I've been doing some load development with the 145 gr CEB Raptor bullets in my 300 WM. Rifle is a factory Ruger MK II M77 with some trigger work done and a new recoil pad. Other than that, it is all factory.

I've been fairly satisfied with a load that has been giving me acceptable groups. However, I've noticed some similar trends with my shots.

Here is a group I shot on Saturday morning. I shot a single fouler on another target and let the gun cool about 4-5 mins while I was finishing cleaning on my 204 Ruger. Then, moved over to this target for a four shot group.

The first two shots are the bottom left and shots three and four are the upper right two.



Here is another group I shot a week back with very similar results, but with three shots. Once again the first two shots are touching with the third being high and right about an inch. I thought I pulled the 3rd shot on this day.



I'm guessing this is a bedding issue?

Thanks,

Have seen it quite often but can only speculate as to the cause. roger

quote:

Originally posted by bartsche:
Have seen it quite often but can only speculate as to the cause. roger

And, then ...

I've heard stories about the lead that's been pounded into the mountains west of Colorado Springs

You just can't shoot!

Jack!

I've been knowin' that for some time now!!!! Don't let Rick tell you any stories though!! No one witnessed mine but me, I was there for his!!!

why not shoot some 10 round groups and see if it fills in. If it continues to have two flyers and the rest group nicely, then I think you have a bedding problem. If it fills in, you just have a 1.5" shooter. That's hard to take off the bench but it'll kill anything you point it at.

Part of me thinks that if I can reliably put the first two right where I want them, who gives a flying flip about shots 3 thru whatever. If I don't connect on the first two, I've got other issues!

Are you sure its number 1 & 2? I had a problem with my ruger like this. At first it was driving tacks, all the sudden it went to crap.I finaly discovered that if i let the gun cool down completly the cold bore shots would practicly be in the same hole. The following shots would be off to the right around 3". I talked to a service guy at ruger and he told me i had a loose barrel.

Its currently being worked on in there shop.

There are several factors that will cause this:
Barrel heat and stock pressure change
Wind change/speed
light change
heat in chamber affecting powder burn rate
bullet fouling
The placement of the rifle in the rifle rest. ( a big deal) as to where the forend touches the pad,towel,etc.
a slight cant to the scope or sights
Different brass/lot numbers
bullet weight slightly different from the others
Different primer lot number
Different crimp force (case trim length.)
Poor Standard divination of fired rounds
Poor trigger control anticipating recoil/blast.
any of these or a combination there of,will cause "fliers"

Now that I think about it, here are some additional groups shot with this same rifle; however, with different bullets and/or powders. All of these I attributed to me pulling the third and final shot.

168 gr Barnes TTSX (shot on Saturday too)


Here are some old loads with the 180 gr Barnes TSX


I'm of the opinion that since the rifle still has the factory pressure point on the forearm, once the barrel heats up it is causing the POI to change. The other interesting thing is that the flying round is always to the right.

The Ruger has a large extractor at 3 o'clock on the bolt. Check that the extractor is not touching the back of the barrel at the shot. Do this by removing the bolt and looking at the back surface of the barrel. If the extractor is touching, there will be a mark on the barrel at 3 o'clock, showing that.

If it is touching, polish the surface of the extractor, that faces the barrel, until it does not. Blacken the polished extractor surface with a felt tip pen, fire a shot, remove the bolt and check the ink. If the ink is marked in any way, polish the extractor surface until the ink does not show any sign of contact.

You cannot do this without shooting to check for contact. The forces that occur when shooting are required to show contact.

There are many things that can cause the double group thing, but the bolt or extractor touching the back of the barrel is most common.

Gerard,

Would I not expect to see this 'touching' until after the first two shots, because of the barrel heating up, or will it be there on the first shot, too, if present?

Thanks,

The contact is usually heavy enough to show on the ink at the first shot, if it is happening. Polish the face of the extractor with fine grit emery tape on a flat surface. There is a lot of meat on the extractor claw and, when it shows no contact, checking with a bit of parcel tape, blackened with a felt tip, is a good way to get peace of mind that it is clear

A couple more things: let someone else shoot the rifle and try another scope.

The scope is a new one, and not the same as some of the older shot groups. Already ruled out scope, loose base, mounts, etc.

Shoot a 10 round group, no cooling between shots, keeping track of where each shot hits. We need to see if the walking of the shots gets bigger, or settles down. Does the group go verticle, horozontal or both???

Then it will be easier to try to figure out what is happening with your rifle

This rifle is not walking the shots. It is putting two together and one away. If you fire a ten shot group here, you will simply have two groups.

Walking the shots is a consistent problem and related to a non concentric barrel. It will walk the shots in a specific direction and the shot placing will be related to the time between shots.

That is why double rifles are such a hassle to regulate.

I had a Remington 700 ADL that did the same thing. It was, for me, a bedding issue. I removed the pressure point and free floated the barrel and it settled down.

I would check the bedding. If that is not a problem check to make sure that you are placing it in the rest the same each time. I would for movement in the stock after a couple of shots. Is it a wood stock?

I had two Shilen barrels do exactly that in 338 RUM. Sent them back and they lapped them and might have re-heat treated them. (Annealed). Problem went away. It is none of the stuff suggested above; it is that particular barrel's molecular structure making it move after the heat of two shots. Then when it cools, it moves back. If it was any of the suggested problems, it would not react that way. Yes, having built and regulated double rifles, it can be challenging, but since you are usually only trying to get them to shoot into a 2 inch circle and the calibers are big, this problem is masked by everything else. Anyway, lap your barrel and see if that works. If not, have it stress relieved. Might work.

I've had the same thing with my .308 Win. It settled down after I relieved an obvious 'pressure point' on the fore-end of the stock.

Having said that, everything everybody else says above, makes perfect sense. Seems you have some work to do?

Just do one thing at a time so that you know what fixes the problem. It is a bit of a process, but it is worth it.

I been going to one shot groups lately.Never any fliers and the groups are one holers.Its a win,win deal.