338 thunder project

That math equation is very similar to the one that got the old adage of needing 1k energy to cleanly kill a whitetailed deer many years ago. I have not been able to locate it, but it is very similar.

Ft. Lbs of energy as well as bc are just guides for comparison. BC values are useful for making your drop charts too, but ft. lbs of energy are best used to shoot the bull around campfires. There is no direct correlation between ft lbs of energy and killing game. There are trends, but bullet selection (FMJ vs SMK vs A-FRAME) and more importantly bullet placement are where the focus should be.
 
SW

I am somewhat verbally challenged so I do not always get a good explanation typed up of what I have calculated.

Sorry if I confused you more than explained.

My calculations are about impulse or impact analysis. The mathematical simplification of a bullet striking a bone can be reduced to a momentum calculation.

My post simply says what was the impulse delivered to the shoulder necessary to break through the shoulder bone into the chest cavity. Shawns data falls in line with the other elk shoulder data I have. That is that you need somewhere about 0.75 - 0.9 #-sec with a very hard bullet to break the near shoulder of an elk.

I have used energy as a metric long ago and it failed me when bullet met bone. I do not intend to fail again nor do I intend to deliberately overshoot my gun.

Now then, If you go back into the forum and look at GG shot on the cow elk last year you will find it took about 0.9#-sec to break a shoulder bone - not blade.

Energy is fine for shooting possums but not for breaking bones IMHO.
 
GG I have a question for you.

I am not bringing up any of this stuff about you telling me not to go for 1500 and 2k shots of a bipod, I could really careless. I am wondering about your choice of bullet?

I am just curious as to why you aren't shooting a true heavy for caliber bullet?? why not some of those 300gr smk slugs or the massive 350 wildcat.

Just curious as to why so small a bullet for so long of range.

take it easy
steve
 
Wow, I have been out practicing on the 12" gong at 1150 yards all morning and I come back and there are lots of posts to answer! Great, I will get started typing and hope to answer a few.

Shawn,
THank you for your q's. The main reasons why I didn't choose the 300 grain bullet for this project was because the case capacity is more optimum for the 225-250 weight class as the speed attainable wouldn't be sufficient or better in the time of flight department. I also will most likely be firing this gun from the prone position off bi-pods and the rifle will only weigh about 9 pounds and the recoil of the 300's are a concern. As you know, energy means nothing if you can't place the bullet properly because of a flinch. The third reason I didn't choose the 300 mk to start with was because if I need it, the 338 MOAG shoots these much faster than the thunder will and it can most certainly be utilized if need be. The fourth reason I didn't go with the MK's is because of my own inexperience with them on big game. I use them all the time for vermin, but I will need to test them before I would set up the reamer for them. I have not used the Scenars on game either, but if they fail my phone book tests, I can easily switch to the 225 accubonds because they are so similiarly shaped and I have plenty of personal close and long range big game data with those! I will surely try the 300 grain MK's on the gong with this rifle, but after measuring about a 1000 of them, I must be honest with you. All in all, the 250 Scenars absolutely put the MK's to shame as far as consistency. Of all the hundreds of bullets I have measured over the years, the 300 grain MK is hands down the worst for bearing surface consistency and meplat uniformity and the 250 Scenars are by far the best.

Good to hear about the bull! Sounds like he was dead before he hit the ground.
IF there are any more q's, please feel free to ask! /ubbthreads/images/graemlins/wink.gif





JB,

THat is a perfectly valid question and thanks for asking it. Part of your q can be answered with a little sentence that comes from my earlier post on this thread that a former member of ours unfortunately failed to read. Here it is:

[ QUOTE ]
I don't know if I will actually take a shot at 1 mile, but 1500 should be realistic at some point if the conditions permit!


[/ QUOTE ]


THe conditions will have to be perfect for me to attempt a 1 mile shot-and yes, I will do it from a bi-pod if need be but I would rather strap my varmint rest to my pack frame for a shot like that. The conditions I will need are as follows:

<font color="red"> Early early morning shot before the sun creates mirage. </font>
<font color="blue"> Dead calm conditions- not even a mouse fart can be felt.
</font> <font color="green"> Bedded down elk, or very docile elk that won't move during flight. </font>
<font color="brown"> A totally comfortable and resting heart beat condition on my part. Can't shoot that far if my lungs are going in and out like an accordion trying to play Van Halen's "eruption". </font>

<font color="blue"> And after all that, I will need to have the gut feeling that I can make the shot. If it just isn't my day, it will be a good day for the elk. </font>


The other part of your q can be answered here:
I didn't admonish Lerch about the bi-pod. In fact, if you look back at that thread, I told him I do see the reason behind what he was trying to do. I did however advise him to get a better bench. This is key in my opinion. Better groups come from better benches. Shooting prone off solid mother earth with a bipod would be better than shooting off a rickety bench- but a good bench is still more solid than prone shooting. If this was not so, you and I and the 1k br crowd would be shooting prone instead of off concrete benches. 7mmrhb's wonderful bench is as steady or steadier than a concrete bench in my opinion and I can shoot better groups off it consistently! That being said, I believe in practicing off bi-pods as well to increase one's ability afield.

As far as respecting p-dogs more than elk, I believe I have answered that already. I do not distinguish between the two. THey both deserve a quick kill regardless of who is bigger. AS Yoda says, "judge me by my size do you?"
That being said, a p-dog is definetly harder to hit than an elk as sewwhat89 said.

ANy more q's will be answered if you have them and sorry for the slow response time. /ubbthreads/images/graemlins/wink.gif




Sewwhat89,

Thank you for clearing that up. I have stirred two big pots since being on this forum and neither were my intention and I apologized to all the board users who had to see that crap. Blame it on my 26 year old strong spirit and my college debate classes! /ubbthreads/images/graemlins/shocked.gif /ubbthreads/images/graemlins/wink.gif That was one "A" that I wish would have been a "C" sometimes!



Buffalobob,
Thank you dearly for crunching those numbers for us. I will use them in my project calculation from here on out!




Lerch,
Please understand that I was not harping on you for using the bi-pod. I think that a grand slam earned off a bipod is a grand slam earned indeed.
A 35-55 pound rifle IS the ticket for 2000 yards IMO and it is almost impossible to shoot that kind of weight accurately from a bi-pod. So my suggestion is to start saving up for the proper equipment now so that when the rifle is done, you can start banging away. When the MOAG was first finished, we used the altered varmint rest for awhile and it was "not it" as Uncle B stated later. YOu can see photos of this first try in the original 338 moag pics thread. We had to build and design a much heavier rest with front and rear pedestals to get the strenght and fine adjustment needed for 2k shooting.

ANyway, hope I have been helpful and please fire off a few more q's if you would like and I will try to answer them more quickly next time.

Thanks. GG
 
Here are some pics for those who are interested.



This is a pic of the first 100 pieces of brass finished and waiting to be fireformed. All have had flash holes deburred, primer pockets uniformed, necks turned, case heads squared, inside necks smoothened, FL sized, and polished. It took about 40 hours to get here and they are not even fireformed yet!
100thunders.jpg





Here is a pic of the nasty 338 ultra brass before all the work standing next to a piece that is done. THe group in the background is also done and the group in the left corner are unfinished:
1done1dirty.jpg




This is a pic of the reamer blueprint that Dave Manson sent me:
thunderblueprint.jpg




And finally, here is a pic of the 3 bullets I sawed in half awhile back. l-r 300mk, 250 scenar, 225 accubond:
3bullets.jpg
 
The 3 bullets stack up as follows:

I usually hunt elk at about 9000 ft so everything is calculated for that. All calcs done by Exbal. Please realize also that I don't believe ft/lbs are the sole thing that kills. It is just one way of comparing bullets.

300 mk at 2800 fps at 1500 yds
velo= 1665
tof=2.08 seconds
energy=1846
moa up=41.75


250 scenar @ 3100 fps at 1500 yds:
velo=1756
tof=1.9 seconds
energy=1711
moa up=35.25


225 accubond @3300 fps at 1500 yds:
velo=1638
tof=1.9 second
energy=1341
moa up=34.50



Now at 9000 ft and at 1 mile (1760 yards)

300 mk at 2800 fps
velo=1500
tof=2.57
energy=1499
moa up=53


250 scenar @ 3100 fps
velo=1566
tof=2.4 seconds
energy=1360
moa up=45.75


225 AB at 3300 fps
velo=1422
tof=2.45 seconds
energy=1010
moa up =45.75



As you can see, all three bullets will kill elk AND break the shoulder blade at both distances going solely off kinetic energy which I will say again is not the only thing that kills.

From more than a dozen kills at long range (600 yards to over 1000) I have come up with my own personal theory that it takes only 800 ft/lbs to break the shoulder blade of a full grown elk. THis number has been backed up by other members of the board in their own calculations and one other gun writer that I know of. Given this info, I have deduced that all three bullets should get the job done (if the consruction of them works) at one mile <font color="blue"> <u>IF</u> I choose to shoot that far. </font>
 
That is a pretty sight! Now go shoot them all and get us some results!

FWIW I found this . . .

Ray Romain uses the 250 Gr in his 338/375 (just an improved Weatherby case) Case and has a 34" barrel. We teamed up on a Colorado Mule deer this past season and he got it at <font color="blue"> </font>1800 yards with his rig. The bullet arrived with <font color="blue"> </font> 800 Foot pounds of energy <font color="blue"> </font> and after closer inspection <font color="blue"> </font> penitrated both shoulders and exited the far side. <font color="blue"> </font> The exit hole was very small being about 1" diameter.
 
How would a Tomahawk (RUM IMP) with the 30cal 240 compare at 3100fps -- you'd get better vels, less recoil, and better BC than the 250 Scenar...

JB
 
[ QUOTE ]
And lose all sense of portability in an elk rifle!

[/ QUOTE ]

Huh? How do you figure?? It is the same case, just a smaller, more sleek bullet of similar weight -- back off the trigger mang...
 
[ QUOTE ]
It would be ok, but have much less barrel life.

[/ QUOTE ]

T'aint no free lunch i spose, but why would you even consider barrel life on a big game rifle?
 
nevermind, i guess the cost of the ABS barrel might be the reason...

THough if you are having them do the barrel, are they doing the electroless silicon-something coating on the bore?? It is "supposed" to greatly extend throat life.
 
Yes, I was asked if I wanted that coating and after having similiar coatings done before and not having them make much difference that I could tell, I opted not to do it this time. It can however be put on later in the barrel life if needs be. I might try it then. /ubbthreads/images/graemlins/wink.gif
 
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