7mm-08 and accuracy at dif barrel lengths and velocities.

Mr. Friendly

Mr. Friendly

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my dream rifle is something small and light in 7mm-08. I'm wondering if there are any reports out there on the performance of this cartridge at different barrel length's...from 16" to 20" in light/heavy/bull contours?

I know it may be a lot to ask or expect, but there is a lot of data out there and maybe, just maybe someone, somewhere did this themselves or compiled data they've discovered while roving about the interwebs.

I know this was done in some form for .308 on TheGunBlog...but 7mm-08 is a different cartridge and may behave differently.

If I can find the data, thinking about commissioning a rifle built out of a Forbes but perhaps shortening the barrel while going with a heavier contour and maintaining or lowering the overall weight of the rifle before scope/ammo is added.

why? because of reasons. :)

any help, thoughts, direction or advise to move towards realizing my dream is greatly appreciated. :D
 
The only data I know of and even its subjective, is any more than about 18 inches barrel will not improve accuracy. If your looking for accuracy, machine tolerances and quality of the barrel will have more to do with accuracy than length or contour.
 
By some accounts 20-30 fps per inch and not enough to worry about it. I would stick with a sporter 22" for these reasons: not enough weight loss per inch of barrel to notice, much more noise as you shorten the barrel, and you simply do not need it. When you get a chrony on the accuracy load...you may want to have second thoughts on the performance you are expecting. 22" is as standard barrel length for a reason...it just works.

Now, go and save weight in other areas such as stock materials, rings/bases, scopes, and accessories. The lighter the rifle the more kick. Skinnier barrels may perform differently after 3 shots than others. So what...your best shot is the first one for hunting.
The biggest deal is where you have young ears behind the butt....stick with the standard barrel length...they will thank you later.

So all have trade offs. My 2c.
 
I have a Model 7 SS in 7mm-08, it isn't my most accurate rifle but it holds an inch at 100 if I do my part. It is an excellent little hunting package though, hence it is still in my safe.
 
Hitzy said:
Barrel length has nothing to do with accuracy of the rifle....it affects velocity, but that's it.
Click to expand...

This!! But, in fact, if one is using open sights, then barrel length does have some effect on how accurately the rifle can be shot.
This is because a longer sight radius will make it easier to shoot it accurately. This does NOT indicate the accuracy of the barrel, per se.

If optics are being used, there is absolutely no accuracy advantage in a longer barrel. More velocity yes, accuracy, no.
As a matter of fact, the shorter barrel may be more accurate, due to being slightly stiffer for a given profile.

Regards, Dave.
 
-Savage- said:
Not true.

Longer barrels become 'whippy' and accuracy decreases accordingly.

Shorter barrels (as used in competition shooting, wherein velocity is unimportant) enhance accuracy.
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So a long heavy 30" barrel used for 1000 yard shooting competition that holds 1/2moa or less is less accurate then a 16" heavy barrel that holds 1/2moa or less out to 200 yard competition.....
I think you are confused.
 
Hitzy said:
So a long heavy 30" barrel used for 1000 yard shooting competition that holds 1/2moa or less is less accurate then a 16" heavy barrel that holds 1/2moa or less out to 200 yard competition...
I think you are confused.
Click to expand...
this is my thread, sir, please don't hijack. :HR:

I know barrel length will affect velocity, but a lot of that will also depend on bullet and type of powder used and it's burn rate, so one would obviously match all variables so they work together in harmony, including twist rate, yes?

what about the contour though...18" of light, vs. heavy vs. bull?

as for barrel length and saving weight vs trimming it from other features, can you make a Montana or Forbes lighter than they already are. damned things start at 4.5lbs. however, I'm open to options.

lastly, has anyone here seen, heard or done did change a barrel on a Montana or Forbes? :confused:
 
I have heard/read that optimum barrel length for a 7-08 hunting! rifle would be between 18-20 inches considering rifle weight/cartridge performance ratio. I also believe the 7-08 is overestimated in terms of recoil friendliness for sensitive shooters when loaded to decent game taking powers. The 7-08 has the .308 as parent which has the 30-06 as parent.... So what would be the advantage of this calibre over the parents?

Personally I prefer the originals parents such as 6.5x55 and 8mm Mauser and btw I shot a couple 7-08s and never could tell the difference between it and the .308 out to 300 meters.
 
Following , keen to know some info.
For the Km 84 with 22 inch barrel , as with the 150gr federal blue box it seemed rather 'bang.. thud' at 90-100m.
Vel must be down.
Will check back in shortly

Cheers

WL
 
Hitzy said:
So a long heavy 30" barrel used for 1000 yard shooting competition that holds 1/2moa or less is less accurate then a 16" heavy barrel that holds 1/2moa or less out to 200 yard competition.....
I think you are confused.
Click to expand...

Mr. Friendly said:
this is my thread, sir, please don't hijack.
Click to expand...

Dafuq? He's talking directly about some of the things you asked in the OP :confused:
 
Salty said:
Dafuq? He's talking directly about some of the things you asked in the OP :confused:
Click to expand...
hey Salty, seems we interpreted the response differently. I see it as contradictory in a away that would have opened an argument that has nothing to do with a lightweight rifle in 7mm-08. I cut the possibility off at the knees before it could start by redirecting the subject to the matter at hand. :)

I respect Hitzy for his experience and knowledge, but arguing about long barrels vs shorter barrels for long distance shooting competition has nothing to do with the matter at hand.

thank you for understanding, :)
 
Mr. Friendly said:
hey Salty, seems we interpreted the response differently. I see it as contradictory in a away that would have opened an argument that has nothing to do with a lightweight rifle in 7mm-08. I cut the possibility off at the knees before it could start by redirecting the subject to the matter at hand. :)

I respect Hitzy for his experience and knowledge, but arguing about long barrels vs shorter barrels for long distance shooting competition has nothing to do with the matter at hand.

thank you for understanding, :)
Click to expand...

I was making a point contradicting an erroneous post, but whatever, you believe what you want to, facts seem to go over your head.
 
Barrel length DOES NOT effect accuracy.

The "whip" in a barrel is natural which changes POI according to where the barrel is vibrating during the shot.Consistency is the key to accuracy.Chose the appropriate load and replicate and practice.

7-08 vs 308 vs 30-06 based on recoil is not the same.Light weight rifles kick harder than heavy rifles.Heavier loaded rifles kick harder than lightly loaded rifles , all other factors remaining the same.

Some noticed recoil could be negated by fit of he rifle to the shooter.

A light weight , short rifle doesn't shoot and better or any worse than a heavier longer rifle.

Build the rifle you want and build a load , if going shorter barrel you may want to use a slightly slower power in order to get the most effiecent burn and use of that powder.

7-08 is one of my favorite chamberings.

Decide on what you want to build , built it.

Decide on intended game and choose and appropriate projectile.

Load for accuracy and be done with it.

Factory twist rates in 7-08 seem to in my experience like 140gr projectiles.

The heavy barrel advantage is for target and long shooting sessions , it simply takes longer to over heat.Some rifles may feel a different "balance" due to where the heavier parts if the rifle are.

A quality barrel will shoot accurately no matter the contour.

Some long range shooting can take advantage of a longer barrel because you are getting closer to the target! ;)

Actually some do this just to obtain a particular performance level out of a particular load or bullet.Has no real practical purpose for a hunting rifle.
 
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