PDA

View Full Version : to my next adventure,bedding a rifle stock



rjc
04-20-2009, 09:02 PM
I have tried a BUNCH of different loads for my 7 mag and the best i can get out of any of them is 1" groups, IT IS A WINCHESTER MODEL 70 LAREDO CLASSIC LR, IT HAS THE ALLUMINUM BLOCKS IN THE RECIVER [sorry about he caps] i would like to see if i can bed the recever? the barrel is floated but i dont know anything about glass bedding or epoxy bedding or where to start i do not know what kind of stock it is ,it is grey- blue with black specks in it, it is pretty heavy and has the wide forend .the barrel is a tapered heavy barrel with a muzzle break not adjustable it has the small holes all the way around the brake, any one know where i can start, i have been reading a bit on web sites but i need that first step or shove in the right direction.thanks.

versifier
04-21-2009, 12:28 AM
If it has aluminum blocks (or good pillars) in the stock, I don't know that bedding it would help much. That doesn't mean you couldn't try it, but I would be trying a dozen bullets of different weights and brands with ladder tests of four or five powders first.

FWIW, 1" groups @ 100yds IME is better than many factory big game rifles will do, even with careful handloading. How did it do with factory ammo and which ones (brands and bullet weights) did you try in it? What bullets and powders have you tried handloading?

rjc
04-21-2009, 09:41 PM
somewhat worse, winchester,remington, and federal were well over an inch prob around 1 1/2"- 2" what about these berger bullets are they all that?i may try some. i have tried R-22,H4350 WITH 160 nosler, hornady162,sierra162,and speer 160 so far and am fixin to try R-19 and H-4831sc,with same bullets. if i can get under 1" with a good hunting load then i will call it good and will use the same set up with targets, i am trying to make a good hunting load that will stay around 3,000 fps and give top notch performance on paper. i may be in for the long haul on this, but its kinda fun and frustrating because i usually figure stuff out fairly fast, but am at a wall on this one.ITS GETTING COSTLY.

versifier
04-21-2009, 11:51 PM
You have a good selection of powders on hand, but you've only tried one weight bullet. Before giving up, I would try Sierra 140 or 150 GK's - your rifle may simply prefer a lighter bullet than you've been trying. I've never shot Bergers in anything. Nothing against them, but I have yet to find a deer hunting accuracy need that can't be met by a Sierra GK, performance on the largest critters that can't be met by a Nosler PAR (not always the most accurate, but they do work well), or a bit of both at woods ranges with my own cast. 140GK's have been stellar performers on deer in 7-08 and 7x57 IME on deer and black bear. Flatter trajectory in your mag, too.

runfiverun
04-21-2009, 11:55 PM
you could try putting a pressure pad at the tip of the forestock with some business cards.
a deresonator that slides up and down the bbl.
have you tried changing primers with your better loads?
just neck sizing,cut your primer flash holes, primer pockets been cut?
have you weighed your fired & trimmed cases?
checked your case and bullet runout?
have you looked at your trigger pull weight,travell and over travell?
have you made a casting of your chamber to ensure concentricity?
does your bbl have tight or loose spots,have you tried lappng it?
just a few things to look at.
you also didn't mention your scope. is it parallax free at the distance you are shooting?
no mirage?
does the first shot stray from the group or is it the tenth?
are the groups round? triangular? slightly vertical?
sometimes groups are ruined just cause the rifle is canted a bit between shots.
have you tried these loads at 2 or 300 yds yet?

rjc
04-22-2009, 01:47 PM
I have been thinking of trying the 150 GK, they are very good in my 308,my gorups in the 7 mag are 3 at about 3/4" 2 almost in the same hole 3rd one opens that group of three up to about 3/4" 4th one opens it up more ,and 5th one more, i have not made any casting's or even measured the headspacing i dont know how to do this stuff yet,the 4th &5th shots start stringing up and to the left with all loads i have tried, more so on some of the hot loads with h-4350 and more so on the 160 speer btsp,and the 162 A-max hornady, im just kinda of worried that i will burn the barrel out before i get to that sweet spot,it was used when i bought it and i have run several hundred rounds threw it, after 10 rounds i always clean it up, a gun smith told me that he thought it had about a thousand rounds threw it, at least compared to rifles he knew that had that many,he did say that he thought it was in good shape though. last night i striped it down and looked it over real good bedding wise,and it does not contact the full length bedding all the way,it kinda tips back and forth from the front of the block to the back of the reciever where it should be contacting the block, when i put it back together i could grab around the front of the stock and barrel and squeeze them togeter and it was flexing at the front of the reciever, i could pull the barrel down to touch the stock the stock does not flex at the front , its the reciver giving at the front of the stock, because of not full contact with the bedding block at the front,this with the reciver bolts real tight.this seems like a problem , but im not sure.

versifier
04-22-2009, 03:37 PM
Your description was excellent. One reason your groups are opening up is because your barrel is heating up. The telltale is that they begin to open up in a gradual spiral in the direction of the barrel's twist. Mags burn a lot of powder and that produces a lot more heat than a medium capacity case. You have to let the barrel cool between shots. Leave the bolt open so air can flow through the barrel to speed the process up a bit. Even in my .308, this can take 15min or even more on a hot day. I usually bring three or four different rifles/pistols to the range. When I am testing loads in one I can practice with the others while it is cooling. A shooter friend and ex-Marine came up with what has come to be known as "The Johnson Test". He said, "If the barrel is so warm that you would be reluctant to touch the chamber area with your (certain very sensitive body part), then it needs to cool off before you do any more testing." Not that he advocated actually using said body part, his point was your barrel will be stringing before it is too hot to be uncomfortable to the touch with your fingers. Kinda like you always check a baby's bath temp with your elbow, not your hand.

This is not a big issue with a hunting rifle as your first two shots (usually all you're going to get) are right on the money. That's why many test their loads with 3shot groups, but I will not as I feel it doesn't give as good a picture of what's happening as 5shot groups do. A great idea I got from another forum is to shoot four 5shot groups with two targets, one on top of the other, and change only the front target each time. This gives you four measurable 5shot groups and a 20shot composite.

IME if the action (or scope mounts) are loose, the shots are all over the place like a shotgun pattern. (I have one rifle that requires Loctite on the action screws.) It is certainly contributing to the problem. The action should never be moving around in the stock. See if as suggested creating a pressure point at the stock's forend will help before you start mixing epoxy. Brownell's Acra Glass and Acra Glass Gel are good bedding compounds that come with excellent instructions. Pay special attention to the release agent and be sure to plug up all the holes in the action.

runfiverun
04-23-2009, 03:53 AM
when it starts to string in a direction it usually indicates something is touching on the other side.
i HAD a 7 short mag [win 70] that had the same flex in the stock you describe i finally had to shim the stock right near the chamber with the flap from an ammo box and kinda move it around till i hit the right spot.
finally had enough, and just went back to shooting my ackley. traded that win for a 7x57 charles daley when remington took over the line and have been plenty happy since.
the aluminum bedding is a good idea but if the whole stock flexes you could be hitting the magazine in there somewhere causing you problems too. or just simply rubbing the bbl chanell when it heats up.

rjc
04-23-2009, 09:57 PM
ok im kinda lost,do you mean stick a shim under the barrel at the very front of the reciever where the barrel will touch the stock,does it need to put pressure on the barrel? here is what i done first , the bbl was hitting on the very front of the reciver i used a business card and ran it all the way down the stock it hit in the front and next to the reciver so i broke it down and removed material from the bbl channel where i could slide the card from the front to the back and not touch any where and it has about 3/32" gap all the way from front to back, not a differance in shot groups,at this point. so i looked it over real good and found that the reciver was hitting at the very back of the reciver on the stock before it contacted the back of the bedding blockbedding block

runfiverun
04-25-2009, 12:15 AM
you might just need a bit of bedding compound right in the spot that floats then. if you don't have good contact between the reciever and the block it is because something is holding it up. [your tang]
it might be the bottom or side of the magazine rubbing in/on the stock holding you up.
if you have a box in the mag well and one side of it makes contact with the stock it will cause the rifle to torque also.

rjc
04-27-2009, 01:17 PM
the box is in the mag well is very tight in the stock on the sides,but it doesnt stick up higher than the stock, it is flush or just a hair shorter that the stock,if letting it cool doesnt fix it then i am going to try the pressure on the barrel and see if that helps,and i will also remove just a bit of the back of the stock so it will contact the block solid on the reciever, i will let yall know how it does,thanks.

rjc
04-30-2009, 01:25 PM
I am going to try the bedding the action first of all because there are points where it does not contact,including the recoil lug ,it has about 1/16 gap at the back of the reciever recoil lug and the recoil lug in the stock,so it has to be moving some i also had noticed a spot that was rubbed shiny on the center of the bedding block on the front of the reciver the hole lenght of the block just in the middle where the the front reciver bolt attaches to the stock block and recoil lug it was not making full contact with the lug just in the very center. my ? is, should the reciver be tight even on the sides of the stock when bedded or just on the bottom of the reciever where it is contacting the bedding, there is a small gap all the way around the reciver at the top of the stock and it is hitting the stock just below the top surface of the stock, should i remove this material and use bedding compound to make the reciever rock solid at all points?

runfiverun
05-01-2009, 11:03 PM
when i bed one thats how i do it.
i lock it in tight.
i also like to remove the stock the instant it's dry enough to remove, then torque it back in.
it might take about 10-20 shots after it's all dry to seat everything and settle it down.

rjc
05-18-2009, 08:55 PM
well , i bedded the action and the barrel down to the end of the chamber a couple weeks ago, and wow! it shoots alot better than i could ever have hoped for, im not bs'ing ,it shoots 3/8" on 2 differant bullets and powders,the same powders and bullets i was using before, my 12 year old daughter even bullseyed with it at 100 yards the bullseye was the size of a dime. i would not have ever figured it would have made that much differance, but it did. i also took my time between shots to.

runfiverun
05-19-2009, 01:27 AM
nice, it's easier than it sounds, but it is a bit daunting to do the first one.
i am glad it worked out for ya.

rjc
06-09-2009, 12:59 PM
Thanks for all the advice.