Gunsmithing 700 Long Action CIP?

[SporterII]

Can cip length mags be made to work in a long action and 7 / 300 mag cartridges?

 

[R700Gunslinger]

I brought this up in a PM between me and SporterII that started out discussing my 7mm Mag/183 SMK load and for others who would like to know, yes, CIP length mags will work in a Rem 700 long action with 7mm and 300 Mag cartridges. The Badger Ordnance LA CIP length M5 will fit the standard LA M5 inlet. You may need to notch the feed ramp on the 700 receiver just like most do on their short actions for the 260 Rem shooting 140 Hybrids. The mag you'll need for this is the Accurate Mag 300 WM 3.850 (3.750 OAL) mag.

 

[R700Gunslinger]

Here's the receiver notch that I'm sure many have seen. This is on my 260 Rem. My gunsmith used and 0.250" end mill and went in 0.125" deep.

 

[R700Gunslinger]

These pictures show the Badger Ordnance LA CIP M5 and standard LA M5 in one of my Manners T4A stocks that I ordered with the M5 inlet. Standard length LA M5 in brown and CIP length LA M5 in black.

 

[jetmd]

This is a very good post which clearly shows the difference of the CIP.

Thank you for posting!

 

[R700Gunslinger]

Here's an update to this thread with the required modifications that will make a CIP length DBM work with a long action Rem 700. For those that have been watching this thread I apologize for not doing this sooner. Some of the pictures aren't clear as it was hard to focus in on some the tight areas.

I have a Rem 700 barreled action that's chambered in 7mm Rem Mag and throated long to shoot the 197 gr. SMK and will be fed from a CIP length Badger M5 and Accurate Mag magazine. When I installed the barreled action along with the CIP Badger M5 for the first time together in a Manners T4A stock the magazine would not go in all the way and latch in the bottom metal. I removed the barreled action and bottom metal from the stock and mounted the bottom metal directly to the barreled action. I inserted the magazine again and what I discovered was that the magazine was making contact with the receiver in the two places shown below.

 

[R700Gunslinger]

To remedy the problem, the receiver will have to be milled at the front and rear of its magwell.

For the front on my receiver approximately 0.035" will need to be milled off of the feed ramp.


For the rear of my receiver this area will need to be milled.


Here's a receiver that I have that's been milled at this location and will work.


Again, here's the receiver that's been milled at the rear. There's enough clearance for the mag to pass at the rear but not the front. If I were to use this receiver with a CIP length DBM the feed ramp would need to be milled too.

 

[R700Gunslinger]

So basically the length of the long action Rem 700 magwell in my case needs to be 3.868" or longer. A little longer would be better so that there's absolutely no possibility of the receiver interfering and allowing the magazine to latch in place.

Receiver magwell length - 3.803"


Internal length of the CIP length Badger M5 - 3.868"

 

[2Barrels]

Interesting info. I have a 300 PRC in the works. Being build on a Rem 700 Ultra Mag action, and I'm contemplating using a DBM vs the BDL bottom metal. Spoke with a local 'smith who had just completed a 300 PRC based on the Ultra Mag action. Stock was a Manners T4A with M5 DBM inlet. DBM of choice for this build was Accurate Mag CIP LA (3.850). 'Smith said and I looked at the build, that the receiver had not been altered (milled) however the stock inlet had to be lengthened slightly to accommodate the AM bottom metal. Mags fit and and rounds feed flawlessly.

All this leads me to wonder if the Ultra Mag action has anything to do with it, or if the AM bottom metal makes the difference.