Headspacing 45acp lead bullets on the bullet

[Billglass]

I've read the sticky and several posts and threads from unclenick about headspacing 45acp lead bullets on the bullet

I generally shoot Penn Bullets 200 grain SWC (H&G68) target grade (14 BHN) 0.452" diameter with O.A.L of 1.25" and a taper crimp at .469 (measured right at the case mouth) out of a Colt Gold Cup National Match and use 4.5 grains of WST or Bullseye

I'd like to try "headspacing on the bullet"

But I have several questions/concerns.

in unclenick's posts, he mentions that it reduces gas escaping around the bullet and that INCREASES PRESSURE..and because of an increase in empty case volume there is also a DECREASE IN PRESSURE.

Is there an overall increase in pressure or pressure spike that would tell me to reduce the starting load (4.4 grains WST)?

Do the increase and decrease of pressure offset each other? (One thing I've learned about this hobby is - it can't be that simple!)

I've seen the scary 30-06 distance off the lands and pressure graph which shows the highest pressure 0.0 off the lands

I am not sure the rifle curve applies here to a 45 ACP....but i want to be safe

Thanks in advance!

[reddog81]

Your OAL's better have 0 variance otherwise you'll be jamming bullets in to rifling and your gun won't lock up. A little bit of lead in the rifling will also cause this problem with bullets seated like that.

I'd guess that it would be next to impossible to know if the increase in pressure and the decrease offset one another. One bullet could get a perfect seal and the next doesn't creating a variance in the pressure and velocity but you'd never know the reason why it happened.

If it's something you want to try I'd go for it. Obviously don't start with a max load. Most .45 ACP loads have a huge range of powder weights compared to other handgun rounds.

[g.willikers]

Also check if those loaded longer rounds will travel up and down in the magazines before making a bunch and finding they don't.
Just a thought.

[Jeffm004]

Plus 1 on the lock-up issue. I have a jar of coated lead .45 just / too long, will not lock up the Colt, so far, they feed in the Sig. I had to buy a case gauge to find it, it was 1 in 50 and the plunk test was not enough.

[Billglass]

WST has a whopping range of 4.4 grains (starting) all the way up to a max of 4.9 grains!

I'd be willing to change powders for safety while experimenting.

[mikld]

Just wondering why? In "normal" reloading it's wise practices to keep bullets away from the rifling a few thousandths...

[243winxb]

Accuracy -- .947" head to shoulder puts the lead in contact with the rifling in my old series 70 GC. It removes end play.
I learned it from a very old NRA reprint on loading for the 45 acp for Bullseye competitions.

Best used for slow fire, but works for timed and rapid fire also. Soft lead is very forgiving if COL is a tiny bit long.

Dont bother if using/loading range brass/mixed headstamp. IMO.

http://i338.photobucket.com/albums/n...47inch_001.jpg My photo.

[Billglass]

I use new 'IMI match' brass developing any 45 acp load
And 1 or 2 times fired cases (so far) for practice shooting targets

[David R]

I have done it for a long time. It makes for more accurate loads. I do not worry about a pressure spike in a lead load 18,000 PSI. Try a fewdozen, shoot groups and see if accuracy has improved. If it does, work up to your max load. I doubt you will even see a difference in velocity compared to Book OAL.

If your throat is LONG, magazine fit may be a problem.

Its worth the try. Works great in my 45.

David

[Jim Watson]

Back when I only owned one .45, I loaded SWCs to "headspace" on the shoulder. Accuracy was good and there were no "pressure signs" but then I was not loading to the maximum. At the time I did not have a chronograph, so whatever would cycle the action and not kick too much was my target load.

This was the recommendation of the NRA, leading gunsmiths like A. Dinan, and the practice of many good shooters.

I guess we now have the Internet to get us timid about every little thing.

[Ozzieman]

Headspacing 45acp lead bullets on the bullet

Its odd here that I use the same exact bullet and have for the past 10 years and mid 70's Gold cup. In my case I use W231.

My question is, what effect does this have?
What are supposed to be the accuracy increases?
1/10 of an inch at 15 yards improvement?
Inch?

[243winxb]

The goal is to have 45 acp target ammo that will stay in the 3.36" , 10 ring at 50 yards for Bullseye pistol for me. Others will aim for the X ring . Testing should be from a machine rest or benchrest.

Logged scores at 50 and 25 yards, firing slow , timed and rapid fire courses give a clue how the accuracy is.
http://www.indecorous.com/bullseye/rings.html

There are a few things that make accurate ammo.

Great bullets- in the order of best accuracy- jacketed, swaged lead, cast, plated. When working up a load using cast bullets, sort them by weight to eliminate ones with air bubbles.

Brass- new, same lot, maximum trim length. (Trimming never needed) Long brass is more accurate.

COL- seating lead bullets to just contact the rifling. This removes end play, slop in the chamber. This can not be done in all guns. The COL may be to long for some.

IMO.

[buck460XVR]

My question is, what effect does this have?
What are supposed to be the accuracy increases?
1/10 of an inch at 15 yards improvement?
Inch?

I have the same question. Does anyone have a side by side comparison of similar loads with the only difference being the headspacing on the case mouth vs headspacing on the bullet? For the most part, I load for 4 1911s. I make ammo that works well in all 4. I do not compete with them, they are range toys and SD/HD firearms. My revolvers are my accuracy workhorses used for long range targets and hunting. While I can see someone shooting highly competitively looking for every 1/10 of an inch, is the difference in accuracy worth the risks/problems for someone like me or should I stick with the standard of headspacing off the case mouth? I mean to me, tenths of an inch are moot, but an inch @ 15 yards is big.

[Billglass]

thanks for all the informative replies and adding to the thread

I have to apologize, the sticky I referred to was on the Shooters Forum.
much good information

https://www.shootersforum.com/handlo...ad-45-acp.html

Unclenick discusses this headspacing on the bullet in posts#8, #12, and 38 of that thread
I won't repeat the details of his posts here - he does a fine enough job on his own

I read certain loads throughout the discussions with Bullseye and W231 - but not in the same paragraph with headspacing on the bullet
so I don't want to take the load out of context or guess.

The missing piece of the puzzle for me is a starting load for Bullseye, W231 and or WST to try this experiment.

[Unclenick]

Originally Posted by Billglass

Is there an overall increase in pressure or pressure spike that would tell me to reduce the starting load (4.4 grains WST)?

The dynamics of the 45 Auto are different than in a high power rifle. The case doesn't stick to the chamber wall, instead backing up under pressure, so this stalls pressure rise in the way gas bypass does in a rifle whose case shoulder is locked in place when the bullet starts to move. Typical cast bullets for the .45 Auto are only about 1/3 as hard as jacketed bullets, so they just don't cause as much starting resistance into the rifling lands. Finally, lead bullets just don't get held as hard by the case as jacketed ones do, so we are really hoping to increase the start pressure a little closer to that of jacketed bullets for improved barrel time consistency.

I have a custom Encore barrel in .45 Auto with a strain gauge for my Pressure Trace on it. If folks are curious, remind me when the weather is better and I'll see if I can't work in some comparisons on several methods of loading lead in the .45 Auto. I could also compare them to standard equivalent loads of jacketed bullets, too. In the meanwhile, I can only say I've certainly never seen a pressure sign loading lead to touch the throat with lead.

I'll mention that I do not normally load jacketed bullets to touch the throat simply because it's unnecessary. I don't see an accuracy improvement doing this with jacketed bullets.


Reddog81,

The exact COL isn't as strict as it would be with jacketed bullets. My illustration shows the back of the case flush with the barrel extension (aka, hood) on the back of a 1911 barrel, but I've had them stick out by 0.010" or so and still feed properly. The lead is so soft it's no challenge for the recoil spring in my guns to start them into the lands.


Ozzie and Buck,

The answer to your question will depend on your chamber. If, as Jim Watson suggested, you can genuinely and repeatably headspace on the case mouth, then you may see less difference that I got when I first discovered this trick (I think quite a number of folk have discovered it independently) back about 1984, I was shooting a 185 grain soft swaged LSWC made by Star over 3.8 grains of Bullseye in my Goldcup for indoor matches (50 foot reduced targets). At that distance, off bags, the original load would shoot about 1 3/8 inch groups of ten at that range. That's dandy for a defensive pistol, but the 10 ring of a 50 foot reduced Conventional Pistol target is 0.9 inches, and so that was not good enough to clean targets. You need groups no bigger than 1.351" C-T-C and perfectly centered to clean that target with no worse than a scratch 10. When I tried that same load seated out to headspace on the bullet, the groups shrank 40% to under 7/8" C-T-C at 50 feet, and I had a gun that could shoot "possibles".

Why would it make so much difference? The comes down to what Jim Watson said about headspacing on the case mouth. If you can do that, you should shoot just as well or close to it. The problem back in the 80's was that .45 Auto pistols were mostly 1911's and, as one of the board's gunsmith members estimated, out of the box about 70% of 1911's he saw were actually headspacing on the extractor hook. In other words, the chamber was so long that the extractor hook was what was actually holding the cartridge still for the firing pin strike. The case mouth wasn't reaching the end of the chamber before this happened. Moreover, because .45 Auto cases don't stick to the chamber, they back up and get swelled shorter and fatter by pressure in the slightly tapered chamber, so they shrink with each load cycle. I've measured my target load cases losing about half a thousandth of an inch each time around. With light loads, by the time a bulk purchase of cases have all split or been lost in the grass, they are well below SAAMI minimum case length and would be headspacing on the extractor hook in about any gun chambered for the .45 Auto anyway. So, even if you don't have the extractor hook headspacing initially, you will later if you are frugal with your brass.

So, what's wrong with headspacing on the extractor hook? For jacketed bullets, nothing except extra extractor fatigue, that I can find. But jacketed bullets in the cartridge are strong enough that they can center themselves well in the barrel as they start to leave the case, and not be distorted by the chore. Lead bullets don't seem to center. If the extractor hook has pivoted the cartridge against the extractor hook side of the chamber with a lead bullet, it seems to swage into the bore at that small angle, shave some lead of against the chamber edge and unbalance and open groups up. As evidence of this, I offer that once you start headspacing lead bullets on the barrel throat, you will notice clean the gun how much less leading there is. Indeed, I've run over 3,000 rounds of lubricated lead 200 grain SWC's over Bullseye without cleaning and the barrel has only a few traces of lead near the throat. In fact, the gun stopped at a little over 3,000 rounds because powder fouling had accumulated between the slide and frame in a cake that finally got thick enough to prevent the slide from closing 100%, and I was having to give it a thumb assist.



Below is the same gun shooting jacketed bullets not headspaced on the bullet and 200 grain cast LSWC, both targets of a Hoppe's pistol rest at 25 yards. The jacketed load shows what the gun was capable of around that (recently fit up). I note that three of the lead bullet holes are touching. Two holes outside of those may be casting issues. These were purchased bullets, and I didn't weigh them first for consistency, which I would have if I'd cast them myself. There is a note in the upper right corner from a few months later indicated that I'd dissolved the lube from a sample of these bullets and found they had a 3 grain weight span. By itself that wouldn't matter if the lighter ones had mass symmetry, which could happen if they are just out of different mold cavities. However, if they were form the same cavity it would likely mean a void or a dross inclusion, and that could throw balance out.

[ShootistPRS]

The 45ACP and most other rimless straight case ammo headspaces on the mouth of the case. There is no way that you can "headspace" on a bullet safely. The chamber is cut with a shoulder at a given length (within tolerances) so the case mouth hits that shoulder to stop the case from going in deeper. If you roll crimp a 45 case it will either not fire or it will cause wear when the round is expanded below the chamber and the mouth of the cartridge is squeezing the bullet to get it to exit the case and go down the bore. New brass is on the verge of being too short but they stay on the operational edge. If your brass gets too long the round will not chamber and it will usually not go into battery to fire. Beyond the chamber there is a tapered area called the lead (or leade). It allows the bullet to move freely and smoothly into the rifling. If you seat the bullet long enough to hit a spot where it is engaging the rifling you are going to turn your pistol into a hand grenade. Maybe not the first, second, or even the third time but as soon as the pressures get high enough you will lose a gun and likely at least the use of your hand for a time.

[rodfac]

Thanks Nick for a great explanation...I shot the .45 in NRA Bullseye for years and found that my 200 grainers, seated out a bit, grouped better than those that were closer to flush, but never knew just why. Al Dinan's old article in the NRA booklet on Cast Bullets explained it somewhat but your post cleaned up my questions. Rod

[Master Blaster]

People who shoot NRA bullseye pistol like to have all the accuracy and consistency they can manage to win matches.

If you can guarantee that the rounds will always feed reliably and function perfectly then head spacing on the bullet for better accuracy is fine.

Mis-feeds and malfunctions cost people matches in competition. Overly long rounds may drag on the magazine or fail to chamber, that can be a big problem in a match. Folks I know who compete seem to like their ammo to be around 1.246 to 1.252 OAL for the 200 LSWC bullet depending on what bullet they use and what they find works most reliably in their pistol.

The Army Marksmanship Unit, AMU uses the Nosler 185 JHP at 1.20 OAL with 4.7 grains of N310 and they seem to win most of the .45 matches at Perry the last 10 years. I have no idea if they have studied loading them so they hit the lands of the barrel but I seriously doubt it.

https://www.ssusa.org/articles/2016/...match-45-load/

[Ozzieman]

Thanks Unclenick for an easy and well explained reason for headspacing.
One more question. Do you then work on case length for any reason? It sounds like with this it wouldn't matter.

[rodfac]

Master

The Army Marksmanship Unit, AMU uses the Nosler 185 JHP at 1.20 OAL with 4.7 grains of N310 and they seem to win most of the .45 matches

The Army service team is using jacketed bullets...if I read UncleNick correctly, he's talking about lead alloy bullets of the SWC variety. Mine were 200 grainers of SWC shape (actually the old H&G #68), and my tests confirmed Uncle's comments regarding seating depth to allow the lead shoulder to contact the leade.

If you can guarantee that the rounds will always feed reliably and function perfectly then head spacing on the bullet for better accuracy is fine.

Yep that's what testing is designed to do...in my case, it was for one gun only, not all of my .45's, just for the one that needed that level of accuracy.

Rod

[Unclenick]

Master Blaster,

I am talking the 1970's. Back then Lake City still loaded the match ammo the military used. The AMU developing and loading its own ammo started later. I'm not sure exactly when.

No, I would not merely move a jacketed bullet into the throat without starting load workup over again. But it's a waste of time. The left group from my Goldcup was with Hornady 200 grain jacketed semi-wadcutters, and that wasn't touching the throat. The jacketed bullets seem to be able to self-align in the bore during firing and without distortion or shaving. Distortion is was screws up lead bullet accuracy.


Ozzieman,

No to case length. As I explained, the cases eventually become way too short. I took some Winchester brass through 50 reloading cycles, at which point three hundred of the original 1000 new bulk cases remained, the rest having split or been lost, and it was all 0.025" shorter by then. No way for it to headspace on a case mouth even in a tight chamber. You do have to adjust your taper crimp die down a bit for that.


ShootistPRS,

The 45ACP and most other rimless straight case ammo headspaces on the mouth of the case. There is no way that you can "headspace" on a bullet safely.

You'll need to produce a citation for that, as I and thousands of others have done it for decades.

The chamber is cut with a shoulder at a given length (within tolerances) so the case mouth hits that shoulder to stop the case from going in deeper.

As Libertarian David Bergland once commented, "Utopia is a place where everyone has everything they want and nothing ever goes wrong. Utopia is not one of the options." Many handguns, 1911's in particular, are put together with fairly rough fitting parts. It's very easy to get one that has more room in the chamber than the length of cases within spec can reach. These cartridges are stopped by the rim finding the extractor hook before they get there. I don't have a sense of how common this is in other pistols, but I've worked on a lot of 1911's and found this happening in at least half of them.

If you roll crimp a 45 case it will either not fire or it will cause wear when the round is expanded below the chamber and the mouth of the cartridge is squeezing the bullet to get it to exit the case and go down the bore.

Go take a look at the old NRA technical information from the 50's and 60's. You'll find a lot of the top shooters of that era roll-crimped their ammo and swore that produced the best accuracy. (They didn't have taper crimp dies commonly back then, so light roll crimps were needed to remove case flare, but some experimented with taking it further. They were doing it for revolvers using half moon clips anyway.) It's the start pressure, again. There are photos of it in those old articles. The trick is that the extractor hook stopped the case from going forward far enough to jam that rolled crimp against the throat.

[243winxb]

Unclenick gives great info, as always.

[Jim Watson]

To quote a usually reliable source (Me!) I did not say anything about headspacing on the case mouth. "Back when I only owned one .45, I loaded SWCs to "headspace" on the shoulder."

MY old technical information from the 1960s, probably the same article rodfac mentions, shows where Mr Dinan recommended a hard roll crimp into the lead of the front band of a semiwadcutter. OAL was controlled to put the shoulder of the SWC against the lands. His headspacing was definitely not off the extractor or the case mouth.

Rules are different for jacketed bullets, as said, they are hard and stiff enough to stand a little jump.
Also a fully accurized 1911 will have been fitted with a short chambered barrel. The final ream to low end of "headspace" is done after the hood length is established. So the jump ain't much.

I taper crimped a lot of .45s on the old Rockchucker by running them into the mouth of the sizing die. Bullets were hand cast Lyman 452460s by a friend and I was glad to pay a nickel a pop for his troubles.

[Billglass]

Thank you all for taking your time to contribute to this thread and answer mine and other's questions.

It's a pleasure reading posts on this forum, they are usually full of fact and thorough explanation....not just guess work or opinion.

Unclenick, as always, the information you offer to reloaders is priceless!

Thanks all!

[David R]

After all that, I hope you try it at least with a starting load.

using a Lyman 452460, 3.5 grains of bullsyse, a Wilsons match barrel fitted, I was getting the accuracy I wanted. Shot tens of thousands of those rounds indoors @ 50 feet and outdoors @ 25 and 50 yards.

David