Dramatic Loss of Accuracy past 100 yards. Anyone have any idea what is going on here
- Thread starter loudandproud
- Start date
When I have full on mirage going I shoot to practice reading the wind and mirage, because shooting tiny groups becomes almost impossible. What were the conditions like?
Also, what scope are you using? 100% positive that parallax was not an issue? Other than mirage and parallax, I don't see what could cause it to open up that bad.
Also, what scope are you using? 100% positive that parallax was not an issue? Other than mirage and parallax, I don't see what could cause it to open up that bad.
Rookie mistake! Do your load development at 200 or 300 yards... not 100.... gives you a better idea what's going on... I've had that happen with a 23rd before.... If you test at 100 your basically getting a 100 yard load... shoot out further to get a true visual of what's going on... you don't have the right load worked up in this case
This is just a suggestion. Sounds like you just need to get down to the very basics and start diagnosing what is going on. Start with the rifle and make sure it is solid and the scope is mounted up completely level. When you start shooting put it in a good rest to rule out human error or have someone you trust can shoot put a few down range. Just eliminate things one at a time. Best of luck.
If I recall it was threaded a 1.2* angle.
See bold.
Savage's QC has suffered greatly over the past few years. If your scope is zero'd and tightened down than this could very well be a receiver issue.
You don't shoot parallel to the ground, you shoot at an angle. If that angle is off because your barrel is canted, than it's definitely not something you would notice @ 100...But @ 300-400 absolutely.
I've seen USMC snipers actually mar the living shit out of their crowns just to shoot the same exact MOA they shot before -- I'm not a believer in the perfect crown "theory", or that it's the end all be all to accuracy and there are many articles about it on the forums...Will it make some difference? Sure...Especially if there's an obstruction...But, cause a 1-4moa POI shift? Nah.
I had that happen with 130 Bergers. First load I tried in my 260 bug holed at 100 and then took it to 600 and it had a pattern a shotgun would laugh at. I stated over at 600 and am glad I did.
I don't mess around with 100 anymore.
I don't mess around with 100 anymore.
Not to question op's load. ;-)
But did you try the same 300 yd with good factory match load? Does it open up like your load or does it give you good grouping?
If a good factory match load give you good grouping, why not take the bullet apart and copy that load.
But did you try the same 300 yd with good factory match load? Does it open up like your load or does it give you good grouping?
If a good factory match load give you good grouping, why not take the bullet apart and copy that load.
There is no factory available match mo for a 7mm wby. The factory weatherby stuff shoots like shit just about everywhere though 2 MOA at 100 yards all the way out to 400 yards.
I have a 243 that does the same thing with 115gr DTAC's, great at 100 and even 200 then it goes to $h!t at 400 I would see a keyhole or 2
. I my case it the barrel it's a 1-8.5 and just isn't fast enough twist for the DTACs. It shoots 105gr AMAX's just fine. I would suggest the same thing others have suggested do a ladder at 300.. I'm betting the bullets are loosing stability.
. I my case it the barrel it's a 1-8.5 and just isn't fast enough twist for the DTACs. It shoots 105gr AMAX's just fine. I would suggest the same thing others have suggested do a ladder at 300.. I'm betting the bullets are loosing stability.
LoudandProud: excellent question! I believe there is nothing wrong with your brake, crown, parallax, or shooting ability. Your extreme spread, Standard Deviation and 100 yard groups indicate quality loads. However, as you know, something is not correct...just as under rotating a bullet can cause stability problems down range, so can over rotating! Your 1 in 9 twist is made for heavier/slower bullets. Believe it or not, slamming a very fast bullet into that fast twist rate DAMAGES the bullet...beyond the design specs of the bullet. The damaged bullet may group OK at 100 yards, but as it goes down range the "damage" contributes more and more error. Switch to a heavier/slower bullet that your barrel was designed for, and you will be a happy shooter.
Your theory may be strengthen after today. Keep in mind, a 7mm Weatherby has almost 3/8" freebore bore the bullet contacts the lands. 3100 fps into high twist lands may be doing something.
Here are the results from today, better but still poor.
There is a lot of Vertical dispersion on the Hornady SST Load (3120 fps)
Also below is a mild 168 SMK (not sgk as the target reads)... 2930 fps.
Much less vertical dispersion, and without that winger (probably me), it would have a good group.
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Hope it all works out. The thing to remember about the 7mm Weatherby, is it was designed in an age when speed was king...It had a 1 in 12 twist! to launch small light bullets and be the fastest kid on the block. Today, we understand and appreciate high BCs. Those high BCs are achieved with long slender HEAVY bullets. So today's manufactures of the 7mm Weatherby increase the twist to 1 in 9 instead the orginal 1 in 12 assuming you will be using the highest BC / heaviest bullet you can get your hands on.
