Home Forums Hunting & Shooting Custom Rifles & Wildcats Bolt Timing

I've seen various posts mentioning "timing the bolt" on Remington 700's. I'm in the dark as to what this involves and what the advantages are. Just 700's, or other actions too. Please help me out on this.

Resoldering the bolt handle so that the lugs are fully engaged when the bolt handle is down. Benefit is the lugs are full engaged in their recesses as from the factory they may not be.

It has to do with primary extraction, not how the lugs are seating.

What is meant by primary extraction? I'm a little slow!

Search "Rem 700 bolt timing" in Google. There are a number of pics and videos.

Primary extraction and resetting the trigger.

When the bolt is closed the lugs should e vertical. Upon opening the bolt, the extraction cam should engage when the lugs clear the seats and the bolt should move rearward the full depth of the cam. If everthing is right, the rifle can be cocked by simply raising and lowering the bolkt handle. If not, the bolt will have to be moved back a little further than the cam will move it. There are some other aspects as well (cocking cam, cocking piece, trigger sear etc.) but this the main part.
Most, if not all, recent Model 700's have no primary extraction, will not re-cock without pulling the bolt back a bit, and the lugs are not vertical. In some special cases, everything which can possibly be wrong with a bolt, is. It is difficult to understand how or why this situation stands. There is no QC system in play. GD

Thanks for information. The more I know the more problems I have.

So if someone wanted to have acu-tig weld the handle, he would have to have the barreled action also?

No.......

In a nut shell, you need to strip the bolt, and use a feel gauge to measure the gap between the bolt handle and rear of the action.

What!!!

I thought bolt timing was about ensuring that the bolt doesn't ROTATE upon dropping the firing pin. In short, it lays down dead while the firing pin travels past the cocking cam to the primer. I've got an M 77 that jumps like an electrocuted frog when the pin drops, it is NOT a tack driver. I can make it shoot, but only if I close the bolt short, exactly the right distance using a spacer. Then the bolt lays dead and does the job.
Another M77 lays dead and makes nice groups. But if I don't close the bolt fully, yep, it makes a mess on the target.

I'll check back on this. I hate being wrong.

That is one aspect of bolt timing. The nose of the cocking piece must be clear of the cocking cam or the bolt body, when the striker is in the fired position. If it hits the off-side side of the cocking cam notch, the bolt handle will jump up. If it is hitting on the cam side, the handle will be pushed down. GD

Send it to Dan @ Accu-Tig. Just got one back from him (Rem 700). WAY better than it was when it left here. Gonna send another out this week.

Plus about 15 that Dan has done for me.

Does one need to contact him first or just send along the bolt and money?

I emailed him ahead of time. However, it's my understanding now that if you enclose a note AND payment, your good to go. Dan does ask that you mark the bolt with the measurement, as well as indicate if any other work has been done to the bolt, any special finishes applied, etc. If you'd like a different bolt handle installed, let him know in your note. I paid with a personal check made out to Dan personally, and had no hold-ups.

One other thing I found out after the fact, is that if you are using 'Euro-optics' as Dan calls them, i.e Swarovski, Kahles,etc, or optics with large ocular bells, it's a good idea to let him know.

Bolt timing on turnbolt actions is usually engineered into the design. USUALLY, needing no alteration, unless an aftermarket cocking piece and/or striker assembly is installed, or in the case of post '64 Winchesters, some Ruger 77's show either poor engineering or poor quality control in manufacturing. As other posters have noted, "timing" sequences should accomplish 3 simple tasks.
1. after a cartridge is fired, the first few degrees of bolt rotation initiates primary extraction, either with the bolt handle root camming on the rear receiver bridge or and inclined plane milled into the bolt lug recesses in the front bridge.
2. just a few degrees after primary extraction is achieved, the bolt sleeve cam begins to lift the cocking piece/striker assy. this retracts the firing pin nose .080 thousandths or so to avoid breaking the firing pin because of an off center primer strike, as the bolt rotates.
2a. now remains the rest of the bolt movement, of no interest to the discussion of timing, completion of cocking (Cock on open designs), secondary extraction, ejection, feeding and chambering
3. now we are "in battery" bolt handle closed, cartridge chambered, cocking piece held rearward with the sear engaged. As mentioned by a poster above with bolt handle "twitch", the third job of timing must be met. a: locking lugs fully engaged b: bolt handle firmly seated on the action rail or whatever register point is designed c, the striker hump PERFECTLY aligned with the longitudinal slot milled in cocking piece. In the perfect world, the striker is free to travel forward without even touching the sides of the slot. Mauser and Mannlicher are about the only actions you see with no bolt twitch. Some commercial actions will display a false twitch, which is caused by the striker hitting the cocking piece long, milliseconds, after the bullet has exited the muzzle. This can usually be detected with a little Dy-kem or a magic marker.

Hope this helps the OP, just my opinion.

Thank you for the answer to my question

Dan is the go-to guy for bolt timing. If you talk to him on the phone........you’ll be there a while.