Author Topic: .30 LFN vs. Spitzer  (Read 1715 times)

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Offline JHG

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.30 LFN vs. Spitzer
« on: October 20, 2004, 04:32:44 PM »
Veral,
I am looking for best accuracy for target shooting at 100 and 200 yards with my Savage Model 12 in .308.  I have a .310 x 1.5 deg. throat reamer and will extend the throat to get maximum support of the longest bullet you make.  Would you recommend a  310 - 206 gr. GC Spitzer over a 310 - 200 gr. LFN because of greater bearing length and BC or does the longer unsupported nose of the Spitzer negate the advantages?
Jack
:grin:

Offline Veral

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.30 LFN vs. Spitzer
« Reply #1 on: October 24, 2004, 08:58:59 AM »
The 200 gr SP is best and has the least overhanging nose weight/most bearing length.

Throating with a .310 1 1/2 deg reamer makes what I believe to be the best throat one can put in a rifle for target work or hunting.  Sizing in a .309 die should produce something around a .3095 bullet diameter, which will slip into the throat easily.  --  Admittedly, I've never been a benchrest shooter, and the winingest shooters in that doctrine use a straight taper from case mouth to top of the lands and swage their bullets in a die cut with the same reamer., then seat bullets so only the gc is inside the case neck.  
It works surperbly, but is useless for anything but benchwork.  I have this 'thing' which forces me toward making ammo that works for all purposes like jacketed ammo does.  The 'ball seat' throat which you will use does that.
Veral Smith

Offline JHG

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.30 LFN vs. Spitzer
« Reply #2 on: October 27, 2004, 01:55:49 AM »
Thanks Veral.  I'll be ordering the SP as you suggest.

Can you tell me where the term "ball seat" comes from?  As a fairly new (2 years) shooter/reloader/caster with rifles, and having read your book several times, the concept of a ball seat being basically a extended bore in the barrel which can support the bullet, went right over my head.  I think the phrase "ball seat" diconnected my brain for a moment.  I had an epiphany recently and now I understand how this little bore can add to performance.  But "ball seat"?  Would you have any idea how some "rifleologist" came up with the phrase?

Thanks,

Jack
 :grin:

Offline Veral

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« Reply #3 on: November 07, 2004, 08:21:15 AM »
I believe ball seat is a military term.  A hangover fromt he days bullets were all called balls.  That is all guess on my part, but I will clarify exactly what a ball seat throat is.

    It is a throating type with a straight cylindrical section larger than bullet diameter, but not necessarily as large as groove diameter.  Some high grade rifles which give superb accuracy even though groove diameter is much larger than bullet diameter, have a close tolerance ball seat throat which removes only part of the rifling, and aligns the bullet perfectly.  Some ball seats are cut way larger than standard bullet diameter, which is detrimental to accuracy.   -- I prefer rifles with ball seats for cast bullets, as fitting bullets requires simply sizing to whatever will fit the ball seat closely.

   The other type of rifle throating is tapered, and the length, angle etc varies dramatically from gun to gun.  Very heavy usage equals a long taper throat, due to powder erosion.  -- To get best results with this type I cut the bullet nose close as possible to groove diameter, or the point in the throat that it will be when chambered.   The bullet body is sized to fill the case neck to a close fit to the chamber, with a bearing length to come close to the throat taper.    If you find all this confusing, don't be concerned about ordering a mold.  Just send a throat slug with your order and I do all the figguring and cut the mold to fit.
Veral Smith

Offline JHG

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.30 LFN vs. Spitzer
« Reply #4 on: January 30, 2005, 05:01:55 PM »
Veral,

The throating and your bullet produced my first ever  :grin: 50 out of a possible 50 in a recent CBA match.  Thanks for your help. :grin:

Offline Veral

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.30 LFN vs. Spitzer
« Reply #5 on: February 01, 2005, 04:39:13 PM »
It's a pleasure to help, especially when you tell me I did!
Veral Smith