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Discussion Starter #1
I'm working up a 155 grain AMAX load for my 30/06. I found the powder and grains of it that give the least velocity variation and get around 0.8-1.0 inch groups at 100 yards. Wanting better performance for some 500 yard shooting, I'm trying to figure out how to best vary the cartridge overall length. I'm currently at 3.210 inches. The maximum SAAMI length is 3.340 inches. The AMAX's ogive is quite different than most spritzer like bullets.

Can any long range load developers out there give me some advice on finding my load's optimum cartridge overall length? I've read that AMAX bullets do well seated near the barrel's lands.

Does someone have access to a Hornady reloading manual that identifies a recommended cartridge overall length for the 155 grain AMAX in a 30/06?

I tried finding the actual distance to the lands in my rifle by loading up a dummy round and marking the bullet in various ways to see land contact. However, I could not get a positive indication and remain unconvinced I found the correct measurement.

My fall back plan is to vary my cartridge overall length in .005 inch increments and see what happens. That being said I still may wind up with the wrong answer.
 

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You're going to need 3 things to start. 1) A comparator that will allow you to measure length from base to ogive. OAL means nothing. 2) An accurate caliper. 3) A rifle accurate enough so you can tell the difference in small incremental changes. OK, actually, you will also need (4), a shooter who can shoot well enough to know when improvents in accuracy are the result of those small changes and not just happenstance and/or dumb luck.

Start by seating a bullet far out of the case and chambering it. The rifleing will push the bullet back into the case. That will be your absolute jam length. Shoot some groups at that length. Then seat the bullets deeper by .010". More shooting. When you think you've reached the length that gives you the best accuracy, seat .005" on either side of that length. More shooting.

Unless you have #3 and #4 (above) don't expect to see much, if any change. Even Benchrest shooters seldom make adjustments smaller than .005" at a time.

Some guys will come on here and tell you not to shoot cartridges with a full jam. They will say that you are sure to blow up your rifle and lose your fingers and eyes in the process. Don't listen to them. Any safe and sane load is not going to be turned into a hand grenade by seating on the jam.

Good luck.

Ray
 

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The first two posters have very good suggestions. As you noted, the Hornady AMAX bullet has a different shape than what you are used to. The most common shape of bullet has a tangent ogive while the AMAX has a secant ogive. The secant ogive is usually more sensitive to seating depth. Start by seating 3 bullets seated 0.020 inches off the lands. Load the next three bullets 0.050 inches off the lands and the next bullets 0.080 inches off the lands. If necessary, continue this pattern. I would expect to see the best group between 0.050 inches and 0.100 inches off the lands.

There is a third commercially made ogive shape referred to as a hybrid secant. It is a cross between the tangent and secant ogive design. Berger bullets has a good discussion on bullet shapes you may be interested in. additional information can be obtained by searching the web using tangent, secant ogive.
 

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The Troll Whisperer (Moderator)
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Anyone remember the "Wasp Waist" design of the coke bottle shaped bullets by Herter's back in the late 50's, early 60's? :)
 
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yes, I bought and shot a lot of them. supposed to have less bullet contact with bbl and reduced the friction caused by the "engraving factor". Most important was that they were very, very cheap!:)
 

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I've played around with bullet jump with my .308 and .243. Emphasis on played. As someone mentioned you need a comparator of some kind. I have the Hornady, it it works well for me. The problem I discovered with both rifles is the throats are really long. They measure out to nearly .10 inch jump. I can't get enough bullet in the case to overcome that. Not saying your rifle will be the same, but you need to get some baseline measurements. It's my understanding that most factory rifles/barrels are like mine.

I avoid typical book OAL with both guns, and have settled for an ogive based oal instead. I'm not crowding the lands but I'm able to get consistency.; in my loads as well as my groups. If I do my part they are both sub moa at 100.
 

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I remember the Herters wasp waist bullets from their catalog, but i don't recall ever using them.
As a young sprout, I killed a truckload of woodchucks with a .243 that started life as a Czeck made 98K that was rebarreled to 243 with a Herters prethreaded and chambered barrel and a Herters Claro walnut stock blank.
Most of the bullets I shot out of that were made by Ernie Gardiner, a small bullet maker that made some very nice bullets. That was pre GCA of 1968.
 

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The Herters Wasp Waist bullets had a conventional ogive. It was the body that was different. The major cause of its undoing was the fact that it wasn't very accurate. The boattail version, the Wasp Waist Sonic, was even worse.

On the right is the Wasp Waist. On the left is the Cubic Spiral bullet as mentioned by chevwilliam. (actually, it's a wire patched cast bullet ;)) Second photo shows the Wasp Waist Sonic.

Ray
 

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Very Interesting Sectioning.

The Wire Wrapped "Cubic Spiral" cast bullet is intriguing, how did it shoot?

Was the Copper wire effective in sealing and keeping barrel 'leading' down?

I am guessing the "Wasp Waist" and "Wasp Waist with Boat Tail" were attempts to apply the 'Area Rule' used on the F104 and F106 to reduce Supersonic flight Drag and would have been 'Very Disturbing' to the Bullet Stability in Transonic or Subsonic velocities, especially as there were no 'wing-fuselage' areas to apply the 'Area Rule' to.

Best Regards,
Chev. William
 

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I've never shot any of the wire patched bullets. They are strictly collectors items from the last century. They were made with both bare copper wire and the cloth covered "bell" wire. You could also buy a mold and make your own. Reports of the day were all very positive. Of course, the reports were written by the guys selling the bullets and molds, or by shooters who were given a bunch for free and asked to write up an endorsement. They were even offered in hand loaded ammunition.

I doubt if George Leonard Herter ever heard of the "area rule" and he definitely never heard of the F104 or F106.
 

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Kelley Johnson proposed the basic F-104 design to the USAF in 1952 and it was first flown in March 1954. Is that too late for Mr. Herter?

Chev. William
 

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Discussion Starter #15
Great advice. I'll load up some rounds and try them out on my next trip to the range. The experience in this forum is a real asset.

I've been developing loads with inexpensive Remington and Federal brass, trimmed as consistently as I can measure. Then I plan to switch to better brass from Norma when I've got the load nearly defined. I've always wondered how much difference you might see between different case manufacturers. I know different manufacturers are able to maintain different levels of concentricity. Given "identical" external dimensions and concentricity are there any other differences that matter? Does Lapua really have some of the best brass or better marketing?
 

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The Troll Whisperer (Moderator)
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The question of whether better brass or better marketing - a little of both.

After years and years of handloading and with just about every brand name (even ex-military) of brass, I'll have to say perhaps Norma and Lapua take more care in the manufacturing process (such things as drilled flashholes as compared to most that are simply punched), but as to longevity - RP, W-W, Federal, Hornady/Frontier, S&B and others lasted just as long with proper care and less than maximum loadings. Some of the above listed cases would vary in weight more that the first two, but to tell the truth, I couldn't detect any difference in accuracy - even when shooting a Remington 40-X customized bench rest job chambered in .308 Win and Weaver T-36 target scope.
 
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I'm not a benchrester just an old guy who reloads and hunts some but I have not seen much if any difference in accuracy because of OAL. Example: I have a 308 Remington 700 VB with the aluminum bedding block. It has been a tack driver right out of the box. I had set up my loads with the 168 Sierra MK's just shy of the lands, very, very good groups from the bench, single loaded. When I went to a NRA Sporting Rifle Match I was unable to "with 4 rounds load" when preparing for the rapid fire prone segment. The OAL was to long to load in or feed through the magazine. I took them home and bumped them down to fit the magazine (about 3/16s inch) When I shot them from the bench there was no difference in the group size that I could detect. As I said I'm no benchrester and don't measure the groups to the nearest ten thousandth.
 

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While this has nothing to do with bullet seating, it may help you at the greater ranges you mentioned.
Uniforming primer pockets, and deburring the flash holes will reduce variations in the manufacturing process, and improve the consistency of your ammunition. Tools for performing these operations are available on line, and are not very costly.
 

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Hornady Handbook of Cartridge Reloading 9th Edition lists the OAL for the 155 grain A-MAX for .30-06 at your current 3.210".
 
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