How Much Variation Is Ok In My Overall Length?

[srv656s]

In my reloading manual it says that the COL should be 1.275. I did a run of about 400 rounds, and most cartridges were between 1.273 - 1.277, however I used my calipers on about a hundred of them and a couple were 1.283. They loaded into a magazine without any problem, but I'm not sure what the acceptable variation is...

Any input is appreciated-

Shawn

[North]

pretty sure that means the maximum overall length. In my springfield 1911 if I load longer than 1.240 the bullets actually lodge against the rifleing and "show clear" is a real pain in the @ss. When I first started reloading I loaded to max overall length listed in the lee manual and found that was too long in all three of my 1911 45ACPs. Now I load around 1.225 to 1.235 inches and everything is fine. Just don't go below minimum overall length.

I my limited experience I have found that differances +/- 0.005" won't make a hill of beans differance.

I would check to see if you can eject a live round loaded by the pistol after a fired shot. That length seems long to me.

Edited April 4, 2006 by North

[Crusher]

What press?

What dies?

What heads?

Yea I know it's .45 but that isn't enough info. A couple of thousandths diffrence is acceptable.

[AustinMike]

The OAL in the manual is maximum. Every gun is different and actual length that you need will vary by the bullet you use. I usually use 1.250 with FMJ, but I've had to so as deep as 1.235 with some bullets, like the Precision coated bullets. Load a dummy round and try dropping it in your barrel. You want the rim to go just a hair below the hood on the barrel. Seat deeper until you find that, then load up several dummys and test feed a mag full through the gun. When setting up your press, always have a case in every station to keep pressure on the tool head consistent. Otherwise, you will see more variance in your measurements.

[srv656s]

The OAL in the manual is maximum. Every gun is different and actual length that you need will vary by the bullet you use. I usually use 1.250 with FMJ, but I've had to so as deep as 1.235 with some bullets, like the Precision coated bullets. Load a dummy round and try dropping it in your barrel. You want the rim to go just a hair below the hood on the barrel. Seat deeper until you find that, then load up several dummys and test feed a mag full through the gun. When setting up your press, always have a case in every station to keep pressure on the tool head consistent. Otherwise, you will see more variance in your measurements.

That's pretty interesting, didn't know that.

I'm loading 230 grn Rainer plated bullets right now on a Dillon XL650 with Dillon dies.

I cycled a few of the rounds through my gun, and they fed fine, but in some cases for the long ones (I saved the longest ones I measured) they didn't eject properly because they were a wee too long. I'll try loading them at 1.25 for my next run.

Shawn

[Bad Flynch]

1.275 inches is the maximum allowable loaded length. That was established by the military and adopted by SAAMI, so that manufacturers could make guns and magazines that would function reliably with standard length cartridges. When you are checking them in your barrel, don't forget to check them in your magazine, too.

When reloading, the overall loaded length will vary a little, depending on the quality and, hence, the uniformity of your bullets' ogives. Cheap bullets mean lots of variation. I am currently loading a batch of match ammo with Sierra 230 gr Tournament Master bullets. When using Redding's micrometer seater die, the lengths overall will be all inside of 0.001" for the whole of the 1000 rounds. But then, Sierra bullets are $16-$17 per hundred.

Another brand of 230 gr FMJs will give me ammo inside of 0.005" in a similar run. That is good enough for everyday use.

The trick is to load, say, 100 or so and then find the longest one and make sure that the loaded round that is probably the longest does not exceed 1.275" and let the rest fall where they will.

[Jaxshooter]

Just adjust your press and run the long ones thru the seater and crimp dies. It will shorten them.

[Merlin Orr]

I had to have the chamber reamed (freebored) on my favorite 1911 when I started shooting the 230 Precision bullets to maintain my prefered 1.250 OAL. Some bullet profiles have less taper toward the nose and this can cause them to contact the lands quicker than other types, brands or styles of bullets. Also be aware that there is a chance for higher than expected pressures if you shorten your long loaded rounds by .025+ to make it function in your gun. If your loads are at 1.275 I would be cautious about bringing the AOL down to 1.235. IMO thats a lot.

[AustinMike]

Very true, Merlin. I should have clarified that I did start the charge low and work up. Interestingly, I was using data that Hogdon shows as using a 1.200" depth!