Just finished these up, they are going on a pre-'64 model 70 in 375 H&H. I normally fit the bases to the action and then mill the final dovetail and contours while on the action, aligned with the barrel. Also a shot of the stock the action will be going into and only started the finish

Love to see them done that way! Very nice.

Jim, Do you have dimensions of the dovetail feature that you can share, or are you just removing material until the rings fit? I've contacted Talley about getting the dimensions of the dovetail, but never got a response.
Greg

I have not measured up the dovetyail and have also asked for dimensions. I cut the flat on the top of the d'tail to .500 and the start by taking an equal amount off both sides with the dovetail cutter untion I get a nic snug fit without too much gap in the clamp piece.

I can imagine it would be easy enough to measure the distance on a set of original Talleys.

J.Earl Bridges made me a set about 10 years ago by attaching bar stock to a M70 action, then milling while on the action to achieve concentricity with the bore. That allowed him to place the scope extremely low, with the best eye alignment of any gun I have ever owned.
The scope was able to be zeroed in the exact center of its' adjustment range because of this alignment. It is not only the most accurate setup I have, but shoots nearly all weight bullets to the same POI at 100 yds (they drop differently at longer ranges, of course). I have QD Talley rings on that rig, and have taken that scope off/ on dozens of times with absolute return to within 1/4" of zero every time.
That is a great way to align bases.Looks like you are doing a great job of it. If I could afford to, all of my scopes would be fit with such bases.

quote:

to achieve concentricity with the bore

I would be interested in hearing how this is done.

I would imagine that one would clamp the action in the Kurt, and then indicate it. But how would that be done? Do you indicate on the inside threads of the action, or the interior of the barrel, or where?

22WRF,

You are going to have to forgive me, I am not a machinist or gunsmith. I am assuming this is a serious question and not a sarcastic one, hard to tell the tone in typewritten words.
J. Earl showed me what he did, I stood at the machine and listened, but could not explain in more detail or in other terms than layman's terms as I have. I probably should have used the phrase "parallel with the concentricity of the bore", or some such, but I explained it as he explained it to me, with 10 years in between to get it not quite right.
If you are interested, I could ask him. He still offers these custom bases and is now working out of Seguin, TX. Or, someone with more detailed knowledge of a machine shop may chime in and tell us. If not, I would be glad to get a detailed description of the process and post it here.
I didn't mean to distract from the original post, nor to take away from his accomplishments. I just saw an idea that I had some limited experience of, and decided to share my experience.

Talley will send you a .pdf or .dxf for the dovetail cuts to match thier rings. The mounts I just did (see a bit below) were made roughly to these dimensions. I found that the rings I had were slightly different dimensions so I made the mounts closer to the rings dimensions.

22WRF, I hesitate to speak for Mr.Earl not knowing him or his process, but based on what Aggie said, I would believe he meant parallel to the centerline of the receiver. There are a number of ways to achieve this with varying degree's of "trueness"

Jim, great looking bases! Mind if I copy them for my next set?

Thanks Fal Grunt. That is exactly what I meant, only took me three tries to get it right!

That's why I've been on this forum 7 years and only posted a hundred or so times. I'm usually better off just keeping my fingers off of the keyboard unless my brain is fully engaged.

Anyway, as an end user of the process, it works and looks good as well.

I was serious about the question.
The reason I was asking is because I have seen other posts on here where it was stated that on many occasions the threads for the barrel are not totally parallel with the rest of the action. So I was thinking that if one set the action up in a vise with an indicator measuring from front to back and side to side to get the action straight in the vise, that wouldn't necessarily mean that the threads, and hence the barrel, would be parallel to the scope bases.

But then, what do I know?

WRF,
That was a good question that deserves a good answer, and you are correct in your analysis, like anything else if done wrong one could ruin a rifle.

I watched Rick Stickley cut dovetails in a Mauser actions front and rear rings and then make a slide that covered them that had retention pin with a spring, and the rifle looked like a clean receiver until you slide those almost hidden covers off and presto you stuck on your scope..It was awesome.

Such inovations as this make a big bore rifle suitable for both irons and scopes as they should be as one of my pet peeves it some of the junky ways some guys cover up the iron sights with bases or make the irons work with high rear and front sights, what a mess....Have they ever shot a damn rifle is my questions when I see such stuff..That is the beauty of the new Ruger African, off comes the scope and presto you see the irons clear as a bell because the base are part of the action rings, I wack off a bit of the comb to get down on the irons and I'm in business with the big kickers. I won't go into the bush after wounded Dangerous Game with a scope, I use irons.

22 WRF,

I understand what your concern is. The rifle in question had been trued, which I'm sure would clean up minor discrepancies between the barrel and action. If there were more blatant issues, I'm not sure that action would be suitable for any custom work, or maybe the bases could be aligned with the chamber and barrel instead of the action. If it were way out of alignment it might look obvious.

As an aside, on the action in question, I had to send 2 actions back to Winchester because the rear receiver ring was(factory) D & T'd WAY out of alignment from the front holes. This was back before the closure of New Haven's plant making M70's. I'm sure those actions could have been made to work with such bases, but they were drilled pretty far off to the side of the ring, and the bases would have looked noticeably different.

quote:

Originally posted by Aggie:
22 WRF,

I understand what your concern is. The rifle in question had been trued, which I'm sure would clean up minor discrepancies between the barrel and action. If there were more blatant issues, I'm not sure that action would be suitable for any custom work, or maybe the bases could be aligned with the chamber and barrel instead of the action. If it were way out of alignment it might look obvious.

As an aside, on the action in question, I had to send 2 actions back to Winchester because the rear receiver ring was(factory) D & T'd WAY out of alignment from the front holes. This was back before the closure of New Haven's plant making M70's. I'm sure those actions could have been made to work with such bases, but they were drilled pretty far off to the side of the ring, and the bases would have looked noticeably different.

I have not yet found a model 70 receiver that hat the guard screws or the scope mount screws in alighment with the centerline of the bore. I normally have to offset one or the other of the bases to compensate for this alignment, in this case the rear base had to be drill of center about .020" to compensate for it. WHen I mill the dovetails, I normally check for alignment with a borescope before I finalize the dovetail cut.

quote:

Originally posted by Jim Kobe:
I have not measured up the dovetyail and have also asked for dimensions. I cut the flat on the top of the d'tail to .500 and the start by taking an equal amount off both sides with the dovetail cutter untion I get a nic snug fit without too much gap in the clamp piece.

I can imagine it would be easy enough to measure the distance on a set of original Talleys.

Thanks Jim, I guess I'll pester them again and if they reply I will share the document. Otherwise I will use your procedure, which is probably best to get a perfect fit for a given set of rings.

22WRF
The two times I've drilled new holes for scope bases, I turned a mandrel between centers to a slip fit with the bolt raceway that was long enough to stick out each end a couple of inches. The action rails (Rem700) were then indicated to make sure the action wasn't rotated in the vice and the holes would end up on TDC (top dead center). Then, indicating off of that mandrel the action was set level and the vice adjusted to give me a reading of +/- .001" at each end, meaning it was parallel to the ways of the milling machine. Lastly, measuring off the mandrel, the mill table was moved to align the spindle with the center line of the action. Everything is then re-checked and when I was happy with the alignment, I drilled and tapped the holes one at a time. If there is a more accurate way, I'm all ears.

A flat bottom action should be easier to set up because it can be bolted to a fixture to hold it level in the mill vice. Same could be done for the round actions too I guess, if you trust the factory to put the action screw holes in the right place, which I don't.