quote:

Originally posted by larrys:
Also Joe, only the foreign made 6.5x55 cases have the different case head diameter. The American cases AND rifles all have the more standard (for America) case head size .473, just like the .308 or 30-06.

So do rifles like the Tikka T3 and CZ that are sold in America use the .479" case-head?

Yes and that's a good thing. Why would anyone want a nonspec chamber in a rifle? The European rifles that have the correct dimensioned chamber that can shoot ALL loads and brass. The American rifles are limited only to .30-06 diameter brass. Not exactly a good situation and nothing to be gained.

I wonder if non-spec .473" case-head brass for the .479" 6.5x55 has a tendency to add 1/2" or more to group sizes? People work hard to get groups down under 1" and even to 1/2". Having a loose rear end for the initial combustion would seem a mite detrimental.

quote:

Originally posted by eagle27:


The 7mm-08 fills the slot between the 243 and 308 very nicely and has all the attributes of the 260, lower recoil and noise, good terminal ballistics, very accurate, etc., but then has better performance and always will have a better range of projectiles.

Nothing wrong with the 260 or any of the 6.5mms if you want one but they all only ever play catch up to the 7mms.

IMO, the 7mm-08 is the perfect medium game cartridge for those that want an efficient package with minimal recoil/muzzle blast.

A modern rendition of the 7 x 57, but when loaded to the same pressure in modern intermediate length M98 bolt actions, the 7 x 57 has the edge by 100fps. I could be wrong, but I think that, unlike the SA M700, the SA M70 is also capable of feeding cartridges of 3" + OAL too.

As far as comparing the 7mm-08 to the 308, the 7mm-08 will out perform the 308 as longer ranges start to favor the better BC (for a given bullet weight range) of the .284" projectiles. The 7mm-08 is the most overall efficient cartridge of the 308 based family.

quote:

Originally posted by wildcat junkie:

quote:

Originally posted by eagle27:


The 7mm-08 fills the slot between the 243 and 308 very nicely and has all the attributes of the 260, lower recoil and noise, good terminal ballistics, very accurate, etc., but then has better performance and always will have a better range of projectiles.

Nothing wrong with the 260 or any of the 6.5mms if you want one but they all only ever play catch up to the 7mms.

IMO, the 7mm-08 is the perfect medium game cartridge for those that want an efficient package with minimal recoil/muzzle blast.

A modern rendition of the 7 x 57, but when loaded to the same pressure in modern intermediate length M98 bolt actions, the 7 x 57 has the edge by 100fps. I could be wrong, but I think that, unlike the SA M700, the SA M70 is also capable of feeding cartridges of 3" + OAL too.

As far as comparing the 7mm-08 to the 308, the 7mm-08 will out perform the 308 as longer ranges start to favor the better BC (for a given bullet weight range) of the .284" projectiles. The 7mm-08 is the most overall efficient cartridge of the 308 based family.

I like the way that you are reasoning and I may have just given a thumb's up.

But I extrapolated a little bit. If we treat 22-24 calibers as the natural domain for varmint and small game, and if we treat 30 caliber as the natural domain for medium calibers after the widespread use of 30 caliber during the first 60-70 years of the last century, then we may come to a different middle node than 7mm.

The middle between 22 and 30 is 26 caliber. And the middle between 24 and 30 is 27 caliber. This can be repeated in millemeters: the difference between 5.6 and 7.6 lands just about on 6.5. And the difference between 6 and 7.6 lands square on 6.8mm (the metrical designation of the 270)!

So in fact, heavy for caliber bullets with high BC's in .264" and .277" are just about exactly what people might want as a light-recoiling compromise.

In another thread we discussed the tendency for people to jump and least 1mm, more commonly 1.5mm or even 2mm when they wanted a significant incremental step up or down in power. The 7-08 is pretty close to the 308 (7.6m), so it seems to sit in the shadow of the 308. that may explain some of the surge of interest in the 6.5/.264". The same argument would lead to a prediction that someone looking for a step up from a 260/270/7mm, might gravitate to a 338 or at least 8mm if they were commonly available. I wouldn't expect many to move from a 270/280 to a 30-06, but they might go to a 30 caliber if they also went up to a 300. Likewise, I wouldn't expect someone with a 7mmMag to switch to a 300 as an incremental increase, though they might naturally be attracted to a 338.

[[A little caveat:
"the 7 x 57 has the edge by 100fps"
Actually, the 7x57 only has an increase in case capacity of 5.25%, which would predict a velocity increase of 1.5%. At velocities in the 2500fps to 3000fps that equates to a velocity increase of . . .
37fps to 45fps. All things equal.]]

Of course, the discussion about significant increments does not apply to the types that just get them all. Me, I just ponder them all, then go back to what I have that is appropriate for the job.

But I might start the grandkids at a different spot.
And the 260, 7-08, and 7x57 (with its more normal casehead than the 6.5x55) would all be excellent stateside candidates as a stouter entry level than the 243 (6mm).

quote:

I wonder if non-spec .473" case-head brass for the .479" 6.5x55 has a tendency to add 1/2" or more to group sizes? People work hard to get groups down under 1" and even to 1/2". Having a loose rear end for the initial combustion would seem a mite detrimental.

It never mattered to my rifle. I have a Win 70 that I stuck a new Douglas barrel on. Before I knew the case head differences, The only thing I found in the Winchester CRF was hard extraction. I found that the case head is the only different dimension. But at that time, I was only using factory ammo.

Since I started reloading for it, I have found it MUCH easier to just use American made cases. Since I never use Lapua or Norma cases for anything else anyway, I am perfectly happy with Remington, which the rifle prefers, Winchester, Federal, Nosler and Hornady. I have since sold all of my S&B and other foreign ammo.

As others have said it is up against, in Yurrup, hard competition from the 6.mm Swedish and other ".260" calibres that have long been popular over here.

But with modern double base powders it maybe has something to offer. But 6.5mm has struggled in the US...remember the 6.5mm Remington Magnum?

I don't quite see what it offers that can't be done as well, if not better, than 7mm-08 or the .257 Roberts.

quote:

I don't quite see what it offers that can't be done as well, if not better, than 7mm-08 or the .257 Roberts.

Well, let's see:
the 243 Win is good
- the 257 Roberts is better
- - the 260 Rem is better
- - - the 7-08 Rem is better
- - - the 7x57 maybe a smidgin better
- - - - the 308 Win is better
That's how it looks if you grab a rifle to walk around in the African bush.


So the 338 WinMag is best?

Think bullets first and headstamps won't matter.

quote:

Well, let's see: The 243 Win is good- the 257 Roberts is better- - the 260 Rem is better- - - the 7-08 Rem is better- - - the 7x57 maybe a smidgin better- - - - the 308 Win is better. That's how it looks if you grab a rifle to walk around in the African bush.

No, not that. It's that the .260 is a niche cartridge. It can do what it does but a 7mm-08 can and go heavier. And a .257 Roberts can go lighter. So it doesn't offer anything that they can't do, and wider than that niche, better. So why would I want a .260 Remington when I can do what it does if I buy a 7mm-08 and yet still have the ability to go two, three, steps on and past that with a step up to 140 grain bullets, 160 grain bullets and 175 grain bullets?


In shot guns it is different. There's a noticeable quarter pound plus difference in weight of the carried gun between a good 16 bore side-by-side and a good 12 bore side-by-side of equal barrel and stock length. If the 16 bore is built, as it should be, on a 16 bore action. As the action and barrels are use measurably less metal. But the weight saved between an equal contour .260 v 7mm-08 barrel is probably not even enough to be noticed on a conventional pounds and ounces set of scales.

quote:

Originally posted by enfieldspares:



In shot guns it is different. There's a noticeable quarter pound plus difference in weight of the carried gun between a good 16 bore side-by-side and a good 12 bore side-by-side of equal barrel and stock length. If the 16 bore is built, as it should be, on a 16 bore action. As the action and barrels are use measurably less metal. But the weight saved between an equal contour .260 v 7mm-08 barrel is probably not even enough to be noticed on a conventional pounds and ounces set of scales.

The 260 will be slightly heavier given an extra .010" barrel wall thickness.

quote:

No, not that. It's that the .260 is a niche cartridge. It can do what it does but a 7mm-08 can and go heavier. And a .257 Roberts can go lighter.

Every cartridge is a niche cartridge. That's the point. The 308 can go heavier than the 7-08, the 260 lighter than the 7-08, etc. etc.

E.g., the 338 Fed can go heavier than the 308.
But at some point a person needs to prop up the case capacity and velocity, resulting in significant weight and recoil increases.

quote:

Originally posted by 416Tanzan:
I wonder if non-spec .473" case-head brass for the .479" 6.5x55 has a tendency to add 1/2" or more to group sizes? People work hard to get groups down under 1" and even to 1/2". Having a loose rear end for the initial combustion would seem a mite detrimental.

Well my plain old Kimber sporterized 96 Mauser will easily shoot inch or less groups all day long with just about any factory ammo I ever tried in it, both foreign and domestic. It really likes the Federal 140 grain blue box loads so I wouldn't worry about it. Those darn Swedes really knew how to build a rifle!

quote:

Originally posted by 416Tanzan:
I wonder if non-spec .473" case-head brass for the .479" 6.5x55 has a tendency to add 1/2" or more to group sizes? People work hard to get groups down under 1" and even to 1/2". Having a loose rear end for the initial combustion would seem a mite detrimental.

If your chamber is snug then, while not ideal, the undersized brass will typically shoot well.

Case in point, I have a .220 Swift that I recently fired some Federal factory loads in. The Federal brass is a full .010" undersized and while firing produced a significant swell, the loads are ridiculously accurate.

In a looser chamber however, the case will sit on the bottom of the chamber causing the bullet to enter the throat at an angle.

One reason to prefer a chamber that has minimal headspace.

quote:

Originally posted by 416Tanzan:

[[A little caveat:
"the 7 x 57 has the edge by 100fps"
Actually, the 7x57 only has an increase in case capacity of 5.25%, which would predict a velocity increase of 1.5%. At velocities in the 2500fps to 3000fps that equates to a velocity increase of . . .
37fps to 45fps. All things equal.

Not sure where you got the 5% difference in case capacity.

Quickload shows 55gr H2O for the 7mm-08 and 59.9gr H20 for the 7 x 57. That's a 9% increase for the 7 x 57.

My own loading bench measurements got 54.2gr H2O for the 7mm-08, 59.7gr H2O for the 7 x 57. A 10% advantage for the 7 x 57.

If we use the QL data that favors the 7mm-08 slightly, and extrapolate your data, that yields a Mv increase of 67 to 81 fps all things being equal.

But they're not equal. If we use SAAMI OAL specs of 2.8" and 3.07" respectively. Employing a Nosler 140gr Ballistic Tip bullet tilts the case capacity advantage for the 7 x 57 to 14%.

Now we have a Mv increase of 103 to 126 fps extrapolating from your data.

Seems the 100 fps advantage for the 7 x 57 is quite conservative.

Hey Wildcat,

I accept your corrections.
And with a 7x57 a person could also load a longer bullet farther forward, since the 2.25" case is often chambered in rifles that could handle a 30-06. It would make it worthwhile to look for a 7x57.

FTR, though, I used AmmoGuide,
with a case capacity of 57.1 gn for the 7x57,
and 55.2gn for the 7-08.
57.1/55.2 = 1.034.
From somewhere else I found a way to give a benefit of the doubt to the 7x57 and went with a 5.25% increase. So the 37-45fps increase still has some support.

But I think that you may be correct with very long bullets like 175 grains. The 7-08 probably loses a greater percentage of capacity and if 14% could be obtained in the 7x57, then a 100fps increase would be fair.

quote:

Originally posted by 416Tanzan:
Hey Wildcat,

I accept your corrections.
And with a 7x57 a person could also load a longer bullet farther forward, since the 2.25" case is often chambered in rifles that could handle a 30-06. It would make it worthwhile to look for a 7x57.


FTR, though, I used AmmoGuide,
with a case capacity of 57.1 gn for the 7x57,
and 55.2gn for the 7-08.
57.1/55.2 = 1.034.
From somewhere else I found a way to give a benefit of the doubt to the 7x57 and went with a 5.25% increase. So the 37-45fps increase still has some support.

But I think that you may be correct with very long bullets like 175 grains. The 7-08 probably loses a greater percentage of capacity and if 14% could be obtained in the 7x57, then a 100fps increase would be fair.

My 7 x 57 Shaw barrel should allow about 3.150" OAL with 140gr Nosler BT bullets.

Since it will be screwed into a circa mid 1960s VZ-500 LT intermediate length M98 action, I have no qualms loading it to the same pressure as the 7mm-08

QL predicts a 51gr load of RL-17 3000 FPS in the 24" barrel @ just under 58K chamber pressure with 98% load density at 3.150" OAL.


Since RL-17 seems to lag about 2gr in actual pressure & Mv a 53gr load @ 101% load density should achieve similar pressure and MV.

I'll start with about 48gr and work up to 3000 FPS

I load 45.7gr RL-17 in the 7mm_08 with the same bullet @ 2.872" OAL (Savage Axis II) and get 2915 FPS.

In 1997 I bought the first 260 rem I ever laid my eyes on. It was a model 700 ssdm embellished receiver. I think I bought it because I always wanted something nobody else had. I got a box of 120gr Remington ammo and went home tickled to death. That was 19 years ago with no regrets. I have never felt the need for a bullet heavier than 120grs so the twist was never a factor. I have taken game from groundhogs to elk and 1 bear. you asked if it would make a comeback? Hell, I never knew it left.

I now have three 260 Remington rifles two savage model 11 and one ar10 .They all shoot awesome way under an inch with lapua bullets usually one big clover leaf or smaller groups .Every kid that shoots them loves them.and they didn't like shooting the 270.I really like it way better than the 243 Winchester .It's way more knock down power and way more accurate than the 243 !