Thread: Obtaining more information from your groups - overlaying groups

Originally Posted by McNotty

Outing to the range (proper range) 18” Tikka 300wsm shooting 168gr AMAX, Re17

Attachment 268812

What do you think?

Unsure what I think. Still coming to terms with the fact that the outliers, are what they are, and aren’t outliers at all. I’m very comfortable at the ranges I shoot that I have an accurate enough rifle.
This was the last time at range a couple weeks ago when I checked zero. Came down 1 MOA and then shot the group today.

It's pretty consistent in MPOI (accounting for your adjustment) & MR between the 2 groups - a good 1.7-1.9 MOA rifle - very representative of what good factory hunting rifles do. Solid zero.

Also shot the 65gr GK 223 load that Id put up a thread on last year. I’ll put up the “seating depth test” I did for load development up for a laugh as well.

Great thread cheers @gimp
I will have the Howa 223 set up soon and will try get some data to add.

My effort with a new put together rifle. Might get it bedded…



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Well my weekend report. Concerning two different 284s. Neither of them mine so I'm not going to post photos but both interesting cases.

So a young chap having trouble with his 284, shooting 162s in reloads. So my initial question "What does it do?" "Well it shoots mostly pretty good groups but then I miss an easy deer" Haha I thought, heard that story plenty of times. So he lays down a 3 shot group at 100M. About 40mm including the cold bore shot. While his barrel cooled I had him shoot a 5 shot group with my 223. Then a other 3 shot group on top of the first. Then another group with the 223, and bugger me, he nailed the 5 shots into a 1 MOA dot . . . Something I've not achieved myself! I shot a 3 shot group with his 284, about 25mm at 100M. His 9 shot group was now 53mm(1.84 moa], with a significant zero offset, which we fixed. The reloads were very good, with a velocity SD of 9.

Now we stepped back to 300M on a 400mm gong. He dialed and shot, the impact was right on the very edge of the gong at 10 o'clock. Another impact, within 25mm of the first. WTF The 3rd shot, right in the centre of the gong , how did that rifle go from a MR of 1.76 cm at 100M to a 200mm group at 300M??? . He laid down a very nice well centred group or 70mm with my 223. So that was a 284 exhibiting behavior I'd not seen before, but at least the use of some decent stats enabled us to clearly establish it had a problem

284 number two, owned by a forumite. He was having doubts about his rifles grouping. He put a group on target at 100Y using my front bench rest, the first shot looked like a "cold bore" but the other 3 went into a nice cloverleaf, an overall group of about 40mm. Rifle was left to cool, then another 4 shot group was fired at 100Y, this time from a bipod. Another nice 25-30mm group. The kicker . . . . If you overlaid the groups they bought in the cold bore shot and gave a very nice 8 shot zero that was spot on. If you'd ignored the supposed cold bore shot and adjusted the zero based on the tiny 3 shot cluster you'd have just put a error of at least 3 clicks in the system. And to prove it, he put 4 shots at a 600M gong of 300mm, wind was a stinker, blowing up the Gulley. First shot was seen, about 25mm high at 1.00 o'clock. 2nd and 3rd were misses not seen, 4th a dead centre hit. All 4 would have nailed a deer with a shoulder hold.

Originally Posted by Dreamer

My effort with a new put together rifle. Might get it bedded…



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Did you break position between these shots? I've got a few groups like that recently which are from letting my barrel/suppressor cool then getting a poi shift.

Nice shooting all the same.

Originally Posted by SPEARONZ

Did you break position between these shots? I've got a few groups like that recently which are from letting my barrel/suppressor cool then getting a poi shift.

Nice shooting all the same.

Only to reload the magazine, otherwise I just lay down and shot the 10 one after the other.


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Originally Posted by Tentman

Well my weekend report. Concerning two different 284s. Neither of them mine so I'm not going to post photos but both interesting cases.

So a young chap having trouble with his 284, shooting 162s in reloads. So my initial question "What does it do?" "Well it shoots mostly pretty good groups but then I miss an easy deer" Haha I thought, heard that story plenty of times. So he lays down a 3 shot group at 100M. About 40mm including the cold bore shot. While his barrel cooled I had him shoot a 5 shot group with my 223. Then a other 3 shot group on top of the first. Then another group with the 223, and bugger me, he nailed the 5 shots into a 1 MOA dot . . . Something I've not achieved myself! I shot a 3 shot group with his 284, about 25mm at 100M. His 9 shot group was now 53mm(1.84 moa], with a significant zero offset, which we fixed. The reloads were very good, with a velocity SD of 9.

Now we stepped back to 300M on a 400mm gong. He dialed and shot, the impact was right on the very edge of the gong at 10 o'clock. Another impact, within 25mm of the first. WTF The 3rd shot, right in the centre of the gong , how did that rifle go from a MR of 1.76 cm at 100M to a 200mm group at 300M??? . He laid down a very nice well centred group or 70mm with my 223. So that was a 284 exhibiting behavior I'd not seen before, but at least the use of some decent stats enabled us to clearly establish it had a problem

284 number two, owned by a forumite. He was having doubts about his rifles grouping. He put a group on target at 100Y using my front bench rest, the first shot looked like a "cold bore" but the other 3 went into a nice cloverleaf, an overall group of about 40mm. Rifle was left to cool, then another 4 shot group was fired at 100Y, this time from a bipod. Another nice 25-30mm group. The kicker . . . . If you overlaid the groups they bought in the cold bore shot and gave a very nice 8 shot zero that was spot on. If you'd ignored the supposed cold bore shot and adjusted the zero based on the tiny 3 shot cluster you'd have just put a error of at least 3 clicks in the system. And to prove it, he put 4 shots at a 600M gong of 300mm, wind was a stinker, blowing up the Gulley. First shot was seen, about 25mm high at 1.00 o'clock. 2nd and 3rd were misses not seen, 4th a dead centre hit. All 4 would have nailed a deer with a shoulder hold.

A system producing a mean radius of 1.76cm at 100m has an expected ø95 of 7.32cm at 100, or just over 210mm at 300m - so a 200m group should happen sometimes

Hey thanks @gimp getting to better understand the power of the stats is cool.

Today's report, weather here shite, frequent showers blown across the range at 90 degrees by a 15-20 km/h westerly. So a compressed session firing as few rounds as necessary. I was tasked by a shop to test a client's rifle he'd been having bother with. I always like a "control" when doing this to verify I'm shooting ok.

So first up, my Savage 308, with 168gn S&B "match" ammo - bugger me doing exactly as the box says, shooting to match standard (in my opinion) and slightly above box velocity at 2713 fps.



Now the clients rifle, a Tikka "Veil" in 6.5 PRC with a Leupold VX3HD 4.4-14 CDS up. I fired two 3 shot groups with a decent interval between to ensure barrel heating wasn't an issue. Here is the full group.



Not too bad for factory ammo, the zero is a tad too far left but nothing to do with the client's "issue" . So I mentioned a CDS dial. It was engraved with the load etc but out past 200 it was "way off". So what might cause this? Well trusting "what's on the box" has been the undoing of many young players and here as well. I had the Garmin chrony running and the Norma Bondstrike 143s were a bit pedestrian! 2670 fps to be precise. That's enough to cause a 0.5 mil difference at 400M over the advertised velocity of 2953, that 20cm more drop. (And the CDS was engraved 2953)

I reported the results but was instructed to actually test at 400M to get an actual measurement on the error, and ensure the scope is good . .. so thats tomorrow's job when the wind abates a bit.

How did you go?

Be interesting to see what those rifles do with more data overlaid

So the Tiika put 3 rounds into just on 1.0 MOA at 366M, the 308 held 0.7 MOA for 5 rounds, then I went back as far as we can go at 571M and shot some gongs, was getting very nice close to centre hits with all my 9 remaining rounds . . .

I'm still battling the Hornardy app, both the groups actually measure slightly smaller than it says ( by 2.0mm on the 308 group), must be a camera of square issue, how does one get a getter photo . . .

Camera off square, dodgy reference measure, wrong distance, wrong bullet diameter.. ? There's a few inputs to get correct