PDA

View Full Version : Pillar bedding non-accur-trigger LA



sa-shooter
02-01-2014, 02:33 PM
I was wondering how some have dealt with the rear pillar for a LA(.223) non-accu-trigger, the sear being so close to the action screw. I think I have a solution but wanted to know what others have done.
Also please explain why you want to only bed the rear of the recoil lug. I know you don't want the lug putting up-ward pressure on the action so it shouldn't bottom out on the stock and you want the barrel-nut free floated,but I am not understandiding why no bedding in front of the lug.I bedded match 54 Anschutz's and always formed a new lug with the bedding material.


Thanks

drybean
02-01-2014, 02:35 PM
notch the rear pillar so it clears the sear

drybean

David_4
02-01-2014, 02:41 PM
Take a look at this

http://www.varminthuntinginternational.com/Stock%20Bedding.html

J.Baker
02-01-2014, 03:53 PM
Grinding on the sear to relieve it just to use a full pillar rather than notching the pillar is a bad idea IMO. A pillar is a pillar - doesn't matter if it's full circle or a half circle. Combine that with the fact that most people seeking the best possible accuracy will glass bed as well which will offer up far more surface contact area than that half a pillar ever would. Sears are also a controlled part from Savage so if you screwed it up you'd be S.O.L. Additionally, notching it light that could weaken it enough to cause other issues and in the absence of any benefit I don't see why anyone would consider taking the risk.

sa-shooter
02-01-2014, 06:36 PM
Thanks everybody for the replies. I also think that notching the sear is not a good idea. only alternative is notching the pillar,but then it has very little foundation for the action to sit on.
here's my plan I will use a 3/4w x 1" L x 1" H block of 6061 aluminum. my stock (Tacti-Cool ) has a set back or notch to clear the sear that is .200 wide. the action screw's hole outside edge forward of the trigger inlet is at .450,so forward of this edge will be solid aluminum that the action will sit on once bedded with Devcon1010 even with the notch I should have a solid pillar. the front pillar will be 1"w x 1" L x 3/4" H and finished off with a traditional round pillar from the bottom. I did a similar pillar bedding for a H&R M-12 the rear action screw was offset also leaving vey lttile pillar foundation,but I didn't have to notch it.
If I remeber I will take some pics as I go along for those who might be interested on how it comes out.

Thanks

foxx
02-01-2014, 08:37 PM
I don't get it. Why not just bed it in Devcon 10110 and not worry about the fact the rear of the rear pillar needs to be notched a bit? As J..Baker said, once its done the pillar doesn't really matter b/c the bedding is covering all the surface area available on the action anyhow.

BillPa
02-01-2014, 09:20 PM
I don't get it. Why not just bed it in Devcon 10110 and not worry about the fact the rear of the rear pillar needs to be notched a bit? As J..Baker said, once its done the pillar doesn't really matter b/c the bedding is covering all the surface area available on the action anyhow.

Because the rear pillar serves the same function as the front one, prevents stock material compression from screw torque.

Bill

sa-shooter
02-01-2014, 09:52 PM
Thanks BillPa for explaning. bedding compund is used to form a surgical glove like fit to the action it fills any voids that the stock inletting may have. pillars are used so as BillPA explained to prevent compression of the stock if no pillars are used you will not have a stable platform for action to sit on, your torque settings would change over time as the stock settles and compress

foxx
02-01-2014, 10:00 PM
Well I don't mean to suggest you don't need pillars. I just don't see why the pillars need to be so large as to completely encircle the screw. The front half of the rear pillar provides support and the bedding is locked into it so the pillar is effectively enlarged, albeit not behind the back half of the rear screw. i.e. just how big of a pillar do you really need?

sa-shooter
02-01-2014, 11:30 PM
Well I don't mean to suggest you don't need pillars. I just don't see why the pillars need to be so large as to completely encircle the screw. The front half of the rear pillar provides support and the bedding is locked into it so the pillar is effectively enlarged, albeit not behind the back half of the rear screw. i.e. just how big of a pillar do you really need?

The idea is to spread as much of the load force being applied to the action screws as the shot is fired, it should aslo help in absorbing the harmonic vibrations caused by the round going off

thomae
02-02-2014, 03:36 PM
The idea is to spread as much of the load force being applied to the action screws as the shot is fired, it should aslo help in absorbing the harmonic vibrations caused by the round going off

Here is some food for thought.

My opinion is that you are overthinking this, and perhaps creating a problem where none really exists.
Many very accurate rifles utilize the pillar cut out for the sear.

Presuming your stock is properly bedded, I don't believe you are going to change the amount of load force being applied to the action screws. Ideally the action screws are centered in the pillars and not actually touching the sides of the pillars. Even if they do touch, the area of the pillar near the trigger has no stock area to which it can transfer any force because it isn't touching anything.

What the pillars do, as stated earlier, is to provide a mechanical top-to-bottom (radial) lockup so the action screws can be torqued consistently each time in order that the load of the rifle action against the bedding is consistent each and every time.

I disagree with your statement about absorbing harmonic vibration. I believe you are mistaken. I wonder where that notion come from? The physical properties of the respective metals dictate that the action, recoil lug, and pillars/action screws and any other metal parts will transfer force with absolutely minimal absorbtion.
Their precise configuration may change the pattern of vibrations, but the harmonic vibrations will still be there and that is why hand loaders develop accuracy loads - to take the harmonic vibration of the barrel into account so that the projectile leaves at approximately the same point in the vibration cycle of the muzzle.

Please don't take this as a personal attack, and you are free to do as you wish. With your obvious attention to detail, I am sure your results will be positive. However, you might achieve the same end results (accuracy or precision) even if you installed your pillars and bedding differently.

foxx
02-02-2014, 03:49 PM
+1 Thomae

That is what I was trying to say and just could not get it said. Doesn't mean it won't work, just don't see why bothering with all that.

sa-shooter
02-02-2014, 08:01 PM
Thomae, I do not take what you or others are saying as a personal attack and if my response to some of the replies made it seem that way I apologize.I ask for opinions on what others have done to deal with the rear pillar as I wanted to see if there was any other ideas that I could use. I was going to use standard round pillars and notch the rear. but I always look at things from a second view or thought just to see if it would make a difference( I guess I have too much time on my hands ) and I do appreciate the suggestions and opinions to just use regular pillars to save me the extra work. On the vibration issue I think I was misunderstood as I don't mean to imply that it will eliminate the vibrations,harmonic vibration will always be there, one school of thought on bedding is to also help absorb vibrations away from the barrel and action, and I understand handloads can be taylored to time if not for a better word the harmonic vibrations or barrrel whip so the bullet exits at the same wave length eveytime. I would be interested in your opinion on barrel tuners the kind that attach to the end of the barrel isn't this to change the harmonics ? I do not handload (as of now) so I am stuck using factory loads, I am just trying to see what I can do to the rifle to make it shoot factory loads better.Thanks

foxx
02-02-2014, 09:19 PM
Hey, sa-shooter I am confident barrel tuners work to improve accuracy by allowing the barrel's harmonics to be tuned to the bullet as opposed to the bullet to the barrel. The Browning's BOSS does this quite well. I own one and have experienced success with it. I have also seen others who use such tuners to further tighten groups after developing hand loads. One of the best examples I have seen of these devices is what Erik Cortina from Team Lapua USA produces and has demonstrated effectively on other web sites.

The theory behind how these work makes sense to me. I don't think it is in any way related to pillar and bedding issues, however.

thomae
02-02-2014, 09:49 PM
There is always more than one way to skin a cat.

If you start out with a round rear pillar, you can also grind off with your dremel the absolute minimum required to ensure clearance with the sear.

Barrel Tuners? I have never used them. My understanding is that they do work, both the Browning BOSS type as well as the Limbsaver-type donut. They change the barrel vibration to match the load, as foxx said ("That's what the foxx says!" ) instead of tuning a load to match the barrel.

Since you will be using factory ammo, yes, I would try a barrel tuner. It certainly can't hurt.