Bullet seating

So I loaded up a dummy round to get my die set at the maximum 'cartridge overall length' (3.340"). This is for a 300 win mag with Winchester 180 gr PP.
The base of the bullet is around the bottom of the shoulder. Is that too far in? Also, the cannelure is below the top of the neck, so that you cannot see it.

I also have factory loaded Winchester PP and the cartridge overall length is slightly less than what is listed in my Lyman manual. And the cannelure is visible just above the top of the neck.

M.O.L. as listed in loading manuals is very general , it all depends on "your rifle ", magazine length , short or long throated chamber,also on bullet design ie; pointed softpoint, round nose , spire point, all this comes into play when determining the overall cartridge length for your firearm.
Where the Ogive is on the bullet is also a determining factore, if the Ogive is to far back and you set the length to have your bullet say just .005 t0 .010 off the lands , your toal O.A.L. may be too long to fit in your magazine.
Very confusing isn't it .
Lots of reading to be done on that subject.

The first thought that comes to my mind is if the cases were trimmed to length? Other than that........

Sorry.

HA

Yes, the cases were trimmed to spec length.

I'm concerned with having the bullet sit so far down into the case. Seems to me like having the pressure hit the bullet on the sides would not be ideal. I would have thought that the bullet base should be in the case neck so that it only has pressure on the bottom of the base.

The factory Winchester PP has a shorter overall length than my hand loads at Lyman's spec, but my hand loads are not touching the lands (used the sharpie method). So I should be safe.

The dummy rounds fits fine in the blind mag.

I just wanted to use the listed cartridge overall length so that I can concentrate on working on the powder charge first, then eventually work on bullet seating depth.

Maximus44

Pressure will be equal on all sides of a bullet that protrudes past the neck and into the case when pressure build up occurs. When the bullet moves forward then pressure follows the path of least resistance behind the bullet.

If you are following recommended loads and practice then you should have no concerns.
As for cannelures ignore them unless you are crimping for a specific load which may be for another rifle using that caliber bullet.



Ed

Jacketed bullets... Doesn't matter how deep the base is into the case as far as what happen when the round is fired.
Cast bullets on the other hand should not go past the neck/shoulder junction of s bottle-neck case.

As mentioned... Optimal seating depth for YOUR rifle will differ from that of someone else's...
Throat length varies from gun to gun...
There are tools/methods you can use to determine the best seating depth for your gun/bullet combo.
Generally I find keeping the ogive a couple thou off the lands nets pretty good results.

Mark the bullet with a black sharpie. You want the bullet to be just off the lands. After you cycle your dummy round if the marker black ink is scratched you are seated out too far.

The conventional thinking used to be, if there was no cannelure don't crimp and crimp if there is a cannelure........ however with the extreme variation in location of cannelure placement (high or low) on the bullet, it has caused most to abandon their use altogether with the exception of use in Semi's, Pumps and Levers with tube mags.

I usually find somewhere very close to .015" to be the best jump to the lands, then I seat OAL to that.

As long as you are safe with listed powder charges and watch for pressure signs you should be fine and if you are using a bolt gun, maybe consider something without a cannelure.

All things being equal, it does sound like that bullet is a little long for that cartridge, but 180 gr is pretty standard for 30 caliber.....Could your rifle handle a longer round? The OAL is an industry standard but some rifles can take longer rounds......

Quote:

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Originally Posted by terrym

Mark the bullet with a black sharpie. You want the bullet to be just off the lands. After you cycle your dummy round if the marker black ink is scratched you are seated out too far.

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Interesting, I do the same thing. Works like a charm.