They shipped on 13 Oct 05 and I got the "parts" on 22 Oct 05: 9 days.

Maybe I will be able to post a picture later.

BTW, some PH is said to have been using this lightweight .423 bullet in a .425 Express (a short magnum like the .416 Taylor), and saved a client's bacon for him with a brain shot on an elephant, IIRC.

Sheep to elephant, like soup to nuts, this bullet will do it all in Africa.

But will the .423 Lapua get it up to 3000 fps???

And Happy Halloween: .338, .375, .423, .458 Lapuas


Left to right above:

1. Norma factory load in .338 Lapua Magnum with 225 grain FMJ steel jacket that gets close to 3100 fps. Norma brass measures same as Lapua.

(next three are Lapua brass)

2. .375 Lapua, 300gr GSC HV, I like it at 2750 fps.

3. .423 Lapua, 380 grain North Fork SP: should easily do over 2600 fps. The 320 grain HV will easily do 2800 fps, I am sure.

4. .458 Lapua, 500 grain Barnes TSX. Ought to do 2500 fps and easily loaf along at 2400 fps.

Compare:

GSC HV bands
North Fork SP grooves
Barnes TSX "cannelures"

The .375 and .458 have been fireformed.

The .458 Lapua has a shoulder of 0.030" step per side, and it is quite beautiful.

The .423 Lapua will have a generous shoulder that no one can say is inadequate.

The .423 Lapua will surely not raise eyebrows with 320 grainers at 2800 fps, like the .404 Jeffery would. Then the 400 grainers could be loaded to a fully functional velocity at low pressure, also unlike the .404 Jeffery in a M98 hack job.

rip...looks great

no 416

boom stick,
Note how perfect the GSC bullet is for a .404 Jeffery. The zero-freebore-leade-only throat of a .404 Jeffery will be best for accuracy with this bullet.

You can seat it with either one or two of the bands showing and see which shoots best, and you will still be off contact with the lands.

However, with 2 bands showing, it is about 3.620" COL and a smidgen too long for the 3.600" common box size, such as in my M70 .404 Jeffery. Of course the CZ 550 is fine with that and more.

Seat it with one band showing and the COL is about 3.530" which is the usual specified max COL for the .404 Jeffery.

Gerard has done his homework and got the numbers correct on this bullet for the .404 Jeffery or any other 10.75mm/.423cal.

The bullet length is about 1.335". When seated properly, the long neck (0.620") of the .404 Jeffery is used up and provides good grip on the bullet.

This is a perfect High Velocity bullet for the .404 Jeffery. HV. Get it?

2750 fps in my 24" barrel sounds right for the .404 Jeffery, though 2800 fps might be possible, and unneccessary.

Look out African Sheep!

.416 Lapua you say?
Not until I have done the .423 Lapua to my specs, since Dakota is keeping theirs so secret.
I also have a bunch of North Forks in all types of 380 grain weight, and a bunch of the 340 grain North Fork SP's I am saving for African Sheep.

Ron,

3000 f/s with 320 grain .423 Lapua would be the equivalent of just on 3000 f/s with 250 grain 338 Lapua. That is based on the kinetic energy increasing or decreasing by 50% of the increase or decrease in bore area.

That formula appears to be very accurate based on loading different calibres on the same case in bench style rifles and loaded to the point where accuracy falls off. Of course it is assumed that equally suitable powder is available for each calibres.

In practice I found that necking up gave a kinteic energy increase that was just slightly less than 50% of the increase in bore area.

I think there are two reasons for this happening. Firstly, calibres that have a big case capacity for the bore size seem to often retain accuracy to a higher pressure. In other words if we chronographed a 308 and 300 Winchester that were loaded to equal pressure then the velocity difference would be "x". But if we then loaded either in bench guns until the point where accuracy fell off then the velocity difference would be a little greater because the 300 Winchester loads would be slightly higher pressure.

Secondly, necking up can result is having less net case capacity. A 460 Wby with 500 grain Hornady seated to the canelure would have a smaller net case capactity than a 25/460 loaded with 100 grain Hornadys.

Mike

Hmmmmm,

A 250 grain GS HV in .338 would be just the ticket in a sniper rifle against morally equivalent peer competitors who are not members of a national army......

This one (in a 338 Win Mag case) weighs 286gr and needs a 1:7" twist to stabilise for +1k. I am working on one for 1:10" twist. Almost there.

quote:

Originally posted by Gerard:


This one (in a 338 Win Mag case) weighs 286gr and needs a 1:7" twist to stabilise for +1k. I am working on one for 1:10" twist. Almost there.

Egad! That one even looks like a lawndart!

Gerard:
Something for a 10" twist would indeed be useful in my AR-30.

Lawndart:
Your scenario sounds good for African Sheep Hunting too.

Mike378:
Glad to see you are still kicking. I like your application of Mike's Interior Ballistic Principles in this case. Bore Law Number One. More encouragement for the .423 Lapua.

Now, Mike, take a look at the shoulder on the .458 Lapua above and tell me, what you think about whether a commercial ammo company could load it in mass quantities for mass produced rifles??? It is .030" step per side and .060" total for neck to shoulder difference, with an unadulterated shoulder angle of the .338 Lapua Magnum (20 degree "semi-angle" per side)???

The .423 Lapua is a beautiful thing.
What are the thoughts on how much freebore it should have???

I will start with a Dave Kiff .338 Lapua reamer with .423 pilot on it, then the neck and throat will be done with a Dave Manson .404 Jeffery reamer, which has ZERO freebore, just the leade.

I need to decide on the freebore for the .423 Lapua, to allow a compromise for long seating of long monometal bullets to 3.750" COL and still handle a stubbier one like the 320 grainer, with good accuracy.

Sumbuddy who help???

quote:

This one (in a 338 Win Mag case) weighs 286gr and needs a 1:7" twist to stabilise for +1k. I am working on one for 1:10" twist. Almost there.

Hi Gerard,
That looks very nice, and I like the bullet mass (18.5 grams). I will PM you with the box length dimensions for the Sako TRG 42 sniper rifle, the HS Precision Sniper rifle and the CZ in 416 Rigby.

I would also like to get a box or two without a hole drilled in the nose. I have a few friends that would be interested in testing those at 1,200 meters. They are willing to give up a small amount of ballistic coefficient to have a less critical ogive. They want something that will perform pretty good in all of their rifles rather than outstanding in some rifles but only so-so in others.

It looks like your new set up is off and running.

lawndart

quote:

The .423 Lapua is a beautiful thing.
What are the thoughts on how much freebore it should have???

Give Dave Kiff a call. He likely cut the original reamers. I'm sure he would give you some great advice without compromising the Dakota blood oath.

quote:

I need to decide on the freebore for the .423 Lapua, to allow a compromise for long seating of long monometal bullets to 3.750" COL and still handle a stubbier one like the 320 grainer, with good accuracy.

Decide how long you will load your long bulet for magazine fit, etc. Set the freebore/lead so that the bullet will have .010" to .020" jump to the rifling. So long as the entire chamber/throat/freebore/lead/barrel complex is cut perfectly straight and true the stubby bullet will do just fine. What I'm really saying is tell Dave Kiff what you want to do. Three weeks later the perfectly dimensioned reamer wil arrive.
LD

Have any of you tried necking a 50 BMG case down to a phonograph needle for 20,000 FPS..

OH, I am sorry, none of you baby boomers will know what a phonograph needle is!

lawndart,
All the HVs have holes but the SP range, like the 338 above, are all spitsers. If one chooses the bullet length and twist rate carefully, they could tumble reliably on impact and that would pretty much spoil the day for a live target that is only 10 inches deep on the chest anyway.

I will watch for your PM

RIP,
Is your AR30 in 338? We don't see those over here.

Ray,
The problem I have not been able to solve with the 50BMG down to .177 is that the decapping pin rod keeps breaking.

And why are you poking fun at those of us who still use a phonograph? The twins treated the wife and me to an evening out at the movies a couple of months back and I was amazed. The movie was in colour and they never stopped once to change the reels!!

Gerard,
I am impressed with that GSC 286gn .338, canyou tell us what vel. you are achieving?

quote:

Originally posted by Gerard:

RIP,
Is your AR30 in 338? We don't see those over here.

Hi Gerard:

Yes, my AR-30 is in .338 Lapua with 10" twist 26" long barrel with tank-style brake, and a 4x-16x Schmidt&Bender Police/Military mildot scope (34 mm tube is bummer big) in Badger rings.

Armalite also makes the AR-30 in .300 WinMag.

I've also got a CZ 550 Mag rebarreled to .338 Lapua for small game. It has a 23" long, stainless, no-brake, 10" twist barrel.

A pic of your for-10"-twist .338 spitzer/target bullet would be interesting when you get the prototype worked out.

quote:

Originally posted by lawndart:

quote:

The .423 Lapua is a beautiful thing.
What are the thoughts on how much freebore it should have???

Give Dave Kiff a call. He likely cut the original reamers. I'm sure he would give you some great advice without compromising the Dakota blood oath.

lawndart,
I'll just wait and see what Dakota does with their throat, case length and shoulder angle.

My .423 Lapua will be a straight neck-up of the .338 Lapua with 0.4000" of tight free bore and 1.5 degree leade.

If Dakota leaves the brass long enough to fireform in my chamber, it will be good.
At least I am using a Dakota action in gratitude for the headstamp.

quote:

lawndart,
I'll just wait and see what Dakota does with their throat, case length and shoulder angle.

My .423 Lapua will be a straight neck-up of the .338 Lapua with 0.4000" of tight free bore and 1.5 degree leade.

If Dakota leaves the brass long enough to fireform in my chamber, it will be good.
At least I am using a Dakota action in gratitude for the headstamp.

Hey Ron,
I like your numbers. I will also be interested to see Dakota's numbers when they are released.

Gerard,
Thanks for your patience. I finally got around to measuring the internal length of the Sako TRG-41/42 magazines. It comes in at 95.25mm/3.750". I will get you the CZ numbers tomorrow. I will ask DJ Paintles to measure the magazine on his HS Precision rifle in .338 Lapua for you as well. Nothing like a juicy little military contract to keep your CNC machines happy and healthy .

quote:

Originally posted by lawndart:

Gerard,
... Nothing like a juicy little military contract to keep your CNC machines happy and healthy .

And don't forget us here at RIP Arms and DOA Ammo.

We will be providing .338 Lapua switch barrels with every rifle in:
.375 Lapua
.416 Lapua
.423 Lapua
.45 Lapua

Now I am gone to hunt deer and coyote with a .338 Lapua.

Woodjack,
We settled on 2868fps as a reasonable load from a 1:10" 338 Win Mag. We were not developing for speed. Our assignment was to ensure proper design of the drive bands, the boat tail and overall length for a 1:7" Twist. The nose profile was specified by the customer and in return they have given us access to their design technology for the nose profiles. We had the chronograph set up at 3 meters and the catch box at 5 meters IIRC. All shots fired, resulted in perfect 2 inch long keyholes in the entrance plate on the box. Used in a 338LM with a 1:7 twist, resulted in accuracy good enough to win the 5th Lapua Sniper Competition.

RIP,
I will be sure to let you know when the 1:10" twist bullet is done. There will be a little delay on these as I Gina has insisted that I finish the refurbishing of another CNC we want to have in production in the next three or four weeks. This is proof that the slave trade is alive and well in Africa.

(DOA Bullets: The Only Kind To Have) I Like that.

Enjoy your hunt

Lawndart,
3.750" Leaves more than an inch ahead of the case mouth and that should be ample. Lets see what the other mag boxes measure to. So far the indications are that the bullet will remain stable going from supersonic to subsonic at sea level. We are testing with a 1:10" 338 Win Mag.

Hey Gerard,
RIP measured his CZ magazine box. It accepts cartridges loaded out to 3.836"/97.45mm.
lawndart

Thanks, Gerard.

A Dummy 3.836" long will work through the box of my CZ 550 Magnum rebarreled to .338 Lapua.

With 2.720" max of case, that is 1.116" of bullet nose ahead of the case mouth.

Then there is trim-to-length of 2.710" IIRC, so there is room to play.

Edit:
Oops. The Lapua manual says 2.724" max so 2.714" would be trim-to.

So: 3.836" - 2.724" = 1.112" of nose jut for the bullet.

Hey Gerard,
I prefer a 1:10" twist. The Sako TRG 41/42 in 338 Lapua Magnum has a 1:12" twist. When you move to America I will finance the development of a long range target bullet without a hole in the nose that is optimized for the 1:12" twist. Who knows; the ones you make for the 1:10" twist may work just fine.

It is all good.

lawndart

Gerard,
The HS Precision HTR in 338 Lapua Magnum has a magazine box length of 3.691/93.75mm" - 3.700/94mm", depending on individual rifle. That is just .010." - 0.19" over Maximum specified cartridge OAL of 93.50mm/3.681".
That leaves a total length for the bullet to protrude from the case of .967"/24.56mm.

So; it is a little tighter than the Sako, and much tighter than a rifle built on a CZ action.

I don't know what the specifications on an AI rifle are, but will find out.

Thankyou Gerard for your responce. 2868fps for286gn/.338, Great! Such aversatile round,and with your efforts even better now.