Problems with OAL

[umstud]

Today I loaded my first batch of .45 auto. Everything went fine except that I could not get a consistent OAL. I was loading 230 FMJ Star bullets behind 5.8 grains of VV 340 powder using Remington cases. I set the bullet seating dies to exactly 1.260 OAL and tightened the locking nut with the ram up and a bullet in the die. I was loading on a Dillon 550b. About 50% of the rounds were on target, but the rest were all above 1.260 and even then they were not consistent. I spoke to Dillon and the rep suggested that the bullet shape was not consistent and accounted for the problem. Has anyone has this problem. Please tell me how to fix it or recommend a better quality bullet.

[Robert the41MagFan]

These things are key in order to get consistent AOL's in 45 acp.

The more fresh the brass is the better.

That ALL the brass is from the same manufacture and same lot.

That all the brass have the same trim length (make sure that the cases have been properly deburred).

That the case mouth be flared enough to allow the bullet to be inserted without too much friction (if you get bullet shavings or there is actual grinding when pressing the bullet, flair the case some more).

A good even stroke of the press.

Remember, this stuff takes considerable practice, it's almost a art form. A few thousandth is OK.

Robert

[WESHOOT2]

Load to a slightly longer OAL like 1.265" and don't worry if they vary slightly (+/-.005").

Only worry about case neck tension.

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"All my ammo is factory ammo"

[Ricciardelli]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Robert the41MagFan:
These things are key in order to get consistent AOL's in 45 acp.

The more fresh the brass is the better.

That ALL the brass is from the same manufacture and same lot.

That all the brass have the same trim length (make sure that the cases have been properly deburred).

That the case mouth be flared enough to allow the bullet to be inserted without too much friction (if you get bullet shavings or there is actual grinding when pressing the bullet, flair the case some more).

A good even stroke of the press.

Remember, this stuff takes considerable practice, it's almost a art form. A few thousandth is OK.

Robert[/quote]

Robert, about the only thing you mentioned which will have any effect on OAL of a cartridge is the operation of the handle...

[roboref]

Make sure the shell plate is set probperly. Just enough to turn with the click sound. If it works loose and is wobbly you will not get consistency. I don't see how case length is going to affect overall length as the press is working off the bullet. The bullets may be inconsistent but I doubt it. Anything that has gone wrong with my ammo loaded on a Dillon is usually operator induced error because of faulty machine setup!

[Bill in NM]

Before I throw in my .02, just HOW MUCH longer are they. You will always have some variation.
Bill

[Menos]

What kind of Rem Brass ? were they nickel plated? I have never been able to get the palted Rem Brass to load consistantly, in fact you will find that many of the bullets may set back in the mag during firing or feeding cycles in that brass ... try to push a bullet back in some of these loads with your fingers ...you may be surprised!

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What part of "INFRINGED" don't they understand?

[WESHOOT2]

Use a Lee "U" undersized sizing die to avoid setback, as pressure can exceed 100,000PSI.

This is NOT good for your gun.

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"All my ammo is factory ammo"

[umstud]

Bill,
The OAL variations are as follows: 1.256 - 1.264 and all others in between. I am using Remington brass cases

[Ricciardelli]

Don't worry about it! It isn't your Dillon, it isn't your dies. And there is nothing you can do about it!

Sit down and measure the length of the bullets you are using. I'll bet that is where you find the variance. Then go to your local friendly gun dealer and bring yout caliper with you. Open a box of match ammo and measure all 50 of those cartridges. You will find the same variance. How do I know? I just did it, and there was 0.007 difference in OAL in one box of match grade factory ammo...

As for the advice about pushing a bullet into the case with your fingers...well, if you can do that, then you are not utilizing your taper crimp die correctly. You are using a taper crimp die, aren't you?

When you sit down and think about it, the difference in your cartridge OAL is only 0.00987381829834962345777920205095337 %!

[Mal H]

Actually the difference is .003 or .3%.

[Ricciardelli]

Hummm....my calculator shows

1.256/1.264=0.993670886075949367088607594936709, or...

1.264/1.256=1.00636942675159235668789808917197...

Regardless, it is meaningless information either way...

[Mal H]

You're right, it is meaningless. But being the anal retentive kind of guys we are ( ), you would take the ratio of the error amount to the nominal OAL or ± (.004 / 1.260) = ±.003 or ±.3%.

[HankL]

Just for fun. 1975 mfg. Match ammo.
Ball M1911 Lot WCC-21-18
Shortest round 1.270
Longest round 1.274
Sample was 50 rounds
Starrett Dial Caliper #120 used
TM 43-0001-27 pg 8-15 says they should be
1.275 OAL
For more fun Measured some TZZ 89 ammo, just a hand full. 1.270 longest 1.273
Now switching to hand loaded 200 gr. lead SWC. Assorted brass etc. Just plinking ammo some were brass some were nickel, just fire and forget stuff. Loaded on a dillon RL-450
using RCBS carbide dies. I will give all 7 measurements if anyone wants to do the math.
1.238 1.240 1.241 1.240 1.239 1.241 1.238
For the reloads the only trick I know was the bullets were base lubed and hard cast and the neck tension is good without having to crimp much. I don't trim these plinking loads, they just have to pass through a case gage. Sorry if I got carried away but it was fun. Nephew brought me a sixer of Shiner Bock from Texas
and I'm having fun.
Best to all,
Hank

[This message has been edited by HankL (edited March 08, 2000).]

[This message has been edited by HankL (edited March 08, 2000).]

[Walt Welch]

Well, anal retentive gentlemen, this obsessive-compulsive, anal retentive doctor (sorry for being redundant; all doctors are that way) would like to point out that you are only taking the two extremes of length.

For meaningful statistics, you should do a RMS of all the OAL's, then a mean and median could be determined, as well, of course, as a standard deviation.

Actually, seriously, I retract my statement; such statistics would be meaningless, as they would have virtually no effect on ammunition performance. But that is what you have been trying to say all along.

The thing I always remember is that the REAL important measurement is the depth to which the bullet is seated; the OAL is an indirect measure of this. A given OAL will only give the same seating depth if the OAL of the bullet is the same as the standard.

I once noted that 115gr. Rem 9mm JHP's changed 0.035" when they changed manufacturing methods (new bullet longer). I nearly missed this, and just about lost sphincter control when I realized that this was the case, as this amount of increased seating depth could easily double the pressure of the 9 x 19.

Walt

[HankL]

Walt, You're not one of those proctologist with a size 18 business finger are you?
Hank