.260 rem, ... 20" or 22' ?

[bluealtered]

Let me throw this one at you, my current .260 is in a 24" 8 twist and i love it. It's also heavy enough that i just use it for bench work.

I love the .260 caliber and am putting one together for a carry hunting rifle, it will be an 8 twist as well and either a sporter or maybe a heavy sporter. I will be using H4350 and starting with hornady 140gr sst's. I also hunt mostly in heavy timber and heavy brush which is why i considering the 20" barrel over the 22". The shots will anywhere from 20' to maybe 400yds.

So the question is, will that 2" really matter ? It will be 140gr no matter what since some of those 20' shots are for bear. Thanks for any thoughts on this, blue.

 

[watercam]

If you figure roughly 25 fps per inch we're only talking 50 fps.. From a 24" barrel you are down 100 fps overall. Use a streamlined bullet if you are really trying for bear at 400 yards though - seems a stretch. I call my son's 6.5x55 a 300 yard gun for game with 130 gr. TSXs @ 2800 fps. His barrel is a 23" #2 Shilen which remains our most accurate rifle match or hunting.
Have fun!

 

[2644ever]

20"? Don't. The blast and the fireball will be fierce, to put it mildly. You might get away with it up to a point by keeping that tube no shorter than 23" and sticking to H4350 or better yet N150.

 

[ktoney]

I run a 20" 6.5x47
123 scenars @2900fps

So yes 260 will work at 20"
No you wont have a fireball on every shot

123Amax would be my bullet of choice
great on paper n game

for hunting/practical rifles 18-22" barrels are perfect
I have zero issues shooting steel @ 1k

 

[2644ever]

Been there, done that : You'll get around 2750 fps with a 123 grainer.
You will also get 11,000psi of pressure at the muzzle and you'll only burn 88% of the powder.
Of course you may choose to call the resulting blast and fireball different names, like "hearing enhancer" and "safety light", but they will still be there.
The 6.5x47 L is not a .260 Rem.

 

[ktoney]

Hmmm
Your right x47 is not a 260...its far better

my setup works like a champ

I know several who shoot 18" barreled 260 with no ill effect

but then they were shooting 139scenars @1k

 

[2644ever]

I know several who shoot 18" barreled 260 with no ill effect
but then they were shooting 139scenars @1k

I agree with you on this last one, the bullet weight makes a huge difference in combustion.
With 37.5 grains of N150 and a molycoated 139 scenar grainer, you'll burn 100% of the powder in the first 10" of barrel.

 

[DanCarey]

"you'll burn 100% of the powder in the first 10" of barrel."

I don't think so. You may peak the pressure at a few inches from the throat of the chamber, and even have all the powder on fire, but in a 260 case you will need a lot more length to burn all the powder 100%. Burning the powder 100% would mean the fire is out and you would not see any flash. Even when all the powder is burning, you have pressure enough left to keep moving the bullet faster. The statement of burning all the powder is just a figure of speech.

 

[2644ever]

I know you'll still see some sort of flash even with 8 grains of Unique, because I tried it, but I know all that powder has already burnt in the first 3" of the barrel. Total combustion and gas expansion are 2 different topics, and it is a fact that there will still be some acceleration of the bullet in a longer barrel (up to a point, of course).
Same with the .22lr in a pistol and in a rifle: there's no question the powder burns in the first inches in both barrels but that you gain some speed with the longer barrel until you reach 15". And in both cases, you might see some light in total darkness...
In my statements, I rely on various softwares like Quickload and LFD plus some experimental stuff that makes the same kind of complex calculus. When I switch to the experimental phase, I've yet to be deeply misled or disappointed.
Bluealtered, do what suits you best. But remember to experiment first.Try 23" first, in field conditions, just before twilight and forget your hearing protectors. See (and hear) if you can live with the results and decide whether it's worth cutting 2 more inches. Always keep in mind you cannot put those inches back.

 

[bluealtered]

Guys thanks for your help and insight here. I don't hunt bear at 400yds, it's simply something that sometimes happens at very close range since i am a predator hunter in heavy brush, most times i can simply let the bear go on his way.

Most of my hunting rifles are 22" and in the 308 family so i have an idea of what the flash/blast is for that group, i do also use a tactical .308 thats 20" and yes it can make a great "nitelight". I have also run across the barrel length question while using the 6.8spc cartridge and found that using H322 works very well in the short barrel, (16-18") of the 6.8. It is quite possible i will end up using another powder/bullet combo for this .260, but to start i would like to simply use what i have at hand. (H4350)

The replies you have given me help quite a bit in choosing the barrel for this rifle, (.260) any more thoughts will help even more. Thanks, blue.

 

[65BR]

For me, 22-23 is perfect for a hunting 6.5mm, unless in a Grendel or BR sized round.

Blast is as much a reason for my choice. Ballistically, all will work if a good bullet hits vitals....

I simply enjoy shooting alot, and once a bbl gets on the real short side of the spectrum, blast takes the fun out of it.

 

[Pendragon]

Let me throw this one at you, my current .260 is in a 24" 8 twist and i love it. It's also heavy enough that i just use it for bench work.

I love the .260 caliber and am putting one together for a carry hunting rifle, it will be an 8 twist as well and either a sporter or maybe a heavy sporter. I will be using H4350 and starting with hornady 140gr sst's. I also hunt mostly in heavy timber and heavy brush which is why i considering the 20" barrel over the 22". The shots will anywhere from 20' to maybe 400yds.

So the question is, will that 2" really matter ? It will be 140gr no matter what since some of those 20' shots are for bear. Thanks for any thoughts on this, blue.

Here's a different thought. Try a #4 contour barrel (or even a 3 1/2) at 24 inches. That should be nice and light and, if you find it cumbersome, you can always shorten it later.

I have shot a number of 24-26 inch barrels with the 260 and 6.5x47. Anyone who is telling you that all the powder is burned and there is no muzzle pressure with a short barrel has probably already lost their hearing. It simply is not so.

One of the effects of "muzzle blast" is an increase in perceived recoil.

H4350 has performed well for me with bullets in the weight range you are considering. I like the 260, but I am not too sure about intentionally hunting bear with it, though I am not a bear hunter.