SA or LA for 7mm-08AI with 162 BTHP??

[VaniB]

I want to have a Remington BDL built in a 7mm-08 AI. I'm interested in using both 139gr and 162gr bullets seated mostly in the case neck to allow as much powder space as possible. I'm wanting these cartridges to fit in the magazine box and feed and extract properly.
Though I intend to feed the rounds into the chamber individually for target work, I still want the repeater action to work properly.

Any functioning particulars or disadvantage in going with the BDL 700 short action?

 

[XTR]

I'm building 2 708s right now, for a 7-08 I'd go short, you can throat it to make it work with the long bullets. Pushing the 162 you will want at least a 1:9 twist, if you are shooting to 1000 and beyond I'd look to get even more, a 1:8 or a 1:8.5. I think they get unstable as they slow down at ranges beyond 1000.

Why do the AI? I'm in the process of building 2 708s right now, one for hunting and one for a tactical competition rifle, and everything I can find says "run away" when you talk about a 708AI.

It doesn't buy you that much, and the PITA to fire form all of your brass is just that and what I've read you're not gaining much at all in performance.

Hunting inside of 500 yards it doesn't make much difference , and if you are tying to drive heavies to long ranges then get a bigger gun, if you are trying to target shoot it's an tweener kind of chambering that is out performed by the 6s and the big 7s that you'd have to shoot against because that's the class you'll be in.

I think the 708 is a great round, my smith has an AI reamer, but I'm buying a straight 708 reamer because I just don't see the AI being worth the trouble.

 

[VaniB]

Thanks for the good info. But, I think I'm just hearing you say that you don't really care for an AI of particularly any kind....and to you it's just not worth the trouble. I respect your opinion.

From what I've been reading in various forums and archives, the 7mm-08 is actually one of the decent AI's that gives about a 6% return in velocity when using the 139 grain bullet. This is one of Kenny Jarret's preferred loadings. A mediocre cartridge candidate for an Ackley (that I had also considered) is the 260AI. So, yes some AI's do perform better then others. I originally was going to do the 280AI which really is a NICE Ackley.....and I'm still deciding and haven't ruled it out. But, the more I thought about it; I don't compete, and I don't hunt. I just want a round that carries critical mass somewhere close to 1000 yards. I though even with a muzzle brake, the 280AI blast and kick just wouldn't be as much fun to shoot after awhile compared to a braked or unbraked 7mm-08.

 

[bozo699]

Thanks for the good info. But, I think I'm just hearing you say that you don't really care for an AI of particularly any kind....and to you it's just not worth the trouble. I respect your opinion.

From what I've been reading in various forums and archives, the 7mm-08 is actually one of the decent AI's that gives about a 6% return in velocity when using the 139 grain bullet. This is one of Kenny Jarret's preferred loadings. A mediocre cartridge candidate for an Ackley (that I had also considered) is the 260AI. So, yes some AI's do perform better then others. I originally was going to do the 280AI which really is a NICE Ackley.....and I'm still deciding and haven't ruled it out. But, the more I thought about it; I don't compete, and I don't hunt. I just want a round that carries critical mass somewhere close to 1000 yards. I though even with a muzzle brake, the 280AI blast and kick just wouldn't be as much fun to shoot after awhile compared to a braked or unbraked 7mm-08.

Van,
I dissagree with XTR the AI is a great way to go IMO especially on a tapered .308 case, You will have no problems reaching 1K with it, nothing special is required in fireforming any of the AI's just load and shoot and all of mine are very accurate just fireforming, I think you will be happy.
Wayne.

 

[oldroper]

Here something to look at

http://www.6mmbr.com/gunweek095.html

 

[bheadboy]

I have personal experience with the 260AI, 7-08, 7-08AI, 280 and 280AI

Bozo is right, in the 7-08AI fire forming is easy, case life is long, velocity gain is excellent, load workup is not a problem, feeding is like grits, accurcy is equal ot or better than the parent case

140s easily exceed 3000fps from a 24" bbl, depending on the accurcy node you are looking for can approach 3100fps.

160s in the 2800-2900 without pushing,

if you are serious about the 160 seated out then the long action may be of advantage, the longer high bc bullets will crowd the 2.800 mag.

Bob

 

[CJ6]

The 162's won't seat IN THE NECK and still make SA mag length (without length modification) 3"+ range

 

[XTR]

I dissagree with XTR the AI is a great way to go IMO especially on a tapered .308 case, You will have no problems reaching 1K with it, nothing special is required in fireforming any of the AI's just load and shoot and all of mine are very accurate just fireforming, I think you will be happy.
Wayne.

I agree that there is no problem getting a 708 to 1000, improved or otherwise. I do it with a 308 all the time, I just meant that if you are shooting long heavies you may want to consider using a tighter twist barrel. That bullet length/diameter/RPM stability thing comes into play once they slow down below 1200FPS a 1:9 may not be getting the job done any more. I'm going to use a 1:9 in my hunting build because there is no realistic need to shoot it that far. My tactical comp rifle tube will probably get something a little tighter because I'm sure I'll be shooting it to longer ranges.

What real world velocity difference do you see between a 708AI and straight 708 for a given bullet, say a 162? Convince me, I still haven't reamed my barrels.

As to seating, the 162 is not a hunting bullet, it's a target bullet so most applications you'd be single loading so length is not a factor, there is a whole 'nother discussion of hunting bullets for a 708 that I started in another thread. If you want to take 700 yard shots on game, then get a bigger round. If you want to put them in a DBM most of those will allow you to load 2.9 or over, so you might be a little into the case, but if I was going to go out to a long action I'd step up to a 284Win.

 

[VaniB]

I'm wanting a large centerfire rifle that is very accurate at the 100 yard target range where I do most of my shooting, but I still want yo know it's capable of 1000 yard shooting. To me, it's hard to ignore the high BC of a Berger or Hornady 162 BTHP bullet. So, that's where I figure a 139 might be nice for 100 yard target shooting, but hate to abandon that great 162 bullet just the same.

I'm being warned about the SA as being a bit tight for the 162.
Soooo.....I'm falling back again to the 280AI which we know can nicely utilize the 162 grain bullets. But, I'm not a guy that participates in formal competition, and I'm wondering if I'm going to get tired of the recoil of a 280AI at the 100 yard range too quick, even with a muzzle brake.

Yes, the 280AI will be the rifle of the "stuff" I'd be proud to own. But will I get tired of the blast real soon? Would a muzzle brake on the 280AI make it all the more tolerable and maybe even enjoyable to shoot. (??)

 

[bheadboy]

the280AI with a quality break should be like a 243

Bob

 

[XTR]

I'm wanting a large centerfire rifle that is very accurate at the 100 yard target range where I do most of my shooting, but I still want yo know it's capable of 1000 yard shooting.

How often do you shoot 1000 yards?

When you shoot at 1000 what discipline, F class, palma, BR, or just for giggles?

 

[Steve Blair]

I dissagree with XTR the AI is a great way to go IMO especially on a tapered .308 case, You will have no problems reaching 1K with it, nothing special is required in fireforming any of the AI's just load and shoot and all of mine are very accurate just fireforming, I think you will be happy.
Wayne.

Wayne,
The .308 and 7-'08 cases have only .016" body taper. The Ackley version cannot add much at all to that. The only substantive difference is the shoulder angle. However, that may add some powder capacity and eliminate the one problem with the .308 family: case lengthening.

 

[bozo699]

I dissagree with XTR the AI is a great way to go IMO especially on a tapered .308 case, You will have no problems reaching 1K with it, nothing special is required in fireforming any of the AI's just load and shoot and all of mine are very accurate just fireforming, I think you will be happy.
Wayne.

Wayne,
The .308 and 7-'08 cases have only .016" body taper. The Ackley version cannot add much at all to that. The only substantive difference is the shoulder angle. However, that may add some powder capacity and eliminate the one problem with the .308 family: case lengthening.

Steve,
I am aware of that, I have several AI's, What I like about them the most is the case life that is added by the straighter wall and 40* shoulder, I don't try to squeeze the last drop of velocity from a case like many people do, for instance I have a 6mmAI that I run 39.0 grains of IMR-3031 and 65 grain v-max bullets to fire form, it will soot in the high two to mid threes fireforming and I continue to shoot the mild load of 39.0 grains of the same powder and bullet in my newly formed AI case,..Why,....because it shoots in the ones and cases will last for almost ever, the one hundred cases I have formed is going to outlast the barrel by a long shot as a matter of a fact I am sure they will be able to wear another barrel out, I could make it go at least another 200 or even 300fps faster, but why at 3500fps + the ground hog out to the 500 yards that the 1:14 is really good for never know the difference in the speed, he is just as dead. If I really wanted speed and case life I guess I could blow the shoulder out on a .378 weatherby case to a 35 or 40* angle and neck it down to .177and turn out some 50 or 75 grain bullets for it, the BC would be phenomenal and I can't even imagine what the velocity would be but ALOTTTTTTTTTTT comes to mind. But back to the topic I personally think a improved case like the Ackley is always a good thing as the cases just don't stretch much, especially if you don't try hot rodding them to the max!
Wayne.

 

[XTR]

The original post leaves a lot of questions open here about how the rifle is intended to be used, esp the target shooting part.

Many of the classes of target shooting don't allow muzzle devices so as someone pointed out about the 280, you can't brake it and shoot it in F class.

If you want to shoot this in F class you can't shoot in TR, that is 308 and 223 only, so you'd have to shoot in Open. In F-Open the 7RSAUMs and WSMs, and probably some of the 6/6.5s would eat your lunch. More powder or more powder and a smaller bullet.

For a tactical rifle then you are looking at needing something that feeds reliably from a DBM. In this class I think the 243s and 260s are the most common in the winner's list, but the 708 is surely viable.

If you are not shooting to 1000 in some kind of competition there are a lot of bullets that will get you there fine w/o having to fret over long action or excessive throat length.

Consider that if you build the chamber to seat the 162s completely in the neck you may have to jump anything else 40 or 50 thousandths. You may have built a one trick pony.


If you are hunting the 162 Amax is a target round, I'm not getting into an argument here about whether or not to use target bullets for hunting. I don't and won't do it. There is a reason that the manufacturers write "Not for hunting" on the boxes. If I am building it for a hunting rifle I'm not concerned about seating the 162.

Build the rife do do what you do the most of and do that well. It will still do the other stuff just not with every advantage. I have two 308s, my F-TR rifle shoots great to 1000 yards and it would shoot great to 300 to kill deer too, but a 16lb (w/o bipod) 30"barrel is not ideal for deer hunting.

In the end, it's your gun, you can build it any way you want.

 

[bozo699]

The original post leaves a lot of questions open here about how the rifle is intended to be used, esp the target shooting part.

Many of the classes of target shooting don't allow muzzle devices so as someone pointed out about the 280, you can't brake it and shoot it in F class.

If you want to shoot this in F class you can't shoot in TR, that is 308 and 223 only, so you'd have to shoot in Open. In F-Open the 7RSAUMs and WSMs, and probably some of the 6/6.5s would eat your lunch. More powder or more powder and a smaller bullet.

For a tactical rifle then you are looking at needing something that feeds reliably from a DBM. In this class I think the 243s and 260s are the most common in the winner's list, but the 708 is surely viable.

If you are not shooting to 1000 in some kind of competition there are a lot of bullets that will get you there fine w/o having to fret over long action or excessive throat length.

Consider that if you build the chamber to seat the 162s completely in the neck you may have to jump anything else 40 or 50 thousandths. You may have built a one trick pony.


If you are hunting the 162 Amax is a target round, I'm not getting into an argument here about whether or not to use target bullets for hunting. I don't and won't do it. There is a reason that the manufacturers write "Not for hunting" on the boxes. If I am building it for a hunting rifle I'm not concerned about seating the 162.
Build the rife do do what you do the most of and do that well. It will still do the other stuff just not with every advantage. I have two 308s, my F-TR rifle shoots great to 1000 yards and it would shoot great to 300 to kill deer too, but a 16lb (w/o bipod) 30"barrel is not ideal for deer hunting.

In the end, it's your gun, you can build it any way you want.

I 100% agree with that for sure!
Wayne.

 

[1holeaddict]

I dissagree with XTR the AI is a great way to go IMO especially on a tapered .308 case, You will have no problems reaching 1K with it, nothing special is required in fireforming any of the AI's just load and shoot and all of mine are very accurate just fireforming, I think you will be happy.
Wayne.

Wayne,
The .308 and 7-'08 cases have only .016" body taper. The Ackley version cannot add much at all to that. The only substantive difference is the shoulder angle. However, that may add some powder capacity and eliminate the one problem with the .308 family: case lengthening.

Steve,
I am aware of that, I have several AI's, What I like about them the most is the case life that is added by the straighter wall and 40* shoulder, I don't try to squeeze the last drop of velocity from a case like many people do, for instance I have a 6mmAI that I run 39.0 grains of IMR-3031 and 65 grain v-max bullets to fire form, it will soot in the high two to mid threes fireforming and I continue to shoot the mild load of 39.0 grains of the same powder and bullet in my newly formed AI case,..Why,....because it shoots in the ones and cases will last for almost ever, the one hundred cases I have formed is going to outlast the barrel by a long shot as a matter of a fact I am sure they will be able to wear another barrel out, I could make it go at least another 200 or even 300fps faster, but why at 3500fps + the ground hog out to the 500 yards that the 1:14 is really good for never know the difference in the speed, he is just as dead. If I really wanted speed and case life I guess I could blow the shoulder out on a .378 weatherby case to a 35 or 40* angle and neck it down to .177and turn out some 50 or 75 grain bullets for it, the BC would be phenomenal and I can't even imagine what the velocity would be but ALOTTTTTTTTTTT comes to mind. But back to the topic I personally think a improved case like the Ackley is always a good thing as the cases just don't stretch much, especially if you don't try hot rodding them to the max!
Wayne.

Very well put. "Speed doesn't kill"

 

[VaniB]

Ok guys. I think by now I'm confusing you as to what I'm trying to have built, and for what purpose.

I want to build a rifle that I can consistantly shoot 5 shot 1/2" groups at the 100 yard range. This is where I spend most of my time. But, I pretty much want to know that this will be my long distance rifle too, should I decide to go for challenging longer range target or hunting shots. But, I don't ever intend to shoot in organized competition.(so it's not intended to meet F class requirements.) For long distance target, the high BC of the Hornady 162 Amax makes a lot of sense to me. So, I figure why not try to focus this rifle at 100 yards with the 162gr bullet. There's no reason why I couldn't load up some 139's for less recoil too. Both weight bulllets would let me enjoy sub 1/2" groups at 100 yards I suppose. But, the whole idea of a big centerfire is to have long range performance. While it's not for hunting (I don't hunt.) wouldn't it still be nice to let a buddy use it for hunting should I decide to stick 160gr Nosler partition bulllets in it?

So essentially I'm looking to build a long distance rifle with a 26" Sendero heft barrel that can deliver a bullet near or far very accurately for none sanctioned shooting. While I realize that this may not be what some of you may want in a rifle, I hope my logic at least now makes some sense to you.

I should be able to ream the throat so it's able to handle both the 139 and 162 grain bullets with the same jump. I simply send Dave kiff two dummy rounds with the 139 and 162 grain bullets seated in the case to a depth where both ogives are at the same depth. I have found that usually under these cicumstances the base of the bullets don't end up being too far away from each other. So they both sit in the neck or near the base of the case neck very close in proximity.

While I feel that a 7mm-08AI would be an easier and more relaxing round to fire, I think the 280AI with a muzzle brake can better handle the 160-162 grain bullets for longer distances. Especially if I should go with a long action anyway.

I hope this makes more sense to some of you guys now. I'm sure folks that don't know about custom rifles have been trying to accomplish the same sought of things for years now with off the shelf 30-06 or 7mmMag rifles.

 

[Steve Blair]

If you want to seat the shank of a 162 A-Max forward of the neck-shoulder junction, the freebore needs to be long enough to allow an overall length of 2.980". That is longer than most short action magazines. If you do not care about seating below the neck when magazine feeding and allowing >.100" jump, it should work. Obviously, a long action would also solve the problem. BTW, at 2.980", the base of the A-Max will be just above the shoulder-body junction.

 

[VaniB]

If you want to seat the shank of a 162 A-Max forward of the neck-shoulder junction, the freebore needs to be long enough to allow an overall length of 2.980". That is longer than most short action magazines. If you do not care about seating below the neck when magazine feeding and allowing >.100" jump, it should work. Obviously, a long action would also solve the problem. BTW, at 2.980", the base of the A-Max will be just above the shoulder-body junction.

Thanks Steve. It would have been easier to settle on a ss short action.

But yes, this thread has now reafirmed that I need to keep looking for a stainless long action. Once I have bought the LA, I can still kick around the decision whether to go with the 7mm-08AI or a 280AI.
Either cartridge with a long seated 162gr bullet will work in an LA.

 

[bozo699]

VaniB,
I have understood from the get go what you wanted and I think it is do able, I hate recoil anymore, if I wasn't hunting and your NOT I wouldn't consider the bigger case I would go with you original thoughts and chamber up a 7mm-08 or the AI version of it, the 162's are very accurate and I think it can be done especially if you don't mind chambering one at a time you really don't want to be below the neck/shoulder junction with the bullet, I am doing that with my .300wm and it shoots awesome but I am always worried about pressure problems loading it that way, the LA is not a bad idea to keep them loaded long and being able to use the mag, the extra few Oz, won't even be noticed, best of luck.
Wayne.