How much soft in a BBBB?

[Beerd]

What percent of total bullet weight do you use in the nose portion of a Bruce B. Bonded Boolit?

(and "It depends" ain't a good answer ;-) )

[BABore]

For a 223 or a 45-70?

For a light for caliber bullet or heavy one?

For a gopher or a buffalo?

For a 1,000 fps or 2,500 fps

For 25 yards or 400?

It all depends![smilie=1:

[leftiye]

Well, you wouldn't want the soft stuff in the part that rides the rifling maybe. Course, that could work too if only the front part of the grooves were soft and you didn't shoot too fast. If yer velocities are up in the light speed area, you need to ask yourself how much of the boolit you want to have shear off from impact. I like the short nose design idea with only the nose portion soft.

[BruceB]

Beerd, sir;

Right at the top of the topics list on this very page, there's a sticky on casting softpoints.

My personal take on the matter is that about 1/3 of total bullet weight in pure lead should be pretty good. I base this on long experience with Nosler Partitions, which use roughly the same distribution between front and rear cores.... about 1/3 of a Partition's weight is forward of the "wall" between cores. The bullets illustrated on that softpoint thread are all composed of 1/3 pure lead with the balance being wheelweight alloy. The .338 is 220 grains, the two .421s are 400, and the .45 is 500 grains.

Bullshop's recent experience with a 50/50 weight distribution .405 bullet on moose tends to confirm the plan, I think. He found a half-ring of pure lead near the exit hole, implying that the shank of the bullet passed through the over-expanded front portion. I'd like to avoid this tendency if possible, and I think the way to do it is to keep a majority of the bullet in harder alloy.

It doesn't take much speed at all to expand pure lead, and using the softpoint will minimize chances of an ineffective bullet performance due to unforeseen conditions. Even at ranges much longer than what might be anticipated, the pure lead nose will still expand, making for much better and more-humane bullet function.

I HOPE to get some bullet testing done in a recovery box in the next week or so. Been saying that for months now, but maybe THIS time it will come to pass.

[Bullshop]

From what I have learned so far I agree with Bruce in that on average about 1/3 is going to be about right. For rifles capable of substancially higher velocities than about 2000 fps I believe even less would be better.
At impact velocities of say about 1800 fps and up the point in the boolit that the bond takes place will continue to expand well into the hardend shank. If just a small ammount of pure lead is used for these higher velocities I feel it will perform much like a Barns X or others that expand to a moderate frontal area but retain very nearly all the origonal weight.
On the single experiance I have hunting with a hard cast soft nose 410gn 50/50 at just over 2000 fps muzzle velocity and an impact range being about 125 yards the expansion was violent. The on side sholder was shattered beyond belief and had excessive tissue damage arround the wound, read that meat loss.
God willing I will be allowed more testing oppertunities in the future. I have some of the same boolit at about 75/25 loaded in 416 Rem mag cases to 2400 fps. It will be interesting to see how they ferform. One problem with boolits of this weight and at these velocities we can really never expect to recover a boolit from most game we have opertunity to shoot at. It may happen under perfect conditions but I generally dont expect it. What we have to go by is the wound channel so lets try for a long one instead of side to side.
There are several grizz hanging arround my house for the last week or so. Perhaps if I leave this machine alone I may go learn something.
BIC/BS

[jhalcott]

On my 458 pointed bullets I tried 1/3 and 1/4 the weight ratios. The 1/4 seemed to penetrate wet phone books deeper. Exits were not as large as with the 1/3 ( soft to hard ) . I tried some in the 35 whelen and got almost identical results. 185 grain 30 calibers and 170 grain 7mm bullets were a little different in expansion results. Maybe because they were fired at a bit HIGHER velocity?? The nose portion was blown away in the first 2 to 3 inches and the rest bored on to as deep as 22" in wet phone books. The 7mm and 30 cal bullets were linotype base and soft lead noses. The larger calibers were Lyman #2 bases. Gas checks and Felix lube. Velocity for the 45's was around 1600 fps . The Whelen was around 2000 and the others were above 2200 fps.

[Beerd]

Bruce – I’ve read your thread on casting soft point boolits more than once. That’s why I posted this question here.

I am using a .360-220 Lee group buy mould and casting the nose portion from 71 grain soft lead .25 cal boolits. Total weight is 218 grains, so I am about 1/3 soft and 2/3 hard. It sounds like I’m in the right ballpark.

I will be moving these at about 2200 fps in a .356 Win.

I have two deer and one elk tags to try these on and will post results, at least on the deer; the elk isn’t such a sure thing. It all depends :-)

Thank you all for your replies.