Discussion in 'Advanced Gunsmithing & Engineering' started by Rustystud, Jun 16, 2015.
Thanks for posting this!
An issue that is much over-looked by many!
Old thread. Same old problem. Deserves an update.
It should be noted that I am not a gunsmith or a machinist but I do have tools and I know how to use them to a degree. Anyway, I bought a stainless 700 single shot action with the RR serial number last year from a reputable distributor. When I got the action it was making contact on one lug only but the contact was just a scratch across the back of one of the lugs. I'd call it 3-5 percent contact. Chucked the action up in the lathe and touched the primary lugs just to clean them up. Only a couple thousands off. That was better. I was then making maybe 50 percent contact on one lug. I built a jig to chuck up the bolt but didn't have the guts to use it so I started lapping. Cleaning up occasionally, using machinist blue to paint the back of the lugs and checking. Finally got it to the point that I was near 100% on one lug and 75% on the other. Good enough to start with.
Tossed a 284 barrel on, a cheap stock that I modified heavily to fit the bull barrel, bedded it and topped it with a Nightforce comp scope. Started shooting and fairly quickly found a load. Actually the biggest problem I was having in load development was that there seemed to be a lot of accuracy nodes. In the end I settled on a load that that was a little lower velocity than I wanted but was consistently shooting 1/4 to 1/2 MOA. Went to a few matches and noticed that occasionally I would have a more difficult time extracting. These are not hot loads and most just popped out. I was not having to beat the bolt back or anything but the extraction did require some effort when it happened. Started researching it the other day after a friend dropped a Pierce action with Bix'n Andy trigger off at the gunsmith that was having some timing issues. Low and behold I discovered my problem in a search that revealed this thread. I have a bolt timing issue.
I'm 99% sure that I did not remove enough to cause this and I have since read that all the Remington actions with the RR serial number have the issue but I'm measuring 40 thousands clearance between the front of the bolt handle and the bridge and 6 thousands between the back of the bolt handle and the rear of the notch. Enough so that there is no primary caming action.
So now it looks like I have four choices. Live with it, tig weld a little material to the receiver cam surface and file it until it works, move the bolt handle forward or build the the rifle into something I can sell and buy a real action from someone who knows how to build a bolt action. I can do the tig welding but I don't have the jigs for the bolt handle move and would need to take that to a real gunsmith. The rifle shoots good and I have a propensity for kicking dead horses so I'm tempted to add material to the cam surface and maybe file the back of the notch a bit to insure that I don't end up head spacing on the back of the bolt handle as the action wears.
P.S. my experience leads me to believe that all attempts to educate Remington how their rifles are designed to operate have fallen on deaf ears.
The RR's that I have dealt with have had excellent lug contact. Two of them required no cutting nor lapping of the lugs at all. Other than that, they are all over the board for everything else--especially primary extraction. Maybe I just got lucky on the lugs.
Anyway, the best all-around fix for primary extraction I've found for RRs (best meaning most bang for the buck) is to put a PTG handle on it. I assume you have a lapping jig for it, so first, un-solder the handle and clean up the bolt body. Put it in the action and put some tension on it at the face with your lapping jig. Now align it as it should be for full battery.
I use an old shroud that has the threads cut down so it will slide in and out of the bolt body while it is in battery. Use this, or whatever method to get the bolt aligned as good as possible as it would be in battery (I use a home-made gauge block in the striker slot of the shroud and the bolt and center it with feeler gauges on the sides, but you can eye-ball it pretty close).
Now clamp the bolt to the action in place with a c-clamp or similar, flip it over and, remove the shroud, etc and put the PTG handle in place. Shim the front of the handle to the bolt slot in the action with a feeler gauge to 10-15 thou. and all the way closed or maybe a hair off the bottom stop. Clamp it in place to the bolt. You'll need a custom clamp of some kind that can clamp onto the handle far enough around to allow the bolt to cycle. I use a needle-nose vice-grip with the jaws ground down in a step to contact the handle right at the step on the handle.
Now you can un-clamp the action bolt clamp used above. You should be able to still cycle the bolt with your vice-grip attached. If not, re-grind the jaws and repeat above steps. If it all cycles to your liking and the striker slot looks good in battery, then you can solder or TIG the handle on and it will be about as good as it gets short of sending it to Alex or Dan.
I learned these tricks from Chad Dixon at LRI, so he deserves any credit (or criticism). I wish I had some pictures or a video, but maybe soon. I've got an RR in a box from Brownells that may soon get the works.
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