Rifle Balance Point

G

gzig5

New member
I've got a Panda in what I believe is a McMillan Hunter stock. Just put a new 26" .22 BR HV barrel on it and it is VERY front heavy. There is currently no weight in the butt. I plan on removing some of the foam and adding a weight system, shape and amount TBD but I want to keep it close to the pad. I think this barrel is about 1 1/2 lbs heavier and 4" longer than the previous 30 cal one so I'll probably need at least a pound of lead. I don't have a weight limit to worry about at this time for what I will use it for. Before I start I'm wondering if there is a rule of thumb or optimum balance point to best ride the bags. Right now the front rest needs to be close to the end of the stock and it still feels light in the rear bag. On a hunting rifle I would try to balance just in front of the action, on a varmint rifle maybe 2-3" out from the action. Same here or how far out from the action face?
It seems like the wall thickness of the stock is about 3/16 of an inch in the rear. Does that carry through towards the front of the butt? That will determine how large and deep a hole I can bore.
Whats the best tool to bore a hole into the foam without tearing it out or walking? I was thinking a Forstner or spade bit instead of a twist drill.

Greg
 
Have you shot this rifle yet? The reason I ask is that it might shoot pretty good as it is.
 
Wilbur said:
Have you shot this rifle yet? The reason I ask is that it might shoot pretty good as it is.
Click to expand...

I put twenty-five rounds through it this weekend to break in and get an idea of what it would do with different bullets. Shoot, clean, adjust scope for the first five and then a few three shot groups with 50, 55, 69, and 75gr bullets with mid-range powder charges. I was pretty pleased with the group results, but they all show vertical which could be the load or the fact that the rifle didn't fit the front bag well, or the balance point. Pic attached. I would normally put the front rest about halfway down the fore end but this rifle tips forward like that. I had the rest an inch or two back from the end and it still felt a little light in the rear bag. The table we use for ground squirrels won't allow it to be that far forward. Definitely need some weight in the back but was seeing if there was a preferred balance spot.
 

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  • Panda 22BR First Groups2.JPG
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How are you shooting the rifle? Are you shouldering it and holding it with your trigger hand? You say that your front bag does not fit the stock. What stock and what bag? I think that that needs to be addressed. I had a friend that had vertical issues with a custom varmint rifle and I think that a lot of it was because he had it in his head that the less that he contacted the rifle the better for accuracy. Years ago he had competed in short range benchrest with a properly stocked and balanced heavy varmint that he shot well that way and I do not think that he could get over that experience even though the varmint rifle and the bags that it sat in were entirely different. On the subject of holding....some fellows try it and fail and discard that method. There are rules, dos and don'ts for holding that I have found to be important and if one does it wrong that may be the problem rather than holding and shouldering in general. Getting back to my friend he added weight to the butt and that did help but the root cause was that he had a fixed idea in his head that he could not get around. He was put off by the pulse that he saw in his scope that came from a strong heart beat in his cheek. All that he would have had to do was use high rings and keep his face of of the stock but that would have been doing something different than he had heard about how to set up a game rifle, so he didn't. It all gets back to Einstien's' definition of insanity, people doing the same experiment over and over and expecting different results.
 
Boyd,
I was holding the rifle. Not a death grip but it was in my shoulder, cheek on stock, and left hand squeezing the rear bag. The front rest is a Sinclair base with a simple top and Protektor #1 bag. The bag is for a sporter type stock and too narrow for the 2 1/4" flat forend to fit in properly. I have a #2C bag on the way which should fit better. I'm weighing my options regarding a new rest top, standard vs windage vs joystick. I'm just starting the tuning and load development process. Definitely have some learning to do regarding bench technique (I do a lot more position shooting), that 36x scope shows every bobble. I have no doubt I'll be adding lead to the buttstock and rather than hogging out the foam and pouring in shot, I'd like to make an adjustable arrangement like I've seen pics of where there is a tube of sorts attached to a plate that can be fitted with differen't amounts of weight for adjustment. I hope to use this setup maybe with a different barrel for matches in the future so I don't want to make the stock permanently heavy.

Greg
 
Thanks for the info. One thing that I forgot to ask you is what trigger you have and what the pull weight is. If your bench is not moving and your rifle is supported with bags that fit, even though you are using a high magnification scope, you should not be seeing much if any movement. I think that it would be worthwhile trying to figure out where that is coming from. Have you done any dry fire practice for the purpose of sorting things out?
 
Trigger is a jewel and is at a few ounces but I haven’t weighed it. I was on the one concrete bench we have. It got better the more I shot but I was seeing 1/2 - 1+ dot worth of wiggle in the beginning of the session. No dry firing yet but that is a good idea.
 
If you are not used to that power you may be thinking that movement caused by mirage is cause by the rifle moving. As the wind increases the mirage will be blown away. It is at its greatest during a complete calm. Shooters that have previously only used scopes up to perhaps 24 power will not be familiar with this. At 36x and up it is quite evident.
 
I'm familiar with mirage from wind reading for LR/Palma/XTC. It was 33 degrees, cloudy, and last hour of light so I don't think there was much mirage. Definitely the rifle bouncing around up/down and some left/right. No doubt my current rest system is lacking and the rifle balance isn't helping.
 
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First balance point for free recoil is about 1.5 to 2" ahead of the front of the receiver. Weight the rear to where you get it. I use a lunch bag taped to the rear of the stock and use shot and pour it in the bag till you get it balanced. Weigh it and you will know what the total weight of the weight will be. I add 1oz. and melt it and pour it in a mold I made, the extra lets me clean it up on the lathe and it fits the hole in the stock. but if you don't have that mix them with epoxy and pour them in the hole you made in the stock. ...... Jim
 
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Jim,
Thanks for the numbers. Using a pencil as a fulcrum, the current balance point is 5" in front of the recoil lug, which is almost exactly halfway to the end of the forearm. Using tape and two lead ingots weighing a total of 1lb 14oz hanging at the rear of the stock, the balance point moved to 1 1/2" in front of the lug. By the time I add a plate and other hardware I'll be a little over 2lbs. If it's too far back I can trim the weight. Right now trying to decide how to best mount the weight. Thinking two stacked 7/8-1"dia by 2" long lead-filled tubes inserted into holes bored in the foam. Should be just enough room. By stacking the weights I get more balancing effect with less weight by having the center of mass closer to the end of the stock. I want to make it removable for future use of lighter 30BR and 6ppc barrels I have. Right now trying to figure out what I have on hand for material and whether to connect the tubes to the butt plate. I have several hundred pounds of lead to melt or I could use the shot and epoxy method. Leaning towards the poured lead option. As-is the stock weighs 1lb -12 1/4oz and the barreled action assy is 9lb-11oz for a total of ~11lbs 7oz. So it will end up at about 13 1/2lbs.
 
jim1K said:
The weights can't move, or you will have more problems.... Jim
Click to expand...

Understood.
Was hoping to knock this out today but I don't have any thin wall stainless on hand, unless I bore out a chunk of solid. Thought was to weld tube to the plate and insert a lead slug. Trim to length for balance and pack it so it won't move. A single 1" dia x 3" long slug would get me 1.74 lbs and with the stainless tube and plate would be close to the test weight. Suffering from a bit of analysis paralysis on the execution but getting closer.
 
There is a simple way a piece of 3/4 or 1" copper pipe cut to length and melt the amount of lead into it . . Jim
 
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