Home Forums Hunting & Shooting Gunsmithing Opening the feed rails on a M700

I bought a bare Remington short action for an upcoming build. It's nominally a plain ol' .473 boltface action. I bought it without a bolt and am fitting a PTG magnum boltface bolt for a 6.5 SAUM build.

I will need to open the feed rails. I have a factory Remington WSM action on hand, so I can get measurements from that for the feed rails for a SAUM/WSM.

Before I do this I thought I'd ask the pros if there are any gotchas to be aware of. Also, do you do this on the mill, or use files? Sure looks like it'd be a quick job with files. I do however have a mill (and appropriate vise jaws to grab round stuff).

Thanks for any info! Appreciated bigly <grin>.

It doesn't look like anyone else is going to respond so I'll put my two cents worth in. I hesitate to use the "D" word (Dremel) in a gunsmithing blog, but that is my tool of choice for action rails. I can have one done with a Dremel before I can even get my mill set up. I start with a carbide burr then finish the job with a Cratex point.

Go take a look at a 700 action and think about what you are doing... if you stand by your comments you need to stop working on guns.

IdiotO should never have started...

Interesting. I know I could do it cleanly on the mill; I know I could do it cleanly with files. Not sure I have a steady enough hand for a Dremel. I'll look at it. Thanks for the help.

Please dont take this as a flame, because it isnt. Im asking out of sheer curiosity. If you were already buying an action for a planed build, why not buy a magnum action to begin with?

I know I have had a few naked actions laying around, none of witch were Magnum actions. I flirted with the idea of making one into a magnum single shooter for the range. Even making one into a repeater. The advice my smith gave me was although it can be done, you'll be happier/better off starting with a magnum action From the start. Cost wise and peace of mind goes a long way.

Hard to find a SAUM or WSM stainless short action M700 donor locally... I found one (the one I have on hand to use as a pattern to cut these rails) but hadn't seen another go by... Bud's sells Remington M700 short actions without a bolt for, if memory serves, $229. A PT&G magnum boltface bolt is $225-ish. So it works on the cost level. I wouldn't slum a modern Remington trigger anyway nor did I want to use ANY of the parts (bottom metal, stock, mag sheetmetal, etc) from a donor for this build so this way was much cleaner in that regard as well.

That leaves modifying the feed rails. At the end of the day that's a metal cutting operation and that's what I do for a living. Modifying them per se appears straightforward but I'm very much still hoping for any pearls the pros care to drop.

Having the one on hand to use as a pattern is a big comfort, I admit. I am contemplating converting my '06 to RUM specs for the next build after this one, and I don't have a factory RUM action to copy. Gonna see how this short action goes before I make the final call on that plan.

I can relate to the "not being able to find one locally" I've taken my search online in the past. I've had good luck finding actions on GB and having my local FFL make the purchase for me. I end up paying cost + Transfer fee.

Great guy to work with that way. I guess he could hit me with cost pluse profit pluse transfer fee, but I do other business with him and he usually just does it as a favor. Could be industry standard for all i know.

I am a CNC machinist by trade as well but Im smart enough to know I should let a competent smith do what I have little experience with. Especially on anything that involves me setting of a detonation at the tip of my nose. Good luck on your endeavor.

It's just the feed rails.... no detonation risk..... I mean look at them. If - big if- that bevel on them really needs to continue (be widened) then it's a bit more complicated. I'd likely modify one of my countersinks and do it on the mill. But I suspect there's plenty of bevel there, and it can just be plain ol' widened up. But I'm still researching this.

On my other action I'd be opening the bolt face as well. That looks like a bit of a pain (eccentric undercut for the clip extractor) unless I mill the bolt for an M16 extractor.

The other cool thing about a truly bare action from Bud's is that I don't end up with yet more barrels, cheap stocks, and other "stuff" piling up everywhere messing with my "no hoarding!" personal mantra.

Manual machinist here BTW.... I did just see a drawing over in PM showing CNC toolpaths for opening a boltface....

Opening feed rails is not a mill operation. My favorite tool for this is a 1" wide plastic handled diamond lap. I use the brass intended to feed as a gauge and open the rails with the diamond to get the release point and angle exactly where I want it. Then I use my trigger stones to polish up the edges so they don't scratch the brass. Takes me about 15-30 minutes to open up an ought six action to Ultra Mag now that I done a bunch.

HiredGun, I thought about calling or PM'ing you. Thanks for the post.

Do you open the boltfaces on those actions too I assume? Woodruff cutter for the extractor undercut or what?

Happy Thanksgiving to all! Hope your days are full of good food and family.

The extractor groove in a 700 bolt face is not round and would be pretty hard to duplicate on a manual machine.

Depending on which bolt I'm opening we just fit an M16 extractor or if there is still undercut left we machine it out and silver solder in a sleeve to get a good solid edge. Then install the M16 extractor. With an M16 extractor on a ultra mag don't forget to make the bolt nose relief large enough to clear the extractor as it jumps the rim on the brass.

Thanks. I have a PTG bolt with M16 cut that I can copy, or for that matter I bet PTG has a drawing I can access. Looked like a 1/4" endmill for the main slot, then offset it .010" for the final .260" width. The pocket in the slot obviously takes a smaller EM. Didn't look difficult. Do you use an endmill to start the hole for the pin? Looked like even a spotting drill might want to scoot off the radius.


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I've got this damn 30-06 <grin>. It was the rifle I got my first deer with. I can't seem to make myself shoot it. Recently I worked up an accurate LR load with the ELD's but I STILL never seem to shoot it. It's unused "stuff" and I'm coming to dislike having unused stuff around.

I also have a nice fast twist fluted Pac-Nor .33 caliber barrel from last year's aborted wild hair to build a big .33. It's also stuff.

Sounds like I'm a hour of feed rail work, a little lathe work opening the bolt face, and an M16 extractor cut away from combining the two unused stuffs into something cool! Sweet.

jggunsmith.wordpress.com/2010/08/07/remington-700-m16-extractor-install/

Why ANYONE responds to the idiot liberal is beyond me. Lots of idiots on the 'Fire it would seem.

AJ, thanks!

I made a couple fixturing blocks to hold the bolt in the Kurt.



As far as drilling the holes for the retaining pin, I think what the guy left out of that J&G blog post was the threaded fixture that screws into the back of the bolt, gets put in a 5c collet in an indexer, then perhaps the firing pin hole gets a dead center on a mill-top tailstock? I've got all that stuff.... conversely it looks like there's just enough to grab with a collet on the front of the bolt (before you'd hit the lugs) and put the back of the bolt w/threaded fixture on the tailstock.

That pin hole looks like more of a pain than the slot!

I just got an order for some parts with metric threads so before I switch the lathe over for that, I think I'll make that threaded fixture.

I love making tooling. Best way to learn IMHO. Made most of my chambering tooling, my JGS floating reamer holder being the main exception.

Threaded fixture for the butt end of the bolt.

Guess I'm committed now!

HiredGun,
I'm impressed. My experience is very few gunsmiths know how to properly tune or modify feed rails to make difficult to feed cartridges function well. I've done a bit of file work and polished M700 rails and ramp to improve feeding on M700's, but changing to a case with significantly different dimensions is something else.

JeffO,
Be careful my man, be very careful..........


Casey

Always liked your .sig line, Casey. Dittos!

I have two that I need to modify. The first is a ".308" action that needs opened to WSM/SAUM specs. In that case, I have a factory Rem WSM action to use as a pattern. Not too worried about that one (famous last words). I'll do that one first.

The second is the "30-06" action I'm gonna make into a RUM. That one is more concerning. I'm months away from crunch time on that one though.

HiredGun is a good dude on many levels.

Not so fast there are some real gems of info to be had..grin

My shoe laces are a bit too long.. any advice?

Do not let JO advise or you will be there all day shaking your head listening to that moron discuss the finer points of aiglets overpenetrating....

Ok, so I'm stuck waiting on material for a paying job so I went after this some more today.

Here's my setup for milling the bolt for an M16 extractor. The crux of the thing (as far as I'm seeing it now) is turning it exactly 90 degrees to drill the retaining pin hole. That's actually kind of a bitch.

So.... I matched the height of the groove in my homemade "jo blocks" to the centerline height of one of my indexers.... pulled the shroud/pin from the bolt.... screwed my threaded arbor into it..... which is then grabbed by the collet in the indexer. So after milling the slot and pocket, I can just loosen the jaws on the Kurt and rack the indexer and violá! 90 degrees.

Matching the height exactly is a tiresome iterative process and not for the impatient.

I thought of a couple other ways to do this but they were finicky and involved more "eyeball" than I like, and were less rigid. This *should* be damn near a production-level solution. Which is great since I'm doing a total of (1) of these.

Go to Brownells, check out their "v" block used for installing sako extractors in Remington bolts. Hint... skip the second "v" block they use, make a couple of straps out of 1/2" X 3/8" CRS.

Wannabe machinist... set-ups look like a monkey phűckin a football.

A monkey fücking a football......... cold as ICE!

Keep in mind that's just a mock-up. The bolt will be much deeper in the V-blocks.

I dunno man, I'm just a grasshoppa here and am always listening but I see a plenty strong, straight, repeatable setup that goes together quick (now that I spent too much time making the parts, haha), has zero finicky or eyeballin' steps, and best of all, cost me nothing.

So in the most humble way possible I will defend that setup as functional and frugal.

................... unless it blows up on me when I'm making the cut! Then it sucks.

"Vee" block I made about 15 years ago to hold bolt to cut for sako/M-16 extractors. Angled surface locates lug surface to set angle. Strap holds bolt ridigidly for machining. Set block in vise, cut slot. Turn block 90°, drill pin hole. Process takes < 45 minutes, no fiddlefűcking with indexers, threaded arbors, spacer blocks or multiple vee block. Good luck...

On the theory that monkeys just shouldn't be fücking footballs in my shop.... I ditched my first method (which was gonna work, dammit! ) and made something similar to what AJ has pictured there.





The gizmo/stop on the front is a much lamer way to clock the bolt than AJ's 45 degree (?) angled ramp, but it works.



Below, it's in the vise with a PTG/M16 bolt I used to set the height of my clocking stop. I made a "key" that sits tightly in the milled extractor slot, then eyeballed it to vertical against a ground test bar in my mill chuck. That what's happening here. Once clocked to vertical I slid the gizmo into contact with the lug and tightened it down. It seems to repeat "perfect" (yeah yeah yeah) but I'll check that more rigorously before I cut anything.



I think I have now overkilled this one to death and can cut the slot in the ONE BOLT I'm planning on modifying.

Have you figured out how much you doing this bolt yourself vs buying a tricked out PTG bolt?

Well........... I don't want to bore you with the details, but modifying this action (cheaply!) cleans up a whole bunch of constipation in my gun safe and moves several chess pieces forward in one move.

That, and I have time right now- it's the slow season for my two main customers. I also confess, shop time spent doing my own projects is very enjoyable to me.