M70 short action mag spacer removal and ejector mod *with pics*

[therifleman556]

Anybody tried drilling the spot welds for the magazine box spacer out of the short action model 70? Is it a simple removal or does the ejector need to be altered or replaced? I'd like to seat my bullets closer to the lands. Specifically, I'm trying my best to get the 120 TTSX to shoot well in my 7mm-08. I keep reading that they like to be jumper and that .050 seems to be the sweet spot, but if I remember correctly the closest I can get is over .100".

 

[Short Case]

Anybody tried drilling the spot welds for the magazine box spacer out of the short action model 70? Is it a simple removal or does the ejector need to be altered or replaced? I'd like to seat my bullets closer to the lands. Specifically, I'm trying my best to get the 120 TTSX to shoot well in my 7mm-08. I keep reading that they like to be jumper and that .050 seems to be the sweet spot, but if I remember correctly the closest I can get is over .100".

It's not that hard, I drill all my Winchester out with a 7/32 inch bit. Just try to center
the bit in the center of the spot weld.

 

[therifleman556]

Does it affect feeding though? It looks like the rounds in the left side of the magazine would be held down by the ejector when the bolt is closed.

 

[Short Case]

Does it affect feeding though? It looks like the rounds in the left side of the magazine would be held down by the ejector when the bolt is closed.

Not on my model 70, they still feed as always

 

[therifleman556]

I'll give it a shot sometime and see how it goes. Got a few other projects to do first.

 

[Boman]

For what it's worth I've always had the best luck seating the TTSX deeper than normal bullets.

 

[therifleman556]

I understand that Barnes likes more jump, but I double checked the other night and the closest I can get is over .200" away from the rifling. My best group so far is 1.25" @ 100, I think that should be fine for a Featherweight with a basic 3-9 scope. It's not like I'm going to be launching them 300 yards. That's what the Creedmoor is for.

 

[therifleman556]

So I finally got around to doing the spacer removal and I thought I should amend this thread instead of starting a new one in case anybody needs this kind of information in the future. I had drilled out the spacer on the Featherweight but had not yet installed it when my Extreme Weather arrived so I decided to try it out on it instead. Observing the rounds in the magazine it became apparent that the ejector would have to be modified. If you'll look at the first image you will see the left side round being held below the feed lip by the ejector.

Here is the bottom view of the feed lip

So out comes the ejector for a little grinding. By looking at the way the bolt depressed the ejector I figured I could notch it instead of outright shortening it, which I feared might affect ejection.

Before: the black is the material to be removed

After

 

[therifleman556]

This is the mag boxes side by side to illustrate what I did with the removed spacer. I cut it down, reversed it, and welded it back in.

And the final result, rounds on the left side are presented as normal, and the ejector length was left unaltered.

I'm going to try it like this for awhile before I go ahead and doctor the second magazine box.

 

[therifleman556]

I should note as well that I can load the 168 grain Bergers to the rifling now and fit them in the magazine with over .050" to spare.

 

[Hondo64d]

Very interesting. Let us know how it cycles.

John

 

[therifleman556]

So I ran into a small hitch with the original mag box modification. When I reversed the spacer it essentially made the magazine box narrower in the rear where the rims sit than factory. This isn't a huge deal, but it causes the cartridges to not lie flat against each other in the magazine (creates a pressure point where the shoulders touch causing a little drag). So the other box got the treatment as well except this time I just ground the whole spacer down and welded it back in, essentially just moving the rear wall of the mag box back .200".

You can somewhat see how the cartridges don't contact the side of the magazine.

The rework

Sorry for the less than perfect pictures, they were taken with a phone on top of my toolbox.

I put 16 rounds thru it today for more break in. Function was typical model 70, buttery smooth. You can hardly tell the bolt is pushing a round out of the magazine.