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I developed a load in my 12 twist 22-250 with 52gr hornady bthp with 33gr of varget. Shoots a bug hole 3 shot group at 100 but I shot at 200 and it opened up to about 3-4". Wait it gets better. I put the same load through another 22-250 12 twist I own. Shoots about 1.5 at 100 then it shrinks to about 3/4" at 200. What's going on here.
And I'm shooting 3616fps average
Short Answer: Go look in a mirror. :p
Long Answer: It's most likely one of two things, either you the shooter or changing conditions. Conditions would have to change a lot to turn a bunghole group at 100 into a 3-4" group at 200, so not likely you missed a condition change that would be that obvious.
Trigger? Scope?
trigger is set to 1.5 lbs and with this scope I've shot 1/2 MOA out to 300 with the same gun but a different load I developed in the winter. Which no longer shoots good. Temps are in the 60s now
And I know it's not the shooter. This same exact thing has happened to me with varget and 50gr nbt. I'm starting to think it's the boat tail bullets. When I was shoot 1/2 MOA 100-300yards it was with flat base bullets 55gr vmax
So compared to the most current data, your load is lighter than starting loads, but running faster. No problem, but you obviously have a different burning rate than what Hodgy tested. Good info to keep about that lot.
Swapping the load into another rifle and expecting the same results, isn't going to happen. Saying it happened to you before, also doesn't rule out the shooter.
But to give you the benefit of the doubt, here are the questions to figure out if it's a component, or you.
1) Powder. You said you developed the load, and a different bullet also had this trouble. So is this the same lot of powder, or are you pretending burning rates don't change? Have you ever adjusted for the change? Have you adjustef the load for the different bullets? For the different rifles?
2) Barrel/crown. Inspect the crown, always a good bit of business. Check the bore. The coatings used in the Extreme powders, create a fouling called "hard carbon" and it's a real bear to get rid of. The smaller the bore, the faster it accumulates. Call Sierra and visit with them about it, if you want another choice on this.
3) Shooter.
If nothing else changed, you got yourself the Alabama shakes ��
In a conversation with one of the owners of Benchmark Barrels he said he used a tight patch with some Simichrome Polish on it to remove this hard carbon. I do know you can't scrub it out with just bore cleaner.Quote:
Originally Posted by darkker
This phenomenon has been observed going back to Dr. Mann's experiments around 1900. The bullet is a gyroscope, and when launched its' axis of rotation can wobble, just as a child's gyroscope does before it "goes to sleep". The wobble of course imposes aerodynamic effects on the bullet's flight, so that it actually travels in a spiral. At some distance from the muzzle, the trajectories of sequential shots will converge, but before and after they will scatter. Important factors that minimize this are the concentricity of the bullets, (form vs. center of mass), the squareness of the base, and the squareness of the barrel crown. Benchrest shooters have been known to use a tool called a "spinner" to sort out bullets that are out of balance.
That should get you started. First thing I would do is try to find better quality bullets.
[QUOTE=darkker;405772]So compared to the most current data, your load is lighter than starting loads, but running faster. No problem, but you obviously have a different burning rate than what Hodgy tested. Good info to keep about that lot.
Swapping the load into another rifle and expecting the same results, isn't going to happen. Saying it happened to you before, also doesn't rule out the shooter.
But to give you the benefit of the doubt, here are the questions to figure out if it's a component, or you.
1) Powder. You said you developed the load, and a different bullet also had this trouble. So is this the same lot of powder, or are you pretending burning rates don't change? Have you ever adjusted for the change? Have you adjustef the load for the different bullets? For the different rifles?
2) Barrel/crown. Inspect the crown, always a good bit of business. Check the bore. The coatings used in the Extreme powders, create a fouling called "hard carbon" and it's a real bear to get rid of. The smaller the bore, the faster it accumulates. Call Sierra and visit with them about it, if you want another choice on this.
3) Shooter.
If nothing else changed, you got yourself the Alabama shakes ��[/QUOT
U get your data from hogdon?? Okay cool. I went from the hornady book because last time I used hogdons I was blowing primers 2gr below max with varget and 55gr pills so I decided to start from what the book said. And ya 3616 was my average for 5 shots with a 14.3 SD. Shooting over the magnetospeed. And I wasn't hoping to to get the same results out of two guns. I thought it was weird that I could shoot a bug while with that load at 100 yards then at 200 it opened up a lot. Then with the other gun it shoots 1 1/2" at 100 and 1/2" at 200. Both with the same load. Only difference between the 2 guns being model and barrel length. I repeat I just thought it was weird.
Try to use flat base bullets for all your testing out to 300 yards. Many a bench rest shooter swear by the FB for short range because they say the bt bullets don't stabilize at those shorter distances.
I think Sierra and Berger both make them.
I've had my best luck with flat base bullets out to 300. So I Plan to go back to that. I have some 60gr sierra hp on the way. Very short bullet for the weight. Shorter than the nosler 55gr bt and vmax
[QUOTE=Savageshooter12;405791]I don't use Hodgy, but that wasn't the point I was trying to make. My point was that no one lists what lots they test, but everyone cautions that lots can vary by 10%. So grabbing a random bottle of powder doesn't mean you have the same thing as was tested in the manual of your choice. Likewise it's accepted standard to test in SAAMI minimum spec pressure barrels, which will be tighter than a mass produced rifle barrel. So while unfortunate you may have to work up another load, it isn't uncommon to have very different results.Quote:
Originally Posted by darkker
If it shoots one group nicely then the next is not so nice, it means you're not in a node.
I've put 3 shots in the same hole with a load that's not in the node so the next 2 shots verify if I'm in the node or not. 3 shot groups don't tell me much about the consistency of the load.
Also. Before I declare a load to be a good one, It has to shoot several groups of 5-shots to my satisfaction. two or three groups is not good enough for me.
Sounds like you're on the edge of a node.
Other things to looks for is bullet and powder lot numbers. When lot number change it's wise to re-test if the load doesn't shoot as good as before.