Coated bullets and lube grooves?

[Mikeinkaty]

Why are people selling coated bullets that have lube grooves? Do the grooves provide functionality other than as a place for lubrication? Bullet accuracy? Less friction? Just curious. The basic question is which should I buy, or make, and why.

Mike

 

[JBnTx]

It's just the molds they have.

The lube groove is not needed but until they buy a new grooveless mold, you'll see coated bullets with grooves.

 

[Nemo288]

I suspect that the (now lubeless) grooves may lower friction a small amount.
I doubt there is much to gain from making new moulds without them just for coated bullets.
You do see some 300 grain 44 designs with one narrow groove and a lot of bearing surface.
They may have the most to gain from coating although testing would be required.
Missouri Bullet .44 Silhouette
Note that many solid monolithic bullets these days have grooves although no lube.
The grooves give the displaced metal somewhere to go and dramatically reduce friction.
.44 200gr Handgun Raptor
GS CUSTOM BULLETS - FN USA Order Form

 

[Mikeinkaty]

What about flight characteristics for the two types? Aerodynamics I guess you would call it. Smooth vs grooved.

 

[OKFC05]

What about flight characteristics for the two types? Aerodynamics I guess you would call it. Smooth vs grooved.

Matters maybe in long range rifle, but not for average pistol shooting at subsonic speeds. I don't make any sight corrections switching from smooth plated to grooved cast from Lee molds.

 

[muddocktor]

Mike, if you look at Bayou and MBC you will see some groove-less 9 MM bullets for sale in 115 and 124 grain RN. Like has been posted above, I think it's just a matter of using old molds that are already bought and paid for in the majority of the cases of what is available that is coated.

 

[Nemo288]

To simplify matters, a vast majority of flight characteristics are determined by the nose shape.
This is where Elmer's SWC might have a slight edge over the WFN.
I do think Hornady might have gone over that edge with the FTX for handgun bullets. JMHO
Not many of us are shooting handguns over 100 yards.
Some, yes, but not many.
Read Hatcher's notebook for a study he and others did with the .30 cal military round and various bullets.

 

[NevadaBob]

I asked my bullet maker the same question. His reply was the same as in post #2 above. He mentioned there's no change in bullet performance between the two.

 

[muddocktor]

To simplify matters, a vast majority of flight characteristics are determined by the nose shape.
This is where Elmer's SWC might have a slight edge over the WFN.
I do think Hornady might have gone over that edge with the FTX for handgun bullets. JMHO
Not many of us are shooting handguns over 100 yards.
Some, yes, but not many.
Read Hatcher's notebook for a study he and others did with the .30 cal military round and various bullets.

Nemo, I think the FTX bullets might see some ballistics advantage with the bullets being shot out of a rifle chambered in a pistol caliber though, such as 357 or 44 Mag. Both of those shot out of a rifle are easily shot at 100 yards or over and the much better ballistic efficiency of the FTX design would mean higher velocity downrange and more retained kinetic energy. Plus, the FTX bullets are also safe to use in tubular magazines such as on the Henry and Rossi carbines. With that said, I haven't actually tried any FTX bullets as I don't hunt any more and don't shoot my Rossi or Browning carbines at any range longer than 100 yards.

 

[fredj338]

LEss bearing surface less friction. There really is no benefit to a grooveless bullets but slightly shorter OAL length.

 

[rwsmith]

I've heard them referred to.....

I've heard them referred to as driving bands and some bullets are made with extra grooves, like Elmer Keith specified that his bullets have three driving bands with 2 grooves.

I believe that a hard cast bullet would have less friction engaging the rifling with bands rather than a hard cast solid bullet.

It also allows material to be moved to other parts of the bullet, like the nose, and give it more length and shape than a solid slug.

 

[Nevada Ed]

A "Coated Bullet" with or with out the lube grove will have little
bearing on how it shoots in pistol or revolver loads for most of us, at or under 50 yards.

I think we are over thinking this one..................

Now the shape of the Ogive is another story and opens up a
can of worms.

 

[rwsmith]

A "Coated Bullet" with or with out the lube grove will have little
bearing on how it shoots in pistol or revolver loads for most of us, at or under 50 yards.

I think we are over thinking this one..................

Now the shape of the Ogive is another story and opens up a
can of worms.

Honestly, any bullets I that were formerly lubed in groove are still good for me now. I thought the same thing like, "Are they coming out with new bullets for one that are coated?" If somebody could find some benefit to making grooveless lead bullets I'd be glad to take a look.

The ogive is a sore spot with me too.

 

[Ivan the Butcher]

If you are using coated bullets with Black Powder, you will want to have lube either in grooves or in a cookie under the bullet. This isn't for bullet lube, but to keep the fouling soft. Hard fouling will affect accuracy even at revolver distances (25 yards +/-).

Ivan

 

[Mikeinkaty]

Matters maybe in long range rifle, but not for average pistol shooting at subsonic speeds. I don't make any sight corrections switching from smooth plated to grooved cast from Lee molds.

I forgot to say in the start of this thread that my main interest was with my 20" lever rifle. 357 mag Henry Big Boy.

 

[ArchAngelCD]

Commercial casters have a lot of money invested in their molds. They aren't going to replace them only because the lube groove is no longer needed when it does not effect performance. The molds they have have been proven over time, no reason to change them. I'm guessing when it's time to replace them they will buy new ones without a lube groove.

 

[mikld]

Why? Because they are there...

 

[Nemo288]

I did a little experiment to see the relative damage, if any, between a taper crimp and a solid profile (roll) crimp
using the MBC HiTek coated 210 grain RNFP 44 bullets.
I took a couple of (dunno how many times) fired W-W 44 special cases and wiped them off with some Hornady One Shot cleaner/lube.
Sized them in a Redding dual carbide 44 special die.
Flared the mouth with a .427" Lyman M die so the bullets just fit without any scraping.
Pressed the bullets in using a flat nose seating stem.
Crimped them with Redding dies.
Yanked the bullets back out with an RCBS collet die puller.
Took pictures.
They don't show as much difference as I see with a close eyeball.
The profile roll crimp was at least twice as difficult to extract.
Look closely and you will see the extra damage to the nose as I had to grab the bullet harder.
I believe the roll crimp damaged the bullet slightly more but it's hard to see in the pictures.
Only the top edge of the lube groove and bullet base were shaved just enough to see the bare metal.
The coating did not crack or peel at all during this test.

I did learn that the roll crimp at least doubles the bullet pull.
The taper crimp version basically jumped right back out.
That coating is pretty slick (that's a double entendre, Son).
I am going to add a slight profile crimp to the taper crimp I used for my first batch of 50 I loaded with these bullets.

 

[Mikeinkaty]

Just off the top of my head I would think that having driving bands on a bullet would allow the rifling lands to better engage with the bullet, producing better flight stability. Then again, high velocities might cause a shearing action which would cause less stability and more lead fouling. Any others have thoughts on this? Mike

I'm reminded of the 8" howitzer projectile that had one brass band about 1/4 of the way up from the bottom. But the mechanics of that is different. The projectile case was steel. The job of the rammer staff crew was to slam the projectile in hard enough to get the brass band well seated with the rifling.

 

[Nemo288]

Since commercial coated bullets are fairly new and a small percentage of revolveros shoot their rounds thru carbines,
you may be the one to tell us how they perform.

I don't think I have ever shot cast bullets thru my carbines as I had not yet discovered the gas check bullet back then.
Now that's my favorite 44 mag load (Cast Perf. 260 WFNGC, 18-19 grains 2400)
but I still have quite a few jacketed rounds loaded up.
I may tear down the ball powder ones as I have found some of them with congealed powder.
Ball powder doesn't store well when compressed.
Got my only stuck bullet firing one of those old loads.

These are a couple of my favorite carbines.
I have a couple of other W94's but they are not built as well.
The '92 is the perfect action for the 44 Mag having been designed for revolver rounds in the first place.

I am still waiting for Bighorn Armory to come out with a version of their 89 in 445 Supermag.
It is specifically designed for the big 1.6" revolver rounds.
I am making do with an Encore for now.
It shoots cast bullets just fine up to 1900 fps (that Cast Perf 260 I mentioned).
When I get some heavier coated bullets, I'll let you know how they work at high velocity.
They may still want a gas check as you get above 1500 fps.

As you may know the twist rates in 44 carbines can vary from 1/38" down to 1/20" and below.
This is going to affect accuracy and stability more than the style of bullet.
Brian Pearce did an eye opening test in a recent edition of Rifle using 44 mag carbines of different twist rates.
We get a lot better performance out of the 444 Marlin 1/38" barrels than he did with the magnum as the velocities are much higher.
Don't know much about the 357 twist rates.