300 WSM bullet choice - T3 Lite

[DDB TX]

Greetings, my first post, been lurking for a while and now here I go. Pardon any newbyitis.

I am a lifelong hunter, but only for texas whitetails mainly, until 2 years ago when I went on my first elk hunt. To honor the horseback Frank Church trip and the game, I bought a Tikka T3 Lite in 300 WSM and began load development. I narrowed down to the Nosler Protected Point in 180 grains.

Since then I have read a lot about the Optimal Barrel Time stuff, have the calculators for OBT, and have been using Quickload to help plan loads in some ordinary and some weird rounds (30-25 WSSM). OBT works a charm in getting you to accuracy nodes, in my experience. Once in the region I do OCW to narrow it down to tack driver.

Now I have another Trip of a Lifetime planned, for elk again. So I was revisiting my old stuff, and noticed the OBT for the Tikka's 24.375 inch barrel were way below the max load shooting 180 grain pills. ALL of them. The gun was only accurate to my standards with about factory load velocities of 2950 fps.

On a whim I plugged in 165 grain TTSXs and Partitions and Accubonds to Quickload, using RL 17. Much to my surprise I found that the programs predicted i could step up the 165s to the node (in OBT terms) that the 180s could not hit and still be 2000 - 3000 psi below max.

In plain terms, it looks like I can take the muzzle energy of a 165 to around 3850 ft-lbs / 3250 fps, and be safe, where the 180s would only reach 3500 ft-lbs/ 2950 fps or so while still in an accuracy node. 300 ft-lbs seems like a lot of advantage. With the accubond for example, that increased the magic 2400 fps hydrostatic shock theshold from high 300 yard territory for the 180 grainer to over 450 yards with the 165. I am a big fan of hydrostatic shock to bring game down fast.

Though I will try and remaster the 400 plus range before the hunt, I don't plan on shooting much further than that.

So my question is, are the 165 grain TTSX, Partitions and Accubonds (et cetera) excellent for a rapid kill of bull elk at those ranges/ velocities? Or should I stick with my 180s?

Great site here, and I appreciate all you all have taught me.

 

[cohunter14]

Everyone is entitled to their own opinion, but mine is that you should shoot at least a 180gr pill for elk, if not more. Plug your rounds into a ballistic calculator and you will see that those 165gr rounds lose their energy a lot quicker than the heavier bullet. If 400 yards is your max, I am sure that the 165's can do the trick, but if it were me I would be looking at something heavier that will maintain the energy down range.

 

[cohunter14]

After looking at the numbers in the ballistic calc, the energy at 400 yards is going to be very similar between the 165, 180, and a 200gr round. It is further down range that you start to see a difference. As I said, anything will work, but if it were me I would be loading up the heavier round. Good luck which ever route you decide to go!

 

[luke]

If it were my hunt I would use 180-190gr for under 500 yards. Past that I would use 200-210. I shot a cow elk in the neck at the base of her head a few years ago with a 165gr gameking at about 80yards.The bullet exploded on impact. There was no exit only a hole about 6" round and in the middle of the nasty carnage was a frag of bullet about 25-30 grains. Didnt kill her either when I got to her she was tossing her head around. For close up (out to 500yards) I would use the barnes berger or accubond. Farther out I would opt for the berger.

 

[MontanaRifleman]

I have shot 180 E-Tips 3200 fps plus safely with RL17 out of my Sako M85 Finnlight 300 WSM. If I was not going to shoot farther than 500 yds, that would be my choice of bullet. Most any other bullet will do the job but I would recommend 180 or higher for elk for insurance.

I am not familiar with the OBT concept, but I would say there are a lot of factors that affect barrel harmonics and would be a little skeptical if they could all be charted for all the possible combos.

If you are not going to shoot beyond 500 yds, then 1 MOA accuracy is all you really need.

Hope you have a great trip and hunt in the Frank Church

 

[DDB TX]

Thanks, gents for the replies! I appreciate your input.

Mark, the OBT or Optimum Barrel Time calculation is based on the fact that upon cartridge ignition, a shockwave runs up and down the barrel at the speed of sound in steel, which is very, very fast, like 22,000 fps if I recall. Whenever the shockwave gets to the muzzle, the muzzle vibrates a little, which opens your group up if the bullet is exiting then. The speed of sound in steel is so great that you can get 2, 3 even 5 times where the muzzle is vibrating from that shockwave, before the bullet leaves. So you try to find a powder load that gives the bullet a barrel travel time which hits the "node" when that shock wave is as far from the muzzle as possible.
In the Quickload program, one thing that is calculated for you is the barrel travel time for each powder and bullet and barrel length you select.
There are a number of ways to address this shockwave effect and get the effect lessened, like those Limbsaver rubber things. The BOSS system is another way to tune your barrel to a particular powder by changing the effect of the shock wave. Basically if you can dampen the vibrations your rifle will "like" a broader range of loads.
Old school fine rifles used to have the barrels bedded pretty firmly in felt, to dampen these vibrations too. I don't know if the old timers knew why it worked, they just knew it worked.
It is why some powder types shoot better than others even though the velocities are similar. A hotter powder seems to have a shorter barrel time with the same muzzle velocity.
It is also why often you need to back off from max load to get best accuracy. In my Tikka, for example, a max load 180 Partition PP is not accurate because it is leaving the barrel while that harmonic is at the muzzle. I have to back it down quite a bit for best accuracy. But those 165s look like they will get out fast enough (barely) using RL 17 to hit the next node.
If you are interested I have a link to the website of the guy who published his research on this, and an Excel calculator for barrel lengths and their best OBT.
Barrel diameter doesnt matter either, though stiffer (thicker) barrels have less of an unstable spot because of their stiffness.
I've found in real life using the calculator and QL and a chrony that it is remarkably accurate at getting you within a half grain of the best accuracy with a given powder, bullet and barrel. Then I do a ladder or OCW to find the absolute best, and hope the temperature etc is close to the same when I go hunting ...
Luke, I would not think a Game King would be a good bullet to shoot super fast at short range at a big animal. What cartridge was it in? A 165 GK hot loaded in a 300 WSM or 300 Mag ought to be going about 3100 fps at 80 yards, that is a lot of terminal energy for that bullet I would think. It's why I am looking at the tougher bullets for the 165 gr. load.

Like i said, currently 400 is a real long poke for me these days, I am way out of practice. Luckily I live 20 minutes from the BOTW range in Liberty Hill. Looks like i have my work cut out for me, soon as I get that 6.5 lb Tikka braked!! I developed a heck of a flinch working up hot 180 grain partition loads for the last hunt..... 25 or 30 rounds and it was a day....

 

[DDB TX]

Mark, thanks for your answer. I truly respect your opinion and those of the other folks who replied too. I am no doubt over- thinking this, and geeking out about it, but I enjoy this kind of thing, and it helps pass the time waiting for September, 2014!

 

[MontanaRifleman]

DDB, Most welcome and welcome to LRH!

I think you might be overthinking it a little but who knows. Speed of sound is actually closer to 1,100 fps. The pressure and velocity of a particular load of powder and bullet will detrmine the barrel's harmonics and other things that affect the equation are type of brass, primer, bullet seating depth, length of throat, temp to name a few. All these will affect pressure and velocity which can and will affect accuracy and/or POI. This is why I am a little skeptical that a program could account for all these parameters. But if you're having sucess with it, that certainly is interesting.

I have found that heavier, stiffer barrels tend to be less affected by harmonincs or at least that's the impression I have based on my experiences with a couple of Senderos I owned. They shot most everything very well and were not fussy about loads. POI would shift slightly between loads which is a harmonics thing.

The way bedding affects harmonics is to keep it consistent from shot to shot. If your action has stresses on it or shifts around in the stock when fired that will induce inconsistencies. Bedding may be old school but you'll find that almost all precision shooters bed their actions to their stocks. It works.

On bullets, Game Kings should work well (never used them). They are like a lot of cup and core bullets and can be frangible which isn't all bad as they tend to do more damage and probably disable and kill a little quicker. That said, for short range shooting I like something like the E-Tip which is tough and holds together and will do a better job smashing through heavy bone, penetrating deeply and exiting. Partitions used to be my bullet of choice before LR hunting and i killed a lot of critters with them but I hated the way their tips deformed in the mag box. They still seemed to shoot well at short range anyway.

Here's some pics of E-Tips I recovered from my 300 RUM behind 400 and 500 yd targets. You'll note they have a flat vs rounded frontal and wide. They were shot into partially frozen gritty ground which is why one is missing part of a petal.

 

[DDB TX]

Mark, thanks for the excellent reply! I know it took a while to create, and I appreciate it.

I was not familiar with the E-tip, and I will definitely be looking into it.

I have shot both the standard 180 grain Partition Soft Point and the 180 grain Partition Protected Point. The 180 gr. Protected Point was designed to address the problem of tip deformation in magnum magazines which you spoke of. But it has a lot lower BC, only .361 compared to the regular partition's .474. It has a slightly more forward bulge to its ogive, different profile, and a flatter tip.

Left to right, the Partition Protected Point next to a regular Partition, and a regular Partition that has been through the recoil of my rifle in its (plastic!) magazine, and has its tip all smeared around.


The felt bedding I was referring to was actually bedding in forends which firmly touched the barrel, not action bedding. I've seen some old english rifles with it, and my old Ruger M77 has some felt between the forend and the barrel too. I think its purpose was to dampen those waves, which are probably the same thing as what you are calling the harmonics.

THe Quickload program actually allows you to change its default value for pretty much everything - such things as case capacity, cartridge COAL, bullet length, etc. So, if you change brass and the lapua has 2 grains more case capacity, you can change that value. There is even a sort of "fudge factor" you can play with to adjust the program's predictions to the actual range performance you are getting. You can even modify the powder data files with all sorts of exotic stuff dealing with burn rate and several other factors. It was written by a German powder engineer and was originally for modeling new light antiaircraft cannon shells! It has preset data (which can be modified) for every bullet i have ever looked for, literally hundreds of bullets from every makerr you ahve ever heard of and a few you havent; about 200 cartridge files preset for COAL, case capacity, max. pressure, etc; and data for every powder made in the world. It is really remarkable what you can do with it.
For example, when I was wildcatting the .30-25 WSSM, I actually modified the 25 WSSM data file to handle a .308 bullet, with same COAL and correct shoulder angle and neck length for my chamber. I got .30-06 +P velocities with short to medium length bullets up to 180 grain, out of an AR15 lower. It was a heck of a learning experience! There was literally zero data for this wildcat so I had to start from scratch, measuring case capacity after modifying cases, that sort of thing. But the program took me right to the sweet spots. (until the weather got to 105 degrees at the range. That really messed with powder burn rates!)

Science commercial: Believe it or not, the speed of sound varies with the medium it is passing through. In air at sea level with humidity at 70% it is 1100 or so fps. At altitude it is lower. In water it is vastly different, as it is in rock, steel, glass etc.

Whatever, it doesn't matter whether it is a speed of sound in steel shockwave or harmonics or little elves with hammers that make there be accuracy nodes in a given powder/bullet/barrel/temperature setup; what matters is the OBT calculator can direct you to the barrel time best suited for your barrel length, and then QL can give you a range of powders to get there, within safe limits.

Of course so can shooting a ladder, or better yet the Optimal Charge Weight method, which takes into account barrel heating as you go through the test better. A lot easier than all the tech stuff I play with as well! But it keeps me off the streets....

Again my thanks for the tip about E-Tips, and for your advice.

-David

 

[MontanaRifleman]

David,

You're right about the speed of sound in different mediums. Didn't think of it as I usually think of it in terms of Mach and atmosphere.

Also glossed ovwer the :barrels" part of the bedding you mentioned, and I have heard of different techniques of bedding barrels or putting pressure points on them to modify the harmonics or vibrations for better accuracy and consistency. I tend to shy away from that as I think that environmental conditions could affect the fore end of the stock and cause inconsistencies in the pressure it puts on the barrel. I have heard it has been used successfully sometimes and I have heard that putting a shim or wrapping the barrel with tape for contact will sometimes correct a poor shooting barrel.

The Quickload program does sound interesting.. still a little skeptical but I might try it someday. For you, I would dismiss the 180's at higher velocities because the program suggests they won't work. I think they are worth giving a try but that's your call and there isn't a lot of difference between 165 and 180.

You mentioned KE as part of your critieria for choosing. I think it can be a little missleading because velocity (squared) is is a much more significant part of the equation than mass. I put a little more weight on momentum than KE.

For short range hunting (less than 500 yds), E-Tips are my first choice because of their tough construction. They are made of guilded metal which is tougher than the copper Barnes mono's. When they expand they produce a wide flat frontal than any other bullets I know, which produces more shock, trauma and a wider wound channel. And comparing to the Partitions, they have a tough trauma resistant tip and higher BC.

For LR work, my 2 first choices are Cutting Edge and Berger bullets for BC and down range expansion. I'll shoot whichever one of those i think will give me best overall down range results with emphasis on accuracy.

Keep us posted on your progress.

Cheers

 

[DDB TX]

Thanks for the answers, Mark. Will do!


-David