Home Forums Hunting & Shooting Custom Rifles & Wildcats Big .270's...

So I have a Sako/MRI (L691 action) rifle in .270 Win. It has a #4 Krieger and nice McMillan. Since I already have two other .270's and no one wants to buy this one, I'm, thinking about making it into a .270 STW or .270 UltraCat (.338 RUM case). It has a 1/10 twist so I'll stick with 150gr Bergers...

Does anyone have any experience with a big .270 wildcat round?

I think you will need a magnum bolt face.

Dink

Yup need a magnum boltface. The 270/7RUM is easier to prep brass. One pass through a 7RUM redding bushing die, with the appropriate sized bushing and your done.

Yup, should be able to open up the bolt to a magnum though.

EddyBo, didn't think about that one, does anyone have a reamer for it? Dies? The .270 STW I can buy preformed brass from Quality Cartridge...but the UltraCat would be cool since its so different...

270RUM, Wow, that would have to be alittle wicked for long range medium game.

270 RUM, IMHO 1,000 shots or less would be all the best barrels would be good for.

I would dought very much that im the first.But I've never seen anyone else with one.
http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/3584822/1
From what i've seen with the bore scope 1000 rounds is pretty optimistic.
Think of a Briggs and Straton 5 hp cart engine thats built to get 20 hps.
So much fun.
So much power
So much performance.

Such a short life.....
I have to write up this last seasons deer hunting adventures with the 270 STW and I will get around to it.
....Thinking theres a guy on here by the name of Tim in Tenn.That built a 7mm RUM.You might want to do a search.

reading for you....

Ill take speed.

http://www.russellthornberry.com/2010/01/introducing-the-257-ferguson-hot-tamale.html
"Extreme velocity produces some astounding effects that seem to defy physical laws. This was brought to my attention years ago when I read an article in Volume I of P.O. Ackley�s classic �Handbook for Shooters & Reloaders.� Ackley noted that his experience proved that a .220 Swift was the most deadly caliber ever produced for deer and similar-sized game. His book was copyrighted in 1962, but his understanding of the compound effects of extreme velocity remains as true today as it was then.

In addition to some extensive shooting tests on animals, Ackley demonstrated his findings by firing two 48-grain bullets from a 220 Swift into half-inch armor plate on the front of a U.S. Army half-track. He also fired 100-grain bullets from a .270 Winchester and armor-piercing rounds from a government .30-06. All shots were fired from a distance of 30 feet.

The results were amazing. Both of the .220 Swift factory loads penetrated completely through the half-inch armor plate, leaving holes approximately 3/8 inch in diameter. The 100-grain .270 bullets managed no penetration whatsoever, leaving only shiny spots on the armor plate, and the .30-06 armor-piercing bullets made only shallow craters.

Suffice to say Ackley made his point about the compounded effects of hypervelocity (muzzle velocity of 4,00fps or more). His .220 Swift bullets exited the barrel at 4,100 fps, practically the same speed that the 100-grain .257 caliber bullet is leaving Ferguson�s Hot Tamale. That�s twice the bullet weight of the 48-grain .220 bullet at the same devastating speed! Little wonder the animals shot with the Hot Tamale were dropping in a heap.

Another and most important aspect of the effects of hypervelocity on game must be understood in order to fully understand its advantages. Liquid can�t be compressed, so when the force of hypervelocity impacts internal organs, the liquid contained therein becomes a deadly weapon in its own right. It explodes away from the impact with such force that it destroys all in its path. Crossing the 4,000-fps threshold of speed creates such intense hydrostatic shock within the animal that the liquid in its vital organs becomes something of an internal bomb. Magnum velocity of 3,000 fps does not approach this devastating threshold, regardless of bullet weights"




dave

"Crossing the 4,000-fps threshold of speed creates such intense hydrostatic shock within the animal that the liquid in its vital organs becomes something of an internal bomb. Magnum velocity of 3,000 fps does not approach this devastating threshold, regardless of bullet weights"

Last week, I checked out a book about science and physics from the local library. There was a chapter on what happens when a fast moving object contacts a liquid filled container.

As I understand it, sound travels in water at about 2200 FPS. When an object moving over 2200 FPS strikes a liquid filled object, a shock wave is created, destroying everything in it's path. Admittedly, it would be a small path, but that is what we are talking about here.

Since a deer body cavity and heart lung area is filled with blood and soft tissue, I think it would be logical to think of it as liguid fill, and blood is similiear to water.

From reading this chapter, I thought it might be possible that the exact same thing happens when a game animal is struck in the body cavity by a high velocity bullet, and what has been referred to for years as hydrostatic shock is actually a shock wave produced by the more than 2200 FPS bullet.

The faster the bullet, in the case above with the Swift, the larger and more devasting the shock wave.

I read this in a science book, but the shock wave destroying the animal's nerve system and much tissue is my own idea for the explanation of why high velocity os so deadly.

Do any of you who have a knowledge of physics have any thoughts on this? To me, it sounded logical, and might be the answer as to why a very high velocity bullet is so devastating.

How much powder would one need to get 4000fps out of 130gr 270 bullet?

Or 110gr TSX?

Energy = mass x ( velocity squared)/2

Also, while the speed of sound is pretty variable; temp and humidity are very influential variables that have to be taken into consideration when calculating the speed of sound.

Generally, it's more like 1050 ~ 1100 fps.

I have the 270/300RUM reamer.

Most people would not burn them out in a lifetime even if it was the only rifle they owned. Get a 223 for volume shoooting save the overbore hot rods for killing stuff.

I like the wsm round but that's not near as fun!

You might get there with a 338 lapua case if you improved it and lessened the case taper a bit. 270/338LM improved sounds sweet. Maybe with about 100grs of vv570 in a long barrel would get you there. I would go a different direction and shoot the highest BC bullet I could find, but understand the need for a flat shooting zinger for certian situations.

.....running a 130 TTSX at 3650 does pretty well.
I ran 110g TTSX and 110 GS-HVs at 3850, they work pretty well to.


dave

What is the BC of the GS 110?

There web sight says .375.

dave

hmmmmm.....that would put the smack down on something without dialing. I gotta wonder what the max point blank range on that would be. Not wondering enough to get my phone or go to my shop computer, but I might have to check that out later.

I have been thinking of building a short range laser for the rut here. I hunt a lot of logging roads where my longest shots are in the 500 range but there is not a lot of time for sight adjustment.

Have you checked the mid-range rise at say 200-225 yards. Let me know. THX
RinB
........................
2 inches high at 100 yards.
3 inches high at 200 yards.
1.5 inches high at 300 yards.
5 inches low at 400 yards.
Thats how I had it set up for my hunting.Distances were all lazered with Geovids.I shot a nice 2 inch 3 shot group at 300 yards just before season.






I switched things up this year and ran a 130 TTSX.If anything is shot flatter than the 110g GS-HV.
It kicked more to.....But that was to be expected.
Freaken thing is LOUD.I have a 300 WM with a break and its louder than that.
I consider the whole project an expermint.I like playing around with stuff thats different and there just arn't that many 270 STWs around.
It does put the smack down on everything I've hit with it so far.Very impressive.
.........So tell me about this 270/300 Rum reamer?You planning on usuing it?
Or are you thinking STW sized?

dave

How about a trade for a Tikka T3 270 WSM, if you want a big 270? PM me if you'd like more detail.