Home Forums Hunting & Shooting Ask The Gunwriters Double Grouping

I have noticed that half the time with my rifle and half the time with other people at the range I help..... the problem is lose scope base screws.

Never lose ring to base.
Never lose ring cap.

This was a mystery to me for years, until figured out it is caused by oil creeping into the crack between the base and the receiver and then recoil can shake it loose. Never happens in 22s or 223s. Not enough recoil.

Excellent point. I tend to mount scopes pretty well--which is why the first suspect is the scope itself!

Looked at bedding Looks good but I did see some small pieces of bedding compound at the bottom of the recoil lug recess. Cleaned that up last nite. Checked clearance on bbl float all good.
On most of my sporters I bed the first inch or so of the bbl tenon. This one is fully floated from action forward.

May be my next step to bed it about 1 1/2"


Wind stops will shoot it today.



Lefty

A very good chance that those little pieces of compound were keeping the rifle from seating fully into the bedding. One of the reasons I like good clearance all around the recoil lug, except the back side of course. A loose fit make it less likely to get shavings and easier to clean out if any debris finds it way in.

Well the wind finally slowed down and got the rifle out to the range. Cleaned up the bedding of the recoil lug checked that the 36BR scope was mounted tightly and fired four 4 shot groups using Berger 140's.

Biggest group was .90 smallest .35. Bit of wind also.

Reason for everything.


Lefty

This can work but if there is much throat erosion chasing the lands can help sometimes. This has happened to me when a proven load started to group poorly for no apparent reason. I was looking at all the other possibilities to no avail and then seated longer and the problem went away.

Try shooting 10 shot groups.
When I worked at Federal we shot 4, 10 shot groups and then take the average.

10 shot groups are just too exhausting. No one wats to do that crap anymore. By the way, the op found out his rifle bedding was the culprit. A tweaked/torqued receiver or one with poor bedding can always be an issue. Hence the reason i always say proper bedding is the foundation for a consistently accurate rifle. Others have been saying the same schidt for a hell of a long time. And yet, you still have guys with improperly bedded, or not bedded at all rifles, and expecting them to drive tacks day in year after year. Let me tell you folks, you are living in a fantasy world. A pipe dream, if you will..

I had this happen with a rifle that was a known shooter. It took me a while but finally determined it was the scope. I sent the Nightforce in and they repaired it. It turns out the glass is bedded and the bedding had worked it's way out, so the glass would shift. Upon return, back to one group. Something to check out.

tansinator,

Thanks for that info. As I noted earlier in this thread, my first suspect when accuracy problems crop up in a usually reliable rifle is the scope--either the scope itself or the mounts. (

Have also seen two problems crop up simultaneously, which can be really confusing--one reason I try not to mount a new scope on a new rifle.

With the hard kickers, best to bed the scope base and action, or epoxy the base on the action, will come off with heat later on if you need for it to.

Heavy scopes move bases and rings.

Another issue, a guy should chronograph his load when the rifle is new were he works up a load. 500 rounds later, a loss of accuracy will be certain if you are not chasing the lands. Also, you will need to add more powder to bring up the velocity where it was when the barrel was new...often this is an easy fix.