45 acp Bullet seating depth???


January 24, 2009, 04:50 PM
I've done a bunch of searching but I've found nothing... How does one decide what depth to seat 45acp? I know different weight bullets are different lengths, so how do I determine depth? Do I measure OAL and subtract the bullet length? and if so what is a standard seating depth? Or do people just arbitrarily seat bullets to whatever they want under 1.275?

BTW, I'm going to try to seat Berry's 200gr jacketed flat points...


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January 24, 2009, 05:44 PM
You should own & use at least one reloading manual.

In it, you will find the recommended OAL, or seating depth for all the various bullets it covers.

That is the recommended seating depth for that bullet with those tested powder charges.

When using an off-brand bullet like the Berry that provides no load data or manual, use the one in the book closest to the same shape & weight as what you are loading.

From there, minor adjustments may need to be made to get best functioning in your specific gun.


January 24, 2009, 05:54 PM
I have the Lee (2nd edition) manual, but it only lists a max OAL (unless I'm dreaming). I'm not seeing any OAL data per bullet weight... I'll look again when I get home. Thanks!

January 24, 2009, 06:08 PM
My Speer #13 manual lists a 200 gr. flat point, two (2) of them from 1.200 to 1.155. That should be somewhere close to the bullet design that you have.

January 24, 2009, 06:11 PM
I'll look again when I get home.Don't bother.
The Lee manual is just a collection of free data from the powder manufactures.

They never give you the seating depth, so it's not worth a whole lot as reloading manuals go.


January 24, 2009, 06:16 PM
Man, this is why I don't often pick up new hobbies (reloading), too damn many pitfalls until you're an expert. Thanks for the help guys, I'll invest in more literature tonight. :banghead:

January 24, 2009, 06:17 PM
Try to find the Lyman #49 manual if you can.

It comes closest to covering all the bases of anything else out there.


January 24, 2009, 06:40 PM
That's just what I'll do. Thanks again!

January 24, 2009, 06:42 PM
Hold on - I don't think the Lee book is a total write off...

Compare it to the Speer book (another one I have) for example... The Speer book starting loads seem HOT when compared to powder manufacturers and, yes, the Lee book. The Speer book, almost UNIVERSALLY, lists starting loads a full grain HIGHER than Lee or the powder manufacturers do. I can't find a single compelling argument for starting that high. Starting loads, in most cases are plenty for target shooting. DISCLAIMER: I'm a relatively new reloader - but I'm fairly well read.

The way I extrapolated my OAL was to measure several different factory rounds using my calipers. Then I went a little bit shorter (maybe .005 to .01" shorter) but didn't approach the MIN OAL that the Lee book provides.

There are several factors one must consider when deciding where to seat the bullet:

a) magazines
b) feed ramps
c) shape of bullet (EX: SWC's have a shoulder - you wouldn't want to seat below that, I wouldn't think)

All OAL data I've seen in any manual or from any manufacture of either powder or bullets also says that it's a recommendation. I would load some small batches at a given powder/bullet combo of varying OAL's (within REASON of course - above the minimums and below max or factory) and see which works for you.

For what it's worth - I've been having great results with the following setup for my .45ACP

Powder: 4.6 gr Win231
Bullet: 230 Grain FMJ RN OR LRN
OAL: 1.269"

At 7 yds with my Springfield XD45 and my dad's Springfield 1911 Loaded I'm shooting 1.5" groups and at 14 yards I'm under 2.5" groups.

Hope this helps.


January 24, 2009, 06:55 PM
When I tried the Berrys 200 Gr FP I loaded it a 1.185

I seat the Berrys 200 GR HP to 1.200 O.A.L.

I much prefer the 200 HP

Dean Williams
January 24, 2009, 08:20 PM
Quote rcmodel:

Don't bother.
The Lee manual is just a collection of free data from the powder manufactures.

They never give you the seating depth, so it's not worth a whole lot as reloading manuals go.

RC, I've seen similar statements a number of times. I have the Lee second edition, and it has a min OAL for every single load. It does not have bullet manufacturer names though.

Eyesac, look in the far right column of the page for the 45 auto listings. It says "Min OAL".

January 24, 2009, 10:23 PM
The Lee manual may be full of the free information, but it is very convenient to have it all laid out in one place right in front of you.

January 25, 2009, 11:11 PM
IMHO, Iheartguns has the definitive answer in his post (#9) - "...see which works....". Before loading a big batch of cartridges, load a few and run them through the firearm(s) they will be used in. No matter what the manuals say, if it won't feed and shoot the round is useless.

Steve C
January 26, 2009, 12:19 AM
Most manuals will tell you the "not to exceed" maximum loaded cartridge length and the length they used with their bullet and load. The OAL listed for a particular brand of bullet may or may not work with one manufactured by a different company or produced by a different mold manufacturer.

When started reloading I reloaded for more than 15 years without a caliper or micrometer. Didn't have the internet then and no one ever told me it was needed. I set my OAL mostly using a factory round for semi auto's or the bullets crimp groove and cannelure for revolver cartridges. I used the removed barrel for a gauge in semi auto cartridges and dropped rounds in the chamber or cylinder of revolvers to check fit.

For loading .45 acp with 200gr SWC's I seat them so the case mouth is perhaps 1/32" below the bullet shoulder, on conical bullets its the same way, on RN or FMJ the bullet is seated so the case mouth is very slightly below the point where the bullet begins its taper to the nose. The rounds must be checked to see that they don't engage the rifling before chambering completely. The OAL is adjusted as needed with small incremental turns of the seating stem. Once they drop into the chamber and fit properly (when compared to a factory round) and fit the magazines for the pistols they'll be shot in, they're tested at the range. If all works well, that OAL is used until that type bullet gets replaced with a different brand.

When I finally got a caliper and measured my OAL's I found that for the most part they where all within the popper dimension allowable. The only thing I check with the caliper now is to make sure a particular bullet's seated at or below maximum allowable OAL.

Its not rocket science, its common sense and a little bit of hit and miss adjustment and checking. Sometimes you know the jproper OAL, most of the time you don't.

January 26, 2009, 12:38 AM
I think the biggest thing to remember is that different bullet types will require different OAL. If you follow the guides they will give a minimum OAL, other sources will give min and max. I have never heard of anyone having problems with a longer OAL, just shorter. Anytime you seat the bullet deaper(shorter OAL) you will push the pressure higher in the case.

February 2, 2009, 03:50 PM
Hi, Folks -
I am in early days of reloading .45 ACP - I hve acquired some 185 gr. button head bullets - I would call them a short LSWC.
When seated to what I would say is proper depth, they measure out at 1.155 - this sems short, but maybe that is the way it is.
I can not seem to find this bullet in the Clays' loading manual.
Any ideas will be appreciated - thank you and standing by.

February 2, 2009, 08:09 PM
If 7 rounds will just squeeze in a 45 automatic magazine without any binding... you found the right length.

CSA 357
February 2, 2009, 08:22 PM
They need to be seated to your gun, take your barrel out and seat them to where they will drop in the chamber and not bind, thats how i do mine any way, then you can get a ocl, the 45 acp head spaces on the case, not the rim, good luck

February 3, 2009, 11:40 AM
Hi, Folks -
Thanks for kind responses.
I spoke with Space Coast Bullets today - they call their 185 gr. 45 ACP "button nose" bullets "MATCH ROUNDS".
Richard at Space Coast (Nice fellow!) said OAL on this bullet is 1.150, with 3.8 - 3.9 of Clays.
I give it a "go"!

The Bushmaster
February 3, 2009, 12:27 PM
Lyman 48th or 49th edition...About $20 +/-....

February 3, 2009, 12:50 PM
In all my auto's I use the barrel as a gauge, I keep seating the bullet back in the case until it can be removed from the barrel easily.
Each bullet will have it's own seating depth, after I am happy with the OAL I
adjust the crimp.
Anyway, that's how I do it. Just like CSA 357

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