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Old August 29, 2005, 12:38 AM   #1
William_IV
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.45acp How close to OAL?

How close is good practice when loading a pistol caliber to OAL spec'd out
in th re-loading handbook. For example .45acp 230 gr TMJ = 1.275

I try to seat for this exactly and say I get some cartridges at 1.279, 1.260, 1.281etc. Is there a good rule of thumb for tolerances to keep within...Or do I get the "As long as it chambers o.k your fine" explanation. Should I try to be right on the money? OR....do I need to load at a few thousandths under the O.A.L. ?
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Old August 29, 2005, 01:04 AM   #2
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It's good to stay at or very close to quoted OAL measurements if you are at or near max loads. Seating deeper can cause a potentially unsafe pressure level. If you're trying to duplicate the performance in the published load data, of course OAL will be a factor.

For mid-range loads, being off from quoted OAL *usually* isn't a problem, within reason. As an example, you probably wouldn't want to go 30-40 thousandths deeper with a caliber like 40 SW. 45 ACP on the other hand is a much lower pressure cartridge and somewhat more forgiving in this respect.

The Lee reloading manual has a pretty good section about pressure. Pick one up and give it a read. Maybe the info there will help you make a better decision for the particular load you are working with.

From an equipment standpoint, most standard dies won't be able to hold an accurate, repeatable seating depth less than 2-3 thousandths. Some have much more slop.

Presses that use a floating shell plate, or a removable tool head will have some slop in them too. Either the dies, shellplate or tool heads having a minute amount of slop usually isn't a big deal for most pistol rounds for plinking.

For rifle loads where extreme accuracy is the goal, this variance can make significant difference.

For more precision and accurate seating depth measurement, a competition seating die with micrometer adjustment (or something similar) will help tremendously. The thing to make sure of with these is that your press and shell plate (or holder) is stable so you can recognize the effects of the comp seating die.

It can be tough finding published data that agrees from one source to the next. Some suggest a minimum OAL, others specify it exactly. The implications of this could be argued ad nauseum without resolution.

Best bet, is to start with a load well below maximum and work up in small increments, watching closely for any signs of pressure.

For 45 ACP, when working up a new load, I start at minumum published charge level, at an OAL that I know feeds well in my gun, and proceed with caution until I find a load that works well or see the first sign of a pressure problem.

Hope some of this helps...

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Old August 29, 2005, 01:10 AM   #3
William_IV
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Yes actually that helps a lot. My d-650 does have a floating shell plate.
And I had contemplated shimming this because it has a little slop.

Thanks
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Old August 29, 2005, 07:30 AM   #4
HSMITH
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Shimming the shellplate isn't going to help. You are pushing down against the ram, the shellplate only pulls the case from the dies.

Shimming the toolhead might help if it is loose.

You are seeing pretty wild swings on the OAL, the first thing I would do is back off the crimp and see what happens.
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Old August 29, 2005, 09:05 AM   #5
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I've noticed that ogilve (spelling) consistancy varies between mfgs and individual bullets and has a big effect on oal. To me, your differences are excessive. Make sure you are using the correct seating stem also. Are you loading one round at a time or are you going full progressive. I've found that sometimes I get some inconsistancies when working up loads using the press in turret mode but it settles out when going to full progressive (all stations loaded). OBTW, shimming the shell plate......er....well.....I wouldn't do it. One other thing, and to me this is the most important thing to get consistantcy: Are you locking down your dies with all stations loaded and the ram full up?
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Old August 29, 2005, 09:12 AM   #6
Zekewolf
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Many pistols won't feed .45ACP loaded as long as 1.275". I generally load no longer than 1.260, with most being around 1.255".
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Old August 29, 2005, 09:33 AM   #7
William_IV
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HSSmith

My mistake.. Actually I would like to shim the tool holder it floats close to a 32cnd of an inch this could be part of the inconsistancy i'm getting when seating a load. I've been contemplating drilling and tapping some 3/32 set screws around the removeable tool holder. When it's in use i'll keep it locked down.
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Old August 29, 2005, 10:33 AM   #8
crazylegs
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William, and I don't mean to belabor this, BUT, If you really, really believe that slop is giving you your problem call Dillon first. They will have some good ideas. Who knows, they may send you a tighter tool head. Consider this before drilling/tapping your rig: Currently in stock form, you have a real 100% life time warranty. If you start to permanently mod that machine, that goes out the window, and rightfully so. If you ever send the unit in for a refurb, guess what? No bananas. Dillon is an A+++++ outfit. Give them a chance. They'll bend over backwards.
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Old August 29, 2005, 03:36 PM   #9
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For what it's worth, I usually load my mid-range 45 ammo to a O.A.L. or 1.260".

I have found over that if you go with published SAAMI lengths (usually around 1.270" ) that the rounds hang up in the magazines and I got a lot of FTF and such.

Of course, these lengths are for 230gr. ball, naturally, when I load 200gr SWC bullets they are a lot shorter.

I mostly shoot 230gr. ball, so the numbers (1.260") stick out in my mind very well.
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Old August 29, 2005, 08:22 PM   #10
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The toolhead slop bothers some people and they have to get it out before they will believe that shimming it tight did absolutely nothing for the consistency of the ammo made. When the cases enter into the dies there is enough resistance to force the toolhead fully up long before the stroke of the ram ends. Yes it floats a little, but it returns to exactly the same place every time. Shimming or bolting the toolhead in isn't going to help, but feel free to give it a shot.

I still think you need to back the crimp off and see what happens to your OAL consistency.....
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Old August 30, 2005, 04:31 AM   #11
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When I first started loading with the Dillon 650, I was getting inconsistant OAL. As it turned out, the shell plate was a little too loose and I was getting varring lengths on the finished bullet.

I'm suing 230gr LRN and I find good consistant feeding in my 1911s at 1.268. I've used 1.275 and at that length, I start to get feeding problems. I picked 1.268 to give me a little leeway.
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Old September 5, 2005, 01:09 PM   #12
William_IV
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Quote:
"The toolhead slop bothers some people and they have to get it out before they will believe that shimming it tight did absolutely nothing for the consistency of the ammo made."
HS

Thats like saying "Go cut me a board 12" plus or minus a foot. We're loading in the thousandths..... But don't worry about the slop on the die holder?

Tell that to a serious BR shooter. If that case is slamming up into the tool holder each time then there is a lot of error to worry about. How about the inconsistancy of force used each time in turret mode by the user. How about the slam on the powder measure each time it dispenses as the case is slamming the die holder. I don't buy the "consistancy in slop" theory. Slop leads to increased wear. This leads to increased slop. Right now i'm noticing fluctuations in OAL and minor powder measure variations. I'll bet the die holder will have something to do with the problem.

Last edited by William_IV; September 5, 2005 at 01:13 PM. Reason: Added quote
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Old September 5, 2005, 02:45 PM   #13
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I wonder how well the 650 is mounted?
I wonder if the bench is moving?
I wonder......
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Old September 5, 2005, 05:44 PM   #14
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William, I guess you are one of the guys that has to shim it out to find out it won't make any difference in the consistency of the loads. Operating the handle consistently, and you have to do that on ANY press, is all that is needed to get very consistent handloads.

The best gun I have is a 1/2 MOA gun, and I can progressively load ammo for it that is 1/2 MOA capable. The slop isn't bothering me or my guns.

As far as increased wear, keep your voice down so my oldest 550B doesn't hear you. It has well over 100K rounds across it and doesn't know it should be worn out, in fact it works just as well as it did the day it came out of the box.

I work in a world of single digit micron tolerances and accuracy, I understand a thing or two about accuracy and consistency AND I have the tools to measure it. In case you don't know a micron is .000039". Try it for yourself and see what you come up with. I did and know what happened.
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