Thread: 6.5 v 7mm

so compare ballistics of both using ...lets say a 145grn factory round.....and whos laughing now????

yeah so close to each other its academic really...... the .270 is finally getting some decent slippery projectiles after playing catch up for years,the newer faster twist barrels coming out for wsms etc SHOULD trickle through one day allowing the likes of those 175grn gamechangers to close the gap even more.
the .280 as std cartridge has been handicapped by pressure levels held back for the likes of the remington woodsmaster pumps...
when you level the playing field,there is nothing in it either way.

and you get them micrometer measuring sticks out and measure unfired projectiles.....you will see my point as to what is closer to 7mm

@Micky Duck. You're right it is academic. It beggars belief,though, that Remington would develop such a fine cartridge and then immediately codemn it by chambering same in pumps. Then very soon after introducing the 7mm Rem Mag. Crazy stuff. Probably got a back hander from Winchester.

Originally Posted by RugerM77

@Micky Duck. You're right it is academic. It beggars belief,though, that Remington would develop such a fine cartridge and then immediately codemn it by chambering same in pumps. Then very soon after introducing the 7mm Rem Mag. Crazy stuff. Probably got a back hander from Winchester.

Remington is top of the field for making a world class cartridge (6.5 Rem Magnum, 280 Rem, 260 Rem, SAUM etc.) and letting it disappear through lack of marketing, quality ammunition/brass and encouraging other rifle makers to chamber it. The lack of 'long range' hype at the time probably confined these cartridges to the back shelves for being too expensive/ having too much 'kick' (admittedly, chambering a Remington 600 for their short mags was probably too much for most to handle! )

Hornady took a lot of inspiration from the early Remington Short Mags (350 Rem Mag in 1965 then 6.5 in 1966), removed the belt and 'created' their current line of hot sellers. Good prices, availability and few youtubers and social media hype have probably doubled their turnover or more.

Originally Posted by caberslash

Remington is top of the field for making a world class cartridge (6.5 Rem Magnum, 280 Rem, 260 Rem, SAUM etc.) and letting it disappear through lack of marketing, quality ammunition/brass and encouraging other rifle makers to chamber it. The lack of 'long range' hype at the time probably confined these cartridges to the back shelves for being too expensive/ having too much 'kick' (admittedly, chambering a Remington 600 for their short mags was probably too much for most to handle! )

Hornady took a lot of inspiration from the early Remington Short Mags (350 Rem Mag in 1965 then 6.5 in 1966), removed the belt and 'created' their current line of hot sellers. Good prices, availability and few youtubers and social media hype have probably doubled their turnover or more.

The 6.5 Rem mag is about perfect for case capacity just a shame it had the belt. But then there are hoards of really good European cartridges that we never see here. The 6.5 x 68 and 8mm x 68 from the 1930's and the 6.5 x 65 RWS from 1988, I know a bloke with a Blaser in this cal and it's pretty snotty

Originally Posted by Moa Hunter

The 6.5 Rem mag is about perfect for case capacity just a shame it had the belt. But then there are hoards of really good European cartridges that we never see here. The 6.5 x 68 and 8mm x 68 from the 1930's and the 6.5 x 65 RWS from 1988, I know a bloke with a Blaser in this cal and it's pretty snotty

Mate in UK has a Blaser in 6.5 x 65 RWS and it’s an empathetic killer of roe deer.
@caberslash - I’m going to take exception to your assertion. My .30-06 Springfield, ..300 Win Mag, .284 Winchester, .270 Winchester say otherwise. My 7 Rem Mag is on your side.

@mickey Duck - FYI Here is a slightly crazy / funny guy shooting a 270 AI over a chrony https://www.youtube.com/watch?v=cz95NcOrcL0

@Moa Hunter am at home with headcold so my patience isnt the best....that was painful to watch....from what I did manage to view..2-400fps better is ummm yeah sort of worth the effort if speed is your thing....interesting as the .280 gets the AI treatment often...but you seldom hear of the mighty .270w getting it done.

Originally Posted by Micky Duck

@Moa Hunter am at home with headcold so my patience isnt the best....that was painful to watch....from what I did manage to view..2-400fps better is ummm yeah sort of worth the effort if speed is your thing....interesting as the .280 gets the AI treatment often...but you seldom hear of the mighty .270w getting it done.

Greetings @Micky Duck,
There is a sound reason why there are not many .270AI rifles around. Both factory and hand load data is pretty stout and there is not much to be gained. Converting any of the 06 chambers to AI gains around 100 fps and often less WHEN LOADED TO THE SAME PRESSURE. In the .280 and .30-06 cartridge factory and hand load pressure is lower so there is more to be gained but you can gain some of that just by loading up to .270 pressures. I did attempt to watch the video but started to lose interest when he pointed the rifle at the camera with the bolt closed. In the interest of science I fast forwarded till the shooting started. Within a few shots he had expanded a case head with an overload and decided that there was little or nothing to be learned by watching any more.
I had a .30-06AI for a bit years ago and found it was only marginally better than the standard version when using pressure tested hand load data. I see from my notes I got 2,830 fps with the 165 grain Hornady in a 24" barrel and fire formed cases.
Hope you are feeling better tomorrow.
Regards Grandpamac.

Originally Posted by grandpamac

Greetings @Micky Duck,
There is a sound reason why there are not many .270AI rifles around. Both factory and hand load data is pretty stout and there is not much to be gained. Converting any of the 06 chambers to AI gains around 100 fps and often less WHEN LOADED TO THE SAME PRESSURE. In the .280 and .30-06 cartridge factory and hand load pressure is lower so there is more to be gained but you can gain some of that just by loading up to .270 pressures. I did attempt to watch the video but started to lose interest when he pointed the rifle at the camera with the bolt closed. In the interest of science I fast forwarded till the shooting started. Within a few shots he had expanded a case head with an overload and decided that there was little or nothing to be learned by watching any more.
I had a .30-06AI for a bit years ago and found it was only marginally better than the standard version when using pressure tested hand load data. I see from my notes I got 2,830 fps with the 165 grain Hornady in a 24" barrel and fire formed cases.
Hope you are feeling better tomorrow.
Regards Grandpamac.

Where ol matey went wrong with his AI was by fireforming cases with hot charges. If he had started with neck sized 270 AI cases he would likely not have blown the primers when he shot the hot loads. Do the fireforming with the standard loads. 200 + fps gain is not to be sneezed at. I have found with the 2506 AI that recoil is very mild. It is with 2506 rifles in general, but with the AI it's like the case pushes outwards in the chamber more than the non AI which thrusts backwards because of the greater taper ?? Have I got a fervent imagination or have others noticed it too ??

yes fireforming with hot charge is definately not in the manual..... small charge of fast powder n some cream of wheat sort of deal or a mild load with cheap projectiles(remember those?)
200fps gain...yeah no point...sell the .308 and go back to using the 30/30
sell the 300wsm and go back to the .308
sell the latest wizzbang creedmore and go back to the carnaco....
velocity is just soo over rated
throw the chronicgraph away completely and you wont notice difference anyway other than it shoots flatter.

Originally Posted by Micky Duck

yes fireforming with hot charge is definately not in the manual..... small charge of fast powder n some cream of wheat sort of deal or a mild load with cheap projectiles(remember those?)
200fps gain...yeah no point...sell the .308 and go back to using the 30/30
sell the 300wsm and go back to the .308
sell the latest wizzbang creedmore and go back to the carnaco....
velocity is just soo over rated
throw the chronicgraph away completely and you wont notice difference anyway other than it shoots flatter.

You are obviously sicker than we thought !

Originally Posted by Fisherman

Hi guys...I use a 284 and send the 162 eldm off at about 2770. I was just running the numbers on the 147 eldm and launched at 2700 it has slightly more velocity and about 100 foot pounds less getting out there, about 2000fps at 600 yards.
Question is, two frangible projectiles about the same velocity and energy, how much difference to killing power does the smaller hole make?

You're over thinking it.... Get a 308, plenty of factory ammo available, and all the velocity/sectional density/felt or perceived recoil rubbish goes away.... are you going hunting or just thinking about it?

Greetings All,
First I must apologise to @Fisherman for hijacking his thread and in penance offer the following. It doesn't matter if you use the 6.5 or 7mm, they are pea's in a pod for any practical purpose so use what you like.
Getting back to the discussion on AI cartridges I did a bit of number crunching with the following results. It is hard to get pressure tested data of the same vintage for standard and AI cartridges but they do exist for the .280. I selected data using a new powder, IMR4451 and the 140 grain Nosler Partition and BT respectively. The relationship between pressure, velocity and powder charge is linear at normal pressures so it is possible to interpolate (calculate) all between start and max loads. Max pressure for the .270 and .280 AI is 65,000 PSI and the .280 only 60,000 PSI. Most handload data is a little under this so I calculated the powder charge needed and velocity for the AI at 280 max pressure. The velocity was near the same for both cartridges but the AI needed an extra grain of powder to get there. The .280 AI max load gained about 70 fps in velocity for another 1.3 grains of powder so most, if not all of this gain would apply to the standard .280 if loaded to AI pressure. This is what has been found in other pressure tested comparisons between standard and AI cartridges that I have read over the years.
Getting back to the .270 as this is already loaded close to 65,000 PSI the AI version loaded to the same pressure does not gain 400 fps, or 100 fps but somewhere between 30 fps and nothing at all. Some will dispute this but the pressure tested data is clear.
Regards Grandpamac.

the std .270w will gain that amount if you gave it another few inches of barrel too.....4-6" longer would make a hell of a lot of difference,oh so many have been knee capped with 21" from factory.

Originally Posted by Nickoli

You're over thinking it.... Get a 308, plenty of factory ammo available, and all the velocity/sectional density/felt or perceived recoil rubbish goes away.... are you going hunting or just thinking about it?

I hunt with a 284 and shoot paper with a 6.5x55 and have been thinking about getting rid of one or the other. I think it's a fascinating conversation with the rise of 6.5's, some saying it makes no difference and others saying that it really does. Its an interesting call because the 6.5 is more than adequate for most of my shots and I'm recoil/muzzle blast sensitive (and I like to shoot my hunting rifle a lot).
I just can't imagine why someone who wants to shoot 600 plus yards would choose a 308 over the 284 (or even a 6.5). You have to have such a big projectile to match the bc and then you really want a wsm etc, I'd love one but then recoil is going north without a muzzle break.