45 ACP Min Case length - Page 2

**Unclenick** · September 24, 2019, 10:41 AM

Anglicanman,

As far as I know, if you don't want to headspace on the extractor and you have short cases, headspacing on the bullet is the only alternative.

If it is any comfort, the 45 Auto cartridge's powder space under the bullet is so small the primer often makes enough pressure to unseat the bullet before the powder burn gets very far underway. So, powder gas pressure often builds with the bullet in contact with the throat anyway. What is different is jacketed bullets are hard enough to steer the cartridge straight when this occurs, while lead tends remain cocked a bit. That's why it deforms.

Another factor is headspacing on the bullet keeps the primer a consistent distance from the breech, so the firing pin jump is consistent. I don't think that makes a big difference to handgun accuracy, but it can't hurt ignition reliability.

Anglicanman · September 24, 2019, 11:52 PM

Thanks for the note about SAAMI! I find a couple of interesting things as I measure cases; for one thing the case mouth is not exactly parallel with the base. If I turn the case I can sometimes vary the measurement in my caliper by a few thousandths. Today I loaded about 170 rounds and just figured if a case is between .888 and .898 it will seat on the case mouth. Half the cases at least, of the ones I have, are too short.
I wonder what the original specification way back in 1912 was for cases. Do you know?
I read the discussion about chambering off the extractor and that with jacketed bullets it may not affect accuracy all that much; just wonder sometimes about doing things in a way Mr. Browning did not intend for them to be done.
And so ... if a person plans to seat the round off the bullet into the rifling how can the overall length of the round be determined? I will have hundreds of too short cases after I use up all the ones which fall in the 10 thousandths range of OK.

Anglicanman · September 25, 2019, 12:11 AM

OK, Uncle Nick and 44, I am starting to get some ideas. I have 4 .45 ACP pistols and I suppose I could take all the barrels out and find out somehow how to get the base of the cartridge to match the barrel end as Nick shows. I could then load bullets that far from the case mouth for each barrel and segregate them somehow except that even with cases all for one barrel case length is a variable which will influence how far a bullet has to be out in each individual case.
Maybe I am getting too worked up about all this, after all eveythng I read seems to say that .45 ACP in 1911 is not all that fussy.
I come to reloading from a background in Motorcycle mechanics. If someone told me that piston ring end gap, for example, is supposed to be .006" +/- .010" I would not know how to act.

**Unclenick** · September 25, 2019, 09:26 AM

Your press seats the nose of the bullet a fixed distance from the backside of the case head. So, if you set the seating die up to produce the length you see in the third image from the left on my drawing, you will get that from every round regardless of case length. It improves consistency of start pressure that way, which is part of why it improves accuracy.

I have found that lead bullets are soft enough that if you have five thousandths of the kind of protrusion you see in the last image on the right end of the drawing, the recoil spring is usually strong enough to seat them anyway. If the head of the case is five or ten thousandths below the back end of the barrel extension (hood), the bullet has started into the throat and will stop before the rim hits the extractor hook in most instances. So there is really a range of bullet lengths that still work well in each gun.

Find which gun makes you seat the bullet deepest and then drop a sample round in the other barrels and see which one lets it fall furthest in. See if that is far enough that the extractor hook will catch it before it goes that far or not. If not, it will usually shoot pretty well and you can use that same seating dept for all you guns. Otherwise, you may find two seating depths, each of which satisfies two of the guns and can divide the ammo up that way. Then you just have to learn how far to turn the seating die setting to switch.

The taper crimp die will have some sensitivity to case length. You want the case mouth to wind up between 0.467" and 0.473" diameter at the mouth for normal headspacing. A lot of the target shooters the '40s, '50s, and '60s both headspaced on the bullet and applied a roll crimp (since the case mouth wasn't close enough to the throat to cause a problem) for extra bullet pull and start pressure and swore that produced the most accurate ammunition. It is probably hard to find a 45 Auto roll crimp die these days. The one I have is in an ancient RCBS die set.

Anglicanman · October 19, 2019, 02:23 AM

Hi Nick and 44;
It's been a few days since I have been on this forum.
I loaded a bunch of 185 gr plated swc rounds at three different lengths, all in cases which measured between .888 and .892 or so (I have never seen a .898 case yet) and found that when I went really short in OAL there were failures to feed I think because the bullet was seated too far in so that the case mouth got hung up on the feed ramp. 1.125 I think, was too short.
Now I have a bunch of cases (a few hundred at least) which are below spec. If I load those to an OAL of 1.250 or so, a length long enough so that when I do a plunk test in a barrel the base of the case is about flush with the hood will that be the way to go? I think that those rounds might well plunk into the barrel but they might not fall out as the bullet might stick in the rifling a bit. I have found that there have been cases where the round would plunk into my spare barrel but I would have to hook onto the rim with my fingernail to extract the round. Your thoughts? I hate to just throw a couple of hundred cases away. I would not be loading the SWC but plated 230 gr round nose. I realize I would be headspacing off the bullet not the case mouth.

**Unclenick** · October 21, 2019, 08:44 AM

Getting the case flush with the hood is what works for me. What cartridge overall length that produces will vary with the bullet design. Seating too deeply can also raise pressure or else cause the primer to start unseating bullets ahead of powder burn, which tends to cause irregular velocities, so seating too deeply is not good from that standpoint. It also tends to cause headspacing on the extractor hook when it is deep enough.

September 24, 2019, 10:41 AM	#26
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	Anglicanman, As far as I know, if you don't want to headspace on the extractor and you have short cases, headspacing on the bullet is the only alternative. If it is any comfort, the 45 Auto cartridge's powder space under the bullet is so small the primer often makes enough pressure to unseat the bullet before the powder burn gets very far underway. So, powder gas pressure often builds with the bullet in contact with the throat anyway. What is different is jacketed bullets are hard enough to steer the cartridge straight when this occurs, while lead tends remain cocked a bit. That's why it deforms. Another factor is headspacing on the bullet keeps the primer a consistent distance from the breech, so the firing pin jump is consistent. I don't think that makes a big difference to handgun accuracy, but it can't hurt ignition reliability. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 25, 2019, 09:26 AM	#29
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	Your press seats the nose of the bullet a fixed distance from the backside of the case head. So, if you set the seating die up to produce the length you see in the third image from the left on my drawing, you will get that from every round regardless of case length. It improves consistency of start pressure that way, which is part of why it improves accuracy. I have found that lead bullets are soft enough that if you have five thousandths of the kind of protrusion you see in the last image on the right end of the drawing, the recoil spring is usually strong enough to seat them anyway. If the head of the case is five or ten thousandths below the back end of the barrel extension (hood), the bullet has started into the throat and will stop before the rim hits the extractor hook in most instances. So there is really a range of bullet lengths that still work well in each gun. Find which gun makes you seat the bullet deepest and then drop a sample round in the other barrels and see which one lets it fall furthest in. See if that is far enough that the extractor hook will catch it before it goes that far or not. If not, it will usually shoot pretty well and you can use that same seating dept for all you guns. Otherwise, you may find two seating depths, each of which satisfies two of the guns and can divide the ammo up that way. Then you just have to learn how far to turn the seating die setting to switch. The taper crimp die will have some sensitivity to case length. You want the case mouth to wind up between 0.467" and 0.473" diameter at the mouth for normal headspacing. A lot of the target shooters the '40s, '50s, and '60s both headspaced on the bullet and applied a roll crimp (since the case mouth wasn't close enough to the throat to cause a problem) for extra bullet pull and start pressure and swore that produced the most accurate ammunition. It is probably hard to find a 45 Auto roll crimp die these days. The one I have is in an ancient RCBS die set. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 21, 2019, 08:44 AM	#31
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	Getting the case flush with the hood is what works for me. What cartridge overall length that produces will vary with the bullet design. Seating too deeply can also raise pressure or else cause the primer to start unseating bullets ahead of powder burn, which tends to cause irregular velocities, so seating too deeply is not good from that standpoint. It also tends to cause headspacing on the extractor hook when it is deep enough. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

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September 24, 2019, 11:52 PM	#27
Anglicanman Junior Member Join Date: September 18, 2019 Location: People's Republick Of Kaliforn Posts: 8	Thanks for the note about SAAMI! I find a couple of interesting things as I measure cases; for one thing the case mouth is not exactly parallel with the base. If I turn the case I can sometimes vary the measurement in my caliper by a few thousandths. Today I loaded about 170 rounds and just figured if a case is between .888 and .898 it will seat on the case mouth. Half the cases at least, of the ones I have, are too short. I wonder what the original specification way back in 1912 was for cases. Do you know? I read the discussion about chambering off the extractor and that with jacketed bullets it may not affect accuracy all that much; just wonder sometimes about doing things in a way Mr. Browning did not intend for them to be done. And so ... if a person plans to seat the round off the bullet into the rifling how can the overall length of the round be determined? I will have hundreds of too short cases after I use up all the ones which fall in the 10 thousandths range of OK.

September 25, 2019, 12:11 AM	#28
Anglicanman Junior Member Join Date: September 18, 2019 Location: People's Republick Of Kaliforn Posts: 8	OK, Uncle Nick and 44, I am starting to get some ideas. I have 4 .45 ACP pistols and I suppose I could take all the barrels out and find out somehow how to get the base of the cartridge to match the barrel end as Nick shows. I could then load bullets that far from the case mouth for each barrel and segregate them somehow except that even with cases all for one barrel case length is a variable which will influence how far a bullet has to be out in each individual case. Maybe I am getting too worked up about all this, after all eveythng I read seems to say that .45 ACP in 1911 is not all that fussy. I come to reloading from a background in Motorcycle mechanics. If someone told me that piston ring end gap, for example, is supposed to be .006" +/- .010" I would not know how to act.

October 19, 2019, 02:23 AM	#30
Anglicanman Junior Member Join Date: September 18, 2019 Location: People's Republick Of Kaliforn Posts: 8	Hi Nick and 44; It's been a few days since I have been on this forum. I loaded a bunch of 185 gr plated swc rounds at three different lengths, all in cases which measured between .888 and .892 or so (I have never seen a .898 case yet) and found that when I went really short in OAL there were failures to feed I think because the bullet was seated too far in so that the case mouth got hung up on the feed ramp. 1.125 I think, was too short. Now I have a bunch of cases (a few hundred at least) which are below spec. If I load those to an OAL of 1.250 or so, a length long enough so that when I do a plunk test in a barrel the base of the case is about flush with the hood will that be the way to go? I think that those rounds might well plunk into the barrel but they might not fall out as the bullet might stick in the rifling a bit. I have found that there have been cases where the round would plunk into my spare barrel but I would have to hook onto the rim with my fingernail to extract the round. Your thoughts? I hate to just throw a couple of hundred cases away. I would not be loading the SWC but plated 230 gr round nose. I realize I would be headspacing off the bullet not the case mouth.