Inconsistent ballistics

[thereal_tlc]

I’m fairly new to reloading basically learned from YouTube. Iv been having issues with my ballistics changing with each new set of loads and can’t figure out what I’m missing. I measure the powder and check it twice for each bullet and they are all pretty close in length. But being a rookie I’m not sure what all can effect it. They are always groups under 1” but one day the drop is 35” at 500 and the next it drops 50”. I’ll post a picture of my drop the last two times out.

 

[archp625]

If you are 100% you are loading the same powder charge from set to set I would say it’s your optics not tracking right. 3 MOA is a huge shift.

 

[Harvey_NW]

I think you're battling a multitude of elements and need to provide way more data or do a lot more testing to narrow any factors down.

First off on your notes I'm assuming those were the two different days of shooting and recording drops? If so the first thing I have an issue with is the fact that one day you have 100, and 200 as dead on. Ballistics are a curve, there will always be a difference/100 yards and that difference needs to be accounted for when you're compensating for and shooting distances of 500 yards +, so your zero needs to be established.

The second set of data looks to be consistently 1 moa-ish low to at least 500, so that would likely indicate a zero shift.

You said they are always groups under 1", at 100? What kind of ES is that load producing? Did you switch ANYTHING with your load; primer, powder charge, seating depth? Virgin brass or reloads, and .002" shoulder bump or hornady youtube video smash back to SAAMI? Were you shooting at the same elevation? Was there a big swing in weather or temp? Are your bases torqued and loctited, rings torqued? What kind of glass? etc..

 

[wind gypsy]

Edit previous. Your data is bad or something wild is going on.

You cant be dead on at both 100 and 200 unless you adjusted zero between the two groups or your zero shifted.

If you are truly dead on at 200 on the first data set and 6" low on the other, you are zeroed 3 MOA off from one set to the next.

Some quick numbers on your dope difference between the two groups, it is very inconsistent indicating poor zero retention and tracking or poor data gathering. Possibilities:

1. your scope doesn't track worth a crap or mounting system is moving
2. you aren't shooting good enough groups to get reliable data
3. you shot or recorded your data incorrectly

I'd bet the farm that this isn't an ammo issue if your data is accurate.

	MOA differrence
200​	-3​
300​	-1.25​
400​	-1.75​
500​	-3​
600​	-4.75​

 

[OXN939]

Edit previous. Your data is bad or something wild is going on.

You cant be dead on at both 100 and 200 unless you adjusted zero between the two groups or your zero shifted.

If you are truly dead on at 200 on the first data set and 6" low on the other, you are zeroed 3 MOA off from one set to the next.

Some quick numbers on your dope difference between the two groups, it is very inconsistent indicating poor zero retention and tracking or poor data gathering. Possibilities:

1. your scope doesn't track worth a crap or mounting system is moving
2. you aren't shooting good enough groups to get reliable data
3. you shot or recorded your data incorrectly

I'd bet the farm that this isn't an ammo issue if your data is accurate.

	MOA differrence
200​	-3​
300​	-1.25​
400​	-1.75​
500​	-3​
600​	-4.75​

Bumping this for a similar issue. I worked up a load and verified it with my standard practice- ensuring consistency between 3 distinct three round groups loaded on different occasions. The largest of these was 2/3MOA. Then shot a 100 yard group today with the exact same load, and the group was right around 2 MOA and center of the group had shifted probably 2 inches down. This is a Winchester Model 70 Extreme Weather SS wearing a Nightforce SHV in Warne rings that I personally lapped, checked the alignment on and assembled. 99% sure no screws are loose. Bullets are Barnes TTSX. Only modification between load development and today was removing the trigger to change the factory springs out for the Mcarbo spring kit. Ideas?

 

[wind gypsy]

Bumping this for a similar issue. I worked up a load and verified it with my standard practice- ensuring consistency between 3 distinct three round groups loaded on different occasions. The largest of these was 2/3MOA. Then shot a 100 yard group today with the exact same load, and the group was right around 2 MOA and center of the group had shifted probably 2 inches down. This is a Winchester Model 70 Extreme Weather SS wearing a Nightforce SHV in Warne rings that I personally lapped, checked the alignment on and assembled. 99% sure no screws are loose. Bullets are Barnes TTSX. Only modification between load development and today was removing the trigger to change the factory springs out for the Mcarbo spring kit. Ideas?

Not familiar with M70's but I assume you had to remove the stock to replace the trigger spring? First guess would be something with how the barreled action is sitting in and torqued to the stock. Any unusual pressure or contact points?

Are the rings horizontal or vertically split?

 

[OXN939]

Not familiar with M70's but I assume you had to remove the stock to replace the trigger spring? First guess would be something with how the barreled action is sitting in and torqued to the stock. Any unusual pressure or contact points?

Are the rings horizontal or vertically split?

Rings vertically split. Barrel is freefloated, stock is a glass bedded Bell and Carlson that I just checked was assembled correctly and action screws torqued to the recommended level.

One of the verification groups from load development. I measure my cartridges by COAL for the time being, which I know some people think is not precise enough for F class level accuracy, but the variations of a few thousandths that might cause is not enough to change a group from this to the size of a baseball. Right?

 

[wind gypsy]

Rings vertically split. Barrel is freefloated, stock is a glass bedded Bell and Carlson that I just checked was assembled correctly and action screws torqued to the recommended level.

One of the verification groups from load development. I measure my cartridges by COAL for the time being, which I know some people think is not precise enough for F class level accuracy, but the variations of a few thousandths that might cause is not enough to change a group from this to the size of a baseball. Right?

View attachment 254164

I don't think a few thou in seating depth change will amount to anything.

3 round groups can be deceiving but it sounds like you had quite the difference.

Ditch the vertically split scope rings. I can't say that is what the problem is but it's just a variable that I would want to eliminate for good. Post #57 in this thread below has more reading than you want to do in relation to problems with vertically split rings.

Rifle Scopes - Vertically split rings

EGW and Burris signature. The motherfucker is asking for practical advice for a Savage with no name. Nobody gives a **** what you got talked into buying

www.snipershide.com

I started a small fire when I mentioned a lot of these problems were directly related to Vertically split rings. Immediately people started calling, writing, asking me to expand and clarify which ones worked and which ones didn’t.

The short answer, spend the money and get quality rings. Shitty, $100 vertically split rings, regardless of the manufacturer are not designed for a precision rifle. Oh sure, they tell you they are, what else would they say. But they are not, they were a qualified problem. We began noting it and sure as hell, each set of vertically split rings we saw created an issue.

Torque can definitely be an issue here, as we cannot know what each ring is torqued too, but there just to many problems with combination for everyone to be a torque problem. You definitely need to understand the torquing spec’s of your scope rings and follow those guidelines as it does make a difference. Don’t believe me, test your scope with the proper torque setting and then test it after increasing the value by 10 inch pounds or more. The order in which you tighten this stuff can have a difference too.

Finding Tracking Errors is easy, do something about it
If it hurts your feelings because you happen to “own” this stuff, I can’t help you. This is the straight scoop, so if they work for you, drive on and ignore me. But if you want to do things right, I recommend you avoid them. Learn from the mistakes of others in case because it probably not “If” only “when”. - Frank Galli

 

[OXN939]

I don't think a few thou in seating depth change will amount to anything.

3 round groups can be deceiving but it sounds like you had quite the difference.

Ditch the vertically split scope rings. I can't say that is what the problem is but it's just a variable that I would want to eliminate for good. Post #57 in this thread below has more reading than you want to do in relation to problems with vertically split rings.

Rifle Scopes - Vertically split rings

EGW and Burris signature. The motherfucker is asking for practical advice for a Savage with no name. Nobody gives a **** what you got talked into buying

www.snipershide.com

Interesting. I guess I'd wonder what the difference is between this scenario and the 4 other centerfire rifles I personally own that consistently group at or below MOA with vertically split rings.

My best guess right now is that it's got something to do with either my dies or the reloading process I'm using- I am by no means a precision rifle reloading guru. Going to run a range with a few different varieties of factory ammo and see what happens from there.

 

[wind gypsy]

Interesting. I guess I'd wonder what the difference is between this scenario and the 4 other centerfire rifles I personally own that consistently group at or below MOA with vertically split rings.

My best guess right now is that it's got something to do with either my dies or the reloading process I'm using- I am by no means a precision rifle reloading guru. Going to run a range with a few different varieties of factory ammo and see what happens from there.

Those vertically split rings have to deform the scope tube pretty notably in order to work. See vid below in relation to what happens when you try to use them with a steel bar. Maybe that SHV has beefy enough scope tube that you've got a little bit of this goin on? spitballin here..

 

[OXN939]

Those vertically split rings have to deform the scope tube pretty notably in order to work. See vid below in relation to what happens when you try to use them with a steel bar. Maybe that SHV has beefy enough scope tube that you've got a little bit of this goin on? spitballin here..

My fault on the misunderstanding here- when I read the phrase "vertically split," I was thinking rings that separate vertically. Mine wears these that I suppose would be considered horizontally split.

 

[Cahunter805]

How many times fired is the brass?
New box of bullets or the same from the previous tests?
New lot of powder or same can?
I assume you reloaded more rounds to shoot today or were the ones fired today loaded at the same time as the other 3 test groups?

 

[OXN939]

How many times fired is the brass?
New box of bullets or the same from the previous tests?
New lot of powder or same can?
I assume you reloaded more rounds to shoot today or were the ones fired today loaded at the same time as the other 3 test groups?

Brass fired now 2x. Same box of bullets. Same powder. The group fired yesterday was loaded at a different time, but my load development process at least theoretically should account for variations in loading conditions- none of the other three verification groups loaded at different times changed like this. Just weird for it to be repeatable 3 times and then vary so widely on the 4th.

 

[MBAO-millennialbyageonly]

Biggest variable is the shooter not throwing rocks but did you change shooting position? Go from a bag to bipod? POI shift and groups spreading from 2/3 to 2in sounds like it would take a substantial deviation in your loading process or something gross in function ie scope rings/action torque

 

[scooter25]

You need to get a chronograph an see what the extreme spread (ES) for your loads are. Even though you may be loading the same charge weights some powders burn more consistent than others and the even the load size can change the burn rate. Ideally you want the ES to be below 20. You'll want to test a range of charge weights that are about .2-.3 grains apart until you find one that has the lowest ES. At a 100yds a difference of 40-50 fps per shot will not manifest itself very clearly. When you stretch the range out past 300yds it becomes very evident.

 

[OXN939]

You need to get a chronograph an see what the extreme spread (ES) for your loads are. Even though you may be loading the same charge weights some powders burn more consistent than others and the even the load size can change the burn rate. Ideally you want the ES to be below 20. You'll want to test a range of charge weights that are about .2-.3 grains apart until you find one that has the lowest ES. At a 100yds a difference of 40-50 fps per shot will not manifest itself very clearly. When you stretch the range out past 300yds it becomes very evident.

Did that first thing with my load development. That's the weird part- ES for this load is the lowest of any I've developed so far, to the tune of 20-25 per group.

Anyone else have this happen with TTSXes? Heard secondhand of something similar happening with a load using LRXes

 

[scooter25]

How did the group size compare to previous times? If the group size stayed consistent and you're getting consistent velocity each time you shoot a group and the atmospheric conditions aren't changing drastically the problem has to be in the optics, rifle or shooter.

 

[BRTreedogs]

I think the zero is shifting on your scope.
I wouldn't think 200 is far enough for velocity to make a 2moa shift.

 

[OXN939]

I think the zero is shifting on your scope.
I wouldn't think 200 is far enough for velocity to make a 2moa shift.

That would honestly make the most sense in this situation. But it's a Nightforce that has been babied... Really, I should try it on a proven rifle, but I only have one other with 30mm rings and don't want to screw with my #1 hunting setup.

 

[BRTreedogs]

That would honestly make the most sense in this situation. But it's a Nightforce that has been babied... Really, I should try it on a proven rifle, but I only have one other with 30mm rings and don't want to screw with my #1 hunting setup.

Something is loose, didn't get back together correctly, Pressure or not on Something new. Or something in the scope.
Nf is not impervious to damage and I believe the shv is a quality scope, but it is also there entry level.
Ammo just doesn't do that at 100 it would have to be wildy inconsistent.
You need to mount a good known scope.