45ACP Seating Depth Issue

[Larry Gibson]

Never said Doug's work was a "waste of money", just saying throating is always a cure for a handgun chambering problem. I've run into similar chambering problems with new 45 ACPs having "match" chambers and newer commercial 9mms with tighter chambers. Many times using .452 or .357 or larger bullets creates the chambering problem similar to yours. Using a taper crimp die, the Lee FCD or just using .451 or .456 sized bullets has always cured the problem. The problem being the tighter chambers, not too short throats.

[cobia]

I had similar issues with new Lee 452-200 SWC but was stove piping, got frustrated, got a NOE HTC 452-230-RF, PC, sized .452 after coat, took a while to get it to pass plunk on all 4 45's i have. Slowly seated until it passed. All 4 were (very) close in tolerance to depth. Went with that, all run 100% with just enough powder to cycle. Chrony says a tad fast? If I survive a KB I still have three other spares..

[BKS]

All of Hodgdon’s data has a 1.20 OAL. I have three different 45acp handguns and two will chamber a longer round than the 1 pistol so I load all of them to fit the short throated one. 1.21

[DougGuy]

It is almost impossible to over pressure a 45ACP by reducing the COL. I only say “almost” to account for the supernatural phenomena of poltergeist living in the powder, or anything else I may have missed.

This is definitely not true. In fact the opposite, is true. It is all but CERTAIN to raise pressure by shortening the COL. Without adjusting load data to compensate for less case volume.

To make the statement that it is impossible to over pressure, flies in the very face of the laws of physics, AND in every single loading manual or load data known to man.

Notice I said RAISE pressure by shorter COL, not over pressure. Over pressure occurs when the pressure generated by firing exceeds SAAMI published data for the caliber and load in question. Meaning that some setback in a round loaded to below max may not in itself be dangerous. The same setback in a round loaded to max or +P pressure, could become extremely dangerous. 9mm, 40S&W, both of these are high pressure rounds in their normal loading, setback as little as .010" can send pressures skyrocketing. So you can't just assume that you can shorten a COL without consequences, either at the loading bench or by boolit setback when cycling in a pistol. You DEFINITELY cannot assume that it is all but impossible to over pressure the 45 ACP by using a shorter COL.

I will put this in red, because it is fact beyond proof: Boolit setback IS a VERY dangerous event that very often leads to catastrophic and potentially fatal results.

There are at least one thread here where a KB did occur with injuries to the shooter and virtual destruction to a 1911 from boolit setback detonating the entire magazine.

Yet one more reason to MAKE SURE your ammo will plunk and spin freely when chambered, how many times do shooters bump the slide with their palm to force it into battery if they have a failure to fire because a round is jammed into the throat? Or lack of a throat? How many times do you reckon the boolit was pushed back a little bit and never caused an over pressure event? How close to an over pressure event blowing the case out and detonating the magazine did they come?

I personally blew up a Para 1911 in 40 caliber by exceeding safe pressures, thank GOD it was a solid cast receiver with plastic grip panels that did not explode in my hands, thank GOD it just blew up a few rounds in the magazine and blew the bottom off sending loaded rounds and shards of brass and lead downward toward my legs and the floor.

[DougGuy]

The problem being the tighter chambers, not too short throats.

Larry Gibson we are VERY fortunate to have you here contributing to this community. Understanding that the majority of shooters here don't have quite as much experience as you, much less pressure testing equipment, they come here to learn, and seeing your posts one can figure out how to feed a 1911 for example, to get it to work successfully with whatever barrel it came with, and the MOST important and MOST overlooked part of the equation is the alloy the boolit is cast in, and the lube.

Just like undersized cylinder throats can be made to shoot acceptably with soft alloy that actually obturates or bumps up larger when it hits the forcing cone and seals in the bore, the same can be applied to the 45 ACP and other autoloaders.

LET ME STATE THERE ARE TWO AREAS OF CONTENTION TO ADDRESS WITH AN AUTOLOADER, THE THROAT, *AND* THE CHAMBER.

Specifically the 1911 in 45 ACP caliber is one of the most popular pistol/caliber choices for a handloader or a caster, it's usually the first step in learning to cast and load one's own ammo, and in nearly every gun made by a multitude of manufacturers, there is nearly no throat, almost certainly no freebore to speak of, and if there is any, it is almost as a rule, smaller in diameter than .452" yes some pistols come with a little freebore in there that you can get a .452" gage pin to go in, but not very many.

Most look like the barrel on the left. Rifling running right down to the chamber mouth where even a .451" loaded to published COA often won't plunk if there is any of the full boolit diameter sitting outside the case mouth, which it would be if you followed the COA listed in load data.



Usually, interference and failure to go into battery can be traced to the boolit being jammed into the rifling as it would be with the barrel on the left in the photo. However, as you mention match chambers this would refer (imo) to chambers themselves cut to minimum specs for both length and diameter. Some ammo won't function in a match chamber unless the shoulder of the case is .472" or less, but let's consider the math. a .472" chamber mouth, minus .011" x2 for case walls only leaves .450" for the boolit! Most 45 ACP chambers will feed a round crimped to .474" and this is a very common dimension to use since this represents a .452" boolit seated in the 45 ACP case.

Case wall thickness is usually the culprit with a tight chamber (match chamber) and a barrel that has enough throat to plunk the loads. Often one interference is mistaken for another interference, i.e. the throat is often blamed because the loaded round is too big for the chamber, or the chamber is blamed for the failure to plunk when in fact it is the throat causing the interference.

With a barrel that has a match chamber, you often need to sort brass by headstamp in order to have good feed and function. Some cases are just too thick to use with a match chamber unless you are using less than .452" boolits.

[fastdadio]

[QUOTE=Larry Gibson;5234937]Never said Doug's work was a "waste of money", just saying throating is always a cure for a handgun chambering problem. /QUOTE]

I realize you weren't implying that. I posted that to clarify that it wasn't done simply to cure the tight chamber problem. To me, it was simply one box to check off on my search for a cure.

[Forrest r]

Actually the "taper crimp" is the most misunderstood part of reloading the 45acp. Typical ball ammo with a .473" crimp and a .452" bullet.
https://www.bing.com/images/search?v...electedIndex=1

I read all the time that "I only crimp enough to remove the flare." Good way to cause nothing but issues!!!

The tried and true h&g #68 seated to 1.250 with a .469/.470" taper crimp. Countless millions of this same reload have been put down range for decades.
[IMG][/IMG]

I target a 3/1000th's+ taper crimp on every semi-auto caliber I reload for. That .469"/.470" is +/- 20/1000th's of an inch long.

When you have a +/- 3/1000th's" taper crimp on your 45acp reloads it takes any loose/tight chamber fit out of play along with tapering the shoulder of your cast bullet to conform to the leade of the tight match bbl's.

My stock springfield armory nm range officer barrel.
[IMG][/IMG]

3 different bullets shooting 5-shot groups @ 50ft. All loads used 4.3gr of clays and all reloads had a .469/.470" taper crimp. The worst group was 1" outside to outside.
[IMG][/IMG]

That h&g #68 reload pictured above, 10-shot groups @ 50ft with a .469/.470" taper crimp.
[IMG][/IMG]

Now that you know how to use the plunk test you should work on the crimps of your reloads. Get the crimp dialed in so your reloads will pass the plunk test in those match bbl's and you'll be shooting bugholes.

And ya, a 3/1000th's taper crimp that's 20/1000th's long is what I use on my 9mm target loads. 10-shot group @ 50ft fired from a box stock springfield armory range officer with a tight nm bbl chambered in 9mm
[IMG][/IMG]

Heck it used to be extremely common to use a .465" taper crimp with the h&g #130's in our custom wadguns. Take a little time and do an internet search to see what the bullseye shooters are doing. Match chambers need match grade ammo.

1 of hundreds of links out there from a web search.
https://www.bullseyeforum.net/t8204-...-on-the-45-acp

It's always good to keep an assortment of springs around, I use a variable power or a strait 10# spring depending on what I'm shooting in the springfield armory ro's.
[IMG][/IMG]

[IMG][/IMG]

At the end of the day you can run a .469/.470" taper crimped 45acp reload in anything from a cheap millspec 1911 to a match grade 1911. A .474" crimp, not so much in the match bbl's.

A .469/.470" taper crimp is your friend.

[9mmskng]

Bullet profile dictates length, NOT quoted OAL! Load that bullet to groove closest to bullet nose, put 4.0/4.5grs Bullseye under it. You can thank me later.

[Kosh75287]

You could ALSO try THIS:
1.) Put a 230 gr. FMJ factory round in the shell holder and run the ram up, as far as it will go (no die at top of press).
2.) With the seating plug elevated so that it won't seat a bullet, put the seating die in the top of the press and turn it downward, using fingers. When the first sign of resistance is felt, stop turning and engage the locking ring.
3.) Screw the seating plug down until it contacts the top of projectile (usually, the first sign of resistance). UNscrew the seating plug 1/4 to 1/2 turn from there.
4.) Remove the factory round and replace it with a primed, powder-charged case, with the projectile of choice started in the case mouth. Run the ram up as far as it will go, finger-tighten the seating plug, then retract the ram. Inspect the round for signs of crimp, and measure the case mouth. The figure that seems to work well is 0.470 + 0.001". It should be found in the top-most groove of the projectile, with the case mouth abutting the "swell" immediately in front of the groove. If part of the top-most groove is visible, adjust either the die or the seating plug down in 1/8th-turn increments until the groove is no longer visible.
5.) At THIS point, it should all be "fine tuning" for the best fit in the chamber of your pistol.

MY experience has been that, with MODERATE charges of propellants that are slower-burning than Bullseye, seating the bullet SLIGHTLY too deeply and/or crimping SLIGHTLY too much elevates pressures A LITTLE, but not enough to be worrisome.

[1hole]

Is that too deep? will that cause dangerous pressure spikes? I have only loaded dummy rounds as I try to get this boolit to work.

You will get no "pressure spikes" in any auto cartridges except the already twitchy high pressure 9mm and 10mm rounds. Adjust your seating to obtain reliable feeding and chambering in your modest pressure .45 ACP and all will be well.

[Larry Gibson]

You will get no "pressure spikes" in any auto cartridges except the already twitchy high pressure 9mm and 10mm rounds. ............

Having measured the pressure of many different auto cartridges, I would not bet the farm on that erroneous conclusion.......

[1hole]

Having measured the pressure of many different auto cartridges, I would not bet the farm on that erroneous conclusion.......

Welll ... I wonder what degree of seating depth changes in what pressure range of cartridges you're supposing.

Seating autoloader ammo long only causes failures to feed and chamber. I do agree that seating modest pressure autoloader cartridges deeper than a half inch would likely raise start pressure of a hot book load above safe limits. But the cartridges would unlikely feed from a magazine so it would be a moot point.

However, if the seating depth variation is within common sense ranges I don't believe the pressure of a book load for any autoloader cartridge (other than already hot loaded, high intensity 9mm and 10mm) will blow anyone's handgun from together. And I'd bet my neighbor's farm on that!

[Burnt Fingers]

You could ALSO try THIS:
1.) Put a 230 gr. FMJ factory round in the shell holder and run the ram up, as far as it will go (no die at top of press).
2.) With the seating plug elevated so that it won't seat a bullet, put the seating die in the top of the press and turn it downward, using fingers. When the first sign of resistance is felt, stop turning and engage the locking ring.
3.) Screw the seating plug down until it contacts the top of projectile (usually, the first sign of resistance). UNscrew the seating plug 1/4 to 1/2 turn from there.
4.) Remove the factory round and replace it with a primed, powder-charged case, with the projectile of choice started in the case mouth. Run the ram up as far as it will go, finger-tighten the seating plug, then retract the ram. Inspect the round for signs of crimp, and measure the case mouth. The figure that seems to work well is 0.470 + 0.001". It should be found in the top-most groove of the projectile, with the case mouth abutting the "swell" immediately in front of the groove. If part of the top-most groove is visible, adjust either the die or the seating plug down in 1/8th-turn increments until the groove is no longer visible.
5.) At THIS point, it should all be "fine tuning" for the best fit in the chamber of your pistol.

MY experience has been that, with MODERATE charges of propellants that are slower-burning than Bullseye, seating the bullet SLIGHTLY too deeply and/or crimping SLIGHTLY too much elevates pressures A LITTLE, but not enough to be worrisome.

This works great if you're using the same exact bullet as the factory round. But using a factory round with a RCBS 225 gr RN profile and then using a Lee 228 gr 1R bullet is going to lead to nothing but cussing.

[DougGuy]

This is very simple, it's the laws of physics that define it, but long story short, the greater the operating pressure, the smaller the amount of seating variation it will take to cause a dangerous spike in pressure. The smaller the amount of case volume, the smaller the amount of seating depth variation it will take to cause a dangerous spike in pressure.

That leaves this conclusion. In a cartridge which operates at middle level pressures, the variation in seating depth can be greater without causing dangerous spikes in pressure.

However, even in the 45 ACP, boolit setback on feeding from the magazine with a round that isn't crimped enough to hold the boolit firmly, CAN AND WILL very easily spike pressure enough to blow out the case web in a non supported area of the chamber, detonate the remaining rounds in the magazine, exploding the wooden grip panels driving shards of brass, lead, and splinters of wood into the shooter's hands and face.

However, if the seating depth variation is within common sense ranges I don't believe the pressure of a book load for any autoloader cartridge (other than already hot loaded, high intensity 9mm and 10mm) will blow anyone's handgun from together. And I'd bet my neighbor's farm on that!

It happened to a member on this forum, exactly as I described above, the thread is still archived here. It's obvious you haven't read this thread.

You didn't read my earlier reply describing my own experience KB'ing a Para in 40 caliber.

[Finster101]

Reading this thread and a couple of others with that bullet, it seems a poor design for the ACP. I believe I would find a mould with a better nose profile and call it a day.

[Char-Gar]

I continue to be amazed at how much dissention and contention can be generated over reloading the 45 ACP round. Countless billions of reloads have been fired in countless 1911 pistols over the past 110 years. It is a remarkably easy round to reload, yet folks can still find issues to stress about. In these kinds of threads there is more taught about human nature, than reloading the 45 ACP round....just saying boys!

[1hole]

I continue to be amazed at how much dissention and contention can be generated over reloading the 45 ACP round. Countless billions of reloads have been fired in countless 1911 pistols over the past 110 years. It is a remarkably easy round to reload, yet folks can still find issues to stress about. In these kinds of threads there is more taught about human nature, than reloading the 45 ACP round....just saying boys!

Yep. And anyone lying to you about blowing the grip panels off a 1911 because of a few thousanths of seating depth will lie to you about other stuff too.

Oh well, it really doesn't matter very much and momentary web experts need a place to play too.

[Char-Gar]

I was told by a law enforcement guy that some years back he and some others were told to destroy some firearms that had accumulated. There were a couple of 1911s in the batch, so they set out to destroy them and learn something in the process. They started with the traditional 5 grains of Bullseye under a 230 RN FMJ bullet. They went up 1/2 grain at a time and all was good till they got to 12.5 grains of Bullseye, which was a really compressed load. The handgun did not come apart or blow the grips off, but the slide expanded enough to cease function.

Bottom line is you could destroy a 1911 but you could not "blow it up".

[Larry Gibson]

1hole

The OP only asked if the seating depth difference could cause "dangerous pressure spikes". Did I miss where a dangerous pressure spike was defined as "blow it up"? I've seen the end result of too many over pressure loads from overloading, double charges or even bullet set back in 45 ACPs in M1911s.... case ruptures at feed ramp, magazine blown out the bottom and damaged beyond repair, grip panels shattered or splintered and hands cut or burned. Most of those M1911s were not damaged and given new grips and a new magazine were back in operation....when the shooters hand healed and he got his nerve back. Maybe some have not seen that, including you, but I have as have many others....and that ain't no lie.....

I've also seen enough bullets set back into the case from hitting or jamming on the feed ramp. I've actually measured such "set back" and founds as much as .25" +. Does such set back cause an increase in pressure? It certainly does.

My pressure testing measuring the pressure difference in numerous auto loading cartridges such as the 380 ACP the 9mm, the 38 Super and the 45 ACP and revolver cartridges of 32 S&WL, 32 H&R, 38 S&W, 38 SPL, 357 Magnum, 44 SPL, 44 magnum, 45 Schofield and 45 Colt indicate that, with a given load and all else being equal, a set back of .2" will get a 10,000 psi plus increase in pressure at lease. A lot depends on the burning rate of the powder used but with the burn rate of most powders used in the 45 ACP that 10,000 psi figure is pretty close. BTW, a .1" set back nets about 5,000 psi gain.

Yes, many get away with firing such in M1911s especially if the loads are in the normal 16 - 18,000 psi range. However, if you are pushing a top end +P load running already at 23,000 psi and you add another 10,000 +/- psi to it because the bullet sets back during feeding or you seat them too deep.....well, very bad things can happen.....and that also ain't no lie......

Now, if you have some pressure test data to the contrary I sure would like to see it?

[Kosh75287]

[QUOTE]This works great if you're using the same exact bullet as the factory round. But using a factory round with a RCBS 225 gr RN profile and then using a Lee 228 gr 1R bullet is going to lead to nothing but cussing./QUOTE]

I'm not sure about it being "the same exact bullet", but the projectile the OP posted in his "o.p." seems sufficiently redolent of a FMJRN that using a factory ball round as a guide would get him very close to where he needs to be. He didn't mention reloading SWCs, TCs, hollow-points, flat points, nor inverted wadcutters. A .45 auto that will feed 230 gr. FMJRNs, but not a reload with a properly cast Lee 228-1R is suffering from problems OTHER than seating depth. On closer examination, I'm not sure I know of a cast projectile that more closely resembles the 230 gr. FMJRN than the 228-1R, so I'm not at all clear about what the source of your trepidation is. <shrug>

[QUOTE]Having measured the pressure of many different auto cartridges, I would not bet the farm on that erroneous conclusion.../QUOTE]
Amen to THAT, sir.