7mm-08 AI in a 16.5” barrel?

[Kck]

Anyone built one of these? I’ve got a Bartlein M24 .284 1:8.7 that I think would be good for anything up to the 168’s sitting on the shelf. I’ve got a standard 7-08 reamer but not in an ackley shoulder so I’ll have to get one. Built and shot a few .308’s on 16.5” barrels with good results but wanted to see what everyone thought of a 7mm or if I should just stay with .308. Will be going in a Manners folder to make as small as possible. I will be shooting it with a brake and suppressed.

 

[NC308]

I’m guessing your not going to see much if any gains going to a AI version on the 7-08. Same as the the 308 AI. I personally don’t thing it’s worth doing. I would just build a 7-08. Or stick with the 308.

 

[std7mag]

Exactly as Josh said.

Going to a 16.5" barrel is self defeating for an AI cartridge.
An AI cartridge based on the 308 family even more so.

They do look cool at band camp though!

 

[Kck]

Thanks gents. Yeah, I didn’t think I’d see much improvement in the ackley shoulder and since I already have a standard 7mm-08 reamer I’ll prolly just go with that. Just not as much info on that cartridge in a shorty so I figured I’d check in here. I see more 16” 6.5 creeds but, honestly, I just wanted something different and figured if the 308 performs in the short barrels a 7-08 should hopefully work out.

 

[NC308]

Thanks gents. Yeah, I didn’t think I’d see much improvement in the ackley shoulder and since I already have a standard 7mm-08 reamer I’ll prolly just go with that. Just not as much info on that cartridge in a shorty so I figured I’d check in here. I see more 16” 6.5 creeds but, honestly, I just wanted something different and figured if the 308 performs in the short barrels a 7-08 should hopefully work out.

i see no reason why a 7-08 won’t work just as good in a short barrel as the 308. You can shoot it the same speed with bullets with a little better BC than the 30 cal within a similar weight range. I think it will be fine.

 

[std7mag]

I haven't tried anything shorter than 22", myself.
Neighbor is looking for a compact youth for his daughter.
Haven't heard any negatives on the 20" barrels.

Just don't expect too much velocity gain if you do the AI treatment. Case isn't long enough, or tapered enough to significantly add volume to the case.

 

[Sniper338]

7mm08 is just fine in a short barrel. Run with it, it will be fine. Anything will shoot in a short barrel. Ive seen it all in specialty pistols. XP-100 specialty pistol guys have done it all. I have a 15 inch 284 win and 6.5x47. They drive tacks... and PLENTY velocity... i wouldnt hesitate to shoot a hog at 800 yards with either it will get there just fine. Ive seen every caliber from 22lr to 300 PRC in a 14 to 15 inch barrel. They all work.


Skip the AI, aint worth nothing but looks.

 

[std7mag]

Had you said, 250 Savage, 257 Roberts ( or any caliber based off the Mauser case), 280 Rem (or anything based off the 06' case) then yeah, the AI treatment is worth it!

 

[sandwarrior]

I shoot a straight up 7mm-08 with a 28" barrel. Use slow powders and heavy bullets. My longtime and still current load is 44.1 gr. of RE-19 behind a 180 gr. bullet. 44.5 if I'm shooting a 175. It's a 1-8" twist barrel. The loads, even though relatively low pressure, get a long push on those bullets. They are compressed loads. Alliant powder lists 47 gr. of RE-19 on their website. That is the max powder charge. I don't believe I got that high up loading the way I did, thus why my loads are 2.5 gr. under that. I get all the speed with a long barrel and slow powder.

Since there was no data on the 180's I started at one grain below the 175's and worked up. I was using 45.1 gr. then dropped that down to achieve less pressure in the case, and therefore less wear and tear on my barrel. It was a hard barrel to find. Brass lasts longer too.

AI'ing that case isn't going to get you a whole lot more. You may improve volume but as noted, it's not a case that really uses improvement well. And, I have to say there are two kinds of Ackley users. Those that hot-rod and can't understand why nothing Ackley lasts, and those who get just that little bit of improvement and enjoy the Ackley benefits. It's a very efficient case as the powder stack wants to ignite when compressing against that steep shoulder. They aren't very good at showing signs of pressure until you are too high. The blown-out case walls grip the chamber walls better. Also, the top of the pressure curve goes steeply upward no matter what powder you use. Something to remember on all Ackley improved cases. One of the benefits of Ackley cases, when you don't hot-rod, is longer lasting brass. Remember, this is based on normal loads. Once the brass is fire-formed it won't want to flow towards the neck as much. Brass remaining the same firing after firing is where you get good accuracy from that aspect.

 

[wbm]

Skip the AI, aint worth nothing but looks.

Good advice that! Especially for a 7mmx08 with a 16.5" barrel.

 

[Kck]

Sold. Thanks for the replies on this one and going with a reamer I already have instead of the AI will make things easier for sure.

 

[std7mag]

Easy is good.

Lots of people trying to push me to 6BR, 6BRA, and the such for my range build.
But i already have the reamer, dies, and tons of data shooting 7mm-08AI.
Building a bench type gun is what's gonna be different.
The practices are still the same, i just need to pay that much more attention to the little details!
And much as i hate to say, as far as bench guns are concerned, this is gonna be a budget build.

I'm anxious to see what a 30" barrel does for the 7mm-08AI!