45 auto headspace

Tex S · February 12, 2009, 09:04 PM

I finished and shot my first batch of 45 auto on Sunday. They shot great in my Springfield GI 1911, but great to me is 2" groups at 15 yards off a makeshift rest (factory ammo groups were twice as large). Nevertheless, I am satisfied with the accuracy for now.

The load is as follows:

Federal 150 Large pistol primers
5.3gr. of Win 231
Lasercast LSWC 200gr.
C.O.L. 1.250

I was cleaning my pistol tonight and slipped a loaded round in the barrel and the case head sat about .025" above flush. Should I seat these bullets deeper so the case head is flush with the barrel? Keep in mind I tested 112 rounds through 2 different 1911 pistols with no feeding issues.

kraigwy · February 12, 2009, 09:40 PM

Not sure I understand the question.

The 45 ACP headspaces on the mouth of the case. If you can get the bullets into the mag, and it feed propertly, and there are no signs of pressure. Whats the problem?

Shoot them, then decide if anything needs to be adjusted.

Tex S · February 12, 2009, 10:21 PM

Let me clarify. I understand the 45 headspaces off the case mouth, but with these Lasercast bullets at a col of 1.250 I am actually headspacing off the bullet.

I just didn't know if this would create any potential problems.

dreamer56 · February 12, 2009, 11:36 PM

That's what I do - I drop my rounds in the barrel I will shoot the reloads out of and look for flush..... and yeah, I adjust the bullet depth and/or crimp to get there - just how I learned to do it -

Doesn't answer your question I know - but my results doing this have been great.

whiplash · February 12, 2009, 11:53 PM

I had similar problems recently with the bullet touching, instead of the case mouth. After all these years I have be seating/crimping the bullet in one step. I then found out that by seating then crimping in two different steps solved my problem. Now the bullet looks much better (no scrapping lead by crimping, causing lead buildup around where the case mouth should be headspaced), and the round falls under flush. My OAL when I was seating/crimping in one step (230RN) was 1.250, which was .010 shorter, so it wouldnt headspace on the bullet. Now that I seat/crimp seperately the same bullet is now 1.260 (as recommended), and falls below flush. You would have to seat all your bullets (raising the die body as to not crimp), then lower the die body, raising seating stem (not contacting bullet), then crimp all the rounds. Not sure if this is actually your problem, but something to think about or try. Eventually I will get a second die (one seat, one crimp) and I wont have to keep adjusting.

Casimer · February 13, 2009, 12:18 AM

It's typically advised to set the COL so that the case head is slightly below the end of the barrel hood. If it's protruding, either the bullet will be pressed further into the case when the pistol is in battery, and/or it will be forced into the leading edge of the lands, where the chamber transitions to the bore. In either case, the final OAL will be set by the pistol itself. This is likely to result in a lot of variability in the resulting pressure of your loads.

How are you determining that your cartridges are headspacing on the bullet?

Jim Watson · February 13, 2009, 09:22 AM

It is usual to seat a SWC so that headspace control is with the shoulder of the bullet against the origin of the rifling holding the case head flush with the hood of the barrel.

But .025" high at 1.250" OAL sounds strange for that bullet. I seat about 1.245" because that is what my shortest chamber calls for.

Are you SURE it is the bullet in contact? Are you taper crimping? If not, they might be held up by case mouth flare wedging in the slight taper of the chamber. What does a factory round do?

Is your gun loose? Is there a gap between the hood and the breechface?

I guess you could leave well enough alone, if they feed reliably and shoot accurately, that is worth more than arbitrary measurements. Still seems a bit strange.

Tex S · February 13, 2009, 09:57 AM

Quote:

How are you determining that your cartridges are headspacing on the bullet?

I colored the end of a loaded round witha black sharpie and inserted it in the barrel. When I pulled it out I could see where the ink had rubbed off.

Quote:

Are you taper crimping?

With a Lee FCD.

Quote:

What does a factory round do?

Headspaces off the mouth and sits about perfectly flush.

Quote:

Is your gun loose? Is there a gap between the hood and the breechface?

I will check this tonight.

TEDDY · February 13, 2009, 02:05 PM

most of headspacing is bull.Jim has it.I load so that the SWC front band is half out of case and roll crimp.the slide closes and the rd is headspaced up agains the slide.so it also does not depend on case lenth.I dont know weather it works but this is what the bullseye shooters do,hamilton ,colt and others.I have never measured the OAL.it fits the mag.

February 12, 2009, 09:04 PM	#1
Tex S Senior Member Join Date: November 12, 2008 Location: Fort Worth, TEXAS Posts: 909	45 auto headspace I finished and shot my first batch of 45 auto on Sunday. They shot great in my Springfield GI 1911, but great to me is 2" groups at 15 yards off a makeshift rest (factory ammo groups were twice as large). Nevertheless, I am satisfied with the accuracy for now. The load is as follows: Federal 150 Large pistol primers 5.3gr. of Win 231 Lasercast LSWC 200gr. C.O.L. 1.250 I was cleaning my pistol tonight and slipped a loaded round in the barrel and the case head sat about .025" above flush. Should I seat these bullets deeper so the case head is flush with the barrel? Keep in mind I tested 112 rounds through 2 different 1911 pistols with no feeding issues.

February 12, 2009, 09:40 PM	#2
kraigwy Senior Member Join Date: June 16, 2008 Location: Wyoming Posts: 11,061	Not sure I understand the question. The 45 ACP headspaces on the mouth of the case. If you can get the bullets into the mag, and it feed propertly, and there are no signs of pressure. Whats the problem? Shoot them, then decide if anything needs to be adjusted. __________________ Kraig Stuart CPT USAR Ret USAMU Sniper School Distinguished Rifle Badge 1071

February 13, 2009, 02:05 PM	#9
TEDDY Junior member Join Date: December 10, 2006 Location: MANNING SC Posts: 837	headspace most of headspacing is bull.Jim has it.I load so that the SWC front band is half out of case and roll crimp.the slide closes and the rd is headspaced up agains the slide.so it also does not depend on case lenth.I dont know weather it works but this is what the bullseye shooters do,hamilton ,colt and others.I have never measured the OAL.it fits the mag.

February 12, 2009, 10:21 PM	#3
Tex S Senior Member Join Date: November 12, 2008 Location: Fort Worth, TEXAS Posts: 909	Let me clarify. I understand the 45 headspaces off the case mouth, but with these Lasercast bullets at a col of 1.250 I am actually headspacing off the bullet. I just didn't know if this would create any potential problems.

February 12, 2009, 11:36 PM	#4
dreamer56 Member Join Date: November 21, 2007 Location: Central Illinois Posts: 42	That's what I do - I drop my rounds in the barrel I will shoot the reloads out of and look for flush..... and yeah, I adjust the bullet depth and/or crimp to get there - just how I learned to do it - Doesn't answer your question I know - but my results doing this have been great.

February 12, 2009, 11:53 PM	#5
whiplash Senior Member Join Date: January 18, 2007 Location: Idaho Posts: 334	I had similar problems recently with the bullet touching, instead of the case mouth. After all these years I have be seating/crimping the bullet in one step. I then found out that by seating then crimping in two different steps solved my problem. Now the bullet looks much better (no scrapping lead by crimping, causing lead buildup around where the case mouth should be headspaced), and the round falls under flush. My OAL when I was seating/crimping in one step (230RN) was 1.250, which was .010 shorter, so it wouldnt headspace on the bullet. Now that I seat/crimp seperately the same bullet is now 1.260 (as recommended), and falls below flush. You would have to seat all your bullets (raising the die body as to not crimp), then lower the die body, raising seating stem (not contacting bullet), then crimp all the rounds. Not sure if this is actually your problem, but something to think about or try. Eventually I will get a second die (one seat, one crimp) and I wont have to keep adjusting.

February 13, 2009, 12:18 AM	#6
Casimer Senior Member Join Date: April 23, 2007 Location: Pennsylvania, USA Posts: 1,918	It's typically advised to set the COL so that the case head is slightly below the end of the barrel hood. If it's protruding, either the bullet will be pressed further into the case when the pistol is in battery, and/or it will be forced into the leading edge of the lands, where the chamber transitions to the bore. In either case, the final OAL will be set by the pistol itself. This is likely to result in a lot of variability in the resulting pressure of your loads. How are you determining that your cartridges are headspacing on the bullet?

February 13, 2009, 09:22 AM	#7
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,535	It is usual to seat a SWC so that headspace control is with the shoulder of the bullet against the origin of the rifling holding the case head flush with the hood of the barrel. But .025" high at 1.250" OAL sounds strange for that bullet. I seat about 1.245" because that is what my shortest chamber calls for. Are you SURE it is the bullet in contact? Are you taper crimping? If not, they might be held up by case mouth flare wedging in the slight taper of the chamber. What does a factory round do? Is your gun loose? Is there a gap between the hood and the breechface? I guess you could leave well enough alone, if they feed reliably and shoot accurately, that is worth more than arbitrary measurements. Still seems a bit strange.