Hi all, I've been reading through tons of posts and haven't really found what I'm looking for...
I'm new to stalking, been a few times and used and estate rifle but am looking to put in for a variation so I can get my own.
It seems .270 .. 6.5CR .. .308 are the most common (from the dozens of posts I've read) but what I would like is a compact/short/light rifle as don't spend time in a high seat, I'm walking for hours.
I like the idea of the flat shooting, low recoil 6.5 but how short can you go in the barrel?
I've seen plenty of posts about 18 or even 16inch 308 but then you have the loopy trajectory which is like the avoid.
Then there's the 270 which I have been using and although I'm not fussed about a bit of recoil as I've only taken 4 shots max on a day, it would be nice to keep the animal in the scope once I've pulled the trigger.
So any advice on calibre / barrel length / make and model suggestions based on the above?
Thanks
Welcome to the world of ballistics, and everybody will give you their own view. But look at the physics first. Velocity at the Muzzle is a function of the force on the bullet over a period of time and length of the barrel. Force provides the accelaration, and accelaration over a period of time gives the muzzle velocity. The period of time is determined by the barrel length and how quickly the bullet accelerates. A longer barrel gives more time for the bullet to accelarate - all other things being equal. So any rifle, using the same ammunition will have a higher muzzle velocity with a longer barrel than a shorter one. In the same cartridge lighter bullets tend to accerate faster than heavier ones..
The force is produced by pressure from the powder burning. Typically pressures in most centrefire deer legal cartridges are about 60,000 pounds per square inch (give or take a few thousand. The pressure is acting on the base of the bullet - this a function of the base area which is Pi x Radius squared. Thus a .243 has a base area of .0.059xPi sq in, whereas a .308 is 0.094xPi sq in. So in a 308 there is more force on the base of the bullet compared to the 243. You also need to take into account the friction of the bullet against the walls of the barrel and this to is a function of the radius of the bore x length of the contact area of the bullet with the bore. Light for calibre bullets will be shorter than heavier for calibre bullets, and thus velocities tend be higher.
Finally you need to consider the powder burn rate. To maximise velocity you need choose a powder which will have a burn rate so that it continues to have positive pressure on the base of the bullet rigth to the end of the barrel, at which point the powder is pretty much used up. Most factory ammunition, and most reloading manuals are based on 22 to 26" barrel lengths, with any thing shorter, the powder used burns too slowly to be completely burnt before the bullet leaves the muzzle ( hence why short barrels are bloody noisy and have huge muzzle flash).
So all things being equal, a bigger bore diameter is easier to get higher velocities than smaller bores, or from cartridges with a large volume of powder. There is a very good reason why likes of 22-250s, 243s, 270s, 300 win mags etc tended to have 24 to 26" barrels. You choose those cartridges because you want velocity for flat shooting.
If you want fast shooting out of a short barrel then a larger bore diameter with light for calibre bullets will get the initial velocity. If you take the 308 based family of cartridges, they all use pretty much the same weight of powder. A 243 will spit out a 100gn bullet at about 3,000 fps, but a 308 can send a 120gn bullet at about 3,100 fps given similar length of barrels.
So if you want a shorter barrel then a larger diameter bore is a good thing.
But, and this very big but, the handiness of a rifle is much much more that barrel length, stock length etc. It is all about weight of barrel, and the stock and how it balances and feels. Last year at the stalking show I picked up a Bergara B13 single shot with 14" thick chunky barrel. This combined with a heavy stainless action and very light synthetic stock made a rifle with all the ergomics of a dumpbell. Contrast that to carrying a fine well balanced shotgun with 28 or 30" barrels - the same overall length as a typical rifle with 24" barrel.
I would go for a normal sporter weight barrel of 20 to 22" long and fit it with a lighweight over barrel moderator that doesn't extend more 4" from the muzzle.
The other real issue with most rifles is the position of the front sling stud on the stock. If you want a nicely balanced rifle for carrying over the shoulder, then use a barrel band on the barrel. Every one will now start shouting that this ruins accuracy. It does if you keep it tight when shooting, it doesnt if you keep it nice and loose.
As for flat shooting - in deer stalking distances -say to 250m, velocity is key to flat shooting. Cartridges such as the 6.5 CM shoot long highly aerodynamic bullets, but at moderatye velocity. They retain their velocity very well, but this is on the 1000m target shooting type distances. But inside 250m, a short light 110gn .308 bullet leaving the muzzle at about 3000 fps will shoot flatter than a 140gn at 2600 fps. Downside of short flat bullets - such as the .308 120gn, is that past 250m they start shedding velocity fast, and thus start dropping quickly. A long 308 bullet will fly just as flat as 140gn 6.5 CM over 1,000m, but it needs to weigh 165 to 180 gn, and the 308 case doesnt really have enough powder, so you need to step up to 30-06, 300 magnum tyoe cartridges.
Don't be in a rush to buy the first rifle you see. Get out stalking with friends or guides and use their rifles. See what you like, see what you don't. I always wanted a stutzen. Then I have shot them - horriible noisy, poorly balanced, kicky nasty little things.
