Thread: Difference for velocity and range - 20.4" vs 22.4" barrel - 7mm 08

Just a noob question re barrel lengths and the effectivness while deer hunting at range.

Both would have cans on.

Would there be much difference in velocity (and other releavnt ballistics for hunting) and distance and accuracy of shooting, with a 2" shorter barrel as above?

Also with a 7mm 08 calibre, what are some throughts on effective distance in metres for deer hunting?

TIA

My guess is circa 100fps loss, as per effective distance depends if you follow the rough plan of foot pounds of energy general rule.....im not going to open that can any further....but you would be looking like 500 to 600 depending on a bunch of factors....others will stretch it futther and then it comes down to ethical kills.

Get ya popcorn ready

Hamish

Without being too dogmatic, here is some info that may help…

I chopped 3” and lost 90fps. So roughly 30fps per inch could be expected.

For reference:

In your 22inch barrel you should expect sako 140gn factory ammo to be about 2700ish

In your 22inch barrel, Hornady precision hunter 150gn will likely be high 2600fps - low 2700

With regard to hunting distances - your skill is the limiting factor not the cartridge. If wanting to shoot in that 300 -500m zone I would strongly encourage you to read the 223 thread on here before selecting a projectile. Buy lots of ammo and learn how you rifle performs at distance on steel before you push things out in the field.

It is possible to effectively kill deer at 600m with a 16 inch barreled 7mm08. It requires the right skill, knowledge and bullet. If you don't wish to push that limit, you'll be fine with any barrel length.

The truth is some rifles in the same chambering, even in the same model, are faster than others, tighter bores, looser chambers, deeper rifling, less or more freebore, so it depends. The short barrel might even go faster by a few feet than the 22 inch barrel! You wont know till you test them with a Chronograph.
But all thing being equal, you will lose about about 50 or 60 fps for two inches shorter. (But again, your 20' barrelled rifle may be much slower than general, you might be shooting 150 fps less in the 20 inch barrel than the 22 inch.) Rifles are individuals.

In my 7mm08, I have a 19 inch barrel, and Winchester 140g factory goes 2650 fps. I am sure it will kill deer I suppose, but I dont like things that don't perform as well as they can, so I have loaded it with 139 grain bullets with 2209 powder and I have it now at 2765 fps, which is about what the old 7x57 used to do for the last hundred years or more. Probably will work. (At normal ranges for deer hunting, I am sure the difference between these will be unmeasurable, but it makes me feel better. If we didn't care at all about velocity we would all be shooting cast lead out of an ancient .44-40. (Umm, which I do, as well..))

As for range, with a standard 3-9 power scope and a 140 grain bullet going 2700 fps, you are good out to 300 metres if you are happy you can shoot that well and understand where your rifle is sighted in where its hitting at that range.

If you would like to shoot further than that you will have to get a better scope and learn what MOA means and get a rangefnder and a kestrel and learn about the corealis effect and study the touch of wind on the shape of bullets. This is, of course, magic masquerading as ballistics. Worse than that, you will have to learn to shoot prone, the most uncomfortable and unproductive position for hunting ever proposed and one to be avoided at all costs. You are lost the day you purchase a bipod. Good luck shooting through tussock grass.

Personally, I find it a lot easier to just sneak up on them on the edge of a clearing and whack one shooting offhand at 80 metres. They are much easier to find afterwards.

To summarise: a 140 grain 7mm bullet at around 2700 fps will do anything you might wish of a 7mm08.

Originally Posted by Mrfants

Just a noob question re barrel lengths and the effectivness while deer hunting at range.

Both would have cans on.

Would there be much difference in velocity (and other releavnt ballistics for hunting) and distance and accuracy of shooting, with a 2" shorter barrel as above?

Also with a 7mm 08 calibre, what are some throughts on effective distance in metres for deer hunting?

TIA

Greetings @Mrfants,
From my own chronographing I would expect around 2750 fps from a 20.5 inch barrel with 140 grain Interlocks or similar. The loss from the 20.5 inch from the 22.5 inch would be around 25 fps per inch or 50 fps total. Difference in performance would be theoretical rather than real.
Regards GPM.

From memory a survey by deerstalkers a few years ago showed that 80 % of deer were shot at under 100 meters and only 5% at over 300. Stick with the percentages. I've never shot one at over 350 m, had plenty of opportunities but the recovery would have been too awkward.

To my mind the velocity difference would hardly be noticeable to the majority of sporting shooters. One must remember that maximum velocity doesn’t get you animals, accurate shooting does. As to effective range, that is dictated by rifle accuracy and operator ability. Shooting paper targets or 1 Moa gongs at say 700yds/m will soon tell you whether to attempt deer at that range. As an example I’m happy to take animals out to 400m with my 223/3-9x scope when conditions are in my favour but then again I’ll generally try to get closer if I can even if I’m using my 6.5cm or 308. Also, I’m shooting 1000+ ungulates per year so I have a fair idea what my rifle can do. Get out there and practice. And good luck with your hunting.

Originally Posted by SPEARONZ

Without being too dogmatic, here is some info that may help…

I chopped 3” and lost 90fps. So roughly 30fps per inch could be expected.

For reference:

In your 22inch barrel you should expect sako 140gn factory ammo to be about 2700ish

In your 22inch barrel, Hornady precision hunter 150gn will likely be high 2600fps - low 2700

With regard to hunting distances - your skill is the limiting factor not the cartridge. If wanting to shoot in that 300 -500m zone I would strongly encourage you to read the 223 thread on here before selecting a projectile. Buy lots of ammo and learn how you rifle performs at distance on steel before you push things out in the field.

Great info TY


Sent from my iPhone using Tapatalk

Looking at it for killing power, the App says my 7mm08 bullets slows down by 200 f/s every 100m . So your 2” of barrell is equivalent of about 50m less range as far as lethality is concerned (even if you can hit them just as well).

I havent shot many animals at 300m but those few have been a bit slower to drop at 300 ( 1350 ft.lb ) than they are at 100m ( 2000 ft.lb ).

People talk about 1000 ft.lb being the lower limit for ethical hunting but actually most deer rifles are more than twice that inside 100m.

Sorry its like 30m lethal range reduction.

Went from 22in down to 20in,308.Velocity dropped from 2880ft/s down to 2836 ft/s using Hornady superformance 150ssts.Have shot a few deer around the 250 to 330yds this summer,bang flop.Ssts got the energy at distance.

Originally Posted by Bagheera

People talk about 1000 ft.lb being the lower limit for ethical hunting

People should really stop talking about that, though

Originally Posted by gimp

People should really stop talking about that, though

@gimp do you think ft.lb is not such a good indicator of lethality or do you think 1000 is too high or too low?

Originally Posted by Trout

Went from 22in down to 20in,308.Velocity dropped from 2880ft/s down to 2836 ft/s using Hornady superformance 150ssts.Have shot a few deer around the 250 to 330yds this summer,bang flop.Ssts got the energy at distance.

My rifle is 7mm 08 - is this the ammo youre referring to:

https://ammodirect.co.nz/online-shop...mance-hornady/

Thx