The TNT's almost can't be run slow enough to stay together. The RPM is just too high, and you have yourself a scatter-gun. I think Kdub called it a "non-flammable tracer"

 

Thank you Darkker. That is kinda what I was looking for. The "spin factor" is what I was concerned about.

Not looking to run over the posted "speed limit". Just shooting, and having fun.

Cheezywan

 

I did a lot of testing of .277" bullets twenty years ago for Handloader magazine, and at that time the Sierra 110 SP gave the best overall accuracy, averaging under 0.70 moa with five different powders. The little 90HP was a close second although it is really a "short range" bullet due to its poor BC, but it should give good expansion. The 110SP is tough enough to work on smaller big game but reportedly expands enough for varmints. The .277" TNT wasn't around back then but based on experience with it in other calibers it will be rather soft.

Velocities ranged from over 3500 fps with the little 90HP to 3300 fps with the 110SP.



.

 

Noslers Ballistic tip varmint bullets are supposed to hold up to any velocity/rpm and while I haven't shot any in a .270 (don't own one) I have shot the Hornady 110 grain Vmax in my 300RUM for very entertaining results on Pdogs out to an easy 350 yards.

I want to try the Hornady 75 grain Vmax in my 25-06 but had a good buy on 5 boxes of Nosler's 85 grain varmint bullet and they are doing pretty well. Maybe not as entertaining as the 110 Vamx in the 300RUM but still fun to watch. The 110 out of the 300RUM (according to Hornady) is scooting out over 3900 fps, making it just double the energy of a 55 grain Vmax out of a 220 Swift.

I can't see the 110 grain Vmax in .277 caliber going 3900 fps out of a 270 Win.

RJ

 

Noslers Ballistic tip varmint bullets are supposed to hold up to any velocity/rpm

I can't see the 110 grain Vmax in .277 caliber going 3900 fps out of a 270 Win.

RJ

You'd have to dig into the archives a bit, but I did a post on RPM's a couple years ago now.
Don't know how well things "scale", but here are some ideas on RPM.

Soft bullets: SXSP, TNT, Hornets, - @220,000
MOST other bullets - @ 290,000 rpm
HARD bullets, such as Sierra & Nosler varmint - @ 320,000 RPM


**** Updated****

Here is the link:
https://www.shootersforum.com/balli...rum.com/ballistics-internal-external/78073-f-y-i-varmint-bullet-rpm-limits.html


I'm guessing that song would sound like a buzz

 

I scored a partial box of Sierra 90 grainers el-cheapo. Looking at Lyman #49. I have IMR's 4064, 4350, and 4831.
Struggling to decide among them, but it is good to have choices. The fact that Lyman used a universal receiver with a 26 inch pipe does little to help narrow that down. Black powder is the last resort. Wonder if Jack O'Connor ever did that?

Thanks,
Cheezywan

 

I wonder how In-A-Gadda-Da-Vida would sound near that speed? Amazing numbers when you consider rifle twist. Number of turns to impact and stuff.

Cheezywan

 

I wonder how In-A-Gadda-Da-Vida would sound near that speed?

Not to hijack the thread, but it would sound like nothing.

A 33⅓ RPM vinyl record played at 320,000 RPM is 9600 times its original speed. I have software that could theoretically speed up a recording that fast, but no one has audio equipment that could reproduce the sound, and you couldn't hear it anyway.

I believe the lowest note in that song is a C on the bass, which has a base sound frequency of 61.74 Hz. Played at 320,000 RPM, it would change to 592,704 Hz, which is far beyond human hearing.

The version of the song I have is exactly three minutes long. Played at 320,000 RPM, it would last 18.75 milliseconds.

 

Cheezywan: My 270 Sako shoots the usual 130 and 140 270 bullets extremely well, but it sets in the safe not used and neglected most of the time other than Deer Season. Until I tried some Hornady 110gr V-Max Bullets and H-380 powder loaded to about 3100 fps several years ago. With this load, my rifle has turned into a Supreme Coyote Killing Machine that will shoot 3/4 of an inch or less at a hundred yards all day long . Now I will grant you it is not very Fur Friendly at all on Coyotes because it will just about turn a Coyote wrong side out when I hit one of them in the body area with it. And Groundhogs, Rockchucks, Badgers, Jackrabbits and Prairie Dogs really do just turn into a Red Mist when I hit one of them. But You said You just wanted to have some fun with Your 270. Well this is about as much fun as the law will allow without taking Your clothes off. And I sunburn to darn quick and am just to darn old for any of that kind of shooting any more. The 30cal Hornady 110gr V-Max bullets works very well in my Son and I`s 308`s & 30-06`s, but not as well as my 270.
ken

 

It never occurs to most shooters, but if the varmint bullet is spinning too fast out of your rifle, this can be addressed by reducing the velocity a tad.

 

I had a Ruger m77 in .243 and I shot a lot of Hornady 58gr bullets out of it. Everyone was astonished at the accuracy I was getting with those light little pills. The secret was to keep muzzle velocity around 3650 FPS or slower. The advertised max velocity for that bullet in .243 is 3,925fps, only 75fps slower than a 50gr .22-250. But most people are preoccupied with getting bullets to move as fast as possible from whatever they are shooting.

I had laser like accuracy and the 58gr was devastating to small critters all the way out to 350 yards for my furthest shot with it on a prairie dog.

 

True Charles, but in some cases, that isn't possible.
Take the 90gr TNT, unless you have a magically smooth barrel, you would be well below any start speed in the 270, and still be over RPM.

 

That's fine. Is about having fun.
I just happened to flip the page over in Lyman#49. 270 Winchester Short Magnum runs them little bullets around 200 fps faster yet! How do they get a chronograph to read lead vapor?

Cheezywan



Edit 592704 hz. Is in the shortwave broadcast band.

 

I regulary shoot 110gn with all of my .270's (M700, and 2 custom K98/Mcgowans) 1/4" groups at 100yds, decent load of IMR4320. Groundhogs never know what hit them.... I find it a good heavy bullet for windy days, as opposed to 50gn fodder from a 22-250.

 

I hear a lot about bullets turning to vapor or blowing up at high velocities but it rarely happens with good jacketed bullets. Super fast rifling twists can be stressful on thin jackets but 220 swift and 17 Rem magnum already shoot 4000 FPS and the 22/250 is not far behind and they don't vaporize or blow up with good bullets.

 

I can't believe you can "pie" any bullet from a 1:10 twist .270 barrel unless you have a really long barrel. I shot 95 grain Sierra Varminters at about 3550 from a 22" .270. That's 255,600 rpm. I have spun 53 grain vmaxes at 316,000 rpm and not had one pie. But I made sharapnel of some speer 52 grain hollowpoints at around 275,000 rpm.

The formula is (720 x muzzle velocity in fps) / twist

It takes some really high rpm to make a bullet go poof a few feet out the muzzle.

 

I have had one for over 20 years ,,, used reloads and factory rounds... all good ...
This caliber is really flat shooting and I have taken deer at 250+ yds .... Hogs no problem , to hit them in the front shoulder and exits out rear quarter.... leaves gapping holes better than my 308... Mostly I have used the 130 PP Remington... for coyotes, raccoons, etc .... remember when reloading faster isn't better nor more accurate... I have shot hundreds of rounds with the 270... I am confident to use it for my main coyote gun (130 gr) , or on elk , Moose or a bear... It penetrated deep and leaves a wicked wound channel.

 

Somebody mentioned the 110 Sierra's, best bet for accuracy. My brother has used them for pronghorn. I'd go to the 130's for that, but it's great varmint round.

 

This is being way over thought. I use Sierra 90gr hp with H-380 as well as Varget and push them to 3400-3500 fps. They hit with great accuracy. Due to the short bullet they will never be able to be seated very long but this has never been an issue for any 270 I have shot them in.

Forget the talk on RPM, over spin, vaporizing bullets and vinyl records. Just load and shoot. You will be impressed.

 

Was more or less going to do just that. Still enjoy reading the discussion by those that have done it before. Grateful for all the comments.

Cheezywan

 

same old stuff.

I would stick with whatever you normally use for hunting.If you are not worried about the pelt,Using your deer load will just help you be that much better a shot when hunting for meat.

 

This is intended as pure fun with a 270. They sure are short (relatively speaking). I made them near 3.170" COAL with the Sierra 90 grainers. I have not done any shooting as of yet though, doing a few things on the rifle first. I fully expect the charge of IMR-4064 to be exhausted before the bullet takes rifling.

The scope is zeroed for 130 grains. I'll just "learn the load" rather than change that.

Cheezywan

 

Load what ever safe loads sounds like fun and go shooting. Shooting a light weight and high speed varmint load can be fun. Saves you buying a new varmint rifle.