Why are first shots different?

by B.B. Pelletier

This post came from a comment left by K. Rihanek, who was surprised that the first shot from his spring gun was so different than the rest of the shots. In fact, this is a phenomenon that applies across the board, and not just to airguns. But, airguns are all that I will address.

Starting with springers
The first shot from a spring gun usually goes faster than the ones that follow. In fact, I can’t remember a time when I saw anything else, though I have heard that in extreme cold, springers do need to warm up before reaching their normal velocity. Anyway, a faster-than-expected first shot was what our reader had noticed.

Some people think that when left to sit, air rifles will weep oil at the piston seal. Either that or the first shot will not inflate the piston seal fast enough, resulting in a slight detonation that boosts velocity. After that, the seal is flexible once more and velocity will remain within the expected range. But, put the gun aside for a length of time (12 hours or longer), and you’re back with the first shot phenomenon again. I believe in the second explanation (stiff seals) over the first (weeping oil), because even guns that are not greased in any way will display this phenomenon.

There’s not much that can be done to prevent this, but hunters and field target competitors will always shoot several shots to get their guns up and running before they go to work.

Pneumatics
Pneumatics are not immune to the first shot phenomenon, either. Precharged pneumatics are the worst, with regulated guns being the absolute worst of all. They always need a first shot to “Wake up the regulator.” Guns with adjustable power, such as the AirForce rifles also need a first shot after a power adjustment before they will shoot as expected. In my experience, they always shoot the first shot after an adjustment on the side from which the adjustment was made. In other words, if they were adjusted from faster to slower, the first shot will be faster. If adjusted up in velocity, the first shot after adjustment will be slower.

Even multi-pumps and single-strokes show a difference with shot No. 1. It seems they also need the exercise of going through the motions of firing before they can settle down and shoot normally. I think that they are no different than the spring guns, in that their seals need to be exercised, however, with these kind of guns the first shot after adjustment is usually slower than expected.

CO2 guns
If a gun was going to be immune from the first shot phenomenon, you would think it would be a CO2 gun. But, again, they do display it. In their case, the first shot is usually slower, though the temperature has something to do with it, as well. If it is very cold, the first shot might be very fast, and the follow-on shots might all be slower, because the gun is cooling and cannot recover.

This is a tip I wanted to pass along to all of you. I always shoot several “wake-up” shots before expecting the gun to perform as expected. I thought everyone did the same, but from the reader’s observation, I’m now guessing they don’t.

30 Responses to “Why are first shots different?”

  • JerryL Says:

    Hi BB
    I have also noticed that when you change brands / type pellet and then go back to what the gun is sighted in with , that the next 2 – 6 shots might be off a tad . But after the couple of shots with the sighted in pellet it settles back down.

  • pestbgone Says:

    B.B.,
    Thank you, Thank you!
    All this time I thought it was me needing to warm up, and for once, that’s not the case.
    Pestbgone

  • twotalon Says:

    My chrono tells me that I need to shoot my talons TWICE after doing anything at all. Tank fill, switching to a new tank, power wheel adjustment, top hat adjustment,final snugging of tophat setscrews, change of pellets, or change of pellet lube.

    Once in a while it only requires one shot, but better to do it twice…and with the pellets you are going to be shooting…to make sure.

    Don’t shoot rejected pellets to conserve on your good ones. Improper pellet fit will not generate the same pressure curve. Most rejected pellets can be used for plinking, and will not be a total loss.

    twotalon

  • pestbgone Says:

    B.B.,
    And maybe someday, if you would be so kind, a similar question about scopes. If the scope is off 1/4″ at 10 yds and the adjustment says 1/4″ per click at 100 yds, why don’t 10 clicks necessasarily fix the POI? Even after several shots to settle the adjustment in.
    Thanks again,
    Pestbgone

  • Anonymous Says:

    BB, and all,

    Have you ever had a rifle that was shooting like a champ with a particular pellet and later decide that it didn’t like that pellet?

    I bought a Crosman G1 Extreme (Phantom) at the local W-Mart last year, and after several thousand shots, it has tamed into a very likable, accurate rifle. Its shooting behavior is sweet, and I can shoot .25” groups at 20 yards with the rifle resting on shooting bags filled with ground walnut shells. I would not say that this rifle is hold sensitive, and it likes almost every kind of pellet I throw at it. The point of impact may change slightly, but the groups remain tight.

    With the luck I’d had with the G1, I decided this spring to purchase a Remington Summit from PyramidAir. The firing behavior was harsh at first, but after a thousand rounds or so, it too began to calm down. Outwardly the guns are identical (action only, the stocks are different) and soon the Summit began to group nicely with RWS Superdomes, and Crosman Premier Domed Lights. I must add that the only change made to both rifles was the addition of the GRT-III trigger. Those of you that have installed them know what I’m talking about.

    My job allows for a lot of free time, so I shoot everyday. It may be a second childhood thing (I wasn’t allowed to have a BB gun “You’ll put your eye out!”) but I’m smitten with airguns in my mid fifties. That being said, I’m getting very comfortable with spring piston powerplants, and it doesn’t take me long to get into the groove.

    In the theme of the “first shot” phenomenon, I always shoot many “first” shots before I begin to evaluate my performance, or the performance of a particular pellet. So a few days after nailing every .25” bullseye at 20 yards with the Summit, it began to spray Crosman Premier Domed Lights all over the place. Just to make sure that it wasn’t me, I shot the G1, and I was once again stacking them. I cleaned the Summit using J-B Non Embedding Bore Cleaning Paste, just as you have described, but the accuracy did not improve.

    We all want every airgun we buy to be a good one, and this purchase was no different. I knew this rifle was accurate, but what was different? I decided to try a few different pellets, so I loaded up some Crosman Premier Supermatch. The groups tightened right up, yet the Supermatch Pellets were NOT grouping with this rifle early in the break in period. I next tried RWS Hobby pellets, and once again, I was stacking them. Yet originally, I could not get a three inch group with those pellets at 20 yards.

    What is it that changes in an air rifle that make it like, then dislike a particular pellet, and then suddenly like a third? With so many variables to choose from, I don’t really know, and I wonder if I ever will. I equate shooting a spring piston air gun to the art of striking a golf ball. You golfers know what I mean. When you finally hit the sweet spot, you never feel it. The same with the springer. In any event, those of us that shoot air guns share a constant source of enjoyment and entertainment seeking these answers.

    Anyone, please chime in.

    Michael in Florida

  • .22 multi-shot Says:

    B.B.

    When you are target/pleasure shooting or hunting, shooting a few rounds first is practical. What about situations where you have to take care of something immediately (a gopher is poking his head out of a hole in your lawn, a rattlesnake has shown up in the yard with your kids, etc.)?

    Thanks,
    .22 multi-shot

  • Anonymous Says:

    micheal in florida,

    there is probably a slight hold difference in the two rifles, and you might have started to hold the summit similar to how you hold the g-1 extreme(btw, what pellets did you have luck with the g-1?). try firing it with more technique, and see what happens. im sure bb will have more advice.

    Dave

  • B.B. Pelletier Says:

    Jerry,

    I haven’t looked for that before, but now that you have alerted me, I’ll keep my eyes open.

    Thanks,

    B.B.

  • B.B. Pelletier Says:

    Pestbgone,

    I will try to answer the scope question soon. There is a real reason it happens.

    B.B.

  • B.B. Pelletier Says:

    Michael,

    Wow! I haven’t seen this sort of performance in any of my guns, but I would suspect that diring break-in the mainspring adjusted itself to different resistances. That’s the best I can come up with. I hope somebody can explain this to me.

    B.B.

  • B.B. Pelletier Says:

    .22 multi-shot,

    Though I didn’t get into it in that post, I do have a solution. My Talon SS and Daystate Harrier are both sighted to the first shot, so they are my go-to guns.

    For hunting deer, I have a .30/06 that puts the first shot in the right place, but will walk shots 2 through 5 into a J-shaped group.

    B.B.

  • twotalon Says:

    Michael……..
    I have gotten hold of a bad tin of pellets. Inconistent size for some reason.
    Got tin of cp hp .177 that would not stay on a soda can at 15ft, where they normally would make just one hole.
    Head diameter was noticeably smaller on about half the pellets when measured or checked for fit in the muzzle of a different rifle.

    twotalon

  • Anonymous Says:

    did you switch to a different lot of pellets. 1 tin can be much different from the next even from the same source

  • twotalon Says:

    There was no lot number on the tin.
    Have gotten the same kind since, but have found them to be very consistent in size with no problems.
    Did get a tin of the same kind recently that had a lot of dirt (small lead particles). Nothing wrong with the pellets. Washed them off in a strainer to remove all the dirt.

    twotalon

  • .22 multi-shot Says:

    Thanks B.B., that must take a while to get the go-to guns sighted in for 1st shot accuracy.

    .22 multi-shot

  • Anonymous Says:

    B.B.,

    Accuracy comes forom the barrel as you have always said. Triggers and all that are just things that determin shootability if thats a word. So i figure if i find out what the best barrel is then i can find the most accurate gun.

    Anschutz barrels are supposably best. Over walther and everything else. I dont see that as a fact.

    I know my theoben has a Anschutz barrel so it should be as accurate as any. I dont know who makes daystate barrels or if they are made by daystate so if you know the answer to that i would love to hear it.

    I am excited for your answer on my question about accracy in different calibers. Thanks for doing a full report on it.

    you have probibly figured out who wrote this comment because its about daystate and accuracy but just so your positive:

    -sumo

  • Anonymous Says:

    B.B.,

    Accuracy comes forom the barrel as you have always said. Triggers and all that are just things that determin shootability if thats a word. So i figure if i find out what the best barrel is then i can find the most accurate gun.

    Anschutz barrels are supposably best. Over walther and everything else. I dont see that as a fact.

    I know my theoben has a Anschutz barrel so it should be as accurate as any. I dont know who makes daystate barrels or if they are made by daystate so if you know the answer to that i would love to hear it.

    I am excited for your answer on my question about accracy in different calibers. Thanks for doing a full report on it.

    you have probibly figured out who wrote this comment because its about daystate and accuracy but just so your positive:

    -sumo

  • Brit Visitor Says:

    Ah, so it hasn’t just been my imagination after all! (-:
    Been finding the “first shot” thing applies to gasrams (perhaps more noticeably so) as well as to conventional springers.

  • Anonymous Says:

    BB.

    Im looking for a smooth springer for long distance accuracy to be used with a peep sight

    thanks

    peeplover

  • pestbgone Says:

    Sumo,
    I am way down on the knowledge curve compared to all you guys, but seems to me that a consistent power plant would have a big effect on accuracy, too. Like having the exact same primer and powder charge in a firearm to accelerate the bullet/pellet down that perfect barrel the same way each time.
    Just my two cents.
    Pestbgone

  • B.B. Pelletier Says:

    .22 multi-shot,

    It really doesn’t take too long with these two guns. I guess that’s why I use them this way.

    My .30/06 came to me sighted in with 150-grain bullets, but I switched to .22 caliber Remington Accellerators. Now THAT took some time! What I did was shoot until I was centered, then let the gun cool for several hours and shoot again. That shot was off, but I treated it like it was a group, and adjusted it to strike center.

    B.B.

  • B.B. Pelletier Says:

    Brit Visitor,

    My oversight!

    I have owned a few gas rams, but maybe not enough to make the connection. I’m glad you were there!

    B.B.

  • B.B. Pelletier Says:

    peeplover,

    How about a Diana 54 with a Williams peep?

    B.B.

  • Anonymous Says:

    pestbgone,

    yes, the power plant has much to do with accuracy. In the guns i have been talking about the powerplant is just about perfect so the barrel is all i think about. I have been talking about a daystate air wolf. The spread is about .2 fps in a ten shot string. That cant have much affect on accuracy.

    -sumo

  • pestbgone Says:

    Sumo,
    .2 fps spread…. Wow, I’d say perfect! Nice to have such great choices.
    Pestbgone

  • Joe in MD Says:

    I have suspected condensation, dust, dirt, etc. as a first-shot phenomenon as not every first-shot seems to be affected. Especially when I take my Steyr from a cool environment to a warm humid one, I believe the first shot should be blown-off.

  • DB Says:

    B.B.,
    Will dry firing one or more shots from a multi pump or PCP solve the first accuracy shot issue?

    I routinely dry fire one shot form my multi pump anyway. This is to clear it of the one pump stored in it from the last outing.

    Also… if you do not shoot for a few hours does the effect return or does it take several ours or days to return?

    Thank you,
    DB

  • B.B. Pelletier Says:

    DB,

    You have a good question that I have not tested. My first shot has always been with a pellet so I could tell the difference. I suppose it should be tested.

    I also shoot off the stored air before shooting.

    B.B.

  • DB Says:

    B.B.,
    It does seem to work on my 1377. Have tested it a couple of times… though it does not yet seem to have a major difference on the first few shots of the day anyway.

    Once my Discovery shows up I’ll test it on that too.

    Like you I’ve avoided wasting CO2with dry fire. But do use the last bit of yesterdays spent CO2 cartridge to exercise the gun before changing it.

    Do you think this is a once a day issue? Or is it any time the gun sits idle for a few hours?

    Thanks,
    DB

  • B.B. Pelletier Says:

    DB,

    I think you have to wake the action up after a longer rest – perhaps 12 hours.

    B.B.

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