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.30-06 COAL question.

4K views 41 replies 9 participants last post by  OldVet 
#1 ·
OK, so...

Using an unprimed, fire-formed case with the neck resized, I just started to seat a bullet. Hornady A-Max. I then chambered the dummy round to seat the bullet using the lands. Now, my understanding is a safe distance is 0.02-0.03" back from the lands is preferred.

The chambered dummy cartridge: 3.413"

minus 0.02" or 0.03" =

3.393" or 3.383"

However... my reloading data says max overall length is 3.340".

Is this a case of bullet shape (ogive determining best OAL?) or is it never ever safe to exceed OAL. The trim length is correct at 2.490".
 
#4 ·
It's not necessarily a safety issue. Since you are creating your own loads you could leave the bullet touching the lands. It would alter your pressure curve (the peak would appear sooner, remain higher longer, and drop more rapidly). Therefore to keep pressure within bounds you would wind up with a lighter load and most likely reduced overall velocity. Accuracy could be either better or worse.

Regarding COAL, it is a standard provided so rifle and barrel makers can guarantee chamber and magazine function. A handload with a longer OAL may be perfect for a particular rifle but unsafe in one with a shorter lead, and may not fit in the magazine; or, may fit but bind in the mag.

edit: To answer your question about ogive, dIfferent ogive shapes will result in differing OAL IF the lands are used as the point of reference. To this point, all .30 cal bullets of the same weight are NOT created equal.

It all depends on what you want out of the bullet. For benchrest or other long range target shooting having to load rounds singly is not a problem and can result in maximum accuracy. For hunting or self defense/battle magazine function is critical.
 
#6 ·
When in doubt, re-read the re-loading manual to be sure you fully understand the processes involved. Lacking some overriding consideration, I would stay within the standards.
 
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#8 ·
I foresee a range session in your future.

So, what wt. bullet and what rifle?

How often has that brass been loaded? Methinks I see stretch marks (rings) toward the base of some cases. Maybe it's just the light.
 
#9 ·
155 gr A-Max, 49 gr IMR 4064, they've only been fired once (these are from my firing of factory ammo in the rifle they will be used in), never full length resized, never reloaded.

They'll be used in this rifle, my 95 year old mistress (although she had some work done about 70 years ago):



(yes the sling has been redone properly since this photo was taken).
 
#10 ·
Just curious - have you tried different charge weights with that bullet yet? While setting the bullet just short of touching the lands is an aid to accuracy, it's kind of a secondary effect. If you haven't already played with a range of charge weights, I'd start there. One you find the charge that's the most accurate, then experiment with OAL to find the sweet spot. It may be an iterative process, as the depth of the bullet in the case obviously has an affect on the pressure developed.

Nice rifle, by the way!
 
#11 ·
Thanks gasmitty, no, not yet! I actually decided to go the way you suggested. I started with just a handful at the starting load for the powder, and seated deep enough to work properly in the M1903 magazine...

My real concern is how much the fire forming changed the shape of the brass near the web and above... even after just one factory shot. All of the cases do have a slight bulge (without exception, Remington and Federal). The paper clip test doesn't find any catching of a thin spot where the bulging stops. It seems like the 03 just has a loose chamber? I'll take more pics, better safe than sorry as a novice.
 
#13 ·
Looks good! are you shooting a vintage match? 200 yards? single load? should be great. you will need to seat the bullets deeper if you have a rapid fire sequence. We have had good luck with the 168 grain AMAX with Varget powder. We are shooting 600 yards. My 1903 is my favorite rifle.
 
#14 ·
Beautiful piece of history you've got there! Those can be very accurate.

If those are only once fired and you've checked with the paper clip test I'd say you are good to go. I'd check again after several times firing though; especially if you start running hot loads. Just to keep track of things.

You seem to be doing everything by the numbers. Carry on.
 
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#17 ·
Now, my understanding is a safe distance is 0.02-0.03" back from the lands is preferred.
Preferred is a nebulous term. Anything short of rifling engagement is good. In MY experience I've had best accuracy seating longer bullets just shy of the rifling, although I couldn't tell you the amount of clearance. I am (and I suppose you are also) trying for best accuracy in MY rifle, not anyone else's. In fact my rounds will not fit a friend's rifle. I don't rely on a quoted Max COL. That is often determined by the data makers rifle/barrel used to develop the load.

Shorter bullets may not allow for such long COLs. Then it out to the range to determine best col versus accuracy. That's part of the enjoyment of handloading. Different bullets of the same weight will not always produce the same COL from an adjusted seating die due to different olgives and shapes. You need to go with works best for you and your rifle for each load.
 
#19 ·
We are going to try Berger bullets this season. the old 2 groove 1943 barrel from my 03 likes the Hornady 168 gr AMAX. The nice thing about the heavier bullet is they are a bit longer and you can set them out easier, just as long as you don't need them to fit down in the mag well.

My question from you is: Does your spent brass size up consistent or not. I noticed some of my brass grows in length more than others and that could affect the distance from the lands. I check and trim my brass each time but I did notice a very slight variance in the length of the neck to the shoulders. I measure from the overall length of the casing, wondering if I will need to measure from the shoulder to end of the neck?
 
#21 ·
It's the ogive, particularly on heavier bullets. I've mostly run into this with my 7.62x53 Mauser; a couple of brands of bullets stuck into the grooves more tightly than the neck, and had to be driven out with the cleaning rod.

Incidentally, I had shot several boxes of that particular load; it was just that I'd never tried unloading a chambered round before firing it until then.
 
#23 ·
The proof's in the pudding! That's pretty nice shooting, if a bit hard on the elbows.

The .30-06 is my favorite rifle cartridge for all time and the Model 1903 one of my favorite rifles. I've loaded it every which-a-way and feed a few '03s. The photo shows fired cases that appear normal to my eyes.

Everyone who has already spoken up in this thread has said all the good stuff about the practice of seating bullets out or varying from standard cartridge overall length.

Good job, .30-06 handloaders!
 
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#24 ·
Pretty good. Rest that puppy on a couple of sand bags and watch it tighten up.
 
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#25 ·
That'd be a 94 or a 96 3X depending on which extra round was tossed. Bet the rifle would duplicate that all day long, prone slow-fire.
 
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#29 ·
In the "Service Rifle" category at the local level, you'd realistically be competitive if your eyes can deal with the Springfield's sights. Practice in your living room with a piece of masking tap with a black dot drawn on it and stuck up on the wall. Get a shooting coat and get into it. Practice positions, use of sling, trigger control (including breath control) and the reload for the rapid-fire stages. You can make up dummy rounds for practice with the stripper clips.

Regular dry-fire practice "in full regalia" does wonders.

Don't be scared of the reload. 60-70 seconds is plenty of time employing stripper clips. Just be prepared to have an audience when you shoot the rapid-fire stages in this day and age.
 
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