Question About Long Unsupported Ogive

[5Shot]

When using the Mountain Molds online program, I will often get the warning about a long unsupported ogive. There are many classic designs that appear to have this issue however, and they are still going strong. For example, in 358 caliber, there is the Lymann 358318/NOE 360-318. Is this really an issue?

[BK7saum]

Goodsteel shoots that or a similar boolit in a 358 winchester. Aparrently it is devasting on deer due to not being very stable. Look up his thread and it touches briefly on his experience with the boolit.

I think the best he could do was 3-4" at 100 yards

[5Shot]

Well...looks like I have some reading to do! Is it on here or his forum?

[BK7saum]

It's on this forum, I'm tryin to fInd it as well.

[5Shot]

It's on this forum, I'm tryin to fInd it as well.

Thanks - I'm looking too. I'll link it if I find it first.

[5Shot]

I did find some mention of it in a thread, but he was not the OP.

[5Shot]

It's on this forum, I'm tryin to fInd it as well.

http://castboolits.gunloads.com/show...18#post1616319

[Outpost75]

Bore-riding forepart should be marked by rifling if you poke the bullet nose into the muzzle. If nose enters muzzle all the way to front driving band without resistance or visible marking you have no hope in obtaining normal accuracy.

Also, contour of bullet nose should enter the throat without forcing the action closed if a dummy round is chambered and extracted without firing. Light engraving which does not cause telescoping of the bullet into the case when a dummy is chambered, and which does or result in debulleting of a loaded round, if extracted without firing, does no harm.

Attachment 188086

[1longshot]

So the bore riding part of the bullet should for all intents and purposes be laying on, but not engraved into, the lands so that it is supported on its ride through the bore? Or engraved just enough to prevent the condition described by Outpost75? It seems like a fine line. Forgive the lack of research, but it seems that a longer chamber throat, just the diameter of the bore riding section before the rifling begin, might help this, and that section of the bullet could be the same diameter as the bullets normal driving area?

[RU shooter]

The Lyman 358315 200 gr rn designed for the 35 Rem is a prime example of the unsupported nose on my old ideal mould the base bands are the proper .360 but the nose directly above the crimp groove on the nose is .347 and touches nothing . It's shoots ok at pinker speeds of say 1200 fps but the faster you go the worse it does

[375RUGER]

No problem with the design, MM just doesn't want to turn them is all. He also doesn't like to cut bore riding designs.

[endwrench]

So does anyone have a theory why a long unsupported ogive works well on a jacketed bullet but not so on a cast bullet?

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[Outpost75]

So the bore riding part of the bullet should for all intents and purposes be laying on, but not engraved into, the lands so that it is supported on its ride through the bore? Or engraved just enough to prevent the condition described by Outpost75? It seems like a fine line. Forgive the lack of research, but it seems that a longer chamber throat, just the diameter of the bore riding section before the rifling begin, might help this, and that section of the bullet could be the same diameter as the bullets normal driving area?

When John Ardito set all of his CBA benchrest records, many of which still stand, he used a "bump" die cut with the same throating reamer used in chambering his rifle barrel. Bullets then fit the throat EXACTLY without interference. He normally used the .308x1.5" cartridge and a 200-grain bullet of .312 base diameter, blended to 24 BHN with linotype and monotype, seated out and held by the base band and the gascheck only, with a compressed charge of RL7 for about 2100 fps with beeswax and STP for lube. He shot amazing groups 25-30 years ago in heavy bench class, many of which still stand.

[Outpost75]

So the bore riding part of the bullet should for all intents and purposes be laying on, but not engraved into, the lands so that it is supported on its ride through the bore? Or engraved just enough to prevent the condition described by Outpost75? It seems like a fine line. Forgive the lack of research, but it seems that a longer chamber throat, just the diameter of the bore riding section before the rifling begin, might help this, and that section of the bullet could be the same diameter as the bullets normal driving area?

When John Ardito set all of his CBA benchrest records, many of which still stand, he used a "bump" die cut with the same throating reamer used in chambering his rifle barrel. Bullets then fit the throat EXACTLY without interference. He normally used the .308x1.5" cartridge and a 200-grain bullet of .312 base diameter, blended to 24 BHN with linotype and monotype, seated out and held by the base band and the gascheck only, with a compressed charge of RL7 for about 2100 fps with beeswax and STP for lube. He shot amazing groups 25-30 years ago in heavy bench class, many of which still stand.

[5Shot]

When John Ardito set all of his CBA benchrest records, many of which still stand, he used a "bump" die cut with the same throating reamer used in chambering his rifle barrel. Bullets then fit the throat EXACTLY without interference. He normally used the .308x1.5" cartridge and a 200-grain bullet of .312 base diameter, blended to 24 BHN with linotype and monotype, seated out and held by the base band and the gascheck only, with a compressed charge of RL7 for about 2100 fps with beeswax and STP for lube. He shot amazing groups 25-30 years ago in heavy bench class, many of which still stand.

That is a bit more work than I am willing to go through for this one, but quite interesting. This will be a hunting rifle, and I'm not looking to set any records. My curiosity, I guess, is when does the length of the Ogive really become an issue. I guess I'll just leave it stubby and blunt and live with it! Some of the spire point designs have extremely long Ogives by comparison, but maybe they don't really shoot all that well.

[Outpost75]

Accurate 31-155D is a plainbase with tapered nose which fits the factory throats of .30-06 hunting rifles. In the .30-30 the nose is lightly engraved upon chambering, but feed and function are unaffected.

Accuracy is wonderful at subsonic velocities with 5.0-7.0 grains of Bullseye in the '06 or using the same amount of Unique or Universal in the .30-30. A charge of 16 grains of 4064, RL15 or Varget in the .30-30 approximates .32-40 ballistics.

If you ordered the mold and asked Tom to add a GC heel to the base you would have about a 170-grain bullet which would stand higher velocity in all the .30 cal. rifles from .30-30 through .30-06. The tapered nose matching the throat angle and with front band of throat diameter is FAR superior to old style 2-diameter bullets with groove diameter bands and parallel bore size nose which may not fit your barrel. Adjusting seating depth to compensate for throat erosion while maintaining proper throat-fit is possibly only with a tapered bullet!

Attachment 188087

[MBTcustom]

Designs like that in the OP are not made for target shooting which many of us tend to gravitate to. While I agree, you can't harvest what you can't hit, you look at this bullet and it seems to be a terrible design.
Is it a target bullet? "No, it's all wrong for that."
Is it a hunting bullet? "Well I read a hunting bullet has to have a big flat nose, so........no?"
Why is it still alive if it shows neither the earmarks of a hunting bullet or a target bullet? "I don't know!!!! Its a freak and it shouldn't exist!!!!!"

Aha, well it's not a freak. It follows a different method than is commonly practiced, but that which was, at one time, the norm.
Fact is, this bullet has several key advantages that have endeared it to its users (myself being one of them).
First of all, this bullet is excellent for use in a situation where you must have reliable feeding. That long nose will make the most finicky of rifles feed well and reliably. This bullet runs in a Remington Model 8 like pouring water through a funnel.
Second, it's very easy to cast, and it keeps all the lube and gas check inside the neck where it belongs, while giving you a 250 grain projectile, and it has a crimp groove so it can take a beating in semi automatic and tubular magazines without losing the seating depth.
It also fits in the sort throat of the 358WCF and 35Remington.
Finally, last and certainly not least...........it tumbles when it hits. It'll keep it together till it hits fur, but then it's going end over end, and frankly, even cast of ice hard metal, it makes the damage caused by a WFN look kind of pitiful.

So think about putting all this together. You load these bullets up hot in a Remington Model 8 or 81 semi auto, and you can belt out 5 of these as fast as you can pull the trigger. When each one hits the bear charging you down it goes end over end as it passes through the enraged animal. The bullets are carrying an enormous amount of energy with them, and they dump most of it in the bear before they exit.
THAT'S why it's still here and THAT'S why it's one of my favorite bullets, even though no match will ever be won with it, and the groups are about double what I get from any other bullet design I've tried.

[Outpost75]

So does anyone have a theory why a long unsupported ogive works well on a jacketed bullet but not so on a cast bullet? Sent from my K011 using Tapatalk

Because jacketed bullets are TAPERED and not shaped like a stepped two-diameter cylinder.

[MT Chambers]

Further more to Ardito's records, he had designs made up between him and Don Eagan, I have an Eagan mold and it is a Ardito design but is not lacking in bore contact. I stay away from those like in the picture, I want as much bore contact as possible. J-word bullets are dif. because they are much harder and will not engage the rifling at an angle, if they do, they tend to straiten out.

[endwrench]

So, if I have complete control of the bullet and throat design and intend to shoot subsonic, do you think there is any possibility of attaining decent accuracy with a long unsupported ogive with a cast bullet?

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