Gunsmithing Surfin the day away. . .

[LRI]

I caught some static last fall with my alternative to bedding chassis stocks like the AICS and bedding block systems used in the H/S Precision and B/C stocks. Well, we went ahead and tried it out anyway on an AICS.

All I know is this: When I took a Stiller TAC30 out of the box and put it in the stock and tightened the rear action screw the receiver lifted over .250" off the front of the stock at the recoil lug well. This was measured in the mill with an indicator. After surfacing I did the same thing and got .004". I wasn't happy with that and learned that the trigger was hanging up by the front retaining pin. I made an addition to the program and it dropped to .0004".

From there it was gravy. Just clearance the lug, the bolt handle, and the safety lever for the Timney 511 that the customer wants to run. We've not shot it yet, but I'm very optimistic. Friday we were on a 19+ hour road trip to CO to pick up our new ceracoat curing oven. We stopped by the folks at Bighorn actions and I showed it to AJ the owner. "That's cool. . ."

If you know AJ and his machining/manufacturing background that kind of endorsement carries some weight. Least it does with me.

I've consolidated this into a single program. It's currently setup for L/H AICS stocks only. It'll only be a matter of mirroring a few features for it to work with the much more common R/H stocks.


Just another way to skin that damn cat!


Enjoy your Sunday germs.

 

[StrayDog]

Wow, wish my LH-AICS came that way!
Dixon and Goddard, there's a fine meeting of the minds.
Great to see a lefty breaking ahead of the pack, please post a final assembled pic?

 

[LRI]

After coating:

Barreled action assembled and mocked up:

Ignore the M700 bolt shroud. I just threw that on as the right one is still hanging in the oven.

 

[E. Bryant]

It makes a ton of sense to inlet the bedding block this way if you have a lot of confidence in the receiver geometry (either because you've measured it, or because it has the sort of consistency that one would expect from a precision-machined object in this modern day and age). Given what I've seen from a very small number of Stiller receivers, I'd expect them to be the ideal candidate for this sort of interface.

Now, if it was a factory receiver that some monkey had "cleaned up" with a belt sander or grinder prior to finishing, and said receiver was not properly characterized and the chassis inletting adjusted accordingly, then I see where a V-block would probably produce equal or better results. I think this is the scenario that caused the noise during your initial post on this topic.

 

[lw8]

Awesome work. Great concept for a non bedded system. If I had an HS stock or one of the aluminum V blocks, I would be considering this.

 

[mdesign]

Interesting Chad...interesting. I remember the comments from last fall but from an engineering perspective, this makes a lot of sense.

True, the Stiller or other quality actions are probably more consistent in size and diameter but still going from .25 to .0004 is a lot of difference. Been cool to see the groups before and after machining.

 

[LRI]

Fitted

It makes a ton of sense to inlet the bedding block this way if you have a lot of confidence in the receiver geometry (either because you've measured it, or because it has the sort of consistency that one would expect from a precision-machined object in this modern day and age). Given what I've seen from a very small number of Stiller receivers, I'd expect them to be the ideal candidate for this sort of interface.

Now, if it was a factory receiver that some monkey had "cleaned up" with a belt sander or grinder prior to finishing, and said receiver was not properly characterized and the chassis inletting adjusted accordingly, then I see where a V-block would probably produce equal or better results. I think this is the scenario that caused the noise during your initial post on this topic.

While I agree in spirit, there's some practical experience here that kinda suggests otherwise. As I mentioned I wrote about this last summer after trying it on H/S fitted M24s used by an international security and risk management company. These are operational weapons used for training. The course of fire is 1500+ rounds per class. The point being these guns are shot. A lot!

I'm in frequent contact w/the head of the training and their staff armorer. Guns are shooting well. Extremely well. Students are posting better scores overall and the guns aren't showing the sensitivity to different ammo lots.

These are M700s guys. Not high dollar custom receivers. The actions were trued by us as well as fitted w/new barrels.

The surface machining op may or may not be responsible for the improved performance. I just simply can't conclusively say that.


What I can say is the rifles are working very well. So its certainly not hurting anything. We've done 31 rifles this way to date.

So maybe a little taper/wiggle in a receiver isn't the end of the earth afterall. Or maybe I'm just getting extremely lucky. The intent is to eliminate the action screw torque sensitivity and to hopefully widen the performance envelope.

Time will tell. . .

 

[coast2coast]

After coating:

That's a work of art, Chad. Nice work.
And x2 on the +1 to a lefty innovator!

 

[armorpl8]

If the AICS started off as a V-block and you resurfaced to a full radius, wouldn't you drastically change the Z-axis relation between the action and the magazine latch?
It seems that the action would now sit much lower in the chassis, causing a problem with the magazine position and maybe even causing the bottom tip of the trigger to interfere with the bottom of the trigger guard part of the molded skins. Just curious how you could do the resurface without changing the vertical necessities without building up more material on top of the chassis frame before cutting?

Thanks for listening to my stupid questions.
Clay.

 

[LRI]

It absolutely alters the relationship between receiver/magazine. So you just shorten the latch and drop the magazine accordingly. Were only talking .05". It's not a drastic change. In the case of the AICS it does require a little extra work though. The AICS magazine release has a pocket on the back side to give the coil spring some additional room. Removal of the .05" "ish" material results in blowing through the pocket. This would mean that only the corners would purchase on the magazine latch feature. So, I just filled the pocket with a touch of filler rod on the TIG welder and that gave me good material to machine into. 10 minute job.

Easy stuff, already addressed, already solved. Runs a magazine like poop through a milk fed goose.

 

[E. Bryant]

So maybe a little taper/wiggle in a receiver isn't the end of the earth afterall.

Nonsense, Chad - I read over on a benchrest forum that this is the end of the world, and that totally trumps any experience you may have with a large number of rifles in the real world.

Insert winking smilies as you see fit.

If you're confident that there is a consistent portion of the receiver, and that you've characterized it properly, and that you've then generated the appropriate geometry in the chassis, then I see absolutely no reason why this wouldn't work superbly.

 

[mdesign]

Chad...I'm curious about the .0004 runout. Would that be typical of a quality pillar bedding job using epoxy and pillars or does this work on a chassis stock produce better results? Seems to me that .0004 is better than most.

 

[300sniper]

Lbs of force required to start a cylinder pulled into a vee block moving vs. a cylinder pulled onto a round channel?

 

[skyesdad]

After reading this thread and having trouble with my bell&carlson stocked rifle I call Chad up and talked to him wound up sending him the rifle and when it returned it was amazing in that it was back to being predictable and grouping. This is not a custom built rifle but a untrued action and stock varmint barreled Remington 700, it is very refreshing to be able to pick the gun up and feel that it is going to do what it is supposed to do before chad got to work on it the best group it would manage was a wonderfully tight 1" at 100 yards period the end when it returned I shot several groups that were 4 shots touching ( could have been 5 but pulled shots blow ) any how if you are on the fence about sending a rifle in that is in a B&C stock do it.

 

[wildcats]

Chad,You need to perform this procedure on the my AICS stock you have there for the remy remix.

 

[LRI]

Will, will do!

Were close to wrapping you up brother. Bolts supposed to be done soon.

C.

 

[JGorski]

Farging shite! Nice work brother, hope to see some pics of my build soon, stock is on it's way this afternoon, you know Im such a pic whore, so.......

 

[xXlojackXx]

Chad...I'm curious about the .0004 runout. Would that be typical of a quality pillar bedding job using epoxy and pillars or does this work on a chassis stock produce better results? Seems to me that .0004 is better than most.

+1. Chad, how does the .0004" runout compare to a properly epoxy bedded action? I would imagine your re-milled bedding block would be more consistent across the board than the same number of epoxy bedded actions, only due to the ability to reproduce the exact same end result on a machine vs. bedding an action by hand?

Would you go as far as to say that you would recommend your new method of milling an aluminum bedding block over epoxy pillar bedding the same action?