What caliber for shooting sports?

[Toster]

Ok, I have been looking at a new STI Trojan for some time now.    I would like to shot both the IDPA, and IPSC events, probably not every week but when I can. My big dilemma is what caliber to get.  I have dies for 9mm, .40, & .45 ACP, also lots of brass for all as well.  I know you have to make a major power factor in order to shoot some of the classes; I just don?t know what caliber will give me the greatest flexibility in the shooting sports, and what classes I will be able to shoot. HELP! 

[FLUFF]

I'd go with the 9mm just for the price of the ammo.
you can load 9mm for half the price of the others.

I'm not sure about the power factor, but I think with a 147Gr bullet the 9mm might make the limit ?

FLUFF

[JimP]

I'd go with the 9mm just for the price of the ammo.
you can load 9mm for half the price of the others.


FLUFF

Savings are actually better on .45 ACP, percentage wise...... but you can load the same number of 9mm for less than .45 ACP..... for awhile anyways: .45 ACP operates at much lower pressures than 9mm, so I would guess 9mm brass will wear out.  I have .45 ACP brass that has been shot and reloaded so many times that you can barely read the headstamps, but only a few of the nickel plate cases have cracked.  Some of those are from the first box of pistol ammo I bought.  Some of them I found in the trash at the range (no telling how many times they have been loaded.  I dont know how long 9mm brass will last- I haven't shot any of it more than once.

[Chris Z]

A .40

9mm cannot be used as a major caliber gun in IDPA or IPSC (unless shooting IPSC Open division, and you will really be pushing the envelope)

.45 is TOO SLOW for IPSC unless you are shooting in the single stack division where everyone is slow!

[David Hineline]

I guess I would say go with 40 short and weak.  In IDPA capacity loss will not matter because they do not think magazines hold more than 10rnds. In IPSC this will make major caliber score without having to goto a full blown race gun, which you then could not use in IDPA, you will loose a bit of capacity compared to a 9mm in IPSC but still good high caps available.  Check the IDPA website rule book cause they have many rules as to what you can/can't do to modify your gun.  I shoot IDPA in stock service pistol, in 9mm and Combat Defense Pistol in 45 and I shoot the 45 in IPSC but not so much anymore due to IDPA shoots being closer in miles.  I tried unlimited with optics but turned out that is not my cup of tea.

[Toster]

If I did do a .40, do you just load it down to help control the recoil?  A .45 has more of a thud recoil than a .40. At lest it seems that way to me.

Any good recipes for .40?  Do you guys just use cast bullets to help keep the cost down?

Also, do you think a STI Trojan http://www.stiguns.com/guns/Trojan5/Trojan5.html, or STI Sentry, http://www.stiguns.com/guns/Sentry/Sentry.html will be a good competition gun for a beginner? ?.I tend to buy a little nicer up front, and then I can rule out the ?this this dam gun thing?.

[Chris Z]

For .40 competition I use a 180 gr. JHP with 5.3 grains of Winchester Super Field Powder. Very smooth shooting load, makes major power factor.

Some guys shoot cast 200 gr .40 bullets..... When you are reloading, the heavier the bullet, the less powder needed, in turn the less recoil. I shoot a Glock, so I tend to stay away from cast bullets.

I don't know the first thing about 1911/2011 pistols, but I will tell you STI seems to be the choice of competitors who use this type of gun.

[JimP]

When you are reloading, the heavier the bullet, the less powder needed, in turn the less recoil.

[JimP]

When you are reloading, the heavier the bullet, the less powder needed, in turn the less recoil.

Nope.  Not really.  It's just physics- While heavier bullets DO use less powder (because their inertia is greater -harder to get them started- pressure builds faster, so you need to use less.... equal charges with a heavier bullet = Very Bad Things in the Pressure Dept.) they will have more recoil, given an equal muzzle velocity. 

Newton's Laws of Motion:

I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

II. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.

 III. For every action there is an equal and opposite reaction.

Recoil is the product of that third law.  It is the reaction of the bullet being pushed forward: the gun pushes to the rear.  Push a heavier bullet forward at a given speed = more recoil force, or push a bullet of a given weight forward faster = more recoil force.

Recoil is damped by the inertia of the gun (First law- the gun is at rest and will stay at rest until acted upon by the force of recoil...)  A heavier gun will resist recoil better than a light one..... shoot the same heavy .357 load in a 6" barreled GP100 and a Scandium J-Frame to test this .

This concludes Dr. Egghead's physics Lecture for today.

[David Hineline]

Going with 40cal in a single stack 1911 will hurt you by one round of capacity in IDPA, I would suggest if you want to shoot 40 you go with a high cap gun 1911 or other.

[Chris Z]

Physics lesson aside, I can tell you that has been my experience with using heavier bullets.

[JimP]

You measure the velocity on those?

[Chris Z]

Average Velocity is 935 FPS. This brings in a power factor of 168.

These loads have been across the chrono as several large USPSA matches, and hit this power factor every time 

[Toster]

Going with 40cal in a single stack 1911 will hurt you by one round of capacity in IDPA, I would suggest if you want to shoot 40 you go with a high cap gun 1911 or other.

So in IDPA what are you limited to for a single stack gun?  Do they make a 10 round mag in a .40 1911, to shoot in a limited 10 class?  Those are all the things I am trying to figure out....what classes would I be able to shoot in with a .40 1911 type of gun?