C.O.L. question

[4ked Horn]

I am seriously looking at some wildcat bullets but I have a question. If I seat the bullets so the major diameter at the base is at the junction of the neck and taper (top picture) then I can't fit the rounds in my mag by about 1/8 - 3/16 inch. This means that if I want to seat the bullets to fit through the mag the bullets will be below the "ring of death" and the base will end up back around the lower part of the case taper. (Lower picture.)

I would appreciate some thoughts on this concerning the pros and cons regarding case pressure, accuracy because of the bullet being seated so far back in the case (below the upper end of the taper) and also having an ULD ogive farther away from the lands.

Give me your thoughts. Should I consider a shorter ogive sacrificing BC to gain desired loading length and to recover possible loss in accuracy?

I don't know. I've never ordered custom bullets before.

Just for the sake of having the numbers:
Bullet OAL 1.315"
Mag useable COL 2.830"
.308 win case OAL 2.005"

 

[Matt27]

4kedhorn

I am guessing you what you mean by "the ring of death" is doghnut issues? You shouldn't have to worry about doughnut issue's with the 308. My understanding of them is when necking up or down and haveing to neck turn the brass.

Until you have seated Richard's bullets you might be surprised that you might be able to fit mag length and not be that far off the lands. In my Lapua i seat my bullets to just off the lands. Between the Sierra's and Richards ,Richards has an shorter overall length than the sierra's but are still the same depth in the case. Like your second pic. Granted i don't have to worry about mag length because i have a single shot but just reporting what i see betwen the sierra's and His bullets.

In getting a stoney point comparator this morning and measuring some bullets(300gr.) base to ogive for Richard's measured right around 2.058" and the Sierra's were right around1.095". Both bullets are same length but the ogive is a little farther forward on Richards bullets.

I have tried to keep all my bullet bases right at the body shoulder juncture when seated. I plan on throat erosion and want to be able to seat the bullets farther out as it gets worn down. I don't think you will ever notice the slight differance in pressure between your two examples versus seating into the land and off the lands with same powder charge.

You won't know about accuracy until you shoot them. It might like a little more jump or it may not. To hard to speculate.

 

[goodgrouper]

Some might argue with me on this one, but I believe there are very few things set in stone when it comes to guns, but vld's liking to be into the riflings is one of those things chisled in on day one.

When dealing with factory throated barrels and factory magazines, you might find that vld's are not the greatest if you plan to have a repeater.
If you have a reamer made with bullet seating depth in mind for use in a magazine, then everything is peachy. Another reason to just build what you want instead of just buying what someone gives you (and 50 million others).

Don't worry about the dreaded donut. Only happens if you neck turn, and neck turn not far down enough at that. And besides, with the clearance that factory guns give you in the neck dimension of your chamber, it wouldn't really affect much anyway if you did have it. If it moves to the inside of the neck, it becomes more of a problem but can still shoot good sometimes.

[ QUOTE ]
Give me your thoughts. Should I consider a shorter ogive sacrificing BC to gain desired loading length and to recover possible loss in accuracy?


[/ QUOTE ]

Hard to say. Shoot them and see what happens. I don't get too frusrated if I can't use my mag on a target or varmint gun. Most of them are single shots anyway. 90% of all the bullets I have ever fired in my life were loaded into the chamber one at a time!

 

[4ked Horn]

Thanks for the input guys. This is the bullet Richard and I have come up with so far.
175 gr
RBBT
ULD ogive
Unbonded core
.030" jacket
Slightly open meplat.

To refresh memories It will be a 100 to 700 yard deer bullet first and chucks and rocks and steel as far as I can go (1200 yds approx).

175 grain, RBBT, ULD are all about that famous BC and velocity ballance. The unbonded core and .030" jacket cut cost and give favorable expansions on deer at .308 velocities out to 700. The meplat left a little open aids in terminal effect on the chucks. Sort of a "gift" if you will.

I'm fairly set on this except for the ogive. Let me ask this. Do I need a ULD shape for a factory .308 at the ranges mentioned? Tell me what you think.

I can almost feel the money leaving my wallet as we sit here.

 

[4ked Horn]

I'm just bumping this back up hoping for some input on the previous question regarding the need for an ULD ogive.

Thanks guys.