Berger Meplats - Improved Uniformity

[elkaholic]

You can never make a small meplat bullet, with a like jacket, expand at as low a velocity as a tipped bullet. That said, it is possible to get good expansion at under 2000' with a jacket in the .012"-.015" wall thickness range. My tipped bullets will expand down to around 1200' because the base of the tip is .200" in diameter which acts much like a .200" hollow point. It also raises the b.c. because of the sharp point. The downside is, it is more explosive than a small meplat bullet at close range. A Berger will penetrate a few inches before expanding (normally) as most of you probably realize. As Phorwath has mentioned earlier, the problem with small meplat bullets is that they are often inconsistent (somewhat unpredictable). Drilling out the tips to a uniform size can not only cause them to expand more easily, but also in a more consistent manner. Using the J4 as an example (Berger) the jacket mouth will run approx. .014" wall thickness depending on style and caliber. You can easily imagine that squeezing this down to a .060" meplat could cause a lot of distortion (folding) at the tip, and often will completely close it. A few thousandths can make the difference in an explosive bullet and one that acts much like a FMJ. I can't remember what #drill bit is .040", but it works well in most cases. You can use a .050" if you want a little easier expansion. The larger hollow point will LOOK as if you have lowered the b.c. but it doesn't as the outside diameter is the amount of surface that is pushing air and it won't change with that size drill bit. Another trick which has been used successfully is to anneal the bullet tip above the lead level. There is a thread out there somewhere on annealing where we used it on the 160 Matrix. Hope this helps.....Rich

 

[MMERSS]

FWIW,

I annealed the tips of 300gr SMKs using a Benchsource. The bullets were placed in an empty 38 special case providing support while turning in the Benchsource. Adjustments with flame and time were made similar to annealing the necks and shoulders of brass. Time was set to move the bullet off the flame as soon as the very tip of the SMK started to glow and Tempilaq green 400 indicated a solid color a fraction of an inch below the tip. When annealing I noticed a few observations. First, the temperature to "glow" the tip was approximately the melting point of lead. Hardness did not seem to change if I could not "glow" the tip. This was examined by pressing the tip against a metal plate. I could not tell any difference with indenting unless the tip turned color. Second, on some of the tips during annealing I could hear a popping sound inside the bullet. This indicated to me the lead near the tip had started to melt. One question came to mind, "Did the molten lead evenly distribute around the centerline of the bullet or did it solidify mostly to one side?"

Precision shooting at 300 yards was conducted with the annealed bullets. There seemed to more inconsistent grouping with the annealed bullets than non-annealed. I gave up on further experimenting after the results. Although relatively small samples of data were obtained with about 40 bullets the small sample results were enough for me to justify "not playing" further with annealing tips of lead core bullets.

Less time is consumed verifying tips of bullets, such as with the Berger bullets I hunt with, were not closed than playing with the annealing machine…. although I will admit it was fun.

 

[Pdvdh]

I wouldn't want to hear that spattering sound - melting lead core.

I think the 300gr SMKs have a thicker jacket, with less depth to the lead core, than the Berger 300gr OTMs? If so, both of those differences could make it easier to anneal and soften the jacket tips on the Berger OTMs.

 

[MMERSS]

I wouldn't want to hear that spattering sound - melting lead core.

I think the 300gr SMKs have a thicker jacket, with less depth to the lead core, than the Berger 300gr OTMs? If so, both of those differences could make it easier to anneal and soften the jacket tips on the Berger OTMs.

Could be. With the advent of the 300gr HH I saw no need to experiment on the 300 OTM. I use the HH for hunting now with the OTM for practice considering there are a few hundred still on my cabinet.

The 230 Hybrid is still up for condideration in the event a HH version is not scheduled to be released in the next year or two.

 

[elkaholic]

I use a ceramic block with holes drilled in it so that just the tips stick out. This helps insulate the jacket (lead) below where you want it annealed. Boiling lead is not good and the bullets should not be moved right away after annealing. I would not attempt to anneal bullets with less than 1/4" hollow point. Usually just drilling out the tips with a .040"-.050" bit is sufficient anyway.....Rich

 

[Pdvdh]

I purchased a few small drill bits today from Trustworthy Hardware. A #56 drill bit measures about 0.045" diameter. A #55 measures about 0.052" diameter.

 

[IAHNTR]

Great - I will pick up a #56 and see how that works. Thanks!!

 

[Broz]

I check my 215 Hybrids and 300 OTM's with a pin vice and wire drills. I use a .027" wire drill for both. I just do this to confirm they are open. A .030" starts to open up the hole and I am not looking for more expansion, only consistent expansion. Especially on the 215's as I feel they already expand a little more than I want under 600 yards. But you have to make a choice, you just don't get perfect on both ends of the impact velocity spectrum.

Jeff

 

[jrock]

Usually just drilling out the tips with a .040"-.050" bit is sufficient anyway.....Rich

How critical is it to line the bullet up perfectly square to the bit? Do you do this by hand or low rpm with a jig in a drill press or lathe?

 

[elkaholic]

I agree that you are essentially toying with the range that you want as optimum and you sacrifice SOMETHING on one end or the other. I have always felt that if the animal is closer, I can more easily place the shot in an area that I am not as concerned about a little extra expansion. I tend to lean more towards assuring long range expansion where shot placement is far more difficult. I have had a couple of pencil holes in the 1000 yard range where a little more open tip would have solved the problem. To be fair though, these were vld's, not the hybrids.....Rich

 

[elkaholic]

How critical is it to line the bullet up perfectly square to the bit? Do you do this by hand or low rpm with a jig in a drill press or lathe?

I have not found it to be an issue with the bullets when they even have a dent in the mouth. They have always centered just fine. Kind of like center punching a piece of metal before you drill. I have NOT done this with the .338's, where some say they are more closed?......Rich

 

[Pdvdh]

Great - I will pick up a #56 and see how that works. Thanks!!

The larger the drill number, the smaller their diameter. So a #57 drill bit is a smaller diameter than a #56, in case you want to go smaller ID on your bullet tips.

 

[Broz]

I agree that you are essentially toying with the range that you want as optimum and you sacrifice SOMETHING on one end or the other. I have always felt that if the animal is closer, I can more easily place the shot in an area that I am not as concerned about a little extra expansion. I tend to lean more towards assuring long range expansion where shot placement is far more difficult. I have had a couple of pencil holes in the 1000 yard range where a little more open tip would have solved the problem. To be fair though, these were vld's, not the hybrids.....Rich

Right on Rich, we should note there are many differences in tip depending on caliber and weight. For example the 215gr and 230 gr 30 cal hybrids have distinct differences in their tips underneath. As does the 300 gr .338 OTM which is close in design to the 30 cal 230 OTM.

The 215s I have shot through soft antelope at 1285 yards with impact velocity in the 1700's and they opened fine. Yet up close they have exhibited more than enough expansion. Last thing I want to do is increase expansion on the 215 Hybrid for my personal needs.

A guy needs to look at as many sample data's as he can get. I would advise against a change from one experience. We all know it is impossible to have two shots the same. Impact velocity, hide toughness, muscle density, bone, no bone, shot angle, brush, wind and bullet pitch and yaw all come into play. We all have taken a lot of game over the years. We all have used lots of different bullet designs. And I will venture to say we all have had one where we say "why did it do that?"

Paul is doing the right way by testing and documenting results. As do I. Then make changes needed to get the bullet of choice to favor your personal needs and hunting style. Been going on for years. In the early days some took their knife and cut an X in the bullet to aid expansion. We have come a long way.

Good thread Paul, and all contributors.

Thanks

Jeff

 

[Broz]

Paul, you have done way more of this than I. I basically just check them to be clear of debris and open. Would you say it is fair to say a little goes "a long way" as far as making a larger hole in general? Seems to me a 50 to 75% dia increase would exhibit big changes?

Jeff