Looking for some info on 7mm-08

[AJCastle]

Hello, this is my first post although I have been following this website for about a year. I have done some F-class and trying to just get more involved in rifle shooting.

I'm working on putting together a tactical/practical rifle and get my rifle reloading going by spring time. I have most of my rifle parts but need to order my chamber reamer and that's where I'm stuck without having my reloading equipment together. This isn't going to be a serious competition rifle but mostly something that I can practice with and use in local competitions.

Bullets and brass will be
Once fired Federal 308 brass necked down
Hornady 162gr A-MAX

The only thing I have on hand is a Federal factory P708B which is nickel plated brass and measures right about .310" neck diameter. I don't know how thick the nickel plating is or how much thicker necking down 308 to 7mm will make the neck. I heard that for this kinda rifle you want about .004" difference between the neck diameter of the chamber and loaded round. If anything I would rather be a little on the loose side since I am trying to avoid neck turning. Does anyone have any hard info on what the neck diameter will be or what the reamer should be cut at?

Thanks in advance

 

[jonbearman]

If you call PTG and talk with Dave Kiff who is the owner. Tell him what bullet you are using and he can tell you what freebore he recommends and make sure you tell him you want a true no turn neck for a hunting rifle. You should be able to neck your brass down without turning but you have to measure the neck thickness and compare it with a known 7-08 cases neck thickness.

 

[Dans40X]

Purchase a D or E pre-fix serial numbered (J-lock)700 Varmint chambered in 7mm08.

Pillar bed & float the Bbl.
Replace the firing pin assy.
Install a Jewell trigger group.
Mount your glass of choice.

Work up a load(s)

Shoot the barrel out

Rebarrel & start over again!

 

[AJCastle]

I called PTG twice and got 2 different women but haven't really gotten anywhere with it, which is why I am asking on here. Although I haven't talked to Dave personally yet, maybe I will call again tomorrow and specifically ask for him. So far they have sent me a print of the reamer but I need to specify the neck diameter.

I pretty much have everything, all I need is a stock/chassis and the reamer since I have a barrel blank sitting in my safe.

 

[XTR]

Don't over think this one.

A no turn reamer is a .317 neck

Use W-W brass if its available. Sizing down 308 is really not worth it in my opinion unless you want to make Lapua Palma into 7-08 to get the small primer (not sure it's useful), or you just have a bunch, or just can't find any 7-08 and 308is all you can get

It needs to be long throated to seat the the Amax ideally, which will make it less than ideal for anything you plan to mag load. Consider that. My reamer is set up for the 162s and I wish is wasn't. I've got an HS DBM system on mine and it really makes the 140s jump. My opinion of the 162 is that everyone jumps on it for the BC but with the 7-08 you lack the boiler to shoot it at good velocity, and you are back up to 308 recoil.

You can load 140s and run them at 3000FPS which for other than long range F class is probably a better option than the 162 because it will be flatter and, the 7-08 is kind of an outcast for anything other than hunting or sillywet shooting. It isn't a 308 so you can't shoot it in F-TR, and it is under gunned in F-Open.

That said, it's my favorite hunting round.

 

[jsthntn247]

Build it on a long action and you don't have to worry about length. I throated mine where a 162 is .020 above the neck shoulder junction. Can't find the 162s so I loaded 168 classic hybrids to 2700 with 4350 and used nosler blemished 7/08 brass from shooters pro shop. After turning the necks I have a good bit of clearance (.009) from .002 tension to fired diameter. Use a neck bushing die to deprime and reduce diameter .005, anneal, then use a fl bushing die to bump shoulders and reduce the final .004. As long as you regularly anneal it won't matter, mine hammers.

 

[AJCastle]

XTR thanks for that, I know I was over thinking this but I really didn't have much info to go off of. Most of my shooting will probably 500-1000 yards with this rifle.

The reason I'm going with Federal 308 is cause I have pretty easy access to a lot of it. In the future if I get more serious about this I will switch to W-W brass.

As far as F-class I actually don't care about the classes cause I'm not that interested in ranking, I mostly shoot it for experience.

Thats interesting about the 140 vs. 162 I will look into that a little more before I order the reamer, thanks for bringing that up. I just wanted to run something a little different than 308 without running a total barrel burner.

JST- its going into a short action gun, going to be fed from a box magazine. thanks for the info though

 

[turbo54]

7mm08 is my favorite short action chambering, and by far the best variant of the 308 case.

That said, I recommend you choose a 260 (or similar) right now. The bullets are just not being made for us 7mm08 guys. Your'e right in zeroing in on the 162 amax. It's the pick of the litter. The 140s are great out to 600 yards, but they really fall off past that whereas the 162s are fantastic out to and beyond 1000 yards.

There are some other choices, but none as well matched to the 7mm08 as the 162. If you're going to fling 140s, might as well do that with a 6.5mm and get some good BC out of it. The 140 7mm Berger is only .510.

If you remain set on the 7mm08, look at the Berger classic hunter 168, and the 168 VLD. The Barnes 171 shoots well, albeit kinda slow, but I've found it to be quite finicky on seating depth. I'd skip the Sierra 150 and 168 for anything but plinking - they have a poor BC, as does the 150gr Lapua. All of them shoot very nicely though, and very forgiving to load.

You'll want to choose an action, bottom metal and magazine that will handle the absolute maximum COAL possible (2.950"), to maximize case capacity and try to get the bullet bearing surface ahead of the shoulder.

My choice is to always get a chamber reamer with a short throat, and use a throating reamer to set the freebore to whatever I desire. I'm sure your gunsmith will have a 7mm throater. Just load a few dummy rounds with various bullets seated to ~2.940" and let your gunsmith decide the best compromise on freebore to give you versatility in which bullet you use. My experience is the 162 is very forgiving on seating depth but the 168 Berger VLD is not. It may come down to a choice you have to make - optimize the freebore for one, or the other - not both.

For chamber neck diameter, .317" is a safe way to go. Loaded Federal cases measure ~.312". Remington and Winchester are about .310". Lapua is coming out with 7mm08 brass soon, don't know what it'll be but I'm sure .317" will do ya. Worst case with Winchester is .0035" clearance per side. That'll work the brass a little bit more, but for a practical/tactical rifle it'll work great. That's where mine is set. I do anneal from time to time.

 

[AJCastle]

Turbo thanks for the response, I really appreciate it. I'm pretty set on the 7-08, so do you use the accurate mags w/o the front blinder?

And just curious but what freebore do you use for the 162, also what kinda muzzle velocity do you get out of it?

 

[turbo54]

I run a Badger Ordnance M2008 action with AIAW magazines. Don't know my free bore number but the 162 kisses the lands at 2.940" COAL.

This is actually my practice/plinking rifle, so no need to run it "hard". I mostly shoot Federal brass which has less case capacity than most, plus it is softer and shows pressure signs sooner. In the Federal brass, ~2750fps with either 42gr Varget or 45.5 H4350 is my velocity from a 26" Bartlein. I can easily run 50fps faster with either powder in RP headstamp 260 or 7mm08 brass.

 

[Terry]

See...

http://forum.accurateshooter.com/index.php?topic=3859757.0

 

[AJCastle]

Thanks for the responses everyone