What does this grouping mean?

[JAYgs8163]

Everyone is giving you multiple items to consider but YOU already know you have issue with cheek weld as you stated in your SECOND post. Trying to hold your head up while shooting groups is not very effective.

1st- Eliminate the cheek weld issue and then go from there. I mentioned this in my prior post. This will probably correct your issue.
2nd- if you are way over max load like @Rflshootr mentioned then back off. After both of those are fixed then try the rest of the suggested items. I would say cheek weld at this point is your biggest issue.

 

[aushunter1]

Started using my hornady comparator to get all my seating depths the same. So for these, they're all seated to be 2.731 base to datum, +/- 0.001

Im not sure what you mean by this?
You mean CBTO or cartridge base to ogive right!
The datum is on the case shoulder & used for your headspace measurement!

I don't have a good cheek weld because my scope is sitting too high... Therefore I sometimes find it hard to duplicate the amount of downward pressure I'm placing onto the stock at the grip.

There is your starting point, eliminate bad shooting/head position & your groups will improve.
Scope height is part of this, your scope should be as close to the bore line as possible imo!

There are a few powder charges is those results you could work on by changing the CBTO.

Everyone has there own process but I always start at .010 off the lands(as long as the mag lets me) find a good node, then start changing my CBTO to 0.05 & 0.015, 0.020.

I have 2 Tikka T3's 260's & they shoot very accurately out of the box for the coin outlay, in saying that I am not a fan of their stock so both of mine are in aftermarket stocks, one with full alloy bedding & the other in a pillar & glass bedded Boyds laminate, Titanuam recoil lug.

If you are going to stick to the factory stock I would be doing something like this recoil lug & pillar upgrade, but thats me

Lumley Tikka T3 Bedding Kit - Titanium Recoil Lug

www.deltatactical.com.au

 

[anwahs]

Have you checked your scope? May not be holding zero.

 

[Jrainey]

Forgive me if this has a

I get these groups with a bit of regularity. The pairs won't necessarily always be in that same spacial orientation. Can anyone tell me what is most likely to be causing it?

I get these groups with a bit of regularity. The pairs won't necessarily always be in that same spacial orientation. Can anyone tell me what is most likely to be causing it?

Forgive me if this has already been mentioned.
I'm far from an authority, but I've seen that a couple times myself. 1 was fixed by bedding recoil lug area in a Remington 700.
2nd was tamed down by running a little load.
3rd was change seating depth by 10 thousandths.
I have also learned that some days I just can't get right!!!!

 

[Tac-O]

I was going to suggest you weight sort your brass until you revealed the issue. You can burn an enormous amount of powder chasing cheek weld. If the gun doesn't snap into place like a lego block you can't focus on the other fundamentals.

I sort my brass. These are all within 1 grain

 

[Tac-O]

How young are you , me hearing 68? This happens to my groupings when I get tired. I am in to BR shooting so even 0, 1 mm. hurts!

I'm 33. is that good or bad in this case?

 

[Tac-O]

"It's a 30 06 tikka t3x superlite stainless barrel synthetic stock. I used a Dremel to remove extra stock material around the forearm to give it extra float."
So this is a plastic stock then.... and you didn't say that it is bedded. The tikka tupperware stocks are weak in the forearm area and you removed more material from the stock. Is this correct? Most of these T3 tupperware...stocks are flexy in the forearm area from the factory and to build yourself a truly stable platform with an eye to consistency, they need to be stabilized in the forearm to get rid of any flex. I don't generally use plastic stocked rifles just for this reason however I did buy a Remmy sp varmint barreled 243 and was able to turn it into a tack driver by not only bedding and putting pillars in the action and first part of the barrel but by stabilizing the stock with Matchgrade Synthetic Stock Stabilizer. My best guess is that this is the area that is causing your troubles. Try twisting your stock forearm...if it moves this will more than likely confirm that you have this issue. You can find this stabilizer kit in the US... just do a search. Also, you can read about this exact issue regarding T3 stocks at ballisticstudies.com. That group in my proflle picture was shot with that Remmy rifle with the stock that I mentioned... and it will consistently lay down groups like this. Do try and flex the forearm on your rifle and let us know what fixes it for you. As other have said this sounds like a stock issue.
Best of luck,
Tens

The foreend of my stock definitely flexes with some effort! Not a lot though. My recoil lug is tight as can be!!! When I've removed it from the stock, I've had to use pliers to grip it to get it out. Would the lug still need bedding?

 

[Tac-O]

As mentioned, this could be several things. What comes to mind is head/eye position and amount of scope shadow, paralax, shooter stability and fundamentals, possibly mirage, barrel contact/bedding/rifle issues, reloading practices, load development process.

I think you can systemically eliminate these and get it to shoot better.

Step 1- Make sure the barrel is free floated and bed your recoil lug. Take mechanical/harmonic variability due to the rifle out of the equation as much as possible.

Step 2- There were a couple groups in there that make it seem like they had some potential (at least based on group size, but that doesn't mean a lot without velocity data). That being said what I see in those groups is consistent inconsistency. There is a lot of horizontal in a bunch of them, which makes me think of 4 things- trigger control, heart beat oscillation, eye position/scope shadow/sight picture/paralax, rifle cant and mirage. If your heart beat is causing a back and forth oscillation and you can't break a shot at the same place that interjects tremendous variability. The easiest way to solve this is with a trigger pull of 1.5lbs or less. Next is just some simple technical things. Set yourself up directly behind the rifle, adjust your paralax, make sure you have the same sight picture with equal amount of scope "shadow" around the image, use a firm rear bag and good front re/bipod so it recoils straight time the rear, and make sure you're level. When shooting for tiny groups even at 100 scope cant can throw you off by 1/4-1/3". Finally, if the mirage is intense all bets are off. Even at 100 yards you dont know if your actually aiming at the same point because the image is literally moving due to light distortion.

Step 3- Make sure your reloading practices are precise. Same brass (don't mix brands), anneal your brass every firing, consistent neck tension, temp stable powders, accurate powder charges, adjust the head space on your brass for your chamber. if your using a beam scale or just a powder drop you can be off by as much as 0.4g in either direction. That takes you out of a lot of nodes.

Step 4- load development. Don't get hung up on what groups are at 100. What matters is POI at distance, and consistent POI at distance is related to consistent MV. You don't necessarily need a chronograph/Magnetospeed/labradar but they truly give insight into the quality of your reloading practices and where pressure velocity nodes are, and that can greatly expedite the process. I use a Magnetospeed to do my initial load development and then shoot loads at promising loads at 300+. The further the better if there's no wind. That will tell you both how well it holds together at distance (likely due to low ES/SD) and using a ballistics calculator will let you true your velocity based on your POI. If it shoots good at distance it'll likely shoot at 100 but the flip side to that often isn't necessarily true.

Do that and I bet any couplets disappear.

I may try out shooting my good load (57.5) at 300 and see what I get. I don't have a Chrono yet!

 

[Tac-O]

The other thing is that it looks like by what is written on your targets that your going up by like 0.4-0.6gr per charge weight. Maybe I'm reading that wrong but IMO that's way to much. Some guys will go up by 0.3 or 0.5 but they are shooting a ladder at distance (typically 500+) not 100. I'd recommend using increments of 0.2gr. Once you are close you can shoot your tie breaker in 0.1gr increments on either side to see which is best.

My understanding in load development is that you start about 10% low of the max charge (in this case 62 gr max) and increase charges by 1% of max, which would be 0.6gr. is this wrong??

 

[Tac-O]

1st off, at 63 grains you are 1 grain over max load according to Hodgdon and 6 grains over Sierra's data with their bullet. The load is out of tune. Normally increasing the powder or seating the bullet deeper in the case would probably straighten it out, but in this case you're already pushing the pressure limit. BACK OFF the powder charge to start with and re-tune the entire load from the beginning!

I have been working off of Lee's manual and hodgdon data, which show 62gr max. Just recently, I noticed that Sierra's Max was much lower than the other two. I just started working up around the max to see if it develops pressure signs and how the loads shoot. Even at 63.0gr, which is 1.0 over my max, the only sign is slightly more flattened primers, but nothing close to many pictures I've seen of flattened primers as examples of when to back off.

I definitely started at the bottom end of 56gr, and 57.5 is the best I saw, then just under 60, and 63 seems decent so far.

 

[Tac-O]

Have you checked your scope? May not be holding zero.

I've only checked the bases and rings for torque. Haven't put a different scope on my rifle (don't have one).

 

[Tac-O]

Everyone is giving you multiple items to consider but YOU already know you have issue with cheek weld as you stated in your SECOND post. Trying to hold your head up while shooting groups is not very effective.

1st- Eliminate the cheek weld issue and then go from there. I mentioned this in my prior post. This will probably correct your issue.
2nd- if you are way over max load like @Rflshootr mentioned then back off. After both of those are fixed then try the rest of the suggested items. I would say cheek weld at this point is your biggest issue.

I know! There's lots of suggestions here. I had planned to get lower scope rings or a Velcro cheek weld to see if it helps. I'm pretty sure it would at least a bit!

 

[orch]

I would Check cheek weld and parallax as already mentioned,
If that is all in order, the one thing my shooting buddies and I have found with groups that consistently show two distinct poi is changing primers... not sure why but it seems to work in some rifles...

Orch

 

[Tac-O]

I would Check cheek weld and parallax as already mentioned,
If that is all in order, the one thing my shooting buddies and I have found with groups that consistently show two distinct poi is changing primers... not sure why but it seems to work in some rifles...

Orch

I'm not sure what people mean by checking parallax. I use a vortex viper HST scope oh, so my parallax is always adjusted to the distance I'm shooting. All I know about parallax is that I need to have my eye close enough to the scope to eliminate any shadow around the edges and make sure that my crosshairs don't shift when I move my head. I do always try to make sure that my eye is centered in the scope and in the same spot when I shoot.

The primer part is interesting... I actually initially developed these loads with CCI 200 primers and then recently switched to the Federal gm210m timers because they were out of the others at my store. I was getting those same groups with the CCI 200 primers as I am with the federal primers. I wish it were that simple for this case!