Home Forums Hunting & Shooting Gunsmithing Model 70 center screw conversion

Just finished this center screw conversion on a Model 70. It came already having been pillar bedded in a McMillan stock. The pillar bedding needed a few minor tweaks but was really pretty well done with the exception of retaining the center screw.

BTW, the areas of attention are commonly seen here with posted pics of 'finished' Model 70 bedding jobs.

The gun shot very well (280 AI) with the screw loosened up...but pretty soon the screw would back out. With the screw tightened up, accuracy went South big time.

Indicator zeroed:


With either the front or rear action screws loosened, it showed .027 movement:


Center screw mod done. An short aluminum pillar is inletted into the stock and epoxied in. A flat headed Allen head cap screw goes into the pillar. The face and O.D. of the screw head are reprofiled so it fits in the stock 82 degree screw recess:


Indicator zeroed after the modification:


Loosening either the front or rear action screws now shows .003 movement...about as good as a Model 70 gets.


This is an easy, simple tweak that can really make a difference in a Model 70. All in all, a fun project on neat rifle for a good guy.

Good shootin' -Al

Wow, Thanks, 'labor saving tips by Nyhus'. Great post.

I've been doing these 'conversions' on Model 70's & Rem 700's for sometime and for anyone wanting to do their first one, I suggest that they avoid a typical round pillar and opt for something square to avoid the pillar turning at some later - and probably inopportune time. Some epoxies are "more equal" than others so it's best to safe than sorry.

On the round pillars, I've at times used a piece of brass rod through the pillar and epoxied into the stock. Have also used square stock as you have for the pillar. And it's no place for a cheap-o 5 minute epoxy or hot glue.





Good shootin' -Al

Very impressive.

Thank you for sharing.

Thanks for posting this Al. Have any of the stocks you have modified like this had the lightweight McMillan Edge fill? This would be a good addition to my 2 pre 64 hunting rifles, but their fill seems pretty weak. My 30-06 split through the web between the mag well and trigger opening just like a wood stock can.

Mike, those splits happen because of poor bedding and the stress load from the center action screw loading the stock and then flexing during recoil. It's particularly bad when there ends up being more than one recoil absorbing area...which is common on 90% of the bedding jobs that are being done to this day on Model 70's. The area ahead of the tang is a major culprit in stock breakage at the 'web' area you've had cracking problem with.

The work around is either an expertly done full length bedding job that utilizes a center pillar or a two-point bedding approach (my favorite) and eliminating the center screw from threading into the action.

Hope this helps. -Al

Thanks Al, good info. That was the one McMillan I have where I took their statement that the stocks did not require bedding at face value and left it as received. It was plenty accurate with my 200 grain partition elk loads. It did not appear to be tight against the tang abutment and the center screw was just slightly snugged up.

Oh well, lesson learned. Fortunately Mcmillan is a short drive away and Lynn there did not seem overly surprised by the split and put a warranty replacement in the queue. She did suggest a heavier fill they had started placing in the front receiver ring area of those stocks which would add about 1.5 ounces. I went that route and did a full action and bottom metal bedding before taking it back for paint. I use layers of 3 mil aluminum tape at the appropriate tang and lug areas and the front and rear screws now reach a quick hard stop when tightened. I think will try your dial indicator setup and proceed from there.

I see I have a couple options to work on with my 1985 fwt.which is now full length bedded but still with so-so accuracy. Many thanks.