My Tikka groups suck

[philcox]

At the suggestion of [mention]ResearchinStuff [/mention] posting this here

Background
Rifles:
- 7PRC - Tikka 7 Rem Mag action, 20” C6 7PRC barrel, Mesa Precision stock, UM Rings, Maven RS 1.2, 8.5 lb
- 6.5CM - Tikka Superlite, Barrel cut to 21”, OEM stock with vert grip, UM Rings, Maven RS 1.2, 8.2 lb
- 223 - Tikka Lite, Barrel cut to 18”, OEM stock with vert grip, UM Rings, Maven RS 1.2. 8.25 lb

Loads:
- 7 PRC: 168 LRX, 67.5g RL26, COAL 3.20, ADG Brass, CCI 250
- 6.5 CM: 127 LRX, 46.5g StaBALL 6.5, COAL 2.750, Peterson Brass, CCI 200
- 6.5 CM: 135 DRT, 46.5g StaBALL 6.5, COAL 2.700, Peterson Brass, CCI 200
- 223: 77 TMK, 26.5 CFE233, COAL 2.285, Starline Brass, CCI 400
- 223: 79 DRT Factory

Conditions when shooting:
- 5000ft, 50deg, imperceivable wind, clear skies
- Garmin XERO Chrono

Possible causes of crappy groups:
1. My technique sucks
- I shot the 7PRC lefty (I am left eye dominant, but right handed), 6.5 & 223 righty
- Shot the 7 in sets of 3, the 65 in sets of 6, 223 sets of 10. I “felt” the brake after each set to see if it was “hot” and thus maybe giving mirage, the would let it cool if so

2. My setup was not consistent
- I was prone, but body was in a kind of a dip (think Upward Dog yoga pose. Not that pronounced, but not flat)
- Protektor Model front rest with an Owl Ear front bag
- Rear was a Molinator and a 2x4x6 “squeeze bag”
3. Rifle’s do not like the loads
4. Rifles are lemons

Things to do to eliminate causes.
1. Have known good shooter shoot the load
2. Shoot from a cement bench with a “Solid” front rest, and rear rest that is consistent

3. Modify loads.
1. Change projectile
- Based on the Rokslide conversations and the fact I live in California, I am basically set on 127 LRX and 135 DRT
- I have a 124 Hammer Hunter Load that I will see how it groups next week. This has historically been my most accurate load, but not great reviews on the bullet lethality.
2. Change powder
1. What I have that I could try (I have tried some before with similar results) are: Varget, RL16, H4350, IMR 4831, Ramshot Hunter, H4831SC, Superformance, RL22, H1000, Ramshot Magnum, CFE223, StaBALL 6.5, N565
3. Change powder charge
4. Change primer
1. I have Lapua SRP and CCI 400 that I could use in the 6.5CM
2. I have Federal 210M that I could use vice the CCI 200
5. Seating depth
- I need the list of podcasts that talk about how seating depth does not have a material difference on accuracy

4. This statistical chances of number three being an issue, are essentially nonexistent. This would mean, I have two factory, Tikka barrels that are lemons and two aftermarket carbon barrels that are lemons. The chances of all the rifles I have being lemons, are essentially zero. So I can eliminate this from the list.

My Current Plan is to:
1. Stick with what I have, know my limitations based on the group sizes I have

2. Use the 223 and practice the “Rifle Drill” that Form posted a while back and try to mitigate “possible cause #1”

3. I have a new 6.5CM in Lefty, that I will throw a SWFA 10x on and shoot my 140 ELDM (46.0 Ramshot Hunter, Peterson, CCI 200) to see what I get. This will be my rifle I will use at the MDT NRL Hunter event (Skills div). As it gives me the 380K PF I need, it’s that or the DRT load (too $$ for an event) or the 7PRC (I am out of RL26, so will need a new load once I expend the 45 loaded bullets I have)

I think that about covers it. Any input on some practical things that might help are appreciated.

Sent from my iPhone using Tapatalk

 

[HuntHarder]

What was the chrono telling you? Based on vertical and horizontal dispersion, I would assume more shooter error than anything else.

 

[doverpack12]

Did you work up your loads or randomly pick powder, charge, bullet, length, etc.

Have you shot better in the past?

Are scopes mounted too far back creating inconsistent parallax/form or limiting ability to see changes with black ring in scope?

Did you dry fire at all each time changing rifle/position?

Were you checking natural point of aim with each setup or muscling the aim and execution?

10 different setups with the PRC to get 30-3 shot cycles. Looks like you settled in pretty good for 21-27.

Similar on your other targets. When I look at shot numbers within the same string or setup they are significantly better.

10 round 77 TMK was your best and all shot in a 10 round string.

I would say the rifles are fine and to focus on fundamentals, natural point of aim, shot execution and positional setup and confirm parallax is set and scopes are not mounted too far back.

 

[BigDuckHunter]

Your mean radii aren’t all that bad. They also go up as your recoil goes up, which is something id expect. As an inexperienced shooter (not saying you are) it’s hard to shoot perfectly consistent every time, especially heavy recoiling rifles with stocks that (in my opinion) are horrible for consistent shooting.

Keep in mind that most people’s 1/2” rifles shoot one 1/2” 3-shot group out of the 15 loads that they test and they assume every group they shoot with that load will do the same.

 

[waspocrew]

How did you arrive at your current loads? Was this the "painless method"?

 

[Brandon.miller.4]

First step, which is extremely easy, and what i do with the people i shoot with...is to have someone else shoot the gun. Preferably someone who is a very skilled shooter, fully supported off of a bench or prone. For example, between three people i know, myself included, the group sizes are different with the same guns. IE, they vary by shooter not by gun. Some guys just flat shoot better than others. Before diving in the weeds I'd rule out human error.

Next i would check torque on everything. Action screws come to mind first...primarily because they are less obvious when slightly loose since you aren't looking at them

Keep us posted

 

[270quest]

At least for the 6.5 - try 42 grains of H4350 with a 210, and a 139 scenar loaded out to where it just barely clears/feeds in the magazine - I have seen that load shoot lights out in 5-6 different tikkas and a couple of savages…will give you 2750-2800 FPS depending on barrel

 

[Castle Rock]

Buy some quality factory ammo

 

[Jason Snyder]

Buy some quality factory ammo

This. Make sure you can shoot well before chasing another variable.

Shoot a group of 10 and then have someone else do the same that you know can shoot.

 

[AZ_Hunter]

Start at 51 minutes.

 

[philcox]

What was the chrono telling you? Based on vertical and horizontal dispersion, I would assume more shooter error than anything else.

Chrono, in what manner? ES & SD? Avg speed is on there.

 

[Harvey_NW]

It sounds like you answered a little bit of your own question with position and stability, that's a key element of tight groups. Also fine tune your parallax.

As far as the load, I know you're in CA and not legal to hunt with, but might be worth testing a bullet designed for the chamber (180-7, 143-6.5) at known charges (41gr H4350), or even just buying a box of factory ammo for each, as an acid check to see if they're just not jiving with mono's. I also suggest ditching the ball powders, I've never had a case where they yielded better results than extruded. Stick with the temp stable staples, Varget, H4350, H4831, H1000, Retumbo, N565, N570.

 

[philcox]

My load dev on these were essentially the "painless", but I don't have a range to "pivot 180 and shoot at 600+y". I essentially did the following for each load:

1. Get load data from reputable source
2. Load up rounds to pressure test. I usually started at 1g under max, and then stepped up .5g to 2 or 2.5 over max. Find pressure, or signs of, and use the charge before that
3. Load up 10, and shoot them to see how they group. Based on the many conversations. I really wanted a load that was 1.0 MOA for 10, but went with the best I got.
4. Did this "zero" off the "best" load I had found for the bullet I wanted to use (Non-Lead)

Here is a summary of all the load dev I have done for the 7 & 65


If there are multiple entries, then I did multiple group shots on diff days with the same load.

As for torque and the likes, I did the "torque and paint" technique on the ring base & caps. I am using the UM WITHOUT the posts. I had an issue with the posts on another set and when talking to UM folks, said not really needed if torqued correctly. I will "validate" the action specs, and may even throw the action in my MDT Chassi to check. Might be nice to shoot the MDT at the MDT NRL match too

 

[philcox]

Start at 51 minutes.

Shorter barrels, larger groups ... well that would explain some things

 

[Harvey_NW]

Shorter barrels, larger groups ... well that would explain some things

They're getting into short short like 12-16" territory, where you could experience noticeable inconsistencies from combustion issues. 18"+ you're likely getting full burn in those calibers with those powders.

If you're only .5gr down from pressure signs, you're too close, IMHO. Maybe try dropping 1-1.5gr and seeing if it improves one of your loads. Hornady does say reducing powder charge can improve dispersion.