.45 ACP O.A.L Question


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MissouriCrowinMass
April 20, 2008, 10:54 PM
First - thanks for all the advice I've received on this Forum. I've been reloading 7.5x55, 9mm, .40 S&W and .45ACP for a little over a year. For my rifle rounds, I was advised to slot an unprimed case mouth with a Dremel Tool and seat a bullet high and then slowly chamber the round to test the OAL. That worked great for my 7.5x55. The guys on the Swiss Forum advise to leave about a .020" gap between the bullet's oglive and lands.

Today, I decided to try it with my .45ACP. I've been loading a lot of 200 gr. Precision Bullets to an OAL of 1.200". I use a case right in the middle of the Min.-Max. Dimension: Case Length - .893.

I pushed the unprimed case into the barrel of a Sig P200 St until the Case Mouth met the end of the chamber, all the while pushing the Precision Bullet against the lands.

I was surprise that there was a .060 gap between the oglive and the lands when I load to 1.200". I like to shoot for accuracy. Do you guys think that pistol accuracy is improved by reducing this distance? I just load for target shooting - 4.1 to 4.3 grs of BE results in a mild recoil. ('Course the weight of the P220 ST helps, too.)

Do you have any recommendations?

Thanks,

John

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243winxb
April 20, 2008, 11:12 PM
Reducing the end play of the round will help accuracy. But if the COL is not controlled perfectly, the action will not close resulting in the gun being taken out of action, not good in a self defence gun. For bullseye target shooting i seat a cast lead bullet just touching the rifling. I control this by measuring the length from the head to the shoulder of the semi wadcutter bullet, not to the nose. This will not work with all guns as barrels are throated different between makes.

freakshow10mm
April 21, 2008, 12:14 AM
I load pistol to the longest OAL that will hand cycle from the mag. I use dummy rounds. I make one up at the SAAMI max OAL and adjust shorter until it will feed from the mag and the slide closes fully. Then I load up a total of 5 dummies to this OAL and load them in the mag.

Then I take the slide back, let it slam home, rip the slide back, let it slam home, etc for about 5 rounds.

I do this three times and if they all run fine, that's my OAL for the load. Start at the minimum charge and work up.

45ACPUSER
April 21, 2008, 01:20 PM
Follow MFG directions....for COAL.

I would use a chamber gauge, ie strip the bbl from the gun and at first make sure the rounds drop in free and drop out.

Then work from there with keeping the ammo as consistent as possible with respect to the bullet limitations.

Then make up dummies for function check work from the magazine.

MissouriCrowinMass
April 21, 2008, 07:44 PM
243, Freakshow and 45ACP....thank you for the advice. Is there any truth that loading the bullet backwards into the casing improves accuracy at close range?

243winxb
April 21, 2008, 11:42 PM
Loading a 45 acp bullet backwards, never heard of that. In the 38 special , some would load a Hollow base wad cutter backwards for more bullet expansion and less penetration. The tests over the years have shown that the 45 acp bullet diameter does the job, choice of bullets is not to important. In 38spec. 9mm, 357 mag. These need some help in the performance department. The Federal Hydro shock is the best way to go for a personal defence ammo in the smaller diameter type rounds.

joneb
April 22, 2008, 01:30 AM
Is there any truth that loading the bullet backwards into the casing improves accuracy at close range?
I have only heard of this for down loading rifle to sub-sonic velocities, where bullet length and barrel twist are not compatible for stabilization. The weight rearward bullet loaded backwards is less likely to tumble, this was done with Lead bullets not sure about jacketed.

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