nancy Tompkins and her husband who claim that moly-coating is a waste of time…

    Mike so that’s what you call the side of the neck shot and the leg shot. Is the leg shot on the inside or outside of the thigh? Both will work, although I guess that the outside is easier to get to. I love hearing bits of evidence of the various techniques which I have (thankfully) never had to use in real life. One of the Russian commandos drilled me on the outside of the thigh with his knee and it hurt like hell. What was most impressive, though, was the sense of control and a vague perception of what could have been unleashed but was not. I do believe that the high kick would represent undesirable escalation as well as leaving you vulnerable. I read the book of the guy who invented verbal judo who, incidentally, also had a background in Tae Kwon Do. Very interesting. Facing a 7 foot lunatic in an alley holding a broken bottle, he says, “I’m asking for a misdemeanor (for tearing up that bar). You’re trying to give me a felony”….


    • Matt61,

      Calling shots was important to me, but following through helped my concentration as well. If you pay very close attention while following through, and do something wrong, you’ll see some directed movement and not just the random movement of recoil. Of course, dry firing tells all, like; bad trigger finger placement or grip, whether your pulling or pushing a shot, or whether or not your following through. If you don’t follow through, then you anticipate the shot going off, and flinch. Basically, you lose all of that good technique that you might have been applying a split second before the shot goes off. If you’re struggling with your trigger squeeze, then the act of squeezing the trigger is full of stress and anticipation, causing you to lose consistency. Even with an airgun, you won’t see what you’ve done wrong for a particular shot.

      Making a conscious effort to follow through, for me, replaces the stress of squeezing a less than perfect, or heavy trigger. For me, it’s natural to only be able to concentration on one thing at a time. Committing to follow through becomes my biggest distraction, which for me is a good thing. Does that make sense?


    • Matt,

      The curve is called the inverted bathtub curve and has been discussed for the past thirty years. Velocity rises until the power curve is met, then holds flat for a number of shots, then falls off again. It looks like a bathtub that’s upside-down.

      That’s if the gun’s valve is set up correctly.


        • Matt,

          Go back to my Marauder article (DECEMBER 2010) where I tuned my rifle. The MIDDLE chart shown there is the “inverted bathtub” form BB refers to. If you happen to have Excel on your computer or another spreadsheet program, you can punch in BB’s numbers here and graph them to see the form – actually an umbrella form or spreadout Bell curve. It’s easy – if you have teenagers at home or college students, they can show you assuming you haven’t played with spreadsheets on computers before now.

          Fred PRoNJ

    • In my dojo, if while sparring we did not adequately block or punch, we were forbidden to block or punch at all during that session, and the opponent was told you punish you.

      When we did tension and breathing exercises, the sensei would try to knock the wind out of you. More advanced students were kicked full force in the stomach. If students from other dojo’s showed up, and there were too many students for the sensei to punch/kicks students individually to test their breathing and tension technique, then he would have everyone lie down in a row, and he would run across the line of students, kicking down into our stomachs with his heel.

      While building up towards tournaments or gradings, they would work us almost to the point of passing out, and if you had never experienced this before, you would know what it means to “catch your second wind”.

      We sparred bear fisted, and only used very small cloth gloves when fighting full-contact that included the face.

      Our dojo was 100% non-profit, and the lineage of sensei’s was unbroken going back to it’s origins in Okinawa. It was formal and traditional to the nth degree. Only 1 out of every 32 students advanced from white belt to their first colored belt. The numbers dropped off dramatically with each successive belt. We didn’t have a full-spectrum of possible colored belts, just blue, green, brown, and black. Each belt was significant, so they weren’t handed out for motivation, or to make you feel good. It takes a minimum of 6 years to earn a black belt, but 8 years was considered fast. For your black belt, in addition to form (kata’s, taiwazi’s, ipon kumite’s, etc.) you have to fight 18 black belts, full-force, full-contact, with the only break being when you bow the next one in. Didn’t matter if you were a small 5 foot tall women, the men did not hold back. It was extremely brutal. Obviously, we had no kid black belts. That would have been impossible.

      During the first day of class for any student, you are told that, if you are here for “exercise”, for “sport”, or any reason, other than to know how to fight, the leave immediately. We were taught that no fight should last more than a couple of minutes, and should end in seconds. We were also taught to avoid all confrontation, and run away, if we could. We were also taught to never say what our rank was. The whole thing was very serious business.

    • I don’t know about the trebuchet, but physicists understand exactly how the bicycle works. At least 25 and maybe 30 years ago the magazine “Physics Today” (published by the American Institute of Physics) ran a beautiful, and fairly non-mathematical, quantitative description. The critical point is where fork and front axle intersect. Because the restoring force is not primarily gyroscopic, but rather is created when the bike tips slightly left/right by the lever between the axis of the steering gear and the axle of the front wheel.

      If the fork comes straight down from the handlebars, and has the wheel axle on that line, the bike is metastable. If the fork bends forward at it’s lower end so that the front wheel touches the ground in front of where the projection of the handlebar axis hits the ground, the bike is stablizable with small movements by the rider.

      But if the fork bends backwards so that where the wheel touches the ground is behind the projection of the handlebar axis, the bike is essentially unridable.


      Note that if the wheel’s contact point is far ahead of the fork/ground intersection, the bike again becomes unridable. Another comment: the article is clear, but by no means easy reading.


    • Matt61, it is on the outside of the leg. However, as you noted, you get the same effect on the inside as well. The strike causes all the effector nerves to fire in a random manner resulting in a lot of pain as the muscle cramps. The end result is most often only a bruise but it sure doesn’t feel like it at the time. I am familiar with “Verbal Judo”. In fact I often used the “Five Step-Hard Style” to gain compliance.


  8. Just FYI for Beeman P17 owners or potential P17 owners…

    I had not fired this pistol in about a month, and left it primed/charged last time I put it away.

    Last night, I pulled it out, loaded a pellet and Bam, dead in the 10 ring without charging the pistol first! To me, this is amazing, as my Beeman P3 would never hold a charge for more than 30 or so minutes and never a full day, even with all new o-rings.

    More reason to check out this low-dollar / hi-quality pistol.

    Disclaimer: I am not Chinese nor do I own any Chinese airgun factories.

    • Brian,

      B.B. put the P17 on his Xmas wish list. Of all the airguns he could have picked, that’s what he wanted. Sounds to me like the P17 is a treasure waiting to be discovered.


        • Well, I used it a lot. Whenever there was a P3 or P17 question I’d drag it out of the gun closet and see what’s what. But the one I thought was mine turned out to be Pyramyd Air’s, so I had to return it.

          Naturally I had to replace it.


          • Not sure how many years the Chi-coms have been making this P17 but, I think they may just have it nailed down and may even have some mfg./process controls in place?

            Of course, they started with a great set of tools and specifications in the P3.

            • Conor, overall the P17 is the same gun as the P3. Others may argue that much of it is cheaper and they are right in some ways. However, mine shoots harder, holds air longer than the P3 and is just as accurate (offhand) as my P3.

              Mine is scoped and will shoot very accurately out to approx 20 yards.

              It’s a low power target pistol and it does that job very well.

            • Conor, that’s a good question. All I know is that the P3 is made in Germany and the P17 in China. I would imagine the P3 is constructed better than the P17 but is it worth 175.00 more? Does anyone know? Thanks! Toby T.

    • Yeah, except for the issues that I’ve had with mine, I really like my P17. For a very inexpensive air pistol, it’s got great sights, is surprisingly accurate, and fits well in my hand.

    • Brian,6 years ago I stopped in a Walmart.In the sporting goods case there was a pistol I had never seen before ,so I asked to see it.The man really fought me about looking at it…..said it was broken.
      It had been returned by someone and the package was trashed.Long story short,it cost me $7.00!
      That same pistol still works and is soda can accurate at 20 plus yards without wind.

      • FrankB

        $7.00!? That’s a great story. What pistol is it?

        I am really happy with the P17, mostly because I did not expect much for $35. I felt that Beeman was just doing it’s best to unload P3 parts in a cheap package. Man, was I wrong. Overall, it is nearly identical to the P3 except for the cheaper rear sights (plastic). And there are a few other, subtle differences in workmanship however, the P17 actually shoots faster than my old P3 (428 fps vs. 401 fps with RWS R10s). I have a 4x BSA scope on it that is .25″ shorter overall than the pistol and it is a tack driver.

  9. Victor,
    Glad you found my moly reference the other day and took it the way it was intended — I think the need for it is limited in airguns, but you aren’t off your rocker :).

    • BGFarmer…..you saved me from pointing out that Dennis Quackenbush actually mentioned putting moly on bullets in one of the articles on his webpage.I can’t provide an exact quote or footnote so
      I held off posting.

    • BG_Farmer,

      You’re response was very good because it filled in some missing perspective. Many things are discovered purely through experimentation, and some discoveries take decades or more to fully realize or bear fruit. Again, what got me thinking about all of this was a discussion about barrel accuracy over time. It’s been realized that some 30 – 40 year old barrels shoot better than brand new state-of-the art barrels. This accuracy is attributed to the fact that after no many rounds, the lead starts to polish the barrel. I think this is really good stuff to know.


  10. B.B.

    I would also like to comment on how well you did on this article explaining the power curve of a PCP. You’ve done it very well in the past too, but this one is tops!

    And once again, I’ll add my praise to the Air Arms S400 series. The adjustable power, single shot AAS400 sidelever will also fit into the MPRFT stock this rifle sports.. I’ve done that several times and it really makes a nice rig..

    I’ve also heard of folks internally adjusting this AAS400 MPRFT your reviewing.. can’t wait to see how hard it is to change back and forth… I think I heard you can get it up to about 16fpe.

    That is really a great shot string and wonderful pressure range to have it in.. not all of the AAS400s I’ve owned and tested could brag such a shot string! That’s a keeper.. tell PA I’d like it when your done… if you’re not keeping it. 🙂

    Wacky Wayne,
    Match Director,
    Ashland Air Rifle Range

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    Get the most out of your equipment when you work with the expert technicians at Pyramyd AIR. With over 25 years of combined experience, we offer a range of comprehensive in-house services tailored to kickstart your next adventure.

    If you're picking up a new air gun, our team can test and tune the equipment before it leaves the warehouse. We can even set up an optic or other equipment so you can get out shooting without the hassle. For bowhunters, our certified master bow technicians provide services such as assembly, optics zeroing, and full equipment setup, which can maximize the potential of your purchase.

    By leveraging our expertise and precision, we ensure that your equipment is finely tuned to meet your specific needs and get you ready for your outdoor pursuits. So look out for our services when shopping for something new, and let our experts help you get the most from your outdoor adventures.

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  • Warranty Info

    Shop and purchase with confidence knowing that all of our air guns (except airsoft) are protected by a minimum 1-year manufacturer's warranty from the date of purchase unless otherwise noted on the product page.

    A warranty is provided by each manufacturer to ensure that your product is free of defect in both materials and workmanship.

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  • Exchanges / Refunds

    Didn't get what you wanted or have a problem? We understand that sometimes things aren't right and our team is serious about resolving these issues quickly. We can often help you fix small to medium issues over the phone or email.

    If you need to return an item please read our return policy.

    Learn About Returns

Get FREE shipping on qualifying orders! Any order $150+ with a shipping address in the contiguous US will receive the option for free ground shipping on items sold & shipped by Pyramyd AIR during checkout. Certain restrictions apply.

Free shipping may not be combined with a coupon unless stated otherwise.

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