Can loose barrels be accurate?

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • Breakbarrels
  • In battery
  • A lathe compound tool rest
  • The point
  • Pistols with fixed barrels
  • M1911 — the barrel movement champ!
  • Summary

I’m doing today’s report for Peter, a reader who expressed concern over the looseness of the barrel on his SIG P226 X5 BB Open pistol. He noticed that when the slide was back after the last shot, the barrel seemed loose and he wondered if that had any impact on accuracy. He is getting dime- and nickel-sized groups of BBs at 15 feet, which he thinks are good and I would agree. But — is he missing out on anything because the barrel is loose? It’s that age-old question — I like what I have now, but is there something more that I don’t know about?

This is a subject a lot of readers probably ponder, but nobody ever addresses it. And I normally wouldn’t address it either, except it is necessary that we understand what’s happening so we can appreciate out airguns to the fullest.

Breakbarrels

Allow me to begin with a short discussion of the breakbarrel spring rifle. I know it doesn’t sound like the same thing that Peter asked about, but stay with me — because it is.

New airgunners tend to think that breakbarrel airguns can’t be as accurate as fixed barrel airguns, simply because their barrels move when they are cocked. How could they possibly return to the same place every time? And yet, there is overwhelming proof that they do! Vintage 10-meter target rifles like the Diana model 65 and the Walther LGV will drill their pellets through the same hole — one after another. Even though their barrels are broken open during cocking, they always manage to return to the same place every time.

Walther LGV Olympia
Walther LGV Olympia is a very accurate breakbarrel.

In battery

That place is called “in battery.” It’s not really, but I’m going to use that term, because it describes so accurately what is happening. In battery is a term that comes from artillery. After a cannon barrel recoils several feet upon firing, the recoil mechanism pushes it back to the same place it started. That way the shell leaves the muzzle at the same place every time. You may recognize this as my explanation of the artillery hold.

I saw this happen hundreds of times on the inside of an M60A1 tank turret when the 105mm M68 cannon fired. The breech recoiled back several feet and extracted the empty shell that fell to the floor of the turret, while the cannon barrel was pushed back into battery by massive coiled steel springs. We considered our gun accurate if we could put several shots through a 24-inch circle at 1,200 yards.

A breakbarrel pellet rifle has a definite place for the barrel to be when it is closed. Target rifles have precision pads and shims to locate the base block precisely when the barrel is closed. If the base block is always in the same place, the barrel it holds will also be in the same place every time. This is difficult for some new airgunners to accept, but it’s true nonetheless. It’s why breakbarrel target rifles can be so accurate.

A lathe compound tool rest

If you have difficulty with my cannon analogy, here’s another one. The compound tool rest that travels along the lathe bed ways on a lathe carriage moves all the time — that is its function. Yet it can be set to return to the same place every time. If that weren’t true, precision machining would be a lot more difficult than it is.

lathe compound tool rest
A lathe tool rest on its carriage (center) moves all the time, but is extremely accurate.

The point

The point I am trying to make is that something can move but can also return to the same place every time if it is designed to do so. Now let’s talk about pistols.

Pistols with fixed barrels

Most centerfire pistols today have barrels that move. In fact, that has been the case since semiautomatic pistols were first invented, back in 1893. The very first semiautomatic pistol was called a Borchardt, and although its barrel appears rigidly mounted to the casual observer, when you examine it closely you discover that it is mounted in a frame that moves as the action cycles.

Borchardt
The Borchardt was the Luger’s predecessor and features a barrel that moves in recoil to kick open the trademark toggle lock. Photo used by permission of Rock Island Auction.

I don’t own a Borchardt, so let’s look at its most popular offspring, the Pistole 08, or what we know as the Luger. Most people look at a Luger and think that the barrel is fixed. They think the toggle lock is what controls the breech. But before the toggle can open, the entire barrel has to move backwards by a fair distance to engage the cams that break open the toggle joint. The barrel is attached to an upper receiver that slides in rails located in the lower receiver. In fact, to disassemble the Luger you must first push the barrel back about a quarter-inch!

Luger
The Luger barrel looks fixed, but it has to move back in recoil so the circular toggle cam (the round black thing) contacts the cams on either side of the frame (the ski jump at the rear of the pistol).

It’s very difficult to find a fixed barrel on a semiautomatic pistol of any size. They are found mostly on .22 rimfire pistols, because the recoil of the cartridge is not excessive. Most gas-operated and recoil-operated semiautomatics have barrels that move in some fashion when the gun is fired. Therefore, they have to be designed so the barrel returns to battery every time the gun fires.

High Standard pistol
Small caliber semiautos like this High Standard pistol are some of the only ones with fixed barrels.

M1911 — the barrel movement champ!

The M1911 pistol barrel moves intentionally when the gun fires. John Browning designed the barrel to be locked to the slide, so when the gun fires, the barrel tries to move back and imparts a rearward push to the slide. But the barrel is held fast to the lower frame of the gun by a link, so when it reaches its limit of movement the link pulls it downward, unlocking the slide and allowing it to continue to move back. The movement of the slide accomplishes all the actions necessary to operate the pistol — extraction of the spent cartridge, compression of the hammer spring, and stripping and chambering a fresh round as the recoil spring returns the slide and — get ready for it — LOCKS UP IN  BATTERY!

1911 barrel lugs
The two lugs on top of the barrel fit into the machined slots in the underside of the slide. The barrel link (arrow) moves the barrel down and away from the slide when it is moving backwards in recoil.

1911 barrel bushing
The barrel bushing (arrow) holds the muzzle tightly. This is where part of the 1911’s accuracy comes from.

1911 slide back
When the slide is back, the barrel flops around loosely. When the slide goes forward, the barrel bushing at the front and the barrel link at the rear lock the barrel tightly.

As the slide moves forward, the barrel link lifts the barrel up and allows the barrel lugs to engage their slots on the inside of the slide. There is more to it than that, of course, but those are the highlights. Loose barrel with the slide open and tight barrel with the slide closed.

The barrel bushing at the front of the pistol and the fit of the barrel link at the back are what keep the barrel in perfect battery every time the gun fires.

Summary

Peter, I didn’t report on the P226 because I don’t own one, but what I have written today applies to all semiauto pistols. The short answer to your question is yes, the barrels on semiauto pistols can be loose — as long as they lock up in battery before the gun fires. The term in battery does not just mean tight and without and looseness. It also means being in the same place, time after time. It is the basis of accuracy in many firearms and also the basis for the artillery hold we airgunners use.

48 thoughts on “Can loose barrels be accurate?

  1. What an excellent explanation of the term battery and or battery position. Blogs like this really are enjoyable to me BB. Best wishes and stay warm. It is cold here in western Idaho. Current temperature is 15 degrees F.


  2. 2 MOA for a cannon is pretty good, especially when you consider the ammo is mass produced. Of course, anything less would be worthless. I am sure we pay well for each of those rounds. I can well imagine what we pay for the M1B “cartridges”.


    • RR,

      I assume you refer to the amor piercing discarding sabot rounds that have a long rod penetrator made of depleted uranium? No doubt they are expensive, but the performance on anything they hit is worth it. Means a second round isn’t needed.

      B.B.


      • BB,

        They also have other rounds such as HE, HEAT, etc., all of which require fairly accurate placement at what can be extremely long ranges to be effective. Many may think that Type 80 MBT is a huge target, but at over 3000 yards it isn’t such a big target after all.


        • RR,

          The HE round used to be called HEP — high explosive — plasticized. At a muzzle velocity of just 2800 f.p.s. (as memory serves) it was the slowest round in the inventory and had a high arc on the way to a target. Does lots of damage to a junk bus, though!

          B.B.


  3. I looked up woolly Peter not long ago after hearing a round called that and learned the round exposes phosphorus to air causing combustion,. Phosphorus burns very hot causing other materials to combustion until it’s gone.



  4. B.B.,

    You haven’t reported on the Sig Sauer P226 firearm, but you did report on the CO2 BB pistol version of it: /blog/2011/08/sig-sauer-p226-x5-bb-pistol-part-4/

    Michael


  5. B.B.,

    An off-topic question, if I may. I was rereading a report of yours from a while back in which you wrote that you doubted you would ever part with your Webley Mk I, even though it isn’t exceptionally powerful or accurate, but because it is such a pleasure to pick up, hold, and admire for its ruggedness and real steel materials.

    Of course sheet steel and pot metal have since then long ruled the day in air guns, but what about the IZH/Baikal Makarov air pistols? Are they actual steel?

    Thanks much,

    Michael


  6. BB– Another off topic question– I recently bought a used umarex Colt 1911 a1 pistol. The finish and the blue case indicate that this is an early version. The trigger is one piece and the pistol seems to be single action only. I have searched for but cannot find any information re this model (date, # made, etc.). Do you have any info re this pistol? Ed


  7. B.B.
    Please excuse another off topic question, but I’m working on my Christmas wish list. 🙂 In addition to the monopod, I am considering putting a new sand bag rest (for rifle use) on my list. Would you mind commenting on the one you use and where it can be obtained?


  8. Way off topic here but after the rant on the last blog I feel I should offer some clarification.
    The manager of my apartment complex has been terminated,leaving the assistant manager which is the manager of my half in charge.
    She is now undergoing retraining to get things right.
    During the mandatory inspections there’s a checklist to be filled out and returned to the occupant after a copy is filed.
    Really wouldn’t be that big of a deal except the timing is just about as bad as it can be.
    Just had the holiday and I’m having to requalify for HUD which means I have to turn in the last year’s income and expenses AND cross my fingers so even though it’s 48℉ I have to ride my bike about 2 miles over there even after having everything else faxed.
    Gotta get on it now because it’s probably gonna take an hour to fill out the paperwork and then ride back.
    See y’all later this evening!



      • Hey, gotta keep your eyes in the thousand yard stare when times get overwhelming, this too shall pass kinda thing. I just keep the perspective of things being moving, not me, I dont have to rush around and get worked up trying to get past situations or tough times because I am a pillar in the middle of the river. Time and obstacles, tasks and life flows around me, I dont fight to get through the river, to get to the water upstream because I dont need to, it will come and go. Maybe a better anology is a table saw, each piece of wood is a task, or even the whole day. I dont go after the wood to cut it, I am stable, solid, and my energy is consistent like the blade spinning, ripping through each thing as it comes, no matter the size or hardness of the “wood”/task/problem. Not to say I dont get burnt out or shut down every once in awhile, but subconsciously I maintain that attitude and when the shtuff hits the fan I remember that my skin sheds off and I can take a shower later, meaning I wont smell like doo-doo forever and I can look forward to that after shower clean feeling!


  9. An exception to the movable barrel center-fire pistol design would be the Makarov. This automatic pistol’s barrel is firmly attached to the frame. It is a blowback-operated design.

    Nothing in there ever goes out of battery. The blowback of the fired round forces the slide back, ejecting the spent casing as the magazine spring raises the next round to be fed into the chamber as the slide returns forward. The slide is returned to its forward position by a strong operating spring that surrounds the barrel. There are only 25 parts in the entire gun, including the assembly screws.

    I really appreciate articles like this one that explain how things work.

    Les



      • B.B.,

        Tom, actually. the barrel on the Colt 1911 is tipped down when the pistol is in battery and is only parallel to the slide rails of the receiver once it is fully unlocked during recoil. This tipping causes a slight bind at the muzzle between the barrel and barrel bushing which helps eliminate excessive play between the two unless there is excessive wear on either as long as the bushing fits the slide without any excessive play. This of course preceded the three fingered bushing. You probably are already aware of this, but it may be of interest to others on the blog.

        I wonder how many of the current new alloy/polymer framed pistols will be around and functional let alone copied a hundred years from now as is the 1911A1?

        I was active Army 1966-1970 had a RA prefix to my SN as you probably did except I was enlisted and you were an officer. Here is an amusing anecdote for you. I enlisted in the USAR in 1976 into the 429th Combat Engineers and we went to Fort Pickett Virginia for AT in the late seventies. Our earth moving platoon was tasked to improving a tank firing range that year. At that time, we would get the weekends off and they had left a D7 Cat bulldozer on the work site, unfortunately, out in the impact area. That weekend a unit from the Virginia National Guard showed up with some M24A1 Dusters and assumed that the dozer was a bonafied target and used it as such. It received five hits from their 40mm cannon! Better than 105mm, I guess!

        Bugbuster




  10. Zimbabweed – the very first Umarex 1911s in 1996 or 97 had a sliding one-piece trigger. It was quickly replaced with the pivoting two-piece type. The one-piece looked more authentic, but gave a very heavy pull – as much as 18 pounds or more in double action (the 2-piece is more like 9 or 10)! Yours may have a fault, or you may just not be putting the required amount of pressure on it in DA.


  11. Geezer— You are right. I tried using 2 fingers and the double action worked. I cannot apply enough pressure with one finger to engage the double action. BB–does this mean that my pistol is more valuable than the 2 piece trigger version? Ed



  12. Reb,

    After you pull the trigger guard down to release the slide, move it to the side so the flat piece that sticks up into the bottom of the gun stays out, keeping the trigger guard down. You won’t get the slide back on unless you do this. When the slide is back in place, move the trigger guard sideways so that flat piece goes back up and the trigger guard will move back into place.

    That may seem obvious, but my gun did not come with instructions and I scratched the outside of the breech area by trying to force the slide back on. Other than that, it is an extremely easy gun to take apart and reassemble. The operating spring is pretty stiff, so have a good grip on the slide until it is all together. It is easy to clean the barrel from the breech end and look through the bore.

    This is my first powder-burning handgun. I really appreciate its simplicity. You can tell how it works just by looking at the parts.

    The only time this gun jammed was when I did not pull the slide back sharply enough. My fault, not the gun’s.

    Les


    • Thanks for that! I don’t have one anymore but I’m sure gonna keep my eye out for another one in good condition. I did carry mine while I had it and it wouldn’t fit in my pocket like the .25 before it but was almost as easy to carry.


  13. Hi BB
       I’m sending this at the end of the day to avoid hijacking the thread too badly. The blog on the Daisy 12-29 got me interested in BB gun accuracy again. Here’s the results of my latest experiments. Nothing too new, but might be of interest. To improve Daisy type BB gun accuracy try the following steps in order until satisfied:
       Select best steel shot
       Muzzle load lead shot, select size for best results. I cock gun, insert at muzzle with fingers and push all the way down with cleaning rod.
       Replace shot tube with rifled barrel and muzzle load. A section of Crosman 7/16 o.d. .177 barrel threaded 7/16 NC works perfectly. Make a bushing of metal, wood or of plastic tape to center the muzzle in the outer barrel. This is a screw  in replacement for the Daisy tube, but requires an older gun like the 102-36.
       Next use pellets. Size and engrave rifling by shoving through another Crosman barrel, then insert carefully in muzzle and rotate until rifling lines up.
       Cut off air tube to get higher velocity to better match the rifling of the barrel. This requires disassembly.
       Each of these steps improves accuracy by a small amount and makes a fun little gun to plink with. If mom or dad  shoot muzzle loading firearms this makes a nice training gun for the kids


  14. Hi, Postwar 102-36 for most tests although a pre-war was similar in tests that didn’t require mod to gun. 5 meters, 5 shot groups, indoor. 1 1/2 inch with steel shot, under 1/2 inch with Hobby pellets, velocity 305 fps avr. (only ones I’ve tried so far). This is close to what my tired old eyes can do with open sights with anything anymore.
    I have some barrel liners with 1 in 20 twist that worked very well with .22 Collibri primer only cartridges I”d like to try. I think they might work very well with low vel pellets. I think one of the more powerful Daisys would work better because of the greater velocity if someone was interested in experimenting.
    Not a 499B, but kind of interesting.


    • Hi BB, I just found your Blog,
      “Can a common BB gun be accurate?”
      Wonderful info, wish I had seen it earlier! I wonder if the reason that a round ball is more accurate in a tight fitting bore is that it equalizes the friction on all sides of the ball and prevents spin that would cause the ball to curve?
      I plan to experiment with some sort of patch, as used in muzzleloader, or sabot to prevent spin. Another avenue is lubrication or grease in the barrel to accomplish the same thing. I’ve seen some promising groups but very hard to repeat conditions from group to group. Any input would be most appreciated!
      I guess my half inch groups with the rifled barrel aren’t really very good. I’d like to get a lightweight springer that’s easy to cock and won’t chew up my indoor backstop, while being accurate enough to be interesting. Fido


      • Fido,

        I know a round ball that doesn’t spin can be accurate at short range, but to be accurate at longer distances, it needs to spin. Kentucky rifles are the best example of that. Without rifling they are accurate ton 50 yards and maybe 100 yards if the shooter is careful. With rifling, they can be accurate to 200 yards and slightly beyond. At at 50 and 100, they are much more accurate than smoothbores.

        B.B.


  15. Hi BB, wow, I even got my name mentioned in one of your blogs! What a fantastic article and as usual, generating so much discussion. This and your other articles have helped me tremendously in my quest to be a better airgunner! I really appreciate your blogs and I’m certain as do your following of readers.

    Regards,
    Peter


  16. Wow! Thank you for the prompt reply! I’ve heard that the majority of Kentucky Rifles were actually smoothbore. In the woods they were accurate enough to hit a deer at the distances they could see one, but could also pattern a small load of shot. I think this is from the Dixie Catalog.
    I’m really enjoying low power airguns. I’m reserving the blasters for Deathwish the Squirrel who is chewing up my garage!
    Thank you again for everything you do!


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