cast bullet base seated below neck

[rp85]

hello;

shooting cast bullets in a 308win.

the cast bullets i'm using are in the 180-190 grain range. to get the bullets to cycle from magazine and into the chamber i need to seat the bullets where the base (gas check and 2 grease groves) of the bullet is below the neck of the case. c.o.l is 2.510".

is this a problem??? thanks for any input..

rp

[Wayne Smith]

According to a Handloader article, either Mike or Brian Pierce, it is. The author showed pics of the difference and it was significant. Small sample, though.

Give it a try and see if you have the same difference - assuming you can load them out and single load to get a sample that isn't seated below the neck.

[Blammer]

I'd say try it yourself and see what you get.

I shoot a 30-06 and load the 311284 so the base is below the neck and this is my results.

http://i54.photobucket.com/albums/g81/blammer8mm/Targets/File0150.jpg

http://i54.photobucket.com/albums/g81/blammer8mm/Cast%20boolits/DSCN6281crop.jpg
(this is for show only, I don't use that type of lube)
sometimes you just gotta DO IT!

[Larry Gibson]

Experience of many years along with the experience of many others tells us that accuracy will most often not be as good as is possible with lube grooves and/or driving bands seated below case necks. Sometimes with some alloys and powders one can get away with reasonable accuracy doing so. Most often not though with what most consider "reasonable accuracy". This has been documented in the NRA cast bullet handbooks, in articles in gun magazines and by many of us here. Most recently John Haviland again documents this with his article, Cast Bullets Below the Neck, in the Febuary 2011 Handloader magazine.

Simply use a bullet with bearing length that does not exceed the length from the bottom of the case neck to the leade. Many times it is possible for excellent accuracy if the GC, but not any more of the bullet, extends below the case neck.

Larry Gibson

[HangFireW8]

The old safety warnings about never seating gas checks below the necks are based on the old slip-on type of Lyman gas checks. Even if pressed through the sizer die, they tended to come off in flight (as they were designed to), or sometimes in the barrel (usually blown out), or sometimes in the case neck (possible problem).

Today's gas checks are crimp-on, as long as your mold is not undersized, it should have a firm grip, and your sizer die should bring it down to the same size as the rest of the boolit. A quick check is to try to rotate the gas check with your fingertips on an unlubed but fully sized boolit. If you can spin it, it is not on tight enough to seat below the neck. If it can't be spun, or removed with a fingernail, and it is sized flush, you are good to go.

As for the gun writer folks who do comparisons, they are valid for their rifles, loads, and techniques only. It is rare I run into any writer on the 'Net that lists their cartridge runout, and I've never seen it in print (outside of Precision Shooting, which is not exactly a cast boolit magazine). So, I can only assume they are not checking concentricity, which means their results are meaningless (to me).

So, size your boolits, check the gas check crimp, make sure it is flush, and then let Perfessor Rifle tell you what works, accuracy-wise, on the topic of above versus below the neck.

-HF

[curator]

If loading boolits below the neck of a bottle neck case is necessary to get them to feed, you might also try using the Spherical Plastic Shot Buffer as a filler over a charge of medium burning range rifle powder. I have had good accuracy with .308, 30-06, and .303 British seating boolits below the case neck and IMR 3031, Reloder7, or IMR4895 powder with PSB filling the case to the shoulder on top of the powder. Yes, you have to start low and work up the load but the plastic filler appears to protect the exposed boolit base. Using this method I have been able to shoot Lyman #311299 in my .308Win rifle with excellent accuracy. Without the plastic filler groups open up to double