What's Wrong with this Picture?

[steve4102]

I borrowed this picture from UncleNick and posted it on another forum. The question was asked, "what OAL for a 45 ACP LSWC", so I put up this picture.

I got spanked by the local reloading guru and I wasn't sure hoe to reply.
Here is some of what he said about this method of determining OAL.

Using the barrel as a gage is OK but do not allow the cartridge to headspace on the bullet. That is NOT OK! The pictures posted by steve4102 indicate it is OK (headspace on the bullet, third choice from the left) and that does not agree with major reloading companies reloading manuals.

In no case should you ever allow the cartridge to headspace on the bullet. That is not OK. The bullet needs some run on engaging the rifling. With out that run the bullet stalls in its exit from the case and the fast rising pressures can become too high. While it may not blow up the gun it may do a number on the case, or blow the primer out of the case and into your face (hot primers on the skin are not conducive to smooth skin!).

[Magnum Wheel Man]

not enough words...

with cast bullets, you often get best accuracy when the bullet engages the rifling... trouble is, if it actually headspaces on the bullet, in a semi auto, the action can push the bullet in further, until the case hits, & cause a pic that looks like the 1st one, which often leads to light strikes, misfires, & can develope higher chamber pressures, depending on the load...

now in a single shot, such as a Contender... not so much a problem...I always try to head space either on the shoulder, rim, or the case mouth, then adjust the bullet length to just engage the rifling... not necessarily "head space" on the bullet

[Brian Pfleuger]

There's nothing wrong with the picture. The respondent is either making unwarranted assumptions or entirely missed the part about lead bullets. Actually, pretty much any cartridge, except maybe those that headspace on the rim, can be made to headspace on the bullet. It just requires appropriate load levels.

[IllinoisCoyoteHunter]

The respondant has no idea what he is talking about. We are talking about lead bullets here. I can swage them down with my fingernail!!! It may raise the pressure a little bit but it is extremely insignificant. I have achieved the best accuracy loading this way. He doesn't seem like much of a reloading guru, IMHO.

[Slamfire]

I used to seat my bullets till everything looked like picture three, but not any longer.

Having an interference fit between the lead bullet and the throat will cause jams.

Throats are different between barrels. I had the unfortunate experience to have 230 LRN prevent the slide from fully going into battery on one M1911. While the ammunition functioned fine in the barrel I used to set the OAL, in the other barrel the lead bullets jammed in the throat. I was unable to force the slide into battery, so I could not shoot the thing out, and I had one of those guide rods, which made it difficult to push the slide open.

I did two things, I used 1.250" as my 230 L overall length. Nothing jams in the throat and ammo functions fine in all my M1911's. I also taper crimp to 0.469".

I removed the guide rod. Now if I have a failure to go into battery, I can put the recoil plug on the end of a table and push the slide open.

As far as accuracy, this benchrest stuff is for bench rest rifles, not pistols.

Practice on your sight alignment and trigger pull.

With my mixed headspace cases and sloppy reloads, I shot this 32 round group at 25 yards offhand with my Les Bauer. These optical sights and a wonderful trigger pull did more for my accuracy than attempting to copy benchrest rifle reloading practices.

[noylj]

The quoted text:
In no case should you ever allow the cartridge to headspace on the bullet. That is not OK. The bullet needs some run on engaging the rifling. With out that run the bullet stalls in its exit from the case and the fast rising pressures can become too high. While it may not blow up the gun it may do a number on the case, or blow the primer out of the case and into your face (hot primers on the skin are not conducive to smooth skin!).

IF the bullet gets a running start and then hits the rifling, that would seem to be a great place for a pressure spike. Perfectly normal in rifles, so it must be OK. If the bullet is in contact with the rifling, by definition it can't get a running start before crashing into the rifling. I sort of think of it as a really good crimp and Unique, Bullseye, and Red Dot seem to burn "cleaner."
Having the bullet shoved into the rifling with a cartridge running at 55k pressure or more might be a problem, but we are talking about less than 35k and, with the .45 target loads, MUCH less.
Aren't battleship rifles always loaded with the bullets in contact with the rifling?
I have been setting up my .45 lead bullets loads to headspace on the bullet shoulder. Extraction has never shown any push-back and the bullet has never been shoved into the rifling more than to just leave a hint of a mark on the bullet. The main issue is feed reliability and fitting the magazine. I personally do not believe there is a better gauge than your own barrel.
Next, as a reloader, I always work up a load and have never NOT started at the starting load, and almost always check multiple manuals for the lowest of the starting loads.

[chris in va]

I had this problem with my CZ 75. Once I found out it needed a .358 boolit, I switched to a 38 Special design and discovered it was too fat to chamber. My OAL had to be tweaked all the way down to 1.01 before it cleared the leade.

Shoots great now though, compared to those .356's I was using.

[Sarge]

Seating hard against the rifling, intentionally or otherwise, is an open invitation for Mr. Murphy to act as your Chief Ballistician.

I'd make a general exception for benchrest folks who load the same bullet, same brass, same rifle continuously for the finest froghair of accuracy; but as a standard rule I recommend against it.

[Slamfire]

Aren't battleship rifles always loaded with the bullets in contact with the rifling?

The big cannon shells had driving bands. The steel shells were undersized for the bore and the driving bands provided the gas seal and kept the steel off the barrel.

I suspect the shells were driven into the lands and grooves. Still, it is an entirely different mechanism, and I suspect the pressures were low. The load was extremely high as there was a lot of surface area.