My quest for speed and accuracy with powder-coated cast bullets

[Intheshop]

I view bag riding like free recoil;

You either go all in or don't do it. Everyone is different just like each rig has it's own personality. So if the stock design,slickness,and bags allow for a good sliding ride... great. But if there's a hitch in the trip... ehh,not so good.

Like free recoil... don't half arse it. You either let the weight and balance of rig do it's thing,recoiling on it's own. Or..... work on maintaining a specific amt of shoulder pressure. Non committal on either just creates more problems.

Not sayin that's the problem here.... just a polite heads up. Heck,most of my hunting rigs have stocks intentionally set up to be grippy.... for all the right reasons. Well they are a blooming handful off formal BR style rests. Slim grippy forearms don't slide worth a hoot. And they torque like crazy. Now add a skinny barrel.

Would love to see a pressure trace as a jacked up '06 shooting 175 CB's at jacketed velocity.... "took off" from its moorings. Look at a top fuel dragster when it wheel hops on launch..... the vibrations go through the whole vehicle just looking for an exit. Cars literally jump off the track.... I'm saying that's what's happening on rifles.

It's happening on bench guns BUT they are designed (some way better than otbers) to cope with it.

 

[JWFilips]

For what it's worth: a fellow member here: Dan (quicksilver) thought me to use lambs skin (wool on) to place under my shooting rest ( Modified Hoppes with lead weights) and another piece in my rabbit ear bag in the rear! This has improved my "straight back" recoil for all my rifles!
I will never shoot without them. Groups tightened appreciably....not as much jump as I used to get

 

[fiver]

good Tip J.W.

 

[Ian]

Back on post #45, wool pads are definitely on the list next time I'm at the hardware store. I saw a photo of the firing line at a military rifle match and just about every setup had sheepskin draped over the bags, the lightbulb went on then because friction has always been an issue for me and talc/graphite on leather or Cordura makes a huge mess.

I have to agree with ItS too, build the whole system right and let it buck, or use a firm, controlling hold, no half-way. I'm pretty much halfway at the moment.

Then there's the "tactical" rifle stock which I just don't understand. Ok, the upright wrist, adjustable comb, stock lines colinear with bore line, all that makes sense...but the wide, heavy forearm is rounded on the bottom and bristling with multiple sling studs....what gives?

 

[fiver]

that's so you can mount a low and a high bi-pod on each of them and still have a sling mount for yote hunting.

 

[RicinYakima]

I have to agree with ItS too, build the whole system right and let it buck, or use a firm, controlling hold, no half-way. I'm pretty much halfway at the moment.

"free recoil" only works well with a benchrest stock, 3" wide flat forend and level line of butt bottom. Since I shoot wood military rifle stocks, a firm hold and light (10 pounds, weight of rifle?) pull back on the shoulder works for me.

 

[Intheshop]

There was a trend five or so years ago for offset forends on BR stocks.

More than likely a rehash or revisit to earlier attempts....dunno? But it was to help tame the torque on fast twist,hard kickers. Forends up to 6" wide get used in heavy varmint class(I think that's it).... anyway,these would have noticeably more stock to the left. That's when it hit me on noticing how much torque my bigger CB rigs were exhibiting. Then I started playing with the 7-08's.

It's funny,on a road racing motorcycle, if you make the chassis too stiff,you loose "feel" when at the limits of tyres adhesion...... BUT,a seasoned rider can get better laptimes. My,and others hypothesis is the process is like a staircase. You have rider development as a "tread".... bike development as the "riser". Taking one without the other don't work as well.

So apply the same thing with rifle stocks. I'm still curious about tupperware factory stocks.... but only from a "rider" development standpoint. I mean come on,think about it.
.... we(I) can dupe stocks,we'll say,or stay with wood here.... pretty much before lunch.Meaning it's stoopid easy. Conversely, laying up "moulded" stocks,be they foam core or lite wood core is also,"not that big of deal" considering any modern millwork facility.

So why not put up and shut up? It's because of the above curiosity about rubbery stocks from the "drivers" perspective,as the major,or tread..... the recoil impulse needs some place to go as the minor,or riser.

I'd love to have enough getup and go(ha) to be willing $$$ wise,to explore bipods,more than the handful of Harris's that are here. I can't seem to get those to work on the rubbery factory forearms.... when they've been clearanced on the BP. And I'm not gonna shoot them unless freefloated. But there are other bipods out there. On the heavier varmint rigs they work. Obviously it's the flimsyness...... and think there's a clue to be had concerning all this. I just haven't been able to put my finger on any exactness to it.

Some rigs will shoot off a Harris,some just get downright cantankerous. My new ADL in the sporter guise is definitely a no-go off a Harris. So it ain't completely tied to backwards recoil. It's more than likely where the vibrations are exiting the platform?

Sorry for the novel. Just a little explanation of my preoccupation with cheesy factory rubber stocks.

 

[popper]

little Hoppe's rest Those things are terrible. I'll trade my adjustable caldwell for a hornady 'delta' anytime.

 

[Ian]

Did a bunch of shooting this afternoon, not really sure what to think at this point. I used cement blocks for a front rest and a sack of shot, it felt good but didn't make any difference.

I brushed and cleaned the bore to get the lead out of the land corners, then shot another ten of the 21 bhn MX3 bullets, this time not sized. Had one case with virtually no tension, saved it for shot #5 so the last 5 would have a chance to group, that one went way low. Target is on upper left, above the last target shot day before yesterday (for comparison). Unsized bullets pretty much took care of the leading.

I cleaned the rifle again and loaded up some 63-grain SMKs. That's the target at upper right.

Since I committed to cleaning jacket fouling, I went ahead and shot six Federal 55-grain ball (first one webt into the pastie) and ten 50-grain tipped varmint rounds, target at lower right. Previously, the 50-grain factory load had shot the best of any factory ammo I had tried.

 

[fiver]

time to go over the rifle with a fine tooth comb and a magnifying glass.
it wants to shoot, but something somewhere is screwing up the harmonics.
the SMK's will shoot and the tipped ones [if they are the 50gr V-max's] will shoot in about anything with a 9 twist and give good groups.

 

[Ian]

At least it shoots the SMKs almost as badly as cast at 2750 fps.

Anyway, that's what I was trying to find out, just should have done it sooner.....rifle is unhappy.

 

[fiver]

you can tell it was trying for a 3/4" group with the smk's it just dropped those others down out of the group.
that seems to be a running theme with it.
it's bowin up on ya, or pressure at the tang, maybe even the magazine is pressin on the stock weird.

 

[Ian]

Pulled the action out of the stock this morning, front action screw was barely snug, a lot less than the 45 inch pounds or so that I torqued it to last. The blue loctite had failed because there is only one thread fully engaging the receiver. Examining the bedding points, I found the bottom of the recoil lug had been banging the stock:



The front pillar is flat on top but the receiver is round, so not much contact there and lots of room for the front receiver ring to walk/fret around, especially if the screw lost its clamp load.

I removed the front screw escutcheon and milled the pillar and stock deeper so the screw would engage fully. I also squared the ragged end of the screw, now it has 3-1/4 turns to 50 inch pounds and 1/4 turn before bottoming out. I relieved the lug recess and recoil surface as well as cut the plastic magwell/bedding block thingy away from the front and rear pillars so some real bedding compound can be put in there.

Another issue was the trigger guard inletting was off-center and putting a side load on the rear screw head. I milled the countersink in the plastic guard to releive that and drilled both pillars out from 1/4" to 17/64ths to relieve stress and bushed the screws with tape to center them and give clearance when the bedding is finished.

 

[Intheshop]

I'd be all over those important,not so little improvements Ian. Nice thing about the Rutledge stocks/action wood...... you can count the lams to check centers N such.

Smooth-On EA40 is the std by which all other epoxy is measured,and pretty much owns the mkt,when dealing with this wood in bow world BTW. I've got gallons of it if you want some. It's just downright comical hearing folks talk up other epoxy....

 

[Ian]

I'm using Pro-Bed these days, I and a lot of others feel pretty much the same way about it since it is made with the correct compression characteristics and uncured viscosity for bedding rifles. Got it curing right now.

 

[fiver]

yeah, you can see how everything was banging around right there even the pillar has some back and bang forth marks as well as the stock right in front of the pillar.

 

[Ian]

The mark right in front of the pillar was from the plastic magwell insert, it filled the area around the pillar and the front edge was getting pinched between the receiver and the wood right there. All that is gone now, replaced with Pro-Bed

 

[Intheshop]

I'll go to the 20$ "bet window" and say you are going to be very pleased with your efforts.

Just an FYI, on wood,.... and we'll stick close to the Rutledge,used to be Maple but now is Russian Birch.... that,50-60 grit grind,or finish is "prime time" for adhesion. Be DANG careful introducing chemicals etc to the cleaning process...... use filtered shop air. Acetone and lacquer thinners can hang around in the fibers,releasing themselves after glue up creating bubbles. Air has to be clean here.... as in "dry".

Try to glue up fairly quickly after grinding..... meaning,grinding( "sanding") a part then waiting a week to glue up is not what we want. Grind the part,shoot it with air,do the glue up. This is BTW,irrespective of glue type.Fine woodworking has done extensive (from a homeboy standpoint) testing on this so,don't take my word for it. This is with glue technology available to hobbyists..... which isn't giving up,that much to industry.

 

[fiver]

small rant.
is everything getting to be like this?
it's engineered and assembled... period, that's all you get.
the screw comes up a little short?
meh,, i'll spec. the next 10-K pillars to be a little shorter when I order them.
keep up the good work out there,, we are right on track to meet the per unit goal numbers this week, looks like your group is gonna be getting that 50$ bonus and the floor fans will be turned around in their direction.

 

[Ian]

I already ranted pretty much that same thing. Marveling at the engineering that went into this, it really is well-made, streamlined, easy to put together, just a few small engineering mistakes, one major part spec problem, and a process issue.

The first engineering mistake is relying on the floating magazine well to be a bedding plate, which to do any good is dependent on the monkey gluing in the pillars to get the depth correct and having some method of pre-tensioning the action in the stock while the epoxy sets. The inletting wasn't exactly to correct depth to allow that to happen, so the pillars alone support the action and the bedding plate floated, and half of the bedding concept fails.

The second engineering mistake is relying on the rear pillar and a flat, machined surface of the action to provide all of the torque support for the action. That lets everything in front of the rear pillar, from receiver rails forward, to twist and flex under recoil. To make matters worse, the process of installing the pillars obviously didn't involve the pillar being torqued to the action first because the top of the pillar and action were not and could not be made to be square with each other, so contact was only at one point, 5-O'clock, which bent and torqued the action when tightened. The screw hole at the front of the receiver had metal pushed up around it in a couple of spots, very irregular, and didn't seat well on the front action pillar...more torquing and tweaking when snugged.

The process error, again, was the pillar installation. I don't know how they did it, but it wasn't done correctly because the pillars didn't fit the action and stress was induced when the screws were tightened.

Then there is that front screw. It is a cheap, standard screw, bought in keg quantities I'm sure, with a rough-sheared end and tapered threads where it matters most. And it was 1/16" short besides. The receiver only has four full threads. If the action had been fully pressed down against the bedding block when installed with the pillars, the screw might have been long enough, but the front pillar was too long to work. There is a removable steel escutcheon for the front screw with a countersunk hole in it which could be shimmed or be selectable to make up for tolerances in stock machining, but this wasn't done.

So basically the rifle could not be put together right due to no way to adjust for tolerances and some critical, time-consuming steps being omitted for bedding the action and pillars into the stock, and the inletting being insufficient for the front tang to float. So the wheels come off the cart.

My challenge was figuring out how to fix all this, particularly since I had no way to make the pillar tops have firm, even contact with the action. If it was anything larger than a 5.56x45, I would have milled the pillars out of the stock and made new ones to fit the action, made some dummy screws to hold them, and bedded the pillars, recoil lug, and receiver rings all in once shot, then milled the pillars to the necessary depth on the bottom and put new action screws of exactly the right length in place. Too damn much work for this turd, so I am relying on the bedding around the rings plus the epoxy that flowed in between action and pillar tops to absorb the stress. When I cracked the action out of the stock this morning it was really obvious where the contact had been and where it is now, and when I cleaned up the action and put it back in, the screw torque didn't move the action around, it just set down in there and stayed put from zero to 45 inch pounds. Loosening either the front or rear screw didn't move the barrel in relation to the forearm tip, which is the ultimate goal of a stress-free bedding job.