What ACTION for a 7mm-338 LAPUA Imp. cartridge?

[goodgrouper]

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I take it most of you guys will be riding me hard when I release my 7mm Allen Mag this summer. I guess I will start getting ready for the rear chewing with this one !!!


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Not at all Kirby. You and I have talked about this before. There is definetely a place for super overbore fire-breathing dragons in this sport. A lot of guys on this forum and others are big game hunters who shoot only several times per year and want a laser gun to shoot their bull out to 6 or 7 hundred yards. For them, nothing could be better than an Allen mag. It will last them many, many long seasons. But for guys like me that shoot all the time, and practice at long range several times per week during the warmer months, they are just not an option. I love to experiment with many different powders, bullets, primers, seating depths, and other nit-picky things. I could have 500 rounds down a new barrel before I am satisfied with the pet load. That is my krutch I guess. /ubbthreads/images/graemlins/crazy.gif

 

[jb1000br]

Without reading every post, 7wsm or 7 dakota is all you need to drive the heavies (not including wildcats new offerings) to their structural limits.

I hate the 7STW/RUM and other giganticlyoverbore rounds.

7 dakota is tough to beat for a 7mm laser.

YMMV,
JB

 

[dakor]

Well GG I will explain it this way. You consider a 300 Win to be as big as you would go in a .30cal and have said it few times to stay away from the 300 Ultra. But isnt the 300 mag bigger than the 30/06 kinda like the STW is bigger than the 7mm Mag? So really there is know difference from what I am saying about the 7 Ultra that you are saying about the 300 Ultra. /ubbthreads/images/graemlins/grin.gif

 

[Fiftydriver]

Goodgrouper,

I totally agree with you on this. While ballistically the smaller bores can be made to be the equal or even exceed the big 338s(you should see what that little 257 Allen does with the 156 gr ULD at 2000 yards compared to the 338 Kahn /ubbthreads/images/graemlins/grin.gif).

Still, they are not rounds designed for heavy rifles that will be used with moderate to high volume shooting. I agree they just are not compatable with long throat life compared to the bigger bore, no question you are 100% correct on that and I tell my customers this.

As you know and we have talked about, the Allen Mags are designed to be used as big game rounds first and formost. They do offer the ballsitics to be true extreme range rounds but they are designed to be chambered in 8 to 9.5 lb rifles and designed to offer long range hunters an option to reach out to at least 600 yards with very minimal vertical adjustment.

This will be the case of the 7mm Allen as well. We are looking to top the performance of the 7.21 Firebird in velocity but also combine the round with conventional big game premium bullets as well as the new Wildcat Bullets which will offer Ballistic Coefficents higher then anything offered yet in a conventional ULD bullet under 50 cal.

This is on paper so far but will let all know how it translates into the real world.

The goal is a +1.000 B.C. bullet launched at +3200 fps and using a bullet jacket designed to expand on game at close range and extreme range.

We will see what happens.

Good Shooting!!

Kirby Allen(50)

 

[goodgrouper]

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But isnt the 300 mag bigger than the 30/06 kinda like the STW is bigger than the 7mm Mag?

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Yes that is correct. I have also stated recently that in all truth, I could have killed that cow at 820 yards with an '06. She would still have died, only difference being that the shooter must compensate a little more for the punier cartridges less flat traj.
I have bashed the .300 ultra in the past because it <font color="red"> IS </font> an overbore cartridge with real life benefits in the field being barely more noticeable than the other smaller 30's. Run the numbers on a 180 grain accubond doing 3400 out of an ultra versus the same bullet doing 3100 (and I get 3200) from a 300 winny. Now zero them both at 300 yards and look at the 500 yard column. 5 or 6 inches at best. That is just 4 lousy clicks at that range, and you burn 20 grains more powder for those 4 clicks!

However, I have stated also in the past that if anyone ever makes decent brass for the Ultra, I would possibly look at getting one made, and hang a 30" barrel on it and shoot only 200 grain or heavier bullets out of it. <font color="blue"> NOTHING LIGHTER. </font> Your margin of advantage narrows drastically with the lighter and lighter bullets you shoot in the Ultra. It has the horsepower to push a 200 grain accubond at sufficient velocities to really shine. But, barrel life is still going to be not too stellar. But that is the price you pay for launching super heavy-for-caliber bullets at high velocities for looong range shooting.
A 7stw or 7 ultra shooting 200 grain bullets will be sweet, but it will exhibit the same or worse wear than a 300 ultra shootin 220 grain bullets.

 

[goodgrouper]

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The goal is a +1.000 B.C. bullet launched at +3200 fps and using a bullet jacket designed to expand on game at close range and extreme range.


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That puppy would outfly a 50 bmg. It would be WAY cool if it works!

The problem I see is this:
Sure, I can make a 2 foot long brass solid projectile, launch it with 1500 grains of some secret powder down a ceramicly lined bore, and have a cannon that would go 15 miles--THEORETICALLY! Whether or not it would actually work or be accurate enough to hit something that far is another matter entirely. Too many variables to guess, it would simply have to be tested before concrete plans could be made.

But it sure would be awesome wouldn't it?

I wish you the best of luck on your projects, and by all means, keep us up to date on those lasers!

 

[guns_and_labs]

Actually, a 7mm-338 Lapua is not that far off of a 7.21 (.284) Firebird, Lazzeroni's entry in the 7mm space. The cartridge is actually a bit larger.

It will definitely reach out and touch anything you'd like, and the recoil isn't any worse than a stout .30-06 (with a good muzzle brake). Mine will go the distance quite nicely with 140 gr. bullets, leaving the muzzle at 3600 fps.

Go find one of the Sako M995 (TRG-S) set-ups, and you can get into it for about a grand.

 

[goodgrouper]

I am aware of this cartridge. He was talking about the 7mm-.338 Lapua IMPROVED. It is quite a bit bigger.

 

[guns_and_labs]

I must be looking in the wrong places, then. Ammoguide shows the .338 Lapua Improved case as still something like 2.725" long and .585" at the base, narrowing to .570". The Firebird case, as I recall, is over 2.9" long, about .6" at the base, though more tapered. But still, the height to the top of the shoulder is still about .1" more on the Firebird than the .338 Lapua Improved. Are you sure the .338 LI has more capacity than the Firebird (or the ballistically similar .30-.378 Weatherby)?

 

[goodgrouper]

Not positive. I was saying that the improved version of the .338 Lap is quite a bit bigger than the standard version as far as case capacity goes.

 

[guns_and_labs]

Of course, now I'm wondering about the performance of a .22-.338 Lapua Improved...hmmm, maybe a little too overbore? /ubbthreads/images/graemlins/crazy.gif

 

[Fiftydriver]

The 338 lapua, and the big Lazzeroni rounds have roughly the same size case head.

The Lapua is a bit shorter but most of that is in the longer neck of the Firebird round but I believe it is still 2.800" or less in length, do not have a case but I know they are significantly shorter then the 300 RUM case.

Good Shooting!!

Kirby Allen(50)

 

[Fiftydriver]

GoodGrouper,

The eternal optomist!!!

I agree, many a rounds have looked impressive on paper only to be a flop when bullets actually fly.

I feel Richard and I have done some good research on this and can make it work to at least come very close to our goals.

When I started the 257 Allen Mag project, many though I was insane to cram a 100 gr capacity case in a 1/4 bore round(they may have been onto something /ubbthreads/images/graemlins/blush.gif!!)

But with properly set up loads with heavy bullets, this round is really a ***** cat. The 7mm Allen Mag has roughly the same porportions as the 257 Allen Mag as far as case capacity to bore volume so we will see what happens.

Like you said, until bullets are landing close to each other at extreme range, its just another crazy idea!!!

Good Shooting!!

Kirby Allen(50)