I hope this photo loads up, it's my first time posting a photo...

I shot this group today, and each shot dropped about a half inch in a perfect line. The first shot was high, then they dropped. My barrel is free-floated, and I was shooting off a bench rest. I allowed 30 seconds or more in between each shot. What's so puzzling, is the horizontal alignment is within 1/4 inch.

Any suggestions on why? Thanks guys.

well, the photo didn't work. Maybe this will..

https://www.facebook.com/photo...00909&type=3&theater

Could it be breathing?

Good luck!

http://www.6mmbr.com/verticaltips.html

I'm not sure there's only one answer to this. OBTW were it not for the stringing, it looks like it may have been quite a nice group.

Verticle stringing is usually caused by the heat and subsequent expansion of the metal causing movement and strain in that direction. Given that your seeing a drop in elevation as it heats up, I'd still say it's the same problem but the pressure is being exerted in a different way. We need to know what you're working with here. Bull barrel, wood, fiberglass, pencil thin ultralite?

Usually it's a bedding issue. So, even though you say it's free floated, I'd suspect that first. I suppose there's a chance the heat could be transfering to the front scope mount but it's not as likely.

I'd try to troubleshoot cheap. Loosen the action screws and snug them no more than about 40 INCH pounds, and try a group letting it cool about the same amount of time as before. Tighten the screws to about 65in/lbs and try a group. I have one that shoots well with the front screw tight, and the back barely snug with the middle screw just tight enough to keep it from falling out.
The next thing I'd try, depending on which action would be to shim it and try it again. Lift the action up a bit. If it's a thin barrel it may need a pressure point out in the end of the forearm and a lot more cooling time between shots.

As for groups, if it's a hunting rifle I shoot hunting groups. I don't shoot a skinny barreled medium bore rifle ten times in a row at game EVER. To know what it will do I try three shot groups and let it cool completely before the next one. If it's a varmint gun that's different, but I use the same approach. If it's something I'm going to be shooting enough to keep it warm then thats the approach I use for groups. For a big game rifle the true way to know what it'll do would be to go shoot one shot every morning.

P.S. WT- good link! I was typing when you answered, or I may have not even bothered.

In the benchrest game other shooters say to add a little more powder when you get verticle groups.

You didn't mention if this gun/load previously shot well and this just started. If it is something that just started I would suspect scope or mounts.

I shot clover leaves with this rifle last year with a different load. Actually, I found the perfect load for it, but now I can't find the powder I was using, (IMR 4350) so I'm back to the drawing board.

It's a 15 year old Savage model 110 7mm rem mag, wood stock. Only thing done to it is the free floated barrel, and the action has been glass bedded. The scope is tight, I just checked it.

I'll try to figure it out, thanks for all the responses, I appreciate it.

BigNate, I took your advice as far as it being a hunting rifle, and went out and shot with a cold barrel. I waited 20 minutes between shots with the bolt open for max cooling, and shot again. The second shot I felt myself pull, so I threw it out and the other 3 literally clover-leafed, not kidding. I ran a snake through the barrel before each shot, including the first. No oil.

Apparently, my barrel is not free floated enough. But, if I can get consistent cold barrel groups, I'll be happy. The first shot is always the most important. I'm glad I posted this and got input, thanks so much.

By the way, the load was:
62.0 grains of H-1000
168 grain Berger classic hunter
.010 off lands (using comparator)

As mentioned you could a number of issues each contributing in part to the situation.

The obvious ones are the rifle moving in the stock ( even after bedding).

If the action bolts contact the sides, you could get this.

One factor that i found early in my shooting days was the way the rifle is rested at the range. If the forend is rested on a pad it can cause vertical stringing. Some rifles string more than others with the forend rested on a a pad.

I always rest the magazine on a pad so that the chamber and barrel are only resting on my palm.

I would be keen to see what you do to solve the problem.

If you are nervous you might be adding down force to the rifle as you shoot. Each time more down force.

To check it out use your weak hand to cradle the rifle at your shoulder and your strong hand with just your trigger finger on the trigger and your thumb on the back of the trigger guard. The rifle will rest without the possibility of any added down force so you can tell if it you or the gun.

If it turns out to be the gun then try resetting your elevation adjustment by backing it up and then back down. If the adjuster is broken it should put your shots high or low from where they were. It might be that the new load you are using it right at the velocity the it catches a whip each time as it fires and as the barrel heats up that harmonic changes.

Dan,

Interesting thread.

I've got a L/H Savage Tactical heavy tubed 7mm Magnum. It is an outstanding Boomer, period - accuracy superb.

It's my second L/H Savage and the initial .30/06 Sprg. was a 1981 L/H Model 110 series vintage, so I've had some exprerience with the two of them. I've also tweaked a handful of Savages for others and usually in conjunction with their barrels and the solid headspacing due to the barrel nut they've all (.30/06 Sprg., .270 Win., 7mm Rem Mag & 300 Win Mag) been outstandingly accurate rifles, wooden stocked or synthetic.

The .30/06 Sprg. was a wooden stocked rifle that I managed to break the stock cleanly in half at the pistol grip while chasing Hogs through the jungles of Hawaii. It wasn't until I purchased a Brown Precision synthetic as a replacement that I began to learn some of the intracacies of the Savage 111/110 series actions/bedding.

I don't know if yours has a detachble magazine or if it is the internal box magazine model but if one ,two or all three of the action screws are out of whack this could cause the issue you are experiencing.

If the wood has been crushed at the action screws or the front or rear ation screw(s) haven been tightened too overly zelously it will actually bind the action to the point where the bolt will not move at all. The result of over-tightening will be the wood has been crushed at one/more of these point(s). The screws could also be bottomed out apparently indicating they are tight when there's actually play but that would have taken some serious screwdriver torque. The front action screw on my old .30/06 Sprg. with the new Brown synthetic had to be shortened just a smidgen due to the new stock size (depth).

Pillar bedding may be a solution also if the following doesn't apply.

Take all the pressure off the wood screw for the trigger guard - just firm enough to ensure it's snug. Then ensure the front action screw is tight; I use a Weaver torque screwdriver to 25 ft. lbs.

Now, attempt to tighten the rear action screw as far as you can take it without damage and you'll note the action bindng immediately. Loosen it until it is just tight enough to remain solid in the action or until the bolt slides freely into/out of the action (use/check the bolt release also) on the action rails and closes snugly.

I would venture to offer that in your search for the cause of the vertical stringing issue you've inspected and taken the action out of the stock and after re-assembly the action screws are now more in harmony vs. the vertical stringing issue you had previously; therefore the better grouping.

Net, with both the wooden stocked and the two synthetics; the screws on these Savage actions really do require attention to detail to obtain best results.

Good Luck.

Check your stock screws.

Jim

I have a 25-06 that shot just under a 1" group with CCI primers. Changed to Winchester primers and had a group that looked just like this one (about 5" in height and 1/4" wide)

quote:

Originally posted by A/C guy:
I have a 25-06 that shot just under a 1" group with CCI primers. Changed to Winchester primers and had a group that looked just like this one (about 5" in height and 1/4" wide)

I am in fact using Winchester primers. (large rifle magnums) maybe I'll try CCI's

vertical stringing is caused when a bullet consistantly prints slightly higher than the last shot.....

quote:

Originally posted by vapodog:
vertical stringing is caused when a bullet consistantly prints slightly higher than the last shot.....

That is the effect, not the cause. FS