Core-Jacket Separation in flight of Varmint Bullets
243/06 Wildcat rifle 87-grain V-Max bullets, 4 below zero 600 feet above sea
level, 25 yard target for half inch low for a 250 yard zero.
Two of the 4 bullets fired resulted in Core-Jacket Separation in flight. The
core of one bullet hit the paper target perfectly sideways.

The first shot from the cold barrel made a perfect hole about an inch low
and nearly dead on. The last two shots with the warmer barrel resulted in
both jackets separating from the cores and the bullet's cores' tumbled
within 25 yards. That would certainly blow a coyote shot!

Fired at a longer distance I would not have known what happened! I called
the ballistics experts at Hornady and he confirmed that the evidence
indicated that the bullets were coming apart in flight.

My 243/06 wildcat has a 25" BBL and 1 n 10 rifling twist. I was using a hot
load, 58 grains of H-4831sc with Fed. 215-PRIs, that were showing a little
pressure on the primers. I have used that same powder and weight with 100
grain bullets for deer and it produced less signs of pressure.

I loaded four cartridges with 57.5 grains of the slower H-1000 to see if
they would hold together.

What do you think, and what is your experience with bullets blowing up in
flight?

http://www.udarrell.com/243-06-6mm-06-87-v-max.htm
Slower trajectory and 25 yard zero chart
http://www.udarrell.com/243-06-6mm-06-87-v-max3503.html Darrell - udarrell

From:	udarrell
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Thu, 20 Jan 2005 07:45:21 -0500

"Michaelb" wrote in message
news:20050119181100.83851.qmail@web52009.mail.yahoo.com...
> > 87-grain V-Max bullets
>
> > My 243/06 wildcat has a 25" BBL and 1 n 10 rifling
> > twist. I was using a [Too Hot] hot
> > load, 58 grains of H-4831sc with Fed. 215-PRIs
>
> > What do you think, and what is your experience with
> > bullets blowing up in flight?
>
> I've talked to folks who have had it happen to them -
> they were shooting at longer ranges and said they saw
> a gray streak that ended short of the target. IIRC
> the Speer TNT bullet comes with a warning not to use
> them in quick twist barrels or above certain
> velocities. If you were going to run light bullets
> exclusively I wonder if a 1:12 wouldn't be a better
> twist rate. In any case it certainly sounds like you
> need to use a stiffer bullet at the velocities you're
> getting. What fun! Good hunting!
>

I loaded four cartridges with 57.5 grains of the slower H-1000 to see if
they would hold together.
All four held together perfectly today, and grouped good. A half grain less
of slower burning H-1000 powder probably helped reduce the stress on the
bullet's jacket that is caused by the rifling. It was also a lot warmer
today, 26 degrees verses 2 to 4 below zero [colder air is heavier] when I
shot the others bullets that blew up.

Yes, a 1:12 twist would be much better for the real light bullets, --except
that Hornady couldn't use the boat tail on their 6mm 95 gr SST bullets
because it wouldn't stabilize in a 1:10 twist 243 Win. I wanted to use the
heavier bullets on deer, so I'm glad I went for the 1:10 twist.

I have used 58 grains of the slower H-1000 with 100 grain bullets for deer
and there were no signs of pressure.

They may have to redesign their fragile light weight varmint bullets for the
new fat 6mm cartridge or end up with core-jacket separation problems.

There stands a huge coyote only 100 yards away, you shoot and the bullet
blows up in mid flight -- what a downer, huh!

I've heard the Speer 70 gr TNT is very explosive. I have never tried it in
my 243 Win, and wouldn't consider using it in my wildcat.

WARNING: TO ALL: Do not use any of my loads for 6mm-06 wildcats or 243/06's
wildcats as they may be too hot for your rifle!
-Darrell

From:	D. J. MCBRIDE
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Thu, 20 Jan 2005 21:39:59 GMT

"udarrell" wrote in message
news:41eff539_2@newspeer2.tds.net...

> I was told by someone that tested the mag primers against the regular
> and
> his findings were that it produced more even ignition velocities and
> little
> noticeable difference in pressures. (He measured everything.) I
> thought it
> might increase the burning rate of the powder near the primer, maybe
> not?

I've never heard that theory. But, the times I have tried magnum
primers I automatically lowered the listed maximum load a full grain.
YMMV.
--
"Dave In Houston

From:	Ted
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Thu, 20 Jan 2005 19:27:12 -0500

> I've heard the Speer 70 gr TNT is very explosive. I have never tried it in
> my 243 Win, and wouldn't consider using it in my wildcat.

Try some Berger MEF if you really want to see something pop. For you
1:10 they recommend nothing less than 88grains. They have an 88grain
Low Drag MEF in both bare copper or Molly. They also have a Very Low
Drag MEF in 95 grains - which is getting a littel heavier than you want
to use but the BC is .524 think of the high velocity down range
performance with that bullet - WOW! Only problem is they recommend 1:9
for that bullet. If you have never shot Berger Varmint bullets - they
are match grade Varmint bullets and tend to be extemely accurate. I use
them in my 22 Rem Bench Rest and they vaporize critters - If you hit
them square - there isn't even a mist that we have been able to see. I
shot the 52 grain MEF and my groups average in the low 2's, I've had a
couple in the .13-.15 range as well - good day no wind. When I get
bored I shhot yellow jackets baited with peanut butter and jelly @ 100
yards - what sport!

--
Sorry for the bad e-mail address
SPAM is just too much to take

From:	D. J. MCBRIDE
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Fri, 21 Jan 2005 04:30:37 GMT

"Ted" wrote in message
news:q9RHd.7515$CI6.5087@trnddc06...
> When I get bored I shhot yellow jackets baited with peanut butter and
> jelly @ 100 yards - what sport!

I'm reminded of a Beverly Hillbillies episode where Uncle Jed and
Jethro are shooting stick matches they have lined up way out at the
front gate(s). Jethro is dismayed following a shot and Mr. Drysdale,
who is spotting through a pair of binoculars, questions Jethro's
disappointment seeing as how he had just shot the head off the match.
Jethro replies that "they wuz just trying to light 'em." ~:o)

Dave In Houston

From:	D. J. MCBRIDE
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Thu, 20 Jan 2005 13:28:33 GMT

"udarrell" wrote in message
news:41ef16ae_1@newspeer2.tds.net...
> "Michaelb" wrote in message
> news:20050119181100.83851.qmail@web52009.mail.yahoo.com...
>> > 87-grain V-Max bullets
> Yes, a 1:12 twist would be much better for the real light
> bullets, --except
> that Hornady couldn't use the boat tail on their 6mm 95 gr SST bullets
> because it wouldn't stabilize in a 1:10 twist 243 Win. I wanted to use
> the
> heavier bullets on deer, so I'm glad I went for the 1:10 twist.
>
> I have used 58 grains of the slower H-1000 with 100 grain bullets for
> deer
> and there were no signs of pressure.
>
> They may have to redesign their fragile light weight varmint bullets
> for the
> new fat 6mm cartridge or end up with core-jacket separation problems.
>
> There stands a huge coyote only 100 yards away, you shoot and the
> bullet
> blows up in mid flight -- what a downer, huh!
>
> I've heard the Speer 70 gr TNT is very explosive. I have never tried
> it in
> my 243 Win, and wouldn't consider using it in my wildcat.

I load for a 6mm Ackley with a 12 twist. I've never (to my
knowledge) had any of the 65 grain V-Max give it up downrange (3700
fps). Ditto for the few 58 grain V-Max I've sent down the tube (3900++
fps).
I'm inclined to think Darrell's issue is one of excess velocity, NOT
the propellant. 4831 may have served him well had he just backed off
the charge weight a couple of grains. And, were magnum primers really
necessary? Perhaps the extreme cold temperatures did require the hotter
primer. But, I've never felt the need for the magnum primers in my .280
Ackley which is also an '06 sized case.
I also have to think that H1000 is far too slow for Darrell's
cartridge/bullet combination. H1000 is typically used in magnum caliber
(and magnum sized) cases and with heavy [for caliber] bullets. If
Darrell is no longer getting jacket separation it's no doubt because
he's getting enough velocity reduction. Chronograph any of these
loads?
In past years I've loaded TNTs in a.243 and in the .280. They are a
"slam-em-down" coyote bullet with virtually zero fur loss. But, you are
correct in the necessity to keep velocities under 3500 fps (if I
remember correctly). If your average shot is a hundred yards or less
why would you need more [velocity]?
In the 6mm Ackley I've had good results shooting the Nosler 95 grain
Ballistic Tip down the 12 twist. Velocities though ran in the 3400 fps
range. You can overcome some twist limitation if you can up the
velocity, in effect, upping the rpms and promoting bullet stabilization.
But, if pressures won't allow it you're going to have to be happy with
the lower velocities. I doubt the 'yote will be able to tell the
difference.

--
Dave In Houston

From:	udarrell
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Thu, 20 Jan 2005 14:30:08 -0600

"D. J. MCBRIDE" wrote in message
news:5mOHd.33358$_56.26355@fe2.texas.rr.com...
> "udarrell" wrote in message
> news:41ef16ae_1@newspeer2.tds.net...
> > "Michaelb" wrote in message
> > news:20050119181100.83851.qmail@web52009.mail.yahoo.com...
> >> > 87-grain V-Max bullets
> > Yes, a 1:12 twist would be much better for the real light
> > bullets, --except
> > that Hornady couldn't use the boat tail on their 6mm 95 gr SST bullets
> > because it wouldn't stabilize in a 1:10 twist 243 Win. I wanted to use
> > the heavier bullets on deer, so I'm glad I went for the 1:10 twist.
> >
> > I have used 58 grains of the slower H-1000 with 100 grain bullets for
> > deer and there were no signs of pressure.
> >
> > They may have to redesign their fragile light weight varmint bullets
> > for the
> > new fat 6mm cartridge or end up with core-jacket separation problems.
> >
> > There stands a huge coyote only 100 yards away, you shoot and the
> > bullet blows up in mid flight -- what a downer, huh!
> >
> > I've heard the Speer 70 gr TNT is very explosive. I have never tried
> > it in my 243 Win, and wouldn't consider using it in my wildcat.
>
> I load for a 6mm Ackley with a 12 twist. I've never (to my
> knowledge) had any of the 65 grain V-Max give it up downrange (3700
> fps). Ditto for the few 58 grain V-Max I've sent down the tube (3900++
> fps).
> I'm inclined to think Darrell's issue is one of excess velocity, NOT
> the propellant. 4831 may have served him well had he just backed off
> the charge weight a couple of grains. And, were magnum primers really
> necessary? Perhaps the extreme cold temperatures did require the hotter
> primer. But, I've never felt the need for the magnum primers in my .280
> Ackley which is also an '06 sized case.
> I also have to think that H1000 is far too slow for Darrell's
> cartridge/bullet combination. H1000 is typically used in magnum caliber
> (and magnum sized) cases and with heavy [for caliber] bullets. If
> Darrell is no longer getting jacket separation it's no doubt because
> he's getting enough velocity reduction. Chronograph any of these
> loads?
> In past years I've loaded TNTs in a.243 and in the .280. They are a
> "slam-em-down" coyote bullet with virtually zero fur loss. But, you are
> correct in the necessity to keep velocities under 3500 fps (if I
> remember correctly). If your average shot is a hundred yards or less
> why would you need more [velocity]?
> In the 6mm Ackley I've had good results shooting the Nosler 95 grain
> Ballistic Tip down the 12 twist. Velocities though ran in the 3400 fps
> range. You can overcome some twist limitation if you can up the
> velocity, in effect, upping the rpms and promoting bullet stabilization.
> But, if pressures won't allow it you're going to have to be happy with
> the lower velocities. I doubt the 'yote will be able to tell the
> difference. -- Dave In Houston

I am in general agreement with all of your statements.
The 6mm Ackley is a real good wildcat cartridge.

With Hornady, the suffix SX means Super Explosive. Hornady Super Explosive
bullets are for varmints, are thinly jacketed, and are designed to do
exactly what their name implies. Suffixed SX-Varmint type bullets (Not
V-Max bullets) are limited to velocities of 3500 fps or less to prevent them
from disintegrating in flight.

Hornady makes other varmint-type V-MAX bullets "that can be driven to very
high velocities." These are the V-MAX (polymer tip) and standard spire
point (SP) bullets. (Those are Hornady's claims.)

I agree I could have simply dropped the H-4831 charge a couple of grains and
stayed with it or even went to RL 19, that should work well with an 87 grain
bullet. I agree that normally H-1000 should only be used with the heaviest
100 grain bullets. IMR 7828 works well with the heavier bullets and it is
close to H-1000 in burning rate.

I was told by someone that tested the mag primers against the regular and
his findings were that it produced more even ignition velocities and little
noticeable difference in pressures. (He measured everything.) I thought it
might increase the burning rate of the powder near the primer, maybe not?
Ball powders like H-414 normally call for the mag primers.

I will load other combinations and then eventually go to the 200 yard range
that is not too far from Cabela's in Prairie du Chien, WI.
Darrell in WI

From:	Michaelb
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Wed, 19 Jan 2005 10:11:00 -0800

> 87-grain V-Max bullets

> My 243/06 wildcat has a 25" BBL and 1 n 10 rifling
> twist. I was using a hot
> load, 58 grains of H-4831sc with Fed. 215-PRIs

> What do you think, and what is your experience with
> bullets blowing up in flight?

I've talked to folks who have had it happen to them -
they were shooting at longer ranges and said they saw
a gray streak that ended short of the target. IIRC
the Speer TNT bullet comes with a warning not to use
them in quick twist barrels or above certain
velocities. If you were going to run light bullets
exclusively I wonder if a 1:12 wouldn't be a better
twist rate. In any case it certainly sounds like you
need to use a stiffer bullet at the velocities you're
getting. What fun! Good hunting!

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From:	jadel
Subject:	Re: Core-Jacket Separation in flight of Varmint Bullets
Date:	Fri, 21 Jan 2005 05:53:05 -0800

Drive a thin-skinned bullet fast enough, and rotational forces can
strip the jacket from the core. Solid copper bullets don't have this
problem.

Back off the load or switch to solids or some sturdier jacketed slug.
J. Del Col