How do you break-in your new Breakbarrel/Underlever Air Rifle?

How do you break-in your new Breakbarrel/Underlever Air Rifle?

There are many theories on how to break in your new breakbarrel/underlever spring/gas piston air rifle. I am going to share the steps that I have been doing for years and it has been quite successful for me.

Shoot the rifle! Do not let the gun sit in the box for several weeks before you shoot it.  This should be a standard practice regardless of what type of airgun you have purchased.  The reason being, most airgun retailers will accept full returns or exchanges within the first 30 days of purchase. You need to thoroughly test the gun to make sure there is no *manufacturer’s defects. I have purchased hundreds of airguns and unfortunately, I have experienced a handful of defective ones. You need to shoot a minimum of 200 rounds right out of the box.  Don’t overly worry about fine tuning your sights at this point. Just get those rounds through the gun during this “Break-in Period.” The phenomenon known as “Dieseling,” can be very common during the break-in period.  This is when the piston seal or the chamber of a spring or gas piston airgun is newly lubricated. Dieseling occurs when some of the newly-applied oil is put under pressure and reacts explosively with air in the compression chamber during the firing cycle. The excessive lubricants will eventually burn up and the rifle will smooth out as you put more pellets through it.

Clean the rifle! After shooting your 200 plus pellets, you need to make sure the barrel is clean and grease free. Many times, these guns are really grimy coming from the factory.  Many of the Chinese built rifles are heavily lubricated to avoid rusting during extensive shipping distances.  Try to avoid using any petroleum-based solvents in the barrel and chamber area.  These products can be harmful to the Breech and Piston seals.  I personally use “Ballistol” it works very well and it is not harmful to the seals. Also, lubricate all the pivoting points on the cocking arm. You can use spring cylinder oil or any light gun oil lubricants for this. I repeat the cleaning and lubricating process every 800-1000 rounds.  Unlike conventional firearms air rifles do not require cleaning after every use.  Although, I do like to wipe the rifle down. I actually have been using WD40 for 40 years. I spray a small amount on a microfiber towel and then wipe the gun down after every use.  By the way do you know what the meaning is of “WD40?”

Tighten all stock screws! Make sure all your stock screws are secure.  I like to remove each screw and put a couple of drops of the “Blue” thread locker and then re-install.

Find the right pellet for your Rifle! Each rifle will have that special pellet that is the most accurate. This is probably the most time consuming and frustrating process. All pellets do not shoot alike and some rifles are more pellet picky than others. What you are looking for is the pellet that gives your rifle the tightest groups. I go through numerous styles and weights researching for that special pellet. Occasionally, in a very rare circumstance, you may find an inexpensive pellet that your rifle likes.  Again, that is extremely rare.  In my experience the top three best pellet manufacturers are Haendler & Natermann (H&N Sport), JSB/Predator International and RWS. 9 out of 10 times the best pellet comes from one of these manufacturers.  

Sight in your gun! Once you find the pellet that groups the best it is then time to sight in your rifle. You may see your groups tighten up quite a bit depending on how you hold the rifle. Remember these are reverse recoil air rifles.  When you pull the trigger, the piston is actually going forward, away from the shooter, creating high pressure in the chamber which forces the pellet out of the barrel.  The piston will make contact with the front of the chamber and begin to bounce backward prior to the pellet leaving the barrel. This is why it is extremely important to hold the gun steady as possible through the entire recoil process. That is why I have found the ultimate accuracy is shooting the breakbarrel rifles off of bipods. Keep in mind, the reverse recoil can be very hard on conventional rifle scopes that are not “AIRGUN” rated. You might need to upgrade your scope to achieve the ultimate accuracy.

*NOTE If you go through all the listed break-in steps and your rifle does not group well it is very possible your gun is defective.  This is uncommon but over the years, I have returned several air rifles as defective because they simply would not group. Look at some reviews and see how well your specific air rifle model shoots.  Compare those groups to your own.

Remember, “Life is too short to worry about the small stuff! Just have fun and shoot some airguns!” (WD40 i.e. Water Displacement and it took 40 times to get the formula just right, invented in San Diego CA in 1953))

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Comments (10)

  • Randy Reply

    Very helpful to read this. Thank you for taking the time to write it, and sharing “know-how!”

    January 21, 2020 at 8:30 pm
  • Steven Suttle Reply

    Very informative and enjoyed very much. I just purchased and hatsan 125 vortex 22 caliber. An older version of the sniper. Has been sitting for awhile grouping not good. Where did you get those bipods from?

    February 28, 2020 at 11:17 am
    • JC Reply

      Look right here on my website for the Bi-pods 🙂

      March 2, 2020 at 11:03 pm
  • Gregory Martucci Reply

    Very helpful! I didn’t understand exactly what dieseling is. I did not know it oil mixed with air acts as combustion, which in theory would add FPS until burned off and maybe stress the seals? However, that would make sense as to why my groupings have gotten “MUCH” tighter. Went from “big” cantaloupe groupings, to quarter sized after 150 shots and getting the same from further distances. Definitely noticed shooting in a prone or sitting position with a bag makes a huge difference. The artillery grip still slides me as I’m used to high powered firearms and holding it the way some of these reviewers do seems so foreign and my instinct fights against it. Those bipods look like they would definitely help my accuracy. I have a Gamo swarm whisper 10x .22, however I’m not sure how I would mark the synthetic stock to line up the rails? Maybe scratch a small reference point to drill with something sharp, just wanna make sure they are symmetrical like you demonstrated with the wood grain stock. I’m comfortable doing the work however the synthetic Gamo stock rail placement slides me. I’ve seen yours however I’m not there yet. I’ll stick to a bag until that annoys me to get the bipod. I only spent $149.99 and I plan on getting a better quality break barrel. However, that 10 shot mag on the Gamo is wonderful for a break barrel. Any suggestions?

    June 3, 2020 at 3:19 pm
  • Estoy Listo Reply

    Excellent article. Thank you. I just bought a Ruger Blackhawk, and I’m looking to start the break in tomorrow.

    I grew up in the once-fine city of Seattle, and I saw a lot of Boeing engineers in the late 60s wearing WD-40 pocket protectors. It was then that one of them explained that it stood for water displacement, which made no sense to me at all.

    December 3, 2020 at 6:23 pm
  • Lynn Sanderson Reply

    Bought bipods and not sure how to shoot with them. They have some back and forward leeway. Should I Push forward, keep in the middle or pull back. Should feet be on firm, grippy surface.

    March 6, 2021 at 9:32 am
    • JC Reply

      I like to keep the pressure forward on the bipods since the initial recoil will go forward. Also, the more stable the base is the better off, so a non-slippery service is always better. You just have to experiment what works for you and your rifle. Try different hold and hand positions as well. Some rifles like a very firm position in the shoulder, other like a lighter touch. Just have fun with it and you will find the position that best works for you and the rifle.

      Happy Shooitng ????

      March 6, 2021 at 10:07 am
  • john dougherty Reply

    I am no expert on air rifles, but I like them. They are very different from firearms and I DO have some experience with them. Being new to pellet rifles (5 so far), I have watched a LOT of YT videos produced by some very experienced pellet rifle shooters (some not so experienced) and I find a lot of inconsistencies with their advice. JC to me is the final word on air rifles and the person I rely on for factual information. Maybe it’s his background, but you can rely on his discipline and experience when it comes to the facts. Can’t do better in my opinion.

    June 6, 2022 at 2:29 pm
    • JC Reply

      John,
      I appreciate your comments and your support. This can be a very addictive hobby, but so much fun because the majority of the airguns can be used in your backyard. Happy Shooting! JC

      September 3, 2022 at 9:22 pm
  • David H. Reply

    Perfect advice! Thank you J.C. for the fantastic trigger screw for the Gamo Air Rifle C.A.T. trigger and the bi pods which greatly enhance accuracy and enjoyment for these fine modern airguns! I’m newly retired and really enjoying the wonderful accuracy of modern airguns in my backyard! Thanks again J.C. for developing and marketing accuracy improvements that enhance our enjoyment of air rifles!

    October 12, 2023 at 3:32 pm

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