Introduction: Bullet Shell Valve Stem Caps

Picture of Bullet Shell Valve Stem Caps

The inner diameter of a 40 cal. bullet shell happens to fit nicely over a valve stem cap. All you have to do tap the shell onto the cap with a hammer. These went to the same friend who got the retractable bullet pen.

Safety first: The shells were already expended by the time I got them. Never attempt to use a live round for any kind of project. Serious injury or death can occur.


poorjohnn (author)2017-11-18

I have seen them using Dice instead and lots of colors to choose from.

spcgentry10 made it! (author)2017-04-26

depends on the valve cap I had to use jb weld to attach cap inside of . .40 casing .

3366carlos (author)2013-03-20

very nice.

the_other_right (author)2012-06-19

all I have to say is I'm just mad that I did not think of it my self props to you

the poodleo (author)2012-01-14

THIS IS AWESOME!!! me and my frkiends ride BMXs, and the ultimate coolness s to have the little bullet shaped valvecap, that you can get from the store -for $10. however, not only would these look cooler, but ièm sure they would be cheaper. can i just ask, where do you get the bullet shell casings from

andrej (author)2011-07-10

it looks nice, but be aware that the shells are quite heavy so don't forget to balance (is this the proper word?) the wheels at tire mechanics. Otherwise you are shortening the life of your wheel bearings.

jrh065 (author)andrej2011-07-10

Not trying to cut you down or anything, but empty shells are really quite light. I would say this probably does little more than triple the tiny weight of the cap. This still may need a re-balance I'm not sure about that.

andrej (author)jrh0652011-07-10

well, the balancing is always done with cap on the wheel. even if the tire is partially wet (slowly went with dry tire through small water pool on the road) the measurement will be affected.
try to weight that empty shell, I'm sure it's more than several grams and the weights for balancing are stepped by 5 grams.

jrh065 (author)andrej2011-07-10

I had no idea wheel weights were stepped by such a small amount. I doubt I'l ever get my hands on a casing.

andrej (author)jrh0652011-07-10

well, driving 50 km/h makes your 16" wheel rotate 662 times per minute.

50 km/h divided by 60 minutes is approx 833 m / min divided by the length of 16" (40cm) wheel is 833 m / (0,40 m * 3.1415) is 833 m / 1,2566 m is about 662 rotations per minute.*+PI)

Driving at highway's allowed 130 km/h makes nearly 1700rpm.*+PI)

Attach 20cm ribbon to an 10g screw and try to rotate it at approx 5 rpm in your hand (which is pretty fast) to get the feeling about the power of centrifugal force. And now imagine the power of centrifugal force that is applied to axis of the wheel by every nonbalanced gram of weight at highway speed.

kneedragon76 (author)andrej2011-07-14

all due respect I have over 1500 rounds of 40 cal in my garage and and know full well that a piece of gravel stuck in the tire would do more to un-balance a tire then a piece of brass or nickel that ways less then 1/4 of an ounce. I mount and balance my own tires to I don't use wheel weights I use plastic beads for airsoft guns 7oz for 33" tires and 1oz to every inch you add to the diameter. I have even ran tires with no weights and the arent effected by anything less then about 3 ounces out of balance. I have had tires (big ones 37") that were 12 ounces out of balance. They ran perfect with 10 ounces of beeds in the tires. even small radials weigh in at 60-70 lbs of rubber/steel or aluminum/ and air. 1/4 ounce won't make a difference and no the tires are not balanced with the valve cap on. Infact in most cases your lucky if you get the same ones back from the tire store since they have thousands laying around on the floor.

f5mando (author)kneedragon762012-01-08

I think we (I) need an instructable from you on bead balancing your tires! How does that work?

f5mando (author)2012-01-08

centrifugal |senˈtrif(y)əgəl|
adjective Physics
moving or tending to move away from a center. The opposite of centripetal .

WyldStyl3 (author)2012-01-08

directx1222 (author)2011-10-02

Hi where can I get some spent bullet cases - these caps look really cool but I'm in the UK.

Mrballeng (author)directx12222011-10-03

try But make sure your not breaking any laws.

asarver (author)Mrballeng2011-11-16

jukeyjean (author)2011-10-02

super dope

kneedragon76 (author)2011-07-14

Pretty cool - it is worth noting that the casings in this picture are Nickle not Brass. Brass would not be near as cool as they would certainly be brown within a week. Use the Nickle casings but be aware they aren't cheap and typically used on defence rounds such as hollow points so they aren't likely going to be lying around at the range.

caarntedd (author)kneedragon762011-10-01

I've used both nickel and brass to make these, and the brass ones stand out more due to the unusual colour. I like them better, unfortunately thieves tend to notice them as well. Good thing I have plenty of spares.

onemoroni1 (author)2011-07-10

This is easy, cheap, and fast. Do you how much chrome valve caps cost? If I ever come across some 40 cal shell you bet I'm going to collect them for my valve caps.

caarntedd (author)onemoroni12011-10-01

Check out my instructable in the related column. I've made the caps with 5 different shell casings cut down to the right length. There are many calibres with similar sized cases necked down to fit the bullet.

Spy1440 (author)2011-08-13

I just made these myself with brass shells 40cal and some epoxy.

Hiroak (author)2011-08-07

This is an excellent reason to go buy and new pistol. I don't have a 40 cal.

abadfart (author)Hiroak2011-08-11

you need a reason??? your married aren't you

onrust (author)2011-08-09


agis68 (author)2011-07-16


niceoboe (author)2011-07-11

Word of warning-- If you plan on traveling to Mexico, keep in mind that even firearm or ammunition components can get you in big trouble with the local law enforcement. Of particular note, anything issued to military or police worldwide can get you in bigger trouble. So keep the fancy tire caps back home and keep spares handy.

crazy_jim (author)2011-07-10

empty shells !? YOU murderer ! :-P

heavyfire88 (author)crazy_jim2011-07-11

aahha :D

WareShoals (author)2011-07-10

Ok... now this is just stinkin' cool. Great idea! My truck is gonna' love it.

Kaelessin (author)2011-06-14

This is pretty cool but I would suggest using some kind of epoxy or adhesive as you never know what bumps and expansion/contractions could loosen the thing just enough to get up to speed and fling of going who knows how fast . . .and into who knows what/whom

great idea though!

mgalyean (author)Kaelessin2011-06-15

That could make it kind of hard to add air to the tire. ;^)

Kaelessin (author)mgalyean2011-06-15

haha I wasn't clear enough I suppose . . .I meant glue the shells to the caps so that you still have a threaded cap but it looks like a bullet shell.

But seriously . . .who needs air in their tires really? ;^)

Scott_Tx (author)Kaelessin2011-07-10

Yeah, I was thinking hot glue maybe. I doubt they'd weigh enough to ruin the balance but I'm no expert on it.

Scott_Tx (author)Scott_Tx2011-07-10

Oh yeah, maybe use a dremel to cut it down a little too. that will help some.

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