Should I Change The Seating Depth On A Bullet With A Canalure

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Quick question on bullet seating depth on 223...
55 Grain FMJ-BT with cannelure
mixed headstamp brass
25 grains of H335

My brass measures out at i.75" subsequently trimming.. Lyman manual says 1.76"

When I seat these bullets to an OAL length of two.260" then cannelure never reaches the case mouth.. The neck tension is solid... Should I leave information technology where its at or seat it until it touches the cannelure?

Thanks in accelerate...
Ummm... all my manuals have the trim to length listed every bit 1.75" and the COAL equally 2.250".
That said, I wound upwards seating the bullet at a level where the cannelure was touched by the case oral fissure. Mine were shorter than two.25 COAL by 1/tenth of an inch. I did that to lucifer the manufacturing plant ammo I had on hand since these were my showtime loads.
If y'all are crimping, you might desire to suit your die so the crimp falls on the cannelure. If you lot are not crimping and it fits your chamber and magazine, you are good to go. The cannelure is for crimping.
Nomenclature for case length tin get confusing.
Generally, 1.76" is the max length for 223 Remington and it should be trimmed when at or longer than that figure.

It is by and large accepted that the "trim to" length is 0.010" less than the maximum length which in 223 Remington's instance would be ane.75"

Sometimes, manuals call the max length "trim length" which means the length at which should the case should be trimmed.

When searching for the data, I like to detect information that gives both numbers regardless what they call them. Then I know the maximum and minimum.

If you want to crimp, seat the bullet deep enough so that the case mouth is nominally in the center of the cannelure. At this depth, the cartridge should fit in the magazine with no problems.

If you exercise non desire to crimp, no problems, practise not crimp. This will allow you to vary the seating depth a fiddling within magazine length, unless yous want to single load.

The cannelure will end upwards where information technology ends up. The cartridge may look a niggling foreign with the cannelure not exactly at the mouth of the contumely.

Promise this helps.
Mine are trimmed to one.750" per the Lee Example Gage trimmer, and my OAL is 2.227" +/- .001". This OAL has worked for me in all of my AR rifles, and usually gets me in the canelure for a very very light crimp with the Lee FCD. I have e'er had skillful neck tension, but I like the extra insurance of a calorie-free crimp. 98% of my rounds are used for tactical rifle matches, or SD classes where I run the rifles hard, and sometimes drop mags.
my trimmer trims to one.sixty, and i use an oal of 2.225
The only way to lucifer things up exactly is to use the trim to length and the verbal bullet used in the transmission. Even so it information technology is off a bit.
Example using Hornady brass and Hornady bullets with their trim length the cannelure should fit in the instance mouth. Fifty-fifty then information technology information technology is sometimes a flake off, I usually do as with revolvers and lead bullets and seat to the cannelure.
Looks like a Hornady 55 FMJ and Hornady recommends 2.200" oal. I seat Hornady's from 2.210"-2.230" which puts the cannelure in position to crimp if you crimp. Hornady'southward 55 FMJ has a blunt rounded shape tip which makes the overall length shorter. Military and another 55 FMJ bullets have a longer sharply pointed tip and their overall length is longer and normal seating is at 2.250". At 2.260" which is maximum magazine length for AR magazines the 55 FMJ's would be seated also far out simply withal would work if you accept acceptable bullet tension. You won't gain in my experience any accuracy by trying to seat 55 FMJ bullets longer. Plus if you lot take a bolt activity burglarize, at least in mine, they would not chamber and would jam the bullet into the rifling. I'd seat the bullets in your pic to at to the lowest degree mid cannelure. Your trim length is correct. Recommended trim length is 1.750" and they are ok as long equally one.760" but should exist trimmed if longer than 1.760"
55 Gr FMJs are not lucifer bullets by any stretch of the imagination. Load them so the case oral fissure is in the middle of the cannelure and they will work just fine. Loaded long may (Or may non.) crusade problems with fitting the mag or feeding.
Seat to whatever works for you. The OALs in the manuals are Not written in stone and are a elementary guideline, not a requirement. Some manuals don't even list the OAL they tested information technology is that unimportant.
This is from Accurate and Ramshot Powders.

SPECIAL Notation ON CARTRIDGE OVERALL LENGTH "COL"
It is important to annotation that the SAAMI "COL" values are for the firearms and armament manufacturers manufacture and must exist seen as a
guideline only.
The individual reloader is costless to adjust this dimension to adapt their item firearm-component-weapon combination.
This parameter is determined past various dimensions such every bit i) magazine length (space), 2) freebore-lead dimensions of the barrel, 3)
ogive or profile of the projectile and 4) position of cannelure or crimp groove.
If y'all can't button the bullet deeper into the case by pushing confronting a wood workbench or such, don't bother crimping anyhow. The neck tension is plenty, and crimping doesn't assist accurateness. Inquire people who shoot ARs competitively if you don't believe me.
This may or may not exist truthful. IME, cervix tension is often times non enough and crimping with the Lee Mill Crimp die increases accurateness.
Here is what Sierra says virtually "Neck Tension" in a Service Rifle.

Neck Tension
When we stop to consider the vigorous (read, downright violent) chambering bicycle a loaded round endures in a Service Burglarize, it becomes pretty clear it suffers abuse that would never happen in a bolt-activity. This is but the nature of the animal. It needs to exist dealt with since in that location is no way around it.

There are two distinctly different forces that need to be considered: those that forcefulness the bullet deeper into the example, and those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper into the case. Due to the abrupt cease the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. Some years ago, we decided to examine this phenomenon more closely. During tests hither at Sierra's range, we chambered a multifariousness of manufactory Friction match armament in an AR-15 rifle. This ammunition was from one of the most popular brands in use today, loaded with Sierra'due south 69 grain MatchKing bullet. To carry the test, we chambered individual rounds by inserting them into the magazines and manually releasing the commodities. Nosotros then repeated the tests by loading 2 rounds into the magazine, chambering and firing the first, and and then extracting and measuring the second circular. This eliminated any potential variation acquired by the difference between a bolt that had been released from an open position (first round in the magazine) and those subsequent rounds that were chambered by the normal semi-automatic operation of the rifle. Measuring the rounds earlier chambering then re-measuring after they were carefully extracted resulted in an average increment of three thousandths (0.003") of forrad bullet movement. Some private rounds showed up to seven thousandths (0.007") movement. Please behave in listen that these results were with manufacturing plant ammunition, normally having a college bullet pull than handloaded armament.

To counteract this tendency, the semi-car shooter is left with basically two options: applying a crimp or increasing neck tension.

Link.
http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm

Here is just i of many accuracy tests using the Lee Mill Crimp Die. Note, that in all 3 rifles and all 3 cartridges, accuracy was Improved by crimping. YMMV

http://www.accuratereloading.com/crimping.html
There is a lot of skillful information here and I'm certain we all appreciate every give-and-take. cowtownup, what are you loading for (gun)? If its an AR then you are budgeted the area where you can experience jamming caused by over length.
That said, the bottom line is unproblematic, the cannelure is designed for the crimp, then use it. Overall length (OAL) is a Maximum length for the circular to work in all firearms. If yous are using an AR I advise that you keep inside the recommended OAL of two.250". If you lot are using a bolt activity or unmarried shot then you might be able to safely exceed that length depending on the finished chamber in your rifle. To determine that you need to measure it. Otherwise, stick to what the books show.

Finally, there is a difference in .223 and 5.56 NATO bedroom measurements; the erstwhile being SAMMI (read http://world wide web.thegunzone.com/556v223.html) and the latter beingness neither SAMMI nor identical to the .223. This means that while one bedroom may take your longer circular without whatsoever problems the .223 SAMMI sleeping accommodation might experience overpressure and other potentially dangerous problems.
Unless you're roll-crimping into a cannelure, you're non going to mitigate bullet move during cycling.
I crimped my .223s for years, using the FCD, until I wised up and stopped crimping, tens of thousands of rounds ago.

Taper crimping will have no effect on bullet move during cycling.