Land-to-Groove on 1911's

[BUTCHER45]

     hey all,

     To all here that have slugged their bores; what are the land/groove measurements of your .45ACPbarrels?  Different than Colt .45 Revolver barrels?    What diameter of bullet works best in it for you in lower-velocity loads (.451, .453?)  Thanks in advance.

                                                                                                   BUTCHER

[Josh M.]

I never slugged a 1911, but it is expected to have a groove dimension of .451, while most .45 Colt bbls should come in at .452.  I have slugged a lot of .45 Colt bbls in Rugers, Marlins, Colts, and Eye-Tal-yon clones...most come in at .452...have seen .453 and .454 on occasion.  - JM

[BUTCHER45]

     So the land to groove would be .450/.451 or .452 for ACP and anywhere from .450/.452 to .450/.454 land/groove for the Colt, is that correct?


                                                                                                           BUTCHER

[Flint]

Wondering why you need a land to groove dimension, do you have an odd number of grooves?  Most barrels have an even number of grooves, and measure land to land or groove to groove.  A Colt ACP should have a .451 groove dimension.

[BUTCHER45]

     I have a .45 caliber rifle that shoots at slow 45ACP velocity at best (265 grains@635fps, 230 grains almost 700fps, 180 grains 780+fps).  It has a .450 barrel and .453 rifling (land/groove) from my understanding.  I am new to all of this terminology and am just starting to figure it out.  I am trying to figure out what .45 guns are set-up with the land/grooves like this and what bullets shoot best out of them at low velocities.
     Wondering why so slow?  It's an air rifle.  Click on the picture.


   

                                                                                               BUTCHER

[Mikey]

butcher45:  This is gonna be a fun topic.  I can't think of a more fun gun than an air rifle and to have one in a big bore caliber is just groovy, so to speak............ How so quiet and incredibly effective.

The latest Shotgun News carried an article about big bore airguns and it may contain some interesting information about bullets and other data you may wish to know.

You will need to slug your barrel to determine the true bore diameter, whether land to land or groove to groove, and then you will know what size bullets you need, whether .451, .452, .453, etc.  One provision from the article stated that you can use standard 45 acp bullets in .451 or .452 in the 180-200 gn range in a Korean made airgun.  HTH.  Mikey.

[Flint]

I'm surprised that an air rifle can get the velocity you are getting, that's the velocity I'd expect from an ACP pistol with gunpowder driven 45ACP ammo.

[BUTCHER45]

     Oh this rifle is far from quiet.  The fun-factor is off-the-charts.  For the caster it can be a dream!
     
]    Picture this.

     You have spent a long, hard night casting bullets for your 45ACP load with your brand-new mold you finally got in the mail.  For some unknown reason your wife has prepared her pride and joy meal (that takes all afternoon to cook and must be served at at a temperature of 101.3 degrees right as Mercury goes into retrograde on a Tuesday for peak flavor) a full hour early.  You thought you would have time to throw together some re-loaded rounds and step out back. 
     No such luck. 
     But the curiosity is killing you with this new mold design famous for it's accuracy and you just have to know it's performance  RIGHT NOW.
     Uh-Oh, wifey is putting the main course on the dinner table!  You know you will not have time to get back out to the shop again until the weekend.  But you just cast your first bullets out of that nice mold you've already waited for for 3 agonizing weeks.  Time is of the essence.
         
     You sieze the moment and take swift, immediate action!
   
     You grab your custom modified .45 air rifle and pick up a round that is cool enough to pick-up.  Put some lube on it real quick and load it directly into the chamber seating it manually against the rifling.  Close the chamber, step out onto the back 40, put that baby to you shoulder, hit the safety and.....hey...there's the coyote that killed the lamb last week... over there by the hen-house at 50 meters....

                                                                !!!!!!!BBBLLLLLLIIIIAAAAAAAPPPPPP!!!!!!!

                                                                      !!!!!SMMMAAAAACCCCKKKK!!!!!

Now you can look forward to checking out that coyote after dessert.

You can check my 909 report in the airgunning section of this site.

                                                                                            BUTCHER
 

[Savage]

Ok, now I'm really curious! How do you pressure up that .45 airgun? Tell us a little about the gun and how it works, please.
Savage

[BUTCHER45]

     You can get a good amount of excercise and use a specially designed pump (Hill Pump w/dry pack being recommended) or you can be lazy and hook it up to a scuba tank and fill it in four seconds.  Nice thing about the pump is if you go out in the woods for awhile and run out of air in the scuba tank (standard 3000psi tank will fill the gun about 9 times for 4-5 full-power shots and 4 lesser power shots) you always have the pump to fall back on.


                                                                                                             BUTCHER