View Full Version : 308 Single Shot Crimp/Neck Tension
Doc_Stihl
07-10-2009, 09:10 AM
Anyone have any tips or suggestions for neck tension/crimping lead boolits?
I just loaded 50 test rounds and rather than roll crimp into the crimp groove I set them out as far as I could(without exposing a lube groove) still about .05 off the lands and just "crimped" them enough to straighten out the bell on the neck.
Anyone using the lee factory crimp dies on lead 308's with success?
I'm no fan of the Lee Factory Crimp die, I've shot some pretty impressive groups with no crimp of any type on the case.
I do what you have done,,,,just crimp enough to remove the bell at the mouth of the case so the cartridge chambers ......I dont put any kind of heavy crimp on my 308 load. I also set the boolit out to within about 0.05" of the lands....
I failed to mention that I also get great results by seating the nose up into the rifling .
In the photo below of a 308 Win. cast bullet round, you can easily see the 6 groove barrel of my Ruger # 1 stainless engraving the nose of the bullet :
http://img.photobucket.com/albums/v494/haysb/PICT0004-12.jpg
felix
07-10-2009, 09:37 AM
Typically, you are short changing yourself when you apply any kind of seating pressure for a single shot. If any boolit resistance is needed to get a group, change to a slightly faster powder speed. The 308W, however, is tricky in that regard especially with the 168 target condom at 14 twist for BR work. Very difficult to get that magic speed out of a can. Thanks for that picture, Ben. It seems that resistance thing holds true for your situation? ... felix
Maybe I'm " all wet " in my thinking Felix but it seems to me if the bullet is seated in the manner that you see in the photo ( assuming the bullet is seated concentrically in the case neck prior to chambering the round ) there is little or no chance for the bullet to start it's trip down the bore in anything but a concentric state.
Yes, it would seem to me from a lot of my shooting that providing some " resistance " to the propellant as it begins it's burn is a positive thing.
Ben
I used the same seating technique described above to shoot this 5 shot group at 50 yds. with my 308 Win.Ruger #1 , stainless with the Lee 155 gr. sized .3094 with 17.5 grs. of 2400 and a Win. LR Primer.
http://img.photobucket.com/albums/v494/haysb/IMG_1075.jpg
felix
07-10-2009, 10:54 AM
Excellent, Ben. No changes needed for that distance for sure. Being concentric is a mechanical problem in addition to that of ignition consistency which is a chemical one. Of course, you know that. ... felix
pietro
07-10-2009, 11:00 AM
IIRC, "bore concentricity" is exactly what old time target shooters were trying to accomplish by casting/using two-diameted slugs, with the smaller/forward/bore diameter section a snug fit w/o having the rifling engraved on it as a possible distortion (?).
I dunno, but they didn't have something there - I've seen where Harry Pope and the like have shot some very small groups indeed, at some 200 yards and more, like clockwork.
.
IIRC, "bore concentricity" is exactly what old time target shooters were trying to accomplish by casting/using two-diameted slugs, with the smaller/forward/bore diameter section a snug fit w/o having the rifling engraved on it as a possible distortion (?).
I dunno, but they didn't have something there - I've seen where Harry Pope and the like have shot some very small groups indeed, at some 200 yards and more, like clockwork.
.
Harry Pope, 200 yards, small groups Yes, and remember ......using plain based bullets.
45 2.1
07-10-2009, 11:23 AM
Harry Pope, 200 yards, small groups Yes, and remember ......using plain based bullets.
No one seems to remember about the breech seating part or the Kings semi smokeless.
felix
07-10-2009, 11:57 AM
Did not Pope use something other than the 308W capacity? Perhaps a more friendly case size for the powders on-hand at that time. ... felix
45 2.1
07-10-2009, 12:05 PM
Did not Pope use something other than the 308W capacity? Perhaps a more friendly case size for the powders on-hand at that time. ... felix
Pope liked the 32-40 & 33-40 (rebored shot-out 32-40).
jhrosier
07-10-2009, 01:36 PM
Did not Pope use something other than the 308W capacity? Perhaps a more friendly case size for the powders on-hand at that time. ... felix
I think that marketing has eliminated most of those options, unless one is willing to put a custom rifle together. Anybody remember that the Remington 788 in 30-30 was discontinued because they weren't selling very well?
I wonder if the 6.8SPC would be a good cartridge for cast boolits?
Jack
felix
07-10-2009, 02:10 PM
Yes, it would. Just slow down the twist so you can get to 2400 fps with accuracy. ... felix
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