Wandering point of impact

[velocette]

Working with my elderly much modified '17 Enfield (US rifle of 1917),

Couldn't seem to get consistent groups. Rifle acted like it did not like fore end pressure from the stock, but that couldn't be because its free floated - - - - - - - or is it?
When I built the rifle about 10 years ago, the barrel was definitely free floated, dollar bill slipped smoothly all the way to barrel base. So I checked it now aaaaand it isn't free floated now. Stock is touching at it's front left side.
So a proper diameter dowel and some 150 paper and a touch up with Minwax oil and the barrel is free floated again. I tested with a dollar bill, clear and clean. Even tried a $20.00 bill, no difference : ) .
So its back to range on Thursday to test the new adjustment.

 

[Hugger-4641]

Nice rifle
When I get wandering POI, the first thing I'm checking is scope base, rings, etc.

 

[Skylerbone]

Just for fun try a business card, with inflation sometimes a $20 bill isn’t enough to get the job done.

 

[Captcurt]

Some rifles shoot better with a little pressure out at the forearm. If your floating doesn't work you might try a couple of business cards about 3 inches back from the forearm tip. Just enough to put a little upward pressure on the barrel. I cured a Mark X Mauser by doing this. It went from 3 inch groups down to 1 1/2".

 

[elktrout]

Lots of things can cause POIs to wander around. What size groups did the rifle shoot when you first built it? How many rounds are you shooting and how fast when you group the rifle? A hot barrel can make things go haywire. Are the guard screws torqued properly? Hugger is correct regarding ensuring the scope bases and rings are snug and torqued properly. Finally, are you shooting the same load as when you built the rifle? Even a grain of two of powder can make a difference. I have a very old Remington 700 in 30-06 that will group well with just about any 150 grain or 180 grain load, but it only likes two loads with 165 grain bullets. All the other 165 loads I tried shot all over the paper.

 

[Archie]

Like elktrout pointed out, loose connection between the barreled action and stock (stock screws loose or not fully tighten) will play havoc. So will a loose scope mount. I had a rifle many years ago that would change point of impact on a 100 yd target every shot. By several inches. But nothing looked amiss. I finally found the mount problem by determining I could move the scope by pressing down hard. (I was a kid, gimme a break.)

Easiest way to begin solving a 'grouping problem' is to examine a group of five to ten rounds - all fired at the same mark - and looking at the shape of the group. A 'group' should be more or less round in external shape. A group close together vertically and loose horizontally shows a side to side play and of course vertical stringing indicates up and down movement. Groups to one diagonal or the other usually comes from the barrel warming up and moving.
Any group where progressive shots 'crawl' in one direction only indicates a specific source. (I can't remember what at the moment, of course.)

If the groups are essentially round - evenly distributed hits - but loose, the ammunition is a bit sloppy, the arm itself is doing the best it can or the shooter is doing the best they can. Brutal honesty with one's self is needed in some cases.

 

[gillmeister692]

Nice rifle
When I get wandering POI, the first thing I'm checking is scope base, rings, etc.

Excellent point! Definitely always check every threaded fastener for tightness FIRST.