Small Rebated Boat Tail On 68 Grain 6mm……Tested Today

[jackieschmidt]

I recently acquired a set of 6mm Carbide Bullet Dies that were part of Ronnie Cheek’s inventory.

They came with several point up die punches, all had a slight flaking at the sharp edge at the mouth of the punch. This is an on going problem with making Boat Tail Bullets, that razor sharp edge will start to get ragged after so many bullets. It shows up on the bullet.

I decided to clean op the face of one of them In my tool grinder, It ended up with about a .015 flat at the mouth of the boat tail cavity. I carefully polished it.

This produces a bullet with a slight rebate at the junction of the boat tail and the bullet shank.

I set my Rail Gun up this morning with a new Bartlien 13.5 twist barrel. I hit a really good tune at a flat 30.0 grns of 2022 N-133, just off the lands.

These bullets shot really well. It is a double ogive, with a body that measures .2432. The shank is relative straight. And of course, it has that slight rebate on the boat tail.

I have two new punches, I hate to try them now.

Here are the four 5 shot groups at 100 yards in a nice readable right to left condition. You can see the slight rebate in the picture of the bullet.

I am, at the moment, pretty pleased.

 

[butchlambert]

Looks great Jackie! Merry Christmas.

 

[Fuj]

Interesting !! Looks like the bullet will engrave and not touch
the tail ??

 

[jackieschmidt]

Interesting !! Looks like the bullet will engrave and not touch
the tail ??

I never thought of that, but it appears that way.

 

[Fuj]

Going to check it out for 300 meters ?? Just saying !!

 

[DocBII]

Jackie,

Looks like you've reproduced what heavier 6 mm bullet users such as Tubb have known for a while if you are attributing results to the boat tail. Re-boated BTs are a decent thing. Lapua has made this argument for years.

If cleaning up the back end of the bullet is the lesson, O.K. I don't shoot SR BR so my comments may not apply, only inflame. Inflammation is not my intention, I greatly respect the experience and wisdom you provide this forum.

Thanks,
DocBII

 

[762willdo]

Didn’t lapua do rebated boat tails?

 

[DocBII]

Didn’t lapua do rebated boat tails?

Yep,

Still have several hundred of different weights and calibers.

Have fun,
DocBii

 

[Tesoro]

Yikes..now I WANT A RAIL GUN!!

 

[jackieschmidt]

Jackie,

Looks like you've reproduced what heavier 6 mm bullet users such as Tubb have known for a while if you are attributing results to the boat tail. Re-boated BTs are a decent thing. Lapua has made this argument for years.

If cleaning up the back end of the bullet is the lesson, O.K. I don't shoot SR BR so my comments may not apply, only inflame. Inflammation is not my intention, I greatly respect the experience and wisdom you provide this forum.

Thanks,
DocBII

I really don’t have much in the way of theory behind this. I did it for one reason. If the sharp edge boat tail punch’s keep flaking off, and this “rebated” punch will last a heck of a lot longer, then what I see as a major problem has been solved.

This mornings session was to see how well they would shoot. If they would not shoot as well as the non rebated punch, then I would have to be buying punches.

But, as you can see, the bullet shoots quite well.

Like a lot of shooters on this Site, I have the means and know how at my disposal to mess around with a lot of ideas. This happens to be one that proved to be fruitful.

I don’t talk much about that closet full junk that took me down that boulevard of broken dreams and failed ideas.

 

[jackieschmidt]

Yikes..now I WANT A RAIL GUN!!

One thing to remember about a Rail Gun. It is one of the most singular purpose pieces of “equipment” you will ever own. What they are designed to do well, they do very well.

But not much more.

It is great when it’s working. But life can be miserable when it’s not.

If it won’t do this in a controlled test, where you are taking your time and watching the conditions as close as physically possible, leaving nothing to chance, then it just might as well be a 85 pound paper weight.

 

[rickiesrevenge]

Nice shooting. I like how your groups are all on one piece of paper. No cherry picking that way

 

[Fuj]

I don’t talk much about that closet full junk that took me down that boulevard of broken dreams and failed ideas.

Like I always say....."Never let a bad Idea go to waste" !! LOL

Now while your on a roll here.....I need a 121 gr. rebated 30 cal
for a........

 

[nakneker]

Thanks for sharing Jackie!

 

[majohnson]

Interesting stuff Jackie! How is the boat business.

 

[AlNyhus]

I don’t talk much about that closet full junk that took me down that boulevard of broken dreams and failed ideas.

Knowing what doesn't work is just as important, right? You should see the 'collection' of race parts here....

 

[Tim Singleton]

Nice shooting Jackie
is it an optical illusion in the pic or is the cup of the jacket still holding on to some of its radius at the base?

 

[Shooter13]

Nice job Jackie!! Looking forward to meeting you at TDV next year! Merry Christmas!

 

[D Coots]

One thing to remember about a Rail Gun. It is one of the most singular purpose pieces of “equipment” you will ever own. What they are designed to do well, they do very well.

But not much more.

It is great when it’s working. But life can be miserable when it’s not.

If it won’t do this in a controlled test, where you are taking your time and watching the conditions as close as physically possible, leaving nothing to chance, then it just might as well be a 85 pound paper weight.

Mine comes in at 125# on the bench. When moving from bench to bench when it's working, it's like 50#. When it's not working, somewhere around 300. Then loading for eight 10 shot groups.......

 

[jackieschmidt]

Nice shooting Jackie
is it an optical illusion in the pic or is the cup of the jacket still holding on to some of its radius at the base?

It’s the way the light hits it. It does appear to have a very slight convex at the very base.