Help with these groups

[tucansam]

OK guys, a little history. This is a Savage 12 in a BVSS stock, bedded with PC7 from the recoil lug to the rear action screw (rear tang not bedded). Heavy factory barrel, YHM Phantom can on the end. I did OCW a few months back and got some decent nodes to test, tried testing those nodes a few weeks ago and everything opened up huge. Noticed that the action was loose in the stock (posted about it here) and got some good advice, tightened everything down with blue loctite.

Well just got back from the range and this is what I've got:

http://i1249.photobucket.com/albums/hh510/tucansam1/20130923_091420.jpg

The time before this, when the groups opened up, I didn't get a chance to photograph the results, but they were nearly vertical strings. If I had brought each round down on the same horizontal plane, they'd form one big hole. The above picture is the same series of loads tested, only done so after I tightened the action screws. Well, lo-and-behold, after today's range session, the action is loose again. If I press down on the barrel in the channel nearest the end of the stock, I can make the rear tang separate completely from the stock, enough to get a business card in it. I'm not sure if the heat of everything expanding did it, or the vibrations from recoil, but the action is loose again. Loose enough that I suspect its contributing to these groups.

The first time I shot these particular loads (OCW) I had several that formed one large hole. Can't get groups like that now no matter what I do. Everything else is GTG -- scope, scope base, rings, etc. Just this effing action being loose. I am about to the point where I am going to grind out and re-bed the entire thing, all the way back to the tang this time.

All ranting aside, can anyone tell me what might be going on here based on the groups? The load in #5 is known to shoot one hole groups, and there are a couple of called flyers all around, but overall the accuracy of this rifle has dropped off quite a bit.

 

[BuzzBoss915]

I seriously think this would be a good place to start: "I am about to the point where I am going to grind out and re-bed the entire thing, all the way back to the tang this time."

If you had it dialed in at one time, with this: " from the recoil lug to the rear action screw (rear tang not bedded)." I am not understanding the why?

Judging by your groups, I think one of two things is going on. You either have a bedding issue or the barrel itself is suspect. Maybe it is one that fouls easily, or you have developed a donut prematurely? Or, some barrels are better than others and you got a bad one. You can chase your tail 'til the cows come home and you can't fix a bad barrel, even a mediocre one.

But, before you throw it away, I think it is worthwhile to look at that bedding job with a critical eye. Good luck. LB

 

[tucansam]

Thanks for the reply. The rifle will shoot bugholes with factory ammo at 50Y, but opens up a bit at 100Y. With handloads I've gotten some hit-or-miss groups, but OCW results were favorable, and I've gone so far as to duplicate the one or two OCW loads that shot into a clover leaf initially -- and they've opened up a bit too. The barrel is a factory Savage, with less than 400 rounds down it, none of which have been very hot. Every time I get the action tightened down, after a range session, it loosens to the point where finger pressure on the top of the barrel and the bottom of the front of the stock, squeezing the two together, results in a little movement. Enough now that, as I said, there is a slight gap under the tang. I am running a YHM can, which isn't terribly heavy, but its not exactly light either. Even on the heavy profile varmint barrel, I'm wondering if this weight at the end is exacerbating the issue.

I am confident in my existing bedding job, other than now wanting some sort of shim under the tang... Rather than grind out the entire job and start over, I think I may just bed the tang now, by itself, and see what happens. I can always go back and re-do the entire job if that doesn't work.

I'm also contemplating bedding out into the barrel channel an inch, maybe two, to offer the barrel some additional support with the can on the end. My only concern with this is that, as the barrel heats, I'm wondering what effect it will have, pressing against the bedding. I may just keep it totally free floated for now, bed the tang, and try the barrel next if the tang bedding doesn't work.

Worst case scenario is I get to re-do the entire thing, which wouldn't be the end of the world... Just stinks trying to pin down the cause of the loose action. Both action screws ride inside pillars, and the action is fully bedded from the rear pillar to the recoil lug. So wherever the screws torque down on the action, there is bedding (and pillars). So its driving my crazy as far as what's causing enough play to make the action move in the bedding. I posted another thread about the loose action a few weeks ago and it was suggested that one of the pillars might be loose. At that point I had already used some blue loctite and wanted to see what effect it had. When I pull the rifle apart tonight to address the tang, I'll be looking very closely at those pillars.

Thanks again for the suggestions.

 

[tucansam]

Disregard all. Loose front pillar!!!!! Gonna open the wood stock up a bit and glue it in place with epoxy, as it was just pressed into place. Might do the rear pillar while I'm at it. This is what happens when I don't listen to the advice from my friends on the hide!!!!!

 

[Grump]

Yeah, the better question to open this thread would have been asking what could possibly make the action shoot loose from the bedding in so few stocks.

Just like those "bad" shooting rifles which are in fact perfect but afflicted with loose/inadequate/crooked/nasty scope bases, NOTHING will help if the action is dancing around between shots. Nothing.

So go ahead and fix that first and tell us what happens next.

 

[bodywerks]

Also, torque the action screws to 60-65in/lbs if you aren't already. I only say this because my savage manuals all say only 35-45 but that's BS. Standard practice torque for 1/4x28 anywhere from 60-120. Only time it's less is if it's a softer material or less than grip length than the diameter of the bolt.

PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg

 

[BuzzBoss915]

As I said above: "Judging by your groups, I think one of two things is going on. You either have a bedding issue or the barrel itself is suspect."

In your most recent posts, there is information that might have been useful, if included in your first post. But anyway, yes, when you have your rifle shooting tight groups and something goes to shit; the first thing to check is something mechanical, bedding or a scope issue.

Now, as to what you think happened, it is possible that the loose front action pillar "could" have been caused by whatever you did with the rear tang? Personally, dealing with pillar bedding, I like both action screws very tight, no possibility of "shooting loose". But, the front screw is tightened first, in my world. BB

 

[tucansam]

Did not bed the tang as everything I've read says to leave the tang on a Savage action floating.... I removed some material from the front pillar channel, roughed up the insides a bit, and applied some of my bedding compound (PC7) to the outside of the pillar and the inside of the channel. I also applied a very small amount over top of the existing bedding material above the hole for the pillar, after roughing up the surface, and tightened the action screws down (I alternated as you would with mounting a scope, but in the future I will tighten the front first). The pillar is now solidly bedded to the stock, the tang floated, and the action very rigid and sturdy in the stock. So for now, all is well. No movement at all.

I'm not sure what happened. The pillar was originally press-fitted into the stock. Not sure how it worked loose, but this is a very heavy barrel (26" factory heavy varmint, the gun is a 12FV) , with a QD mount, and a 20oz can on the end. I'm wondering if all the weight forward of the recoil lug, with the can attached, could have either caused the pillar to work loose, or just made worse a problem that was already present and went unnoticed by me. I'm hoping that bedding the pillar will be a permanent fix, but the only way to find out is to shoot the hell out of it. I don't want to be overly gentle with this rifle, but now I'm paranoid that if I catch the barrel on a fencepost or tree or something similar in the field, the pillar bedding job will crack loose.

I've about 50% convinced myself to buy a B&C Medalist with an aluminum block and be done with it. But this existing stock is hardwood laminate and gorgeous, and I really hope the fix works long term.

Thanks again to all for the help.

 

[Clout]

I think a wise place to start is to remove all existing bedding and pillars and start fresh. Bed the action and pillars all at once with a proven compound like devcon or marinetex and go from there...I have best luck with bedding savages from the recoil lug to the rear action screw the best way to do this is wrapping the barrel with tape midway down and a couple pieces of tape under the rear tang to float the action parallel to the stock.

 

[bodywerks]

If you've glued in those pillars and did a good bedding job and like the looks/fell of the stock you're gtg. A b&c would not be an upgrade.

PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg

 

[tucansam]

I just noticed you're in Tucson Bodywerks. Me too.

I'm not questioning your judgement, just wondering why you would consider a B&C a step down from the factory wood laminate. I had thought a reasonable entry level stock like that, esp with an aluminum block, would be better.

 

[arnie19]

I never did see what caliber your shooting .I have a Savage single shot varmint in 223 .It is a real early one .No piller bedding and no fancy trigger .I bought an after market trigger but never could get it to set right because when I would tighten down the action things would change .I had a smith bed the action and pillar bed it and now it is a tack driver .Best factory ammo I found was Norma Diamond line that was made for Norma by Black Hills . Arnie

 

[tucansam]

223 as well, blind mag. Started as a 12FV in a rubber stock. Shot pretty well but I wanted something a little more firm as I was shooting primarily from a bipod. Picked up a BVSS stock off ebay many years ago for a song. The rifle was my very first attempt at bedding and its not perfect, but it was a learning experience and it came out well. The pillar coming loose threw a wrench into the mess but its locked up tight now so I'll take it back out to the range and see what happens.

 

[bodywerks]

Not a step down. Just saying a properly bedded laminated stock is a darn good way to go. Super solid.
If i were to do a composite stock the only way if go would be manners or McMillan, and this coming from someone that rubs an hs precision!

PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg