.45 ACP Measurement

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Morrey

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Wanted to reach out for measurement info if anyone can help out.

I am loading .45 ACP for the first time and setting up new Dillon dies in my Dillon RL 550B press now. The bullet I am using is RMR 230 gr Hardcore Match round nose. Can anyone tell me the COAL measurement so I know how deeply to seat this bullet for starters? Of course I will only load a handful to plunk test and cycle test by live firing my Glock before moving into a bigger load run. I can always adjust the COAL as a fine tune, but just wanted a ballpark seating depth to get started.

Also, any idea what my crimp diameter should be? I know to leave a tiny shoulder on my taper crimp for proper operation and to keep from digging into the plating.

Thanks for any info you can share.
 
Recommended OAL varies with different powders, range from 1.190" to 2.260" in one of my manuals. Others may vary. Crimp around .472" could vary due to bulet diameter and exact case wall thickness. YMMV

Lafitte
 
For a round nose .45 ACP load it at 1.260 to 1.265 and try that. It should work for all but the bluntest "round" nose. Anything resembling military ball will work at that OAL.
 
SAAMI shows 0.473" diameter at case mouth, and anywhere from 1.190" to 1.275" for COL.

Your Dillon .45ACP dies do not have a combination seat/crimp die. Station 3 is the seating die and station 4 is the crimp die, which is a taper crimp.

The intent of the taper crimp is to just remove the "bell" created by the powder die at station 2. (Some believe this really shouldn't be called a crimp...) Don't overdo it...

I looked at your bullet on the factory's site and it looks a little like the Rainier RN I have used in the past.

I have had good results with this bullet seated to 1.260" COL, but there is quite a bit of variation in feed ramps and chamber throating so, as you have said, you will need to do some trial and error.
 
dmazur said:
SAAMI shows 0.473" diameter at case mouth, and anywhere from 1.190" to 1.275" for COL.

Your Dillon .45ACP dies do not have a combination seat/crimp die. Station 3 is the seating die and station 4 is the crimp die, which is a taper crimp.

The intent of the taper crimp is to just remove the "bell" created by the powder die at station 2. (Some believe this really shouldn't be called a crimp...) Don't overdo it...

I looked at your bullet on the factory's site and it looks a little like the Rainier RN I have used in the past.

I have had good results with this bullet seated to 1.260" COL, but there is quite a bit of variation in feed ramps and chamber throating so, as you have said, you will need to do some trial and error.
Click to expand...
I am always a bit hesitant to put much of a crimp on a plated bullet, so I kept tweaking the taper until it dropped smoothly into my Wilson gauge. It wouldn't drop (plunk) in the gauge at first until I got the taper adjusted. My OAL right now is at 1.250. I just finished loading some test rounds for plunking in my Glock and then will live fire to check function.

Walkalong....my father-in-law has some military hardball 45 he used in the service. I measured the OAL of one of those rounds and set my depth with that round as my guide. Thanks for the feedback!!
 
I am always a bit hesitant to put much of a crimp on a plated bullet
Click to expand...

I believe no benefits occur by crimping any bullet which does not have either a groove (lead) or a cannelure (jacketed) designed to receive it. So, even if you had jacketed RN bullets, there is still no reason to crimp into the bullet for .45ACP.

By reducing the diameter at the case mouth, excessive crimping can interfere with headspacing for cartridges which headspace on the case mouth.

Also, excessive crimping can actually cause a decrease in tension, which can lead to bullet setback.

This is one of the things in life where more is not necessarily better. :)

However, as you are "sneaking up on" the crimp, your method should avoid overcrimping. I just thought I would mention that a bullet with a thicker jacket should not change your procedures.
 
Last edited:
The RMR 230s need to be seated to a shorter OAL than some others due to the shape of the bullet.
Do the plunk test to see how long an OAL you can use. I can use 1.23 in my 1911 but a friends wants 1.20
BDS has some pics of different .45 RN 230s here someplace.

The RMR sare sort of short and stubby for a 230 RN and have a longer bearing surface than some others.
I really like them they shoot well for me.
Don't forget RMR offers THR members a 5% discount.
 
I've been noticing short throats in some newer pistols. In particular a CZ97 and a Ruger 1911. Overall lengths that work fine in my 1911's fail to come into battery with these two guns. Also while the throat seems long enough in my Sig P220 the magazines hang up with flat points. Best advise is to do a plunk test.
 
.472 is the absolute max diameter. Expect jams beyond that. Target .469 on average. Measure multiple sides. ... They're not always perfectly round either. Brass length determines crimp diameter, so measure a bunch before you lock down your dies.
 
Dudedog said:
The RMR 230s need to be seated to a shorter OAL than some others due to the shape of the bullet.

Do the plunk test to see how long an OAL you can use. I can use 1.23 in my 1911 but a friends wants 1.20

The RMR sare sort of short and stubby for a 230 RN and have a longer bearing surface than some others.
Click to expand...
RMR 230 gr HM RN (which are thick plataed) indeed has shorter nose with longer base/bearing surface like MBC 9mm 124 gr RN (SmallBall) and depending on your barrel's leade/freebore length, you may need to load shorter than typical 230 gr FMJ/RN to clear the start of rifling.

attachment.php


Comparison picture above shows difference between Berry's 230 gr RN on the left with RMR 230 gr HM RN on the right - notice the shorter nose with longer bullet base.

Comparison picture below shows RMR 230 gr HM RN with factory PMC 230 gr FMJ on the right. For SA/RIA 1911s with longer leade, 1.230" worked as max OAL but for my Sig 1911 with very short leade, I needed to load shorter at 1.200".

BTW, taper crimp used was .471" which worked well even in my Sig 1911 barrel with tight chamber.

attachment.php
 
Thanks BDS for great photos and info...
I thought 1.25 was the standard for 45ACP as that functions well in my martial Colts, RemRand, and also my Kimber. Never realized 1.19 to 1.27 fit other guns better. For someone who spent years in the retail gun business, I find out so much cool info every day on THR! Thanks :)

Love the RMR and Missouri 5% discount
But lately X treme bullets have been shooting great for me.
http://www.xtremebullets.com/45-230-RN-p/xc45-230rn-b0500.htm
 
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