I have been noticing a less than accurate load with my 303-25. I fired a test 'pattern' and stopped after three shots when the 'pattern' appeared identical to previous ones. This is a 100m target of 90mm accross the outer black square. The load is not too hot, with reasonable rounding on the primer and firing pin indent edges. Load is 36.6gr Varget/AR2208 under 100gr Sierra SP.

At first I thought "bad rifle" or "bad load" but a consistent angled string makes me wonder what I might be missing? Scope is a HunTsman by Kilwell4-12x40 AO with parallex adjustment.

OH CRUDD!!! I was just checking it out by feeling the scope base and guess what? The darn scope base is loose! Who the hell mounts a scope base without a bedding compound! You know, it have checked the screws for tightness so that means the base is moving under the screw. I can only feel it by squeezing the front of the scope sideways.

Thanks anyway!

You're Welcome!!

I took the base off and found the rear screw was bottomed out on its head - the base had been machined so thin there was just no purchase left. I did get the impression this rifle was accurate at first. Now I will leave the loads alone and go and re-test the rifle!

303Guy

That sounds like something Starmetal would do

Larry Gibson

303; I found out many years ago that transporting guns in a vehicle on long trips will loosen scope bases and sights. Anymore I locktite screws when installed. I drove to Alaska about 10 years ago, took a dozen rifles in a Walmart 12 gun safe, laid it in the back of my pickup w/ canopy, each rifle wrapped in a blanket and safe locked. I found several loose bases and front sights after the trip, something about the vibration I guess. I have a Marlin 783, tube fed 22 mag that I carried behind the PU seat, pulled it out one day and front sight fell off, it is now epoxied in place. I've notice tools in my tool box unscrew, unthread themselves after a while.

They do that! But this one was just not strong enough. The screw itself was still tight. But it won't move again!

Actually, I have been thinking about going over all my guns, checking for loose screws and ensuring that the stock screws are snug. It wouldn't hurt to take the scope mounts apart, clean, and re-assemble before groundhog season starts!!

See!!?? I am not always the only loose screw in the equation!!

quote:

Originally posted by 303Guy:
...The darn scope base is loose! ...

Had that happen to a buddy, Don, just after we had been checking the Point-of-Impact. All was fine when we shot at paper.

The next day Don's first shot was at a nice Buck just after sunrise. He was watching two Bucks fighting about 300yds off. Finally the smaller one went into that set of woods and the Big Buck headed across the field in Don's direction. Don rolled the Buck at about 200yds and thought it was all over. While climbing down, the Buck jumped up and ran about 1.5 miles into a different set of woods. Another buddy, John, actually Grunted it in and Killed it with a shoulder shot.

We discovered that Don's shot had hit 3.5 feet left and 1 foot high from where he was aiming. The Bullet hit just above the hams and slightly under the skin. Same thing - loose Scope Base.

Glad you figured it out.

I have also seen vertical string being caused by other factors as well .

Lets hope yours is just a lose base . If not ? We will discuss other causes for it later .

I have a few "guesstimations" as well.

quote:

... caused by other factors as well.

Now that you mention it, I checked my powder measure and it was waaayyy out! I could not recall changing it but anyway, I rechecked it with the hopper full ..... what can I say? I had let the level fall because I was out of powder but I neglected to keep a check on the accuracy. Now I have a whole bunch of ammo to unload and redo! And a some re-zeroing too!
I was getting the odd 'flyer' (with my No.4) which I put down to a bad muzzle - I actually trimmed and recrowned it - but I also noticed what seemed like differences in recoil and report. Oh well, we live and re-learn! Looking at it on the bright side 'though, now I am driven to get out and do some load testing and sighting in! And I had always planned to remove and inch off the muzzle after fire-lapping.

On the subject of inconsistant powder measure throws, I have been thinking along the lines of finding a load that is insensitive to powder charge variations. It might mean moving away from the most accurate load possible.

quote:

Same thing - loose Scope Base.

That happened to me with my first (and only) deer! First time in my life. I used to check and double check and get real anal but now I am getting somewhat absent-minded! (But when I find myself making the same mistake twice ... Mind you, it makes seeing other folks making mistakes real funny!)

quote:

Originally posted by 303Guy:
I had let the level fall because I was out of powder, but I neglected to keep a check on the accuracy.

Do you have a baffle in the measure's reservoir?