Re-chambering recommendations for 7mm Mauser

[Utah Shotgunner]

This is my first post, so apologies if I have it in the wrong place.

I have an older Magnaported Atkinson barrel that is currently chambered in 7mm Mauser.

It seems like a good first project after being directed to this site. It has always preferred heavier bullets, in particular the 168gr SMK.

I would like to pick up the velocity.

What would you folks recommend for a new chamber. Improved version of the Mauser, .284 Win, or ????? It currently has a long throat, mounted on a 788 action with both Canjar and Timney triggers ready to install. Built as a silhouette rifle in the 80's.

I drifted away from rifles into SxS shotguns 10 years ago, and this site inspired me to start playing with my rifles again.

Thanks in advance,

Mike

 

[Black Diamond 408]

Welcome Utah Shotgunner!

First i would say to stay away from the 788 action, your asking for problems with that one. Rem quit making it because it couldnt take the high pressures. I would look for a good rem 700 action or a custom 700 clone. Depending on how much money you want to spend on the whole project. As far as what calibers to choose, there are lots! What twist is your barrel? How long is it? .284 is a good round, 280 AI remmy if you want more speed.

 

[Utah Shotgunner]

[ QUOTE ]
Welcome Utah Shotgunner!

First i would say to stay away from the 788 action, your asking for problems with that one. Rem quit making it because it couldnt take the high pressures. I would look for a good rem 700 action or a custom 700 clone. Depending on how much money you want to spend on the whole project. As far as what calibers to choose, there are lots! What twist is your barrel? How long is it? .284 is a good round, 280 AI remmy if you want more speed.

[/ QUOTE ]

BD 408,

I knew those questions would come up. I used to know the twist rate and I believe it is a 24" barrel. I will check all of this when I get home.

For now I am comfortable with building on the 788 action. The rear locking lugs can be a bear, but these were lapped rather well (many years ago).

I have another silhouette rifle built on a 700 action in 7-08 with a Shilen barrel and Hart 2oz trigger. I have a new (15y.o.) Shilen barrel in 7 BR for this one.

For now I am on a relatively tight budget, with most work done by me for the forseeable future. (Not the re-chambering though.) I have a couple of shotgun events to attend this year so loading dollars and practice time will go there.

I just want to get my "feet wet" again with this 788, then I will build something from scratch.

Plans are (very) preliminary at the moment, but I am thinking of two rifles. A .223 on an AR platform and a 6 or 6.5 on a 700 action.

I still need to do load development for the .450 BPE double rifle I bought over a year ago......


****, I should never have clicked into this site! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/shocked.gif

Mike

 

[Bart B]

[ QUOTE ]
I still need to do load development for the .450 BPE double rifle I bought over a year ago......

[/ QUOTE ]Here's a web site for info in reloading ammo for your DR:

http://forums.nitroexpress.com/postlist.php?Cat=&Board=reloading

 

[Utah Shotgunner]

Bart,

Thanks! That is great site that I hadn't looked at in quite a while.

I should only have to fine tune for regulation. Sherman Bell did several articles in The Double Gun Journal about loading for double rifles. Luckily for me his guinea pig cartridge was the .450 BPE. So good modern low pressure data is readily available.

 

[UT Shotgunner]

My post from last night appears to have not made it onto the board.

I finally checked the items in question.

The barrel is 1 in 8 1/2" twist and 22 1/2" long.
Stainless barrel 1.2' diameter for the first 2" then tapering to .790" at the muzzle.

If I rechamber I have decided to go with an improved version of the current Mauser chambering.

I am out of 168gr SMK so I picked up some Hornady 162gr A-Max. This will give me the chance to work up a new load from scratch and think through the whole process instead of just loading up something from my notes.

Does anyone know of a 'smith in the Salt Lake City area that might have this reamer and can handle this work? I am comfortable with shipping the rifled action if need be as I have shipped shotguns all over the country for work.

I suspect I might need to rent/purchase a reamer. Who would you recommend for this? The current chamber is VERY tight w/ minimum dimensions, but a standard neck diameter.

Thanks,

Mike

 

[Utah Shotgunner]

It would seem that this rifle will stay unaltered from its current condition.

While not my first choice, a friend found another 788 for me to play with. I should be picking it up today.

http://longrangehunting.com/ubbthreads/s...p;page=0#109483

Thanks everyone for the information.

Best regards,

Mike

 

[Utah Shotgunner]

After ten years in the back of the safe with a broken Canjar trigger this gun was finally shot again this morning.

With 162gr A-Max and some of my old horde of DuPont IMR 4831 and the 3-9x Weaver off my -06 it shot just over 1/2" at 100 yards using a Harris bipod and an improvised rear rest. Not to shabby.

Things I learned today. 1) I don't like the Timney that is on it now as much as the old Canjar. 2) My shooting technique is really rusty after 10 years playing with shotguns.

Good fun though. Seven rifles went to the range along with my XP and Contender. Single projectile firearms are still fun!