22 Cal Backstop

[roo_ster]

Howdy:

I bought a Crickett for my son for Christmas and am getting the backstop ready for the garage.

We'll use the Aguila Super Colibris, 20gr@500fps, instead fo the usual .22LR.

I searched around for penetration tests on .22s, and was surprised at how penetrative they were.  The bullet trap is good for high-velocity .22LR, but my plans for a larger plywood or OSD backstop behind it were inadequate.  Most testers found .22LR penetrates several inches of wood.

I'll still use a 48"x48" OSB/plywood backstop last resort, but I have decided to go with several inches of sand immediately surrounding the bullet trap.:


The laundry detergent boxes are 4-6" deep, which matches the sand penetration of high-velocity .22LR (40gr at ~1200fps) I saw on the web.  The one on the left sucked up 55lbs of sand and the one on the right 65lbs.  I strapped the heck out of them with the fiberglass-reinforced strapping tape and will use the same to patch future holes.

The bucket will be used until I find another laundry detergent box.  It will be mounted on top of the trap.

Any inexpensive ideas on how to improve the rig?

[geronimotwo]

  i would like to see at least 4' (to each side and above)of continuous or overlaping material behind the trap. sand will likely stop the bullet, but a few holes may turn those containers into seives. we use 1/2" steel plate at a 45 for our local range.  of course, that is for larger calibers.  i would think 1/4" plate at a 45 degree downward slant would work for the calibri, but i have no actual experience to back that up. is there anyone behind the area you are shooting into?

[French G.]

I always used City yellow pages wrapped in duct tape when the situation demanded in living room ballistic solutions. Amazing the crap you can do when you are single.

[Chuck Dye]

My bullet trap for Super Colibri from handguns is a cardboard box with about nine inches of old magazines and catalogs behind about six inches of old cotton trousers (Cabela's chinos,) fairly loosely packed (they don't bulge the cardboard box.)  I do not have any penetration beyond an inch of the magazines.  I can only guess what the impact velocity comparison between my handguns at 7 feet and your Cricket at whatever your range might be, but I suspect you may be over estimating your needs (not a bad thing, at all.)  The real issue I would pursue is lateral coverage, especially if your son is a complete noob and prone to Maggie's Drawers.

[AJ Dual]

Roughly 20 firmly stacked National Geographics will stop 9mm ball.

[Hawkmoon]

 i would like to see at least 4' (to each side and above)of continuous or overlaping material behind the trap. sand will likely stop the bullet, but a few holes may turn those containers into seives. we use 1/2" steel plate at a 45 for our local range.  of course, that is for larger calibers.  i would think 1/4" plate at a 45 degree downward slant would work for the calibri, but i have no actual experience to back that up. is there anyone behind the area you are shooting into?

For .22 Colibri I think a sheet of moderately heavy gauge steel sheet (not dimension-thickness steel plate) laminated to a sheet of 3/4" or 1" plywood or MDO and set at a 45-degree angle, with a sand trap at the base, would be plenty. After all, how heavy is the steel in that bullet trap? Can't be thicker than 12-gauge -- it sure isn't 1/8".

I share the concern that you need your backstop to extend farther on each side and above the actual bullet trap.

[Jim147]

A fifty five gallon drum will stop those rounds out of my much longer barreled Remington .22. And that is the steel on the first side.

I shot a possum with one. It turned and looked at me and ran off. No blood. I had to get him the next day with a regular round.

Make sure the rounds are getting out of the barrel. I shot a few out of my Model 60. My first round of regular ammo was load and split the case and tore the rim off.

jim

[Zardozimo Oprah Bannedalas]

Orphanages work for me. 

You could try .22 CB shorts. Extremely quiet. And while they are low-powered (more so than the Aguilas, AFAIK), in the hundreds I've fired I've never had one fail to leave the rifle barrel.

For .22 Colibri I think a sheet of moderately heavy gauge steel sheet (not dimension-thickness steel plate) laminated to a sheet of 3/4" or 1" plywood or MDO and set at a 45-degree angle, with a sand trap at the base, would be plenty. After all, how heavy is the steel in that bullet trap? Can't be thicker than 12-gauge -- it sure isn't 1/8".

It might be cheaper to get Lexan or similar high-grade plastic.
From here:
http://www.professionalplastics.com/LEXANSHEET9034
I get a $160 quote on a 4ft*8ft section. Not sure of the current price of steel.

[Triphammer]

 I bought a 4 x 10 sheet of 16 ga black last week for about $60. That, laminated to 5/8th OSB set @ a 45 will deflect Colobis & CB caps.

[Chuck Dye]

Triphammer is probably correct.  I have a steel sheet of unknown thickness mounted vertically behind my wood stove that Super Colibri have only dented, though even angled I would not want to try .22 shorts on it.  The shorts I have on hand are the CCI CB Mini-Cap, 29gr @ 727fps, are a good deal louder than Aguila Super Colibri.  The other shorts in my software's ammo library list as 27-30gr @ up to 1164fps and surely louder still.  I concur on the caution about Colibri or Super Colibri in rifle barrels, but have fired both through my Ruger 77/22 and other rifles without problems.  The Aguila powderless loads are a bit dirty, though, and stinky.

[HankB]

Densely packed dry newspaper is surprisingly resistant - in testing some years ago, we found that an 8" thickness will stop a full power .41 Magnum. (Key is densely packed.)

[Gowen]

How about some old phone books, you could post a wanted ad on craigslist.  You will probably get them for free, heck you could look for some of the vacant houses in your area and get new ones for free.

[roo_ster]

I concur on the caution about Colibri or Super Colibri in rifle barrels, but have fired both through my Ruger 77/22 and other rifles without problems.  The Aguila powderless loads are a bit dirty, though, and stinky.

I've shot a few out of the Crickett's 16" bbl with decent results into the mulch ground in the back yard.  Mild air rifle report and it exited the bbl no problem.  Will keep an eye on that issue, though.

You could try .22 CB shorts. Extremely quiet. And while they are low-powered (more so than the Aguilas, AFAIK), in the hundreds I've fired I've never had one fail to leave the rifle barrel.

Both CB Shorts & Long are rated 30gr@710fps w/ ~32ft-lbsE.  Aguila Super Colibris are next less powerful with 20gr@500fps w/ ~11ft-lbsE.  Least powerful are Aguila Colibris with 20gr@375fps / ~6ft-lbsE and there are many warnings not to use them with rifles, as the pill sometimes doesn't get out of the longer rifle bbl.  These are all factory stats, YMMV with particular weapons.


As a comparison, the highest energy factory air rifle I have seen was a .25cal Beeman Kodiak Super Mag, which started around 30ft-lbE.  Usual beefy "magnum" hunting air rifles generate about half that, 15ft-lbsE.  I have seen pellet traps rated up to 18ft-lbE by using only about 2" ballistic putty/duct seal.  Folk online show that 1" of duct seal is plenty for up to 14.5gr .22cal pelleat at 800fps (20ft-lbE) pellets:
http://www.archerairguns.com/airgun-pellet-trap-s/6.htm

I like the idea of angling the plywood at 45deg and applying heavy sheet metal to it.  It would be 40" tall and 48" wide.  Instead of a sand trap at the bottom, I think perhaps a duct seal trap along the edge.  Later, I might get rid of the $50 .22cal bullet trap I bought and run with a "silent" duct seal-type trap as shown in the video.

I started looking from the higher-end: .22LR on down. "What will stop a .22LR?"  Really, these Super Colibris are not quite magnum air rifle power, some (.22cal & .25cal) of which use pellets heavier than the 20gr Super Colibri projectile (though their shape looks more likely to deform on impact, reducing penetration.  I think I am really, really overbuilding this deal.

Behind trap and and sand/plywood backstop will be solid reinforced concrete pier & beam foundation up to 18" or so.  Above 18", the layers go like this: 1/4" pegboard, 5/8" wall boards, some fibrous board, brick.  This assumes I hit no 2x4s.

[geronimotwo]

IF sheet steel will stop callibri, and cost is a consideration, how about a couple of old refrigerater doors from the local landfill?  our landfill has a dumpster full of steel. check with a local scrap yard, or fabricator.  i just bought some 1/8" aluminum from a local fabricator.  they sell it to me at their cost, if they have it in stock.