# Blank-firing .22 conversion **URL:** \ **Category:** Factual Questions\ **Created:** [August 10, 2005, 4:06pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454 "2005-08-10T16:06:11Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 10, 2005, 4:06pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/1 "2005-08-10T16:06:11Z")
As partial payment of my work on some recent projects, my business partner bought me a Walther P22 pistol. It would make a _great_ prop in the upcoming project, but obviously we must use blanks. The problem with blanks is that they won’t cycle the action. The P22 has barrels that can easily be changed. [/list][li]How would we modify the barrel (Pard Jerry has experience machining firearms) to _ **safely** _ convert it to blanks-only such that there will be enough back pressure to operate the action?[/li][li]Where do we find safe .22LR blanks?[/list][/li]There are blank-firing replicas available that look really good – until you pull the trigger. They have sparks coming out of the breech that destroy the effect. Incidentally, I found a fake supressor online. Should work well for the Assassin character. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 10, 2005, 4:09pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/2 "2005-08-10T16:09:56Z")
Let me try that again… [ul][li]How would we modify the barrel (Pard Jerry has experience machining firearms) to _ **safely** _ convert it to blanks-only such that there will be enough back pressure to operate the action?[/li]Where do we find safe .22LR blanks?[/ul] ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [August 10, 2005, 4:25pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/3 "2005-08-10T16:25:08Z")
I’m not sure you can make that work. Blank firing adapters work on rifles because nearly all of them are gas operated. If you restrict the gas leaving the barrel somewhat there is enough gas pressure escaping from the port to cycle the action. I doubt if you could get that to work with a .22LR blowback operated pistol. In any case I would be hesitant to even make one for a P22 because as you may have noticided it is much more lightly constructed than typical .22 semi auto pistols. Restricting the barrel too much could easily cause the blowback pressure to break the slide. I’d consider trying that with a Ruger possibly but not my P22. I’ll check with a friend who may know or at least have some resources in the NFA community. He’s got a Gemtech suppressor for his which allows little more sound than the slide moving back and forth. Would you consider using a real suppressor and editing so the actual firing can be with live ammunition? Another thought but I’ve read that the H&K Mk23 can have the slide locked closed for suppressor use so there is little noise as possible. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [August 10, 2005, 4:27pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/4 "2005-08-10T16:27:38Z")
The device that plugs the barrel allows a blank to cycle is Blank Firing Adapter (BFA). They’re routinely used by the military to allow soldiers on field exercises to blast away at each other with blanks. The BFA is the yellow plug at the end of an M16 barrel. Hollywood films use a less-obvious internal plug. Finding a BFA for a specific pistol might be a bit tricky. If you MUST get an exterior plug, paint if black or make it look like a silencer. This will, though, start to defeat the safety features of the device itself. Alternatives include using your fake silencer and having an actor pretend to recoil, and dub in the sound effect. Alternately, have the camera focus on the actor while the end of his weapon’s barrel is just out of frame. Use a strobe light and smoke generator (and post production sound effects) to simulate a gunshot. It may end up looking cheesy, but these thing aren’t toys and unless you’re willing to hire a film firearms expert, you should probably drop the whole blanks idea. Remember Brandon Lee. ---
**Author:** ![jimpatro](https://avatars.discourse-cdn.com/v4/letter/j/b9e5f3/32.png) [@jimpatro](https://boards.straightdope.com/u/jimpatro)\ **Post date:** [August 10, 2005, 4:36pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/5 "2005-08-10T16:36:41Z")
**Johnny** , I think you should invoke dramatic license on this one. Consider what percentage of the audience will really care about sparks from the breech. Most won’t know it’s “wrong”. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 10, 2005, 4:42pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/6 "2005-08-10T16:42:45Z")
> [@Padeye](#): > > I’d consider trying that with a Ruger possibly but not my P22. > > \ > > Would you consider using a real suppressor and editing so the actual firing can be with live ammunition? AFAIK, the barrel of my Mk.II is not removable. (At least, it’s not easily done.) Real supressors are legal here in Washington, but there’s still the issue of jumping through the BATF hoops. As for firing live ammo, there’s _no way_ I’d do that in a film. :eek: I wouldn’t want live ammo anywhere near the set. > [@Bryan Ekers](#): > > The device that plugs the barrel allows a blank to cycle is Blank Firing Adapter (BFA). > > \ > > If you MUST get an exterior plug, paint if black or make it look like a silencer. I’m familiar with AR-15 BFAs. I have a couple around here somewhere. (They’re the ‘Hollywood-style’, not the big cages the military use.) I found a source for AR-15/M-16 BFAs whose ports are designed to use full-power ‘Hollywood’ blanks instead of the weaker military ones. AFAIK we’re not using long-arms in this film though. As I said, I did find a fake supressor. I suppose it could be modified to provide back pressure. The blanks themselves will be difficult, since I haven’t heard of any that are available. Ideally I’d like to use plastic blanks like the .38s we used on _Cut Up_. Very safe. I suppose we could crimp down some .22MAG cases, but I don’t really want little bits of metal flying out the end of the barrel. Jerry made a blank barrel years ago my tapping the inside and screwing in a plug. I’m aware that it’s highly unlikely that such a plug would have its threads stripped and fly out the barrel – but ‘unlikely’ isn’t good enough. At the least, I’d want a roll pin behind it. (i.e., a pin inserted through a hole drilled crosswise through the barrel.) ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 10, 2005, 4:44pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/7 "2005-08-10T16:44:32Z")
> [@jimpatro](#): > > **Johnny** , I think you should invoke dramatic license on this one. > Consider what percentage of the audience will really care about sparks from the breech. Most won’t know it’s “wrong”. Some will. But this is the only thing we can do if we decide to use a Beretta 93R. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [August 10, 2005, 5:10pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/8 "2005-08-10T17:10:52Z")
> [@Johnny L.A.](#): > > AFAIK, the barrel of my Mk.II is not removable. (At least, it’s not easily done.) Real supressors are legal here in Washington, but there’s still the issue of jumping through the BATF hoops. As for firing live ammo, there’s _no way_ I’d do that in a film. :eek: I wouldn’t want live ammo anywhere near the set. The suppressors on Ruger MkII pistols are integrated or the barrel has to be threaded. The P22 has become popular for suppressor because the barrel is already threaded so an adaptor can be easily installed in place of the barrel nut. I wasn’t suggesting using live ammo on the set but shooting actual firing on a controlled and safe range. If you could find someone with a real suppressor for one it might add a nice bit of realism. Not as good as doing the shot on set without a cut but much much safer. I have to agree with **Bryan Ekers** that a real gun should be supervised by a certified person even if there is no live ammunition on the set. > [@](#): > > The blanks themselves will be difficult, since I haven’t heard of any that are available. Ideally I’d like to use plastic blanks like the .38s we used on _Cut Up_. Very safe. I suppose we could crimp down some .22MAG cases, but I don’t really want little bits of metal flying out the end of the barrel. You have me confused here. How does crimping a .22 mag cartridge allow it to fit into a .22LR chamber and how does it make metal come out the end of the barrel? A star crimp which is stadard for all blanks I have seen will only allow a small bit of wadding to come out the end of the barrel. This isn’t my area of expertise but I would not allow a blank to be fired in any situation that wouldn’t be safe to fire live ammunition. I’d hate to see you f\*@& up a perfectly good gun by trying to make it do what it wasn’t designed for. They couldn’t get a 1911 to cycle with blanks for Gary Cooper so just edit in a shot of someone firing a Luger and say it’s an homage to _Sgt York_ 😃 FWIW I like shooting my P22 but have you actually done any film shots with someone handling it? It’s so small it looks like a derringer in my hand. The movie _Copycat_ had a police officer using a similar size Sig P230 but the only reason it looked normal size is because Holly Hunter has such small hands. Still the P22 a wicked bad looking little piece. FWIW you can get an optical sight mount or integrated laser for it. The perfect weapon for 007 to shoot rats at the city dump. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 10, 2005, 5:28pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/9 "2005-08-10T17:28:12Z")
> [@Padeye](#): > > I have to agree with **Bryan Ekers** that a real gun should be supervised by a certified person even if there is no live ammunition on the set. I have about 26 years of experience handling (real) guns, and Jerry has a similar amount and was in the army. We’re both rather fanatical about safety. I was the gun handler on one low-budget film and one short film. > [@Padeye](#): > > You have me confused here. How does crimping a .22 mag cartridge allow it to fit into a .22LR chamber and how does it make metal come out the end of the barrel? A star crimp which is stadard for all blanks I have seen will only allow a small bit of wadding to come out the end of the barrel. This isn’t my area of expertise but I would not allow a blank to be fired in any situation that wouldn’t be safe to fire live ammunition. Cutting and crimping a .22MAG cartridge would make it the same length as a .22LR with a bullet in it. When a case is crimped, there is the possibility of little bits of brass to break off during firing. The danger of injury is there, but it’s small. One good thing about film is that you can ‘cheat’ the angles to make it look as if the barrel is inline with the target, but in reality is offset. In other films where we’ve used guns, the ‘target’ was not in frame and the camera was offset from the barrel. For the short film we used military blanks and a ‘Hollywood-style’ BFA. We also used my FN-FAL that I had at the time without a BFA for a single shot. (Looked great!) For the feature we used .38 revolvers and the plastic blanks. On my first film, a super-8 I did for a class in college, I did use live ammo. The Hero used a neighbour’s Hi-Standard and we were shooting the film (and the gun) in the desert where people often shot. Side angles on that one. For the Girl With The Rifle we used my .22 bolt-action and had her simulate recoil with an unloaded gun. (We did have her shoot a round or two when we used a different angle.) > [@Paydeye](#): > > I’d hate to see you f\*@& up a perfectly good gun by trying to make it do what it wasn’t designed for. That’s why I like the changeable barrel. 😉 Thanks for the warning about the slide. > [@Padeye](#): > > The P22 has become popular for suppressor because the barrel is already threaded I know that Walther stopped shipping P22s with threaded barrels to California. I don’t know if _all_ P22s are now shipped with unthreaded barrels. I’m in Washington (for now) so if CA is the only place they’re not shipping them mine may be threaded. I also don’t know how long it’s been sitting in the dealer’s safe, and that could be a factor. FWIW, I’m getting the one with the green body and with the compensator. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [August 10, 2005, 5:46pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/10 "2005-08-10T17:46:20Z")
I did not mean to disparage your expertise in firearms. I know from your posts that you have a lot of experience. My point was that real firearms should have a dedicated handler who isn’t concerned about any other aspect of production. If I was doing this I would make sure it was the only thing I was responsible for. Again, I don’t have experience with filmmaking so I might not allow something that is considered standard practice. Still I look at gun safety with the attitude that I **will** have an accidental discharge when I least expect and that there are no retakes when something goes badly with a gun. FWIW the compensator is fake. All it does it provide a little weight and a place to mount the front sight further forward. Interesting about the California version as this would prevent one from switching barrels on the P22 in the normal way. On mine the barrel nut holds a sleeve in place that in turn holds the barrel to the reciever. You can shorten a .22 mag cartridge to the same length as .22LR but it still won’t fit because the body and rim diameter are bigger. .22 short through long rifle use a heeled bullet, that is the bullet is stepped down at the rear to fit a casing that is the same diameter as the large part of the bullet. .22 mag uses a conventional bullet so the case is larger in diameter. A star crimp over a wad should not cause any metal to come loose on firing but I’ve never made my own blanks. ---
**Author:** ![UncleBeer](https://avatars.discourse-cdn.com/v4/letter/u/977dab/32.png) [@UncleBeer](https://boards.straightdope.com/u/UncleBeer)\ **Post date:** [August 10, 2005, 6:16pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/11 "2005-08-10T18:16:12Z")
I’m not sure you’d get a cut and crimped .22Mag to feed properly even if it would fit a chamber designed for .22LR. You might get it to chamber properly with a little experimentation in the crimp profile. But, I’d be very surprised if the cartridge extracts and ejects correctly. A .22LR case is supposed to be .595" long. If you’re cutting a .22Mag case to the length of a .22LR case + the exposed bullet (Which is another what? 3/16" or so? Oddly, I don’t have any .22LR in my car here at the office, so I can’t measure one today.), I think you’ll find ejection an insurmountable problem. From what I’ve heard, the P22 is pretty finicky about feeding ammo, too. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 10, 2005, 6:19pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/12 "2005-08-10T18:19:28Z")
I really don’t want to make blanks. I’d rather find commercially-made ones that have been tested extensively. I didn’t know about the OD of the Mag round. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [August 11, 2005, 5:23pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/13 "2005-08-11T17:23:12Z")
My previous job involved working on the electronics used in [MILES](http://www.fas.org/man/dod-101/sys/land/miles.htm) gear. Basically we were a contractor providing one-stop-shopping for the training needs of a three letter agency. We had a couple of gunsmiths and mechanical engineers that worked out blank adaptations. There were some off-the-shelf BFA solutions for gas long arms. The laser transmitters were mounted outboard. Handguns were a whole nother can of worms. There were few exixting BFA’s, and the customer demanded that the laser transmitter be internal, as an outboard transmitter would drastically change the feel, and holstering of a handgun. Recoil operated, locked breech semi-autos were modified to defeat the locking mechanism, and operated as simple blowback…this varied by weapon, but in principal, mostly involved milling the locking lugs off the barrel. With the barrel suitably restricted, nearly all autos will function in blowback mode. In addition to making the weapon cycle, we required, after a fatal training incident , that the weapons be further modified so that live ammunition would not chamber. This involved fairly tight tolerances, as the blanks were made to be dimensionally close to live ammo for proper feeding. The handguns used all plastic cases, so they were a little easier. The plastic “bullet nose” would deform against the live ammo stop pin, allowing the breech to close far enough to enable the disconnector. The modifications to preclude chambering of live ammo essentially precluded that barrell from ever being used as a “real” gun. The barells were cross drilled, and a pin inserted from the side. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [August 11, 2005, 5:39pm UTC](https://boards.straightdope.com/t/blank-firing-22-conversion/316454/14 "2005-08-11T17:39:09Z")
Johnny, my friend the gunsmith replied with some thoughts on a BFA. I’ll issue all the standard disclamiers for others with less expertise than you, as always don’t try this at home, YMMV, caveat emptor and if you blow your head off don’t come running to me. Experimenting with firearms modifications is potentially very dangerous. He said that BFAs for 9mm subguns such as the Sten and Uzi typically have an aperture of about 1/8" which restricts gas enough to operate the blowback action. He suggested starting here which almost certainly won’t work with a .22LR then gradually working smaller since a too-small aperture can result in a catrastrophic faiure of the slide. In any event he also said it may be nearly impssble to get blanks to feed in the P22 so you may be left editing single gunshots together. Anyway good luck with your project.