Home Blog  
Air Guns SigAir Super Target pistol revisited: Part Two

SigAir Super Target pistol revisited: Part Two

Sig Super Target
Sig Super Target air pistol.

Link to Part 4 of previous reports
Part 1

This report covers:

  • Today?
  • Testing as is
  • Oiling the piston
  • Shimming the factory seal
  • The square-section o-ring
  • Discussion
  • Steveoo’s final comments 
  • Where is 400 f.p.s.?
  • Single-stroke velocity boost
  • Velocity with five pump strokes
  • Summary

Before we begin I have a small update. Remember the tuned HW 30S I wrote about in the report titled, What a difference a stock makes? I set that rifle up to kill pests in and around the house. At the end of last week I used it that way for the first time. A small lizard came in my front door when I opened it. Lizards are not welcome in Casa Pelletier.

When I had my cat, Dale Evans, she was the lizard hunter in the house, but she’s not with me any longer. So I grabbed the rifle, used a pellet from the pouch that is attached to the triggerguard and shot the lizard in the head from 10 feet. If that sounds simple try shooing anything at 10 feet when your rifle is sighted for 10 METERS (33 feet)! I hit the critter in the head and it never moved — a perfect shot!


Today we’re going to try a recommendation for improving the velocity of the SigAir Super Target air pistol. I found this on the Airgun Nation website. Member Steveoo tells how to boost the muzzle velocity of a SigAir Super Target air pistol by up to 50 f.p.s. Actually he talked about the FAS 6004, but as you learned in Part 1, the two air pistols are essentially the same.

I wanted to copy what I read on the Airgun Nation website for you to read but their software prevents that, so I will tell you. In February of 2021, member Steveoo told everyone that when FAS switched from the hand-built model 604 to the production model 6004 they stopped using a thick proprietary breech seal and used an off-the-shelf o-ring instead. He criticized FAS for that. I applaud them for entering the 20th century. He said the o-ring sits too low in its groove and looses 50 f.p.s. velocity.

He then said there are two ways to gain up to 50 f.p.s. more velocity. One is to shim the existing o-ring breech seal with a 0.3mm shim. The other is to use a square-section o-ring. He posted pictures of the parts to buy from McMasters-Carr, so I bought them. With shipping the purchase came to $40.88. Today I will install both solutions and show you how they affected my pistol.

Sig Super Target parts
These are the parts Steveoo recommended.

Now we will learn whether a forum recommendation works or not.

Sig Super Target factory seal
The factory breech seal. It looks a little low, but it’s hard to tell.

Testing as is

The first test was with the pistol as it was. Nothing was done. I shot five RWS Hobby pellets that were used for all tests today. The factory breech seal that is an o-ring sits proud of the barrel, and I don’t think it is a problem. Steveoo said it sits too low in its groove, so his recommendations will hopefully be changing that.


The average for this string is 347 f.p.s. The spread is 14 f.p.s. This is where the pistol is today and back in November of 2019 ten Hobbys averaged 338 f.p.s. with a 10 f.p.s. spread. Not much has changed in the last 4.5 years.

Oiling the piston

I injected two drops of ATF Sealant oil through the intake air hole to oil the piston seal. You probably aren’t supposed to do that, but air pump pistons do need oil to seal well so why not? Then I shot five more Hobbys.


I see no real change. The average of this string is 348 f.p.s. and the spread is 6 f.p.s. The spread did get a little tighter.

Shimming the factory seal

Now I removed the factory seal and installed a shim. The shim Steveoo recommended did not fit directly, but after 10 minutes work with a diamond file it did. The factory o-ring seal went on top of the shim and the gun was ready to go. This is one of the two fixes that Steveoo says gives up to 50 f.p.s. more velocity.

Sig Super Target factory seal and shim
Factory seal and shim.

Sig Super Target factory seal shimmed
Factory seal shimmed. It clearly sits higher in the breech.


There was a SLIGHT velocity increase (8 f.p.s.) with the shim. The average for five Hobbys is 356 f.p.s. The spread is 18 f.p.s. This doesn’t seem worth doing — at least not on my pistol.

Stock up on Air Gun Ammo

The square-section o-ring

The next test was to try the square-section o-ring. I removed the factory breech seal and shim and installed the square-section o-ring that fit the groove perfectly.

Sig Super Target square-section ring
The square-section o-ring.

Sig Super Target with square ring
The square o-ring also sits higher in the breech.


The average for this string is 348 f.p.s. which is exactly what the factory seal gave after I oiled the piston seal. The spread is 7 f.p.s.

What about shimming the square-section o-ring? I tried it and no dice. The breech refused to lock closed.


From what I see neither of these two recommendations do much for my Sig Super Target pistol. And that is why we test.

After reading about the velocity improvements Steveoo posted on Airgun Nation I had high hopes for some velocity improvement, but it didn’t happen.

Steveoo’s final comments 

Steveoo said he did contact Chiappa (for whom the FAS 6004 is made) to “show them where they were going wrong, but they were not listening to a better engineer.” I submit that perhaps they did listen but knew they got it right the first time.

Where is 400 f.p.s.?

Manufacturers have to list the highest possible velocity for an airgun in their advertisements for liability reasons. FAS and all retailers list the 6004 and the SigAir Super Target at 400 f.p.s. When I tested it in 2019 I got a top speed of 413 f.p.s. with 5.25-grain Sig Match Ballistic Alloy pellets. But I did it in a funny way. 

Single-stroke velocity boost

To boost the velocity of ANY single stroke pneumatic, pump the gun 3/4 of the way five times for each shot. Only close the pump on the last stroke. The average for Sig Match Ballistic Alloy pellets in 2019 shooting the normal way was 385 f.p.s. With the trick I just shared the average increased to 408 f.p.s. So I did the same today, only with Hobbys.

Velocity with five pump strokes


The average for this string is 377 f.p.s. The spread is 21 f.p.s. The boost is nice but it’s too much work when you just want to shoot the pistol. It’s just a trick. I have found for when single-stroke seals are hardening with age. This is a way to bring them back. But with age-hardened seals this fix is just temporary.


Today we have taken the time (and spent the money) to check on one airgunner’s recommendations for improving the performance of the FAS 6004 target pistol, which is a close cousin of the Sig Super Target single-stroke pneumatic pistol. You must decide whether it was worth the effort, but at least now you know.

On the other hand, in my research I found a lot of praise for the earlier FAS 604 pistol. Every review I read says it is the better pistol, compared to the 6004. I have therefore hopefully made arrangements to get one to test for you. I want to see if it really is better or is it just guys talking on forums without really knowing?

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.

32 thoughts on “SigAir Super Target pistol revisited: Part Two”

    • Siraniko,

      My plan is to also do an accuracy test because there are .177 pellets that were not around when I tested it last. And I just received a few more of them.


  1. BB
    Is the barrel able to be moved in and out some? If so, perhaps they simply pushed it up against the smaller new seal to eliminate any gap. I would suggest a talcum powder seal check but since it slides into place it probably would not give a good indication.

  2. Not long ago I found a snake that appeared to be trying to get into our garage. I had my Crosman 2240 pistol handy and shot the snake in the head. It took me a couple of shots to hit it. But when I did, it was killed instantly.
    Thanks for the interesting report. I would have thought that a tissue paper test might show if the seal was leaking substantially. Did Steveoo say anything about doing a tissue paper test before he swapped seals? I am looking forward to the accuracy tests.

    Edit: After thinking about it further, there doesn’t appear to be a good place to place a tissue paper (like there is on a break barrel rifle). If you see this edit, it means the edit function works now on my iPad.

    • Derrick,

      I realize that each airgun is slightly different, but I would have been happy to see even a 25 f.p.s. increase. I did this test just to see if Steveoo was possibly right. It was worth it to find out he wasn’t and that the SigAir Supewr Target was made right to begin with.

      Now I am looking forward to seeing that 604, to see what everyone is talking about.


  3. Good morning all!

    As this is an imported product I wonder why Steveoo didn’t use a pre-made metric, vs. SAE, size square o-ring and shim; both in stock from McC. These are also Buna with a slightly “softer” 70A durometer. (May I suggest Viton is overkill for this application?)

    Apart from the high freight charges, McC has good service and always has the metric o-rings, seals & other hardware I need for my “old gals” and old motorcycles.

    • Both in my career work, and for Pelletgage, McMaster Carr was a good supplier. They have huge inventory, and ship immediately. Their online catalog is excellent, and you can get efficient telephone support if needed. Not always the lowest price, but usually OK.
      I have used another supplier lately that has done a great job, and has good pricing and shipping charges – that is Bolt Depot.

  4. BB

    Just wondering,, how much “Kentucky windage” did you use for the lizard shot? Whatever it was it appears that it was enough. Sometimes close shots are harder than those that are farther away. Good on ya.


    The edit function is back.

  5. B.B.,

    As promised:
    I shot my early production #2XX SigAir Super Target
    Pellet was RWS 7.0 gr. R-10 Match; straight from the tin
    I used my LabRADAR Doppler chronograph

    Average: 380
    Highest: 383
    Lowest: 377
    Extreme Spread: 6
    Standard Deviation: 2.3
    Number of Shots: 10

    I fired 3-5 blank shots to warm up the pump seal.
    I used a straight pump action trying to pump with the same force/action each shot cycle.


    PS: original O-Ring in Breech

  6. “Dale Evans, she was the lizard hunter in the house, but she’s not with me any longer.”

    BB, that is so sad; she was such a sweet and awesome kitty; I’m sure she is missed.

  7. BB inserted this for thedavemeister,

    I hope someday, when the time is right, that you get another kitty.
    Our dog, and all ten cats here at the farm are all rescues.
    The oldest indoor cat we have is Sallie Mae, a really sweet fluff ball that is 16-years-old.
    We rescued a kitten, Kelli, to which Sallie Mae became a surrogate momma.
    Kelli sleeps on her “momma” like she’s a pillow.
    I’m afraid when Sallie Mae passes away that I won’t be able to wait; I’ll have to call a few shelters I know and ask for a nice senior female cat that no one wants, then see if she can bond with Kelli before the little spud freaks out. I’ll likely freak out myself a bit; Sallie Mae’s been a staple around here for years.
    Blessings to you,

Leave a Comment

Buy With Confidence

  • Free Shipping

    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.

    View Shipping Info

  • Shipping Time Frame

    We work hard to get all orders placed by 12 pm EST out the door within 24 hours on weekdays because we know how excited you are to receive your order. Weekends and holiday shipping times will vary.

    During busy holidays, we step our efforts to ship all orders as fast as possible, but you may experience an additional 1-2 day delay before your order ships. This may also happen if you change your order during processing.

    View Shipping Times

  • Shipping Restrictions

    It's important to know that due to state and local laws, there are certain restrictions for various products. It's up to you to research and comply with the laws in your state, county, and city. If you live in a state or city where air guns are treated as firearms you may be able to take advantage of our FFL special program.

    U.S. federal law requires that all airsoft guns are sold with a 1/4-inch blaze orange muzzle or an orange flash hider to avoid the guns being mistaken for firearms.

    View Shipping Restrictions

  • Expert Service and Repair

    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.

    View Service Info

  • 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.

    View Warranty Details

  • 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.

View Shipping Info

Text JOIN to 91256 and get $10 OFF Your Next $50+ Order!

* By providing your number above, you agree to receive recurring autodialed marketing text msgs (e.g. cart reminders) to the mobile number used at opt-in from Pyramyd AIR on 91256. Reply with birthday MM/DD/YYYY to verify legal age of 18+ in order to receive texts. Consent is not a condition of purchase. Msg frequency may vary. Msg & data rates may apply. Reply HELP for help and STOP to cancel. See Terms and Conditions & Privacy Policy.