Flat shooting Elk gun?

[rost495]

Kirby

I have to disagree politely with one thing. I now suggest to keep shooting till the animal is down. If it goes another 100 yards no big deal. But as a guide I've seen what looked like perfect shots get up and walk off to create mess. One deer that was a double main frame walked away after I saw the round go where it was supposed to. Only thing is is deflected off a rib and went on another not so nice path.(small bullet/caliber). After taking almost 22 hours to find the deer(long story) I now shoot till they are dead, regardless of what I know or think I know.

Other than that I can almost agree on both sides of everything. Though I'll stick with a larger frontal diameter nowdays, given the choice, on larger game.

But that 7 Allen sounds awful good for long deer shoots. Wonder if it can fit in my 70 Long Action?

Just gotta find funds somewhere and with family health issues now it seems like the safe will stay locked even longer.....

Jeff

 

[rblum]

A 30-06 is fine, if you REALLY must use a cannon, then consider a .300 win mag. Try to sneak within 250 yards of the elk. C'est voila, a dead elk. Pass on shots greater than 300 yards. That should work.

 

[Fiftydriver]

Rost495,

As long as we get our critters killed quickly that is the only thing that matters in my opinion.

I do not feel the M70 is a good option for the 7mm Allen Mag. The bolt locking lug on the extractor side is just to small for this very large case head. I would only recommend Rem 700s, Wby MkV or the big Sakos for factory options with this new magnum.

Good SHooting!!

Kirby Allen(50)

 

[Brent]

I would feel much more comfortable using a .338 300gr SMK on an Elk than a 200gr 7mm, at any range... but maybe that's just me. That is not saying I would NOT use a 7mm, just what my preference would be... The higher SD goes to the .338 300gr as well, more of an "apples to apples" comparison.

Kirby,
What length barrel are you looking to achieve 3200 in with the 200gr bullet?

What do you think you'd get for speed in a 30" bbl with that bullet by necking down and improving the 30/378 Wby case? I think it's going to take about that much case capacity myself, because I do know the 338 Lapua case with it's internal capacity does have it's limitations, as does the Ultra Mag case. Because of this I'll be doing some testing this fall on a several LR cartridges based off the .416 Rigby case, and the .408 CT case. Testing will include 7mm, .308 and .338 as the initial reamers are both in 7mm. I am designing and will be manufacturing a center feed 5rd. drop box magazine (internal length of 4.0") along with matching bottom metal for the Rem. 700, which will only require little machining to fit the existing BDL.

Efficiency is nice but, more powder will simply have to be burnt to achieve your MV goal at some point, and a longer/larger case will ultimately provide the highest MV, or equal any other but do so with less chamber pressure.

The 338/416 Rigby Imp. pushing a 300gr SMK at 3200-3300 fps in a 36" bbl is probably the pinicle of performance and will take alot to be beat ballistically, save the .50 BMG. The 338/408 CT will be a fun project but it simply will not work in the Rem. 700 action so, the 500 Jeffery case that will may get closer attention even though brass price is much higher than the other two, it does have potential to be king of the hill over the 338/416 Rigby Imp though.

And, I fall into the "really must use a cannon" crowd and I doubt I'd pass on a shot based on distance alone, although I do have my limits, just a bit more than 300 yards. /ubbthreads/images/graemlins/smile.gif

 

[Fiftydriver]

Brent,

Out projections are from a 30" Lilja 3 groove barrel.

The final bullet weight has been set at 210 gr which has a S.D. of .372 compared to the 300 gr 338 bullet at .375 or for all intent and purpose identical to each other. You would just be comparing a B.C. in the high .9 range with the 7mm with one in the high .7 to low .8 range for the 338.

I personally feel the 30-378 is to large for the 7mm bore unless your goign with a 34 to 36" barrel. My 7mm Allen Mag will have noticably more powder capacity then the 7.21 Firebird from Lazzeroni.

You are right the larger the case capacity, the lower your pressures need to be for a certain velocity goal. The problem you run into though with small caliber bores is that with the powders used, you really need to be running at near top pressures to get a clean powder burn.

I have seen this in my 257 Allen Mag with WC872 and AA8700. With top loads if performs very well, with slightly reduced loads it powder fouls severely. IT is really a balancing game between velocity, pressure and fouling.

I am curious to hear what loads you are using in your 338-416 Imp to get 3200 to 3300 fps with a 300 gr bullet in a 36" barrel. My 338 Kahn has significantly more case capacity then the 416 imp version and I am topping out in the 3100 fps range with a 34.5" barrel. The big 338s will gain about 18 fps at most per inch of barrel length past 30" so I would say your loads are pretty hot to reach this level.

I will say that I have heard WC872 is getting higher velocities so until I test that in my Kahn I will take you at your word on the velocities.

I will also say that from a purely Ballistical standpoint, my 257 Allen Mag will out perform teh 338-416 Imp by a fair margin as it will drive a 156 gr bullet to 3300 fps which has a B.C. of .820 and this out of a 30" barrel. This little pill is adding 42 fps per inch of barrel from 26 to 30" as well so with a 36" pipe I would guess 3450 fps would be rather comfortable with the 257 AM. I am trying to talk myself into building a heavy V-Block rifle with this barrel length just to see what it would do but as this is a big game round I really do not want to advertise it as a higher volume long range round as barrel life would be to short for most.

The only place the 50 BMG wins ballistically is in energy of course and wind drift. When the 7mm Allen Mag gets up and running, we are predicting the only edge the big 50 will have is in energy!!

I would be curious about your 338-416 load data as I would like to get this level out of my 338 Kahn(338-378 Wby Imp)

Good Shooting!!

Kirby Allen(50)

 

[257speed]

I side with Kirby on the 338/416 velocity, seems very optomistic. check out: http://viersco.com/ and his 338 sniper-tac (338/408CT) I know him and he is an honest guy and he claims 3350 with the 300gn smk. Thats the one I am interested in. /ubbthreads/images/graemlins/grin.gif

 

[Matt27]

Kirby and 257

Darryl Cassel over on another forum has a 338/416 and is pushing those velocities and he uses WC872 from the posts i have read.

He is over at www.WildcatShooting.com

You might even be able to search here on this forum under his name. Use to post here.

(edited name)

 

[Fiftydriver]

Matt27,

I have hear this with WC872. That is why I ordered 32 lbs of the stuff in the same lot for my Allen Mags as well as the 338 Kahn. I have just not had a chance to run it though the paces yet. Perhaps I need to take a weekend off and test some of my own toys!!!

Thanks for the information!

Kirby Allen(50)

 

[Matt27]

Kirby

Where did you get your WC872? I had a wesite bookmarked but got a new computer and can't find the place again. It had the powder for $50 or $60 per 32 pounds.

 

[Fiftydriver]

Matt,

I went through Jeff at www.gibrass.com

Great stuff, clean, fresh and very professional dealing with him.

This WC872 ran $40 per 8 lb keg. I have used some surplus powder suppliers in the past that had cheaper powder but everytime I got what I paid for. Jeff has my business from now on. For clean reliable powder I will shell out $188 for 32 lbs of powder, that includes all Haz charge and shipping.

Good SHooting!!

Kirby Allen (50)

 

[Brent]

Thanks Kirby.

The .257's BC of .820 is impressive but I wonder how accurate that number is? I know that the 300gr SMK's actual BC is higher than Sierra states, but it's not in the .8's though.

The 3200-3300 fps are numbers quoted many times by Darryl Cassel, as Matt27 said, in what I believe was a 36" K&P barrel. He used WC872 as well. I'm not sure what OAL he used, as it would make a difference.

My brother gets a consistant 3000 fps with 118gr H870 in his 338/378 Wby using the 300gr SMK in a 32" Pac-Nor, his is throated for a 4.1" OAL though, so I'm sure 3100 is possible if your 338 Kahn is an improved version of the 338/378 Wby.

Darryl's 338/416 Rigby Imp. cases that he sent me held 138-140gr of water as I remember, but his case is formed so it has a .400 neck length, which is very long when compared to most other Imp. cartidges. Derrick's 338/378 Wby by comparison held 132gr water.

In comparison the 408 CT cases I checked held about 165gr water.

The 500 Jeffery was about 145gr water (that measurement is a bit foggy but close). I'll have to check a few again.

The .257 pill with the .820 BC, what length is it and what twist do use it in sucessfully?

 

[Brent]

I have not chambered the 338/416 Rigby Imp. yet. The beltless Rigby case is a superior design to the 338/378's belted case, tis why I'm using it, that and it will offer a bit more case capacity as well.

What's the water capacity of the 338 Kahn?

 

[Brent]

257,

Dave is an honest guy and yes he gets 3350 and at 3400 pressure signs start, quite awesome numbers! Speed with the 250gr SMK was 3750 but was too hot. 200gr BT's run at 3700 very accurately, about 1/3 MOA. I think Dave's using a 35" bbl on it.

 

[Matt27]

Thanks Kirby.

I just found his site last night searching.