Home Forums Hunting & Shooting Gunsmithing Installing M70Tubb speed lock FP

Redneck or whomever

I have never done this before - M70 XTR featherweight - instructions straightforward EXCEPT:

On factory fp there is a flat, that a screw on left side of shroud protrudes into. Firing pin retainer into shroud, looks like. Win FP inserts into shroud from back, Tubb goes in from front, will not slide into or out back

Is this screw needed on Tubb system? If not, what do I do with it - shorten it so it sets flush, set it with Locktite protruding? le

Do I need to file a flat on the Tubb fp to mimic factory? (haven't answered back yet). Step 8 Tubb instructions?

You have to machine out the flat like the factory pin gas. I took mine to my smith to do only took a few minutes.

Why? I can see no useful function for this on the Tubb. Pin goes in from front, cannot exit the back. Slight pin shoulder and springs keep it from doing so. Cocking pc keeps it from going forward within it's range.

It is for the safety.

Um - NO.... The safety notch is on the cocking piece, not the firing pin shaft where the flat is for that retaining screw ..
Many models of the M70 have no FP retaining screw, depending on the year..

What are you trying to achieve?

OK I just know he had to machine something to make it all work. He mentioned it was for the safety? But it works very well on my 300 WSM classic.

Hey Redneck

Could you explain the pros/cons of the safety with the retaining screw vs without? I have always been curious. Thanks.

That FP retaining screw has zero relationship to the safety.... Zero. It's truly an unnecessary item.. Remove it and the rifle works just fine.. I haven't done it, but some people (in order to not leave a hole) have simply ground down the screw's length and then replaced it in the shroud..

The screw is a carryover from the late Mod 54's. Its purpose was to stop the firing pin in the event of the firing pin spring sleeve failing with a case head failure, blowing the pin to the rear. The screw was dropped in 1968 when the shrouded bolt sleeve was adopted.

Incorrect.. I personally have several M70s way past '68 that have that FP retaining screw...

That's what I did after checking with Lee on PM. Ground that sucker down and plugged the hole with it, With a dab of blue.

Not knowing exactly what I was doing, it took a LOOOONG time with dykem and small files to get that safety working on the Tubb. Slicker than snail snot on a shiny slide, now. More metal to be removed than the instructions led me to believe, initially. Mostly in assembly/disassembly, and waiting for the dykem to dry for the next fit... And most of the rest hunting the retaining washer between spring and clip. Three times.... I did learn to close the garage bay door after the first time. The factory spring has a range of about 40', the retaining washer another 7 or 8 FYI. Big magnet with a 6" chunk of 1" square stock to cut the attraction turned out to be an excellent gunsmithing aid out there in the gravel....

Turned out I could have done the same with the original - and "saved" $115 for the Tubb, delivered.. Education doesn't come cheap - and if it does, probably isn't worth it anyway.

Anyone need a hardly used 1981 70XTR fwt FP assembly and spring? Cheap. . And yes, it does have the shroud screw flat in it.

Speedlock FP protrusion screwed all the way in was .083, within Tubb's "acceptable" .085 maximum. It backed out just a teeny bit when I drilled the crosspin hole- didn't measure that, but it is now .069, a bit longer than the .060 "recommended". Doesn't punch holes, anyway.

I sure hope that Tubb FP upgrade improves the accuracy as promised. .

This was with the original FP, after full length glass bedding from recoil lug forward, as I was getting the scope tuned in and waiting for the Tubb. True, it's only one group, so we'll see. The shoot-for-group (and POI) 5-9 was with the ammo I'll be hunting caribou (Fed Pro hunter 140 in 7x57mm) within a couple weeks, all the rest were 140 Corelokts which were up and left, last one just visible at top were chasing the bullet hole adjustment shots. I did call # 9 for what it's worth. Got antsy. Range was 94 yards- far as I can shoot in my yard.

So I now know roughy how these two ammos compare in POI., and also the adjustments on the 2.5 X8 VXIII, which is NOT 1/4" per click! Closer to 1/2". A valuable piece of information. Pretty sure the Corelokts will be just as accurate, just different POI. 1.5 inches higher, 1.5 inches lefter...

The VXII 3.5x10 on the '98 is also about 1/3" per click, not 1/4 as claimed.

Both ammos (have 10 rounds each left) came partial box with the rifle, and I still have a full box of Fed 175s (also included) to check out.

gotta load the pic to imgur...



One more thing- Win cut that bbl channel way deep but left a half dozen or so pressure points in it. Hence the opening up and full-length pour.

That epoxy runs deep- rifle may be a few ounces heavier than "featherweight" anymore. . I'll weigh it again to see, and post some of my rifle weights for comparison in the general BS section.

IIRC, the '94 30-30 with aperture sight is the lightest. Gets good groups (2" or so) with my poor eyes at 94 yards. I want to shoot it at 200 yet..if I can find a place. It is going to go as primary if i can see well enough - it is accurate enough; the 70 as backup. 70 is virgin for me, but I once killed a white-tail doe with the '94.

In 1966....

Good job, las....