Need some help figuring out some groups

[cj1026]

Wondering if anyone can help me with a problem I'm having with my 30-06.
Rifle is a Ruger M77 Mkii with a McGowen barrel in an HS Persion stock. I'm using Nosler brass, Barnes 150 TTSX and CCI 200 primers. I have tried a few different powders. Seating depths of .050 to .080.

I'm shooting 3 shot groups at 100 yards. With some of the loads the groups suck. But I have a few that have shown some promise but I keep having the same problem. And I'm having the same problem with different powders.

The problem is I keep getting the 1st and 3rd shot touching. The second shot shoots left and a little high or low. It has been anywhere from 1" to 2" out.

Anyone have any ideas? I'm stumped.

 

[Deleted member 20812]

Have you bedded the rifle?

 

[SoCalHuntr]

That is such a loaded question. So many variables in your post. Overall length different powder charges. Concentricity differences... personal issues with the shooter... these issues could be small but can make differences. Barrel temperature? I think you have to document each round and verify grains oal of shell and bullet seating. Try to document all of these and with each shot go from there and document where the shots hit. And keep consistency with the shooting. Ie wind barrel heat etc

 

[cj1026]

Have you bedded the rifle?

No I have not.

 

[Addicting]

Check the pillars in the stock. Do they have a shiny spot on them in the center? My guess is that the stock is shifting around after each shot. Bedding the recoil lug would fix it.

 

[cj1026]

Check the pillars in the stock. Do they have a shiny spot on them in the center? My guess is that the stock is shifting around after each shot. Bedding the recoil lug would fix it.

I will take it a part and check it out.

 

[Cerebral Stalker]

I'd start shooting 5 shot groups. 3 shot groups don't tell you a whole lot.

 

[Deleted member 20812]

I'd start shooting 5 shot groups. 3 shot groups don't tell you a whole lot.

If three shot groups suck, the five shot groups aren't going to get any better.

 

[Cerebral Stalker]

If three shot groups suck, the five shot groups aren't going to get any better.
[/QUOTI

What I'm saying is a lot of three shot groups are going to have a flier. I mean let's say you shoot two shot groups and "dag-gum-it I always have a flier." Well that "flier" is not a flier, the gun just doesn't like the load or the gun just doesn't shoot. All I'm suggesting to the OP is to get a larger sample size and therefore increased confidence in what the gun is doing by shooting higher shot groups. 3 shot groups don't tell the whole story.

 

[Bluejeep]

For me, a 5 shot group is always my minimum.

Have you chronographed your rounds? If you have a high ES/SD, you will typically have larger groups (ie flyers).

 

[Deleted member 20812]

I use five shot groups as well when I’m finishing up load development. However, if the shooter is confident in his abilities, a bad two or three shot group is enough to tell you the load sucks, find a different one.

I get that three shot groups aren’t always illustrative of the whole story. However, in this case he’s having the same results with a variety of powders. To me, that indicates an issue with the gun or scope. My money is on the stock needs bedded.

 

[cahunter805]

Stock needs bedded and action screws torqued. Also check barrel channel and free float it.

 

[Sweede82]

Ii have a rugar m77 270. It doesn't matter what I do with powder, primers, or seating depth, or bullet brand 150 gr lead will not group out of it. Hope this helps.

 

[VikingsGuy]

Lots of good advice above, your answer is probably up there. I will add one thing I have seen at the range from time to time. A guy shooting off of bags or front rest - the first shot is fine, but he doesn't not fully return the fore-end of the rifle all the way back to original position before taking a second shot. During the second shot under recoil the gun slides back enough that the front sling stud catches the front of the bag/rest causing a flyer. Now the guy is curious/concerned so he pays more attention to setting up the third shot and gets the fore-end back out far enough and has a good third shot. YMMV

 

[tom338]

VikingsGuy --been there and done that before, very easy to forget to check that

 

[Brian in Montana]

Lots of good advice above, your answer is probably up there. I will add one thing I have seen at the range from time to time. A guy shooting off of bags or front rest - the first shot is fine, but he doesn't not fully return the fore-end of the rifle all the way back to original position before taking a second shot. During the second shot under recoil the gun slides back enough that the front sling stud catches the front of the bag/rest causing a flyer. Now the guy is curious/concerned so he pays more attention to setting up the third shot and gets the fore-end back out far enough and has a good third shot. YMMV

I too have done this.

Its pretty easy to do something a little different between the 1st and 2nd shot. I generally rebuild my platform with every shot and shoot 5 shot groups. You might try shooting groups using a leadsled to see if that makes a difference. Concerning 5 shot groups, its kind of amazing how much patterns tend to come into focus with 2 extra shots.

 

[Brian in Montana]

Also, not to impune the advice of others, but my opinion is that its probably something other than the bedding. You seem to have a pattern with your fliers. I'd expect that if the stock is shifting around much, it would be less predictable than this sounds.

 

[ImBillT]

If three shot groups suck, the five shot groups aren't going to get any better.

Obviously not, but that doesn’t mean that five shot groups don’t contain any relevant data. Personally, I’ve never seen a group get any better after the FIRST shot. Four shots touching and one out could be indicative of something very different from what two shot touching and three out might indicate. You would never know without firing the next two shots. Statistically, even five shots is a very small data set. It takes very high end equipment, shooting real matchgrade/custom bullets, in the hands of a very experienced tuner to do anything useful by looking at three shot groups. If any of the above is lacking, it becomes impossible to sort through all the possibilities.

 

[VikingsGuy]

Obviously not, but that doesn’t mean that five shot groups don’t contain any relevant data. Personally, I’ve never seen a group get any better after the FIRST shot. Four shots touching and one out could be indicative of something very different from what two shot touching and three out might indicate. You would never know without firing the next two shots. Statistically, even five shots is a very small data set. It takes very high end equipment, shooting real matchgrade/custom bullets, in the hands of a very experienced tuner to do anything useful by looking at three shot groups. If any of the above is lacking, it becomes impossible to sort through all the possibilities.

A while back I read a fairly lengthy statistical analysis of the statistical merit of various target group sizes where it said any real mathematical certainty (“power”) requires at least 10 shots, but a minimum of 7 was still statistically useful in less demanding circumstances. That being said, I try to be pragmatic about ammo usage, barrel life and shooting time, so I use a mix of 3 shot and 5 shot groups as I build up a load. As a hunter that seems to be plenty good enough for me. If I wanted to win a precision target competition I would use 10 shot groups to validate my handloading.

 

[ImBillT]

Hence the voodoo and superstition that has become common in certain shooting sports. The results are so close in benchrest these days(well, really for a few decades) that it takes many matches over the course of a season to figure out who is actually better than who. The difference between first and last place is often smaller than the difference between the winners best and worst groups.

There was a fairly well known fellow that would get so worked up that he’d pull a barrel and chuck it in the trash during matches after a few bad groups. Another shooter began pulling those barrels from the trash can, and after beating the shooter who’d thrown them away with his own trash can barrels, the first shooter started cutting his used barrels in half with a chop saw after blaming them for a bad group.