Interlock and Interbond bullets

[longgun]

I've always been intrigued by making jacketed bullets.  But I know that at my age ( 70 yo) I have waited too long to get started.  I've read post here that making interbond bullets is not much more difficult a process.

Been looking at Hornady's home page about interlock SST bullets and it looks as if the cannelure is what makes the lock process.   However on the interbond bullets what makes the bond between the lead and jacket? Is it the thickness of the jacket or is bonded to the lead by some other process like heat, etc...  

Obviously the thicker jacket would make the bullet more durable than other types.  But will the interlock be any advantage over just plain jacketed bullets.

This looks like a place where there is a lot of knowledge in bullet making.  I am looking for a magic bullet for taking the Rams at 500 meters in the rifle silhouette game.    Once I tried heat treating the bullets, but was not convinced that this helped any.  In addition it may have decreased the accuracy of my 168 gr 7 mm Sierra Match King bullets.

Was just wondering what your thoughts are on the various  bullets that are available that a shooter can afford to buy.   Don

[talon]

You have 2 questions: what really is an 'interbond', and what is the best bullet to whack a 500yd Ram. The first is a real easy one; the 2nd will have a lot of opinions. An 'interbond' is nothing more than a lead core soldiered to the jacket. There is no magic to this, thou the results are huge. The molecular bond between the lead and jacket causes at least a 92%, often a 98%, weight retention after the bullet plows thru it's target. It mushrooms, but doesn't separate. Very efficient. Almost makes partition, or semi-partition bullets obsolete. And, from the producer's point of view, a lot more easier to make. The technique is to apply soldiering flux (an acid) to the inside of the jacket, drop in the lead core, heat to melting, let it cool, wash away the residue flux, swage the lead tightly into the jacket ( it will stick to the copper where unsoldered lead cores wouldn't), and then swage the nose shape. Some companies call this "Core Bonding".
  Core bonding in itself won't affect accuracy one way or the other as compared to a similar bullet without bonding (as long as the core is solidly swaged in). If you heat up a formed bullet and let it cool, that may affect accuracy because you've changed the temper of the copper jacket, and if any of the core melted out of the bullet, the weight not only would have changed, but its mass semidry would also be (probably) off balance.
  It's the external shape of the bullet, it's BC and CG, it's velocity and weight, the twist rate and length of the barrel, the sighting and holding skill of the shooter, and much more, that comes into play, not whether the bullet is core bonded, partitioned, wasp-wasted,or whatever,  that will put you on that Ram. If we were talking about terminal ballistics, what happens when the bullet hits and then effects the target, then the bullet internals are very important.

[longgun]

Talon,  Thx for taking the time to explain about bonded bullets.  Will try some to see what they will to.   Don

[Donna]

Hello Don,

The question that really pertains to you is, what type of bullet that you can get that will drop the Rams at 500 meters? The Hornady's interlock SST or the bonded core bullets will work fine but that is not their intended target or the target that they shine, these bullets do their best in expansion to getting the game not just to imparting energy for knocking it over as in metal silhouette. Teat treating a bullet is the wrong way to go. The harder the bullet is the more likely it is to shatter thereby dispersing most of its energy in the shattering and sending shrapnel at right angles or more away from the Ram and very little energy to the Ram for knocking it over. What is needed is a very soft target bullet. 1) Your bullet needs to be very precise to help in accuracy. Your trying to sight in free handed at 500 meters, a hunting bullet can be off as much as three to four inches at 200 yards to still achieve a good kill, but if you an inch inside the outer edges and your hunting bullet has an offset of three inches at 200 yards that’s more than 8 inches radius, lots of room for missing. This is of course for commercial bullets not swaggers. 2) The bullet needs to be as soft as possible so that when it hits it will flatten out on the Ram to impart as much energy as possible to the Ram in knocking it over, any shattering, Rick-a-shays, or bouncing off the Ram means that energy is used and wasted instead of going into the Ram, even the flattening out of the bullet on the Ram is wasted energy but this takes far less energy than shattering, Rick-a-shays, or bouncing off the Ram would take. 3) A thin jacket is best in this case; a thick or heavy jacket takes away from the mass density of the bullet making it more susceptible to drag and wind drift or wind deflection. Plus your range officer will get kind-of mift at you if you start punching holes in his Ram.

For metal silhouette shooting I make an ultra low drag, open tip with a thin jacket and pure lead core bullet relatively the same type of bullet that I would make for extreme long range shooting, in excess of 1500 yard shooting.

Donna