Group size increase

HeathSexton · Jun 6, 2006

I have a friend who has loaded some shell for my 260 Rem, 46grs of Reloader 19 125gr Partition. When I run them through the other day I shot a 5/8" group at 50yds. Since then my scope ring has stripped, been replaced, rebore sighted. I went out today to rezero, so I figured might as well start at 50yds. On a clean barrel I got the thing back down where it needed to be after 6 shots. I fired a 4 shot group at 50yds, it was about 2". The wind was up a little, blowing lefty to right, the groups was up and down on a 2" spread. Was this just me, or is something up?

Thanks

live to shoot · Jun 6, 2006

I wouldn't think that wind would have much of an affect. Are you shure that everything is tight ? screws on scope rings have a funny way of coming loose when you know that everything is "tight" Also are you useing the same scope?

JD338 · Jun 6, 2006

HeathSexton,

live to shoot has some good points. You might also want to check the bedding screws as well.
What kind of rifle and scope are you shooting? 1.5"-2" groups at 50 yds seams to be bigger than they should be. This would equate to 3-4" groups at 100 yds and 6-8" at 200 yds.
Also, how are you resting the rifle and is the barrel clear from touching anything like a snd bag, etc.
We will do our best to help you out.

JD338

HeathSexton · Jun 6, 2006

Thanks for the help guys. Well, I called a friend who is a gunsmith, we talked about how teh powder charges could be off and possibly throwing vertical strands. He says, did the gun shoot good with these loads before the ring problem?" It did, "well you have a scope problem, take it off, check everything, call me back." I am shooting a Leupold 3x9x40 VXII, Leupold Rings, Millett bases, well, I have owned this gun for a couple years never really fired it much because the factory shells weren't that great. Anyway, When I checked the rear base, one hole was stripped almost clean, the threads in the other were raised and fixing to go, the front base was one screw tightened til it hit the barrel and the other was pulled up and almost stripped. This was done by the store that the gun was purchased from, it was a gift and came fully built. The gun is in teh shop now I hope the threads can be chased, but I really think they will have to be drilled and tapped. I am very much mad, I have wrenched quite a bit and you know when you strip something, you would think the store it was bought from would've owned up to this from day one. If I break something I will for dang sure let it be known and it will be fixed.

Thanks for the help, hopefully I can get this sucker squared away!

Thanks again

Blaine · Jun 6, 2006

A couple of questions come to mind:
1) Are the loads you shot THIS TIME from the same "batch" as before?
2) Was the air temperature the same as the first time?
3) Are you sure you were shooting from a really clean barrel....meaning no copper deposits in the grooves of the rifling?
4) Does your scope have a parallax adjustment on it? If not, it probably is not set for 50 yards at the factory (More likely it is pre-set at 100-150 yds). You may have to double check to see that the cross hairs are REALLY on the bull by holding the rifle steady while moving your head slightly from side to side to see if the cross hair sight picture moves from side to side on the target. If it does, make sure it appears to move the same distance on each side of the center as you move your head back and forth.
5) Are you resting the forearm on the bag at the same spot each time...ideally it should rest as close to the trigger guard as possible?
6) As mentioned above, check action screws, base screws, ring screws, etc.
7) You might also ask your friend if all the rounds he gave you were built using the same lot numbers of powder and primer....sometimes a little thing like that can mess up some good groups.
8) You can also check the spent cases to be sure all had the same head stamp (brand)

Blaine

HeathSexton · Jun 6, 2006

Answers:

1. nope different batch
2. air temp was within a few degrees, humidity was close also
3. Very clean barrel
4. Scope is none adjustable objective
5. I am shooting from sand bags, front is a longer bag, my other rifles shoot great from this set up, I made sure to not put down pressure on the forearms also
6. much loseness with bases
7. Cases, powder, and primers were from the same batch

Thanks again

JD338 · Jun 6, 2006

I would say that once you get the bases properly torqued down to the receiver, you will see quite an improvement in accuracy. At 50 yds, you should be an inch or less.
Let us know how she shoots when you get her back from the smith.

JD338

HeathSexton · Jun 8, 2006

Ok, got the gun back. With 46gr of RL19 125gr PT 2.78 OAL, wild as a buck, shot strings everywhere. I call back the smith to discuss loads and such. He had 2 boxes of 140gr A-Max over 44gr of 4831 2.800 OAL, at 50yds, they shot a 4 shot group from outside to outside all the way around the size of a penny. He also broke out the Nosler 5th edition and loaded up a 120gr BT over 45.0gr of H414 2.800 OAL, 3 shot group at 50 is a super tight clover leaf, absolutely awesome. I know it is just at 50 and I am waiting for the wind to die and I am going to stretch is some.

Thanks for the help