Cannot make ballistic program and POI match!

[bigngreen]

Do not let the bottom of the grip rid up on the bag OR hit your free hand in any way during recoil, this will definitely drop rounds low. How your rifle rides the bag can have a dramatic effect on your vertical. Narrower, firmer bags along with loading your bipod forward well let the rifle ride the center of it's movement more than the tail end.

Head wind and tail winds will make a difference at these ranges but no large enough to account for what your seeing without terrain to give it a lot of vertical components.

 

[Tumbleweed]

Do not let the bottom of the grip rid up on the bag OR hit your free hand in any way during recoil, this will definitely drop rounds low. How your rifle rides the bag can have a dramatic effect on your vertical. Narrower, firmer bags along with loading your bipod forward well let the rifle ride the center of it's movement more than the tail end.

Head wind and tail winds will make a difference at these ranges but no large enough to account for what your seeing without terrain to give it a lot of vertical components.

That is precisely what i guesstimated when I looked at the bag under the grip and rear of stock. Just looked like it was cause a slight roll and lift the stock.


"Narrower, firmer bags along with loading your bipod forward well let the rifle ride the center of it's movement more than the tail end."


Can you elaborate on the above statement about the bag location? Does my bag look too big? I understand the loading of the bipod.

 

[bigngreen]

You have two points of contact with the ground, the bipod is easy to control just load it forward so the recoil comes back through the free movement in the bipod but not allowing it to hit the end and hop or scoot, this keeps the front tracking.

The rear is more complicated due to stock design, the rifle has to move back and it will follow the bottom of the stock so you want that movement the same every time. Get the bag back as far as you can, I pull the swivel studs on most of my guns but the ones that have them that's my rearward limit. You also have to keep the bag small enough that as it recoils it can come back unobstructed. My wife makes my bags from jeans also, I found my pant legs were to large and made for a soft long topped bag, I then used my daughters jeans and with rice it made a perfect bag, solid with a good surface to recoil on.

Get all set up behind the rifle, firm up your bag with your free hand just like your going to shoot, back your shoulder of and just pull straight back on your rifle and watch through the scope and see how it tracks. I don't shoot till that rifle is tracking straight back and to a constant point in vertical. With that thumb hole just move it back and forth till it's tracking and returning to the same point.

 

[Tumbleweed]

You have two points of contact with the ground, the bipod is easy to control just load it forward so the recoil comes back through the free movement in the bipod but not allowing it to hit the end and hop or scoot, this keeps the front tracking.

The rear is more complicated due to stock design, the rifle has to move back and it will follow the bottom of the stock so you want that movement the same every time. Get the bag back as far as you can, I pull the swivel studs on most of my guns but the ones that have them that's my rearward limit. You also have to keep the bag small enough that as it recoils it can come back unobstructed. My wife makes my bags from jeans also, I found my pant legs were to large and made for a soft long topped bag, I then used my daughters jeans and with rice it made a perfect bag, solid with a good surface to recoil on.

Get all set up behind the rifle, firm up your bag with your free hand just like your going to shoot, back your shoulder of and just pull straight back on your rifle and watch through the scope and see how it tracks. I don't shoot till that rifle is tracking straight back and to a constant point in vertical. With that thumb hole just move it back and forth till it's tracking and returning to the same point.

Great, thank you! We'll make a smaller bag then. I will keep the sling stud in my stock as it's a hunting rifle and the strap will be on it while hunting anyway. I would just swing the strap out of the way of the bag under hunting conditions. So if I understand you correctly, the smaller bag that I need to make will go just ahead of the sling stud? Is it possible for you to take a photo of your rifle stock setting on your rear bag positioned the way you shoot most consistently? Thanks again!

 

[cohunter14]

Tumbleweed, instead of a new bag try flipping your current one on it's side. That way you will only have 3-4 inches touching your stock instead of that entire length of the bag. Does that make sense?

 

[Tumbleweed]

Tumbleweed, instead of a new bag try flipping your current one on it's side. That way you will only have 3-4 inches touching your stock instead of that entire length of the bag. Does that make sense?

Yes. I would do that but it's just too large. It would prop the rear of the stock up way too much. I'm gonna have my wife help me make a smaller one tonight and try and dial this in.

 

[Tumbleweed]

Update on these issues:
Ok, so it took some troubleshooting and tests to resolve the issues with both rifles and I wanted to give an update so others can learn from this.
lightbulb

Starting with my 300Rum, I ended up discovering that my brass was in bad need of annealing. I have around 5 reloads on the brass and seating effort had gotten pretty stiff. So, either the lack of annealing itself caused groups to open and inconsistency to show up or... the increased seating resistance actually deformed my bullets slightly causing the same thing. Either way, after annealing and resizing it appears my rifle is back to it's old happy self. I may anneal after every two firings from now on just to keep things consistent.

With the 300 H&H, I discovered that out of this rifle I could not push the 215's fast enough to fully stabilize them causing inconsistency in groups. After running my numbers through the Berger Stability calculator that was clear. In fact I was giving up a lot of the bullet's potential B/C due to lack of stabilization. I also discovered that the rifle was in bad need of a good receiver bedding job.
After bedding the receiver and finding a load with 200 Berger Hybrids, accuracy is back and more importantly consistency is back. I'm running the 200's at 2,850fps.

Along the way I discovered problems with my rear shooting bag and the way I was using it. I made some new ones out of old jean pant legs filled with rice. The rear of the rifles are better supported now and I know this contributed to some of my problems.