7/08 Ai . The little round that could !

[TZaun]

@ShootDots Ben, I'm very curious to see what you find. I hope you take the time to give us the play by play. I've been playing with QL since reading your earlier post. From what I'm coming up with, RL-16 will give ~2780 fps with the 180 Hybrid and ~2880 fps with the 168 VLD. Difference on a missed wind call of 5 MPH only favors the 180 Hybrid by .1 MOA @ 1,000. Nearly a wash. It leaves the door open to try the 168s, if a guy would want to. Sounds like a fun venture. Hope it turns out great for you.

 

[ShootDots]

@ShootDots Ben, I'm very curious to see what you find. I hope you take the time to give us the play by play. I've been playing with QL since reading your earlier post. From what I'm coming up with, RL-16 will give ~2780 fps with the 180 Hybrid and ~2880 fps with the 168 VLD. Difference on a missed wind call of 5 MPH only favors the 180 Hybrid by .1 MOA @ 1,000. Nearly a wash. It leaves the door open to try the 168s, if a guy would want to. Sounds like a fun venture. Hope it turns out great for you.

Oh I intend to give a good write up. I get these "ideas" from time to time and most work out>>> I had a 30-06A.I. project that did not perform as well as I anticipated. This one I am really hopeful about.

 

[jsthntn247]

Back 5 years a go a friend of mine said he was going to win every match around with his new cartridge idea. He bought brass, reamer, barrel, action and stock for it to get back in Fclass. It was a 7-08AI throated for 180's. He passed away before it could get chambered. I would like to see if his idea would have worked out because I laughed at him then about that little cartridge beating up on the big boomers.

 

[usmc45]

OK.......I'm so far from an expert its not even funny. But some of the numbers on here just dont work. I love the
7mm-08 and it AI brother but some of these numbers are pretty wild. But it would help if we could share barrel lengths and COL data. Are you guys running 32" barrels and COL's of 2.950" at max pressure? Its the only way i can get QL to give me this kind of data.

As stated im no expert, so what im really saying is help me get there to I love the numbers but i cant get there without feeling unsafe. Am i doing something wrong?

Thanks to everyone for sharing.

Happy shooting.

 

[Laurie]

But some of the numbers on here just dont work. I love the
7mm-08 and it AI brother but some of these numbers are pretty wild. But it would help if we could share barrel lengths and COL data. Are you guys running 32" barrels and COL's of 2.950" at max pressure? Its the only way i can get QL to give me this kind of data.

I can't comment on the AI, but have been running the standard version mostly using reformed 308 Lapua Palma small primer brass for the last three years. I did consider the AI version when I had the rifle rebarreled and sometimes wish I'd gone ahead with that, but at the time it was the tail end of the great US tools and components shortages and off the shelf AI dies weren't available. In fact, there was doubt as to whether some manufacturers would resume their production. So, the quicker / safer option was the standard version.

But to get back to the question ..... Yes, to achieve anything like these results, a very long freebore chamber and good barrel length are essential. I had my rifle chambered for the 168gn Berger VLD seated optimally in the neck when just touching the lands. This would have given a COAL right on 3-inches if done as I wanted, in the event it came back marginally shorter at 2.960". Not that it mattered as the barrel apparently doesn't like the VLD.

I run the 160gn Sierra TMK at 2,825 fps from a 31-inch barrel using a case-full of relatively cool burning Viht N160. It makes a very accurate and effective short to mid-range load for F-Class with little recoil and what should be good barrel life. Modern low drag 160-168gn bullets have similar BCs to equivalent 6.5mm 140s, so MVs above 2,800 fps (or heavier higher BC bullets at suitable MVs), are needed to produce any ballistic advantage over the mid-size 6.5s these days ... or even ballistic comparability. (Barrel life will be better for the 7mm though all other things equal.)

I have tried the 175gn Sierra MK which I'm a fan of and worked up the occasional 180 load. As I have a 284 for long-range matches, I didn't find any benefit and recoil was much more pronounced. The standard case struggles with these bullet weights / lengths and charges become so heavily compressed that COALs become inconsistent. If looking to use the heavier bullets, I'd say the AI version becomes essential, even though the extra case capacity is modest.

 

[NortexDM]

I run the 160gn Sierra TMK at 2,825 fps from a 31-inch barrel using a case-full of relatively cool burning Viht N160.

What bc are you using for the 160? I've found very little info on it in general.

 

[Laurie]

It's pretty close to that of the 162gn Hornady AMax (G7 0.306 from memory). I input 0.300 into my ballistics program to get rough come-ups from my 100 yard zero and have found them reasonably close at that value.

 

[Mi223]

Can any of you guys give any advice as to what freebore would be needed to get a 162 eldx an oal of 2.975ish?

Sorry to bump an old thread. this is the most recent thread i have found on the 708ai. I am thinking of ordering a reamer just trying to figure out the specs

 

[Edwin Gideons]

Oh I intend to give a good write up. I get these "ideas" from time to time and most work out>>> I had a 30-06A.I. project that did not perform as well as I anticipated. This one I am really hopeful about.

Very curious to know how this project came out. I am looking at doing the same thing...just can't ignore the massive BCs of the 7mm bullets. I have heard of a few different reamer versions with some being much more effective than others. Would also like to hear any opinions/sources for reamers.

Thanks

 

[ShootDots]

Very curious to know how this project came out. I am looking at doing the same thing...just can't ignore the massive BCs of the 7mm bullets. I have heard of a few different reamer versions with some being much more effective than others. Would also like to hear any opinions/sources for reamers.

Thanks

I did an entire write up from beginning to end. It is somewhere in the "search forums" section..

 

[KenOath]

Very curious to know how this project came out. I am looking at doing the same thing...just can't ignore the massive BCs of the 7mm bullets. I have heard of a few different reamer versions with some being much more effective than others. Would also like to hear any opinions/sources for reamers.

Thanks

Quickoz on this forum knows a little about the 708AI also.. maybe send him a PM.