I have a Tikka T3x 7mm rem Mag, just hit about 120 rounds. I have 2 loads that I had success with, both shooting around 1/2 MOA. I tried a different bullet this am, same seating depth, and they were all over, about 1.5- 2MOA @ 100yds. So just for peace of mind, I wanted to shoot my proven loads, and same thing. Nothing in the reloading recipe has changed, brass is still on the same firing. Also the POA was 2 MOA ish low @ 100yds(hard to tell exactly when the groups are they big). Everything is tight on the scope and on the action, is it possible that my lands have moved a couple thousands? Put a bore scope down it, all looks good, no carbon ring or anything like that. Any help is appreciated.
Any ideas?
- Thread starter DesertBoy
- Start date
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Sealesniper
Well-Known Member
Sounds like your scope or rings/bases are loose or the reticle is broken. Set it on the bench and strap it down. While lookign through it, lightly tap on the scope and see if your crosshairs move and jump.
When I had this issue in the past, was a scope/ring base issue. Not being funny, but did you have a good bench, rest and good trigger pull. Just making sure we check off all the variable, and I knwo I am the biggest variable in accurate shooting.
When I had this issue in the past, was a scope/ring base issue. Not being funny, but did you have a good bench, rest and good trigger pull. Just making sure we check off all the variable, and I knwo I am the biggest variable in accurate shooting.
I had good holds all morning, and was shooting off concrete tables, so I feel confident in my shooting. I checked the rail, rings and action for tightness, all is torqued properly. It's a newer Nightforce, I just don't think it's in the scope itself. Going to play with seating depth and see what comes of it.
How many rounds of the new bullet did you shoot, and did you clean before testing the new bullet? When you went back to the old bullet did you clean before switching? I have had some weirdness similar to this and I attributed it to different jacket materials. Cleaning the copper out of the barrel completely fixed the issue and the old load was shooting great again. I try to swab out most of the carbon when switching powders and using the same bullet, and clean to bare steel when switching to a new bullet so I have a 'clean' test meaning I can repeat the results. I have personally and I have seen others shoot 5 or 6 different bullets in the same session without a bit of issue, and my issue was with a rifle that copper fouls pretty quickly, but once something bites me I will change my practices and not look back especially when the cost is a couple minutes and a few patches.
I shot 4 of the new bullet (190gr Berger Hybrid.) The other loads I had were the 175gr EH and the 195gr EH. Both shot 1/2MOA at 100yds, and tracked well out to 900yds plus. The last session I had was at 865yds, the 195's vertically shot 1/2MOA, and horizontally shot right around 1 MOA, which I wasn't concerned with, because it was a tricky wind. 8-10mph gusts, over two shallow canyons. After last session I gave the gun a good cleaning. I generally do after 10-15 shots or so. My dad got a really bad carbon ring in one of his .338's and it took him a ton of elbow grease to get it out, after I saw that, I started cleaning after every 15 shots or so. So the barrel was clean, and copper free.
birddog 68
Well-Known Member
I would mount a different scope and shoot it again. You may need to adjust your seating depth but I don't think you would have went from.5 to 1.5" groups overnight.
POA shift is a red flag for me. Do you have a brake or suppressor mounted? If so, make sure it hasn't come loose. I've seen groups open and point of impact move down when a suppressor gets just a little loose. It's thrown me for a loop a couple times.
It was my first outing with a new Ti Pro 3. I bought it with the timing piece and had it pretty snug. I thought it was the brake for sure. I actually paid for another shooting session at the range, drove home and got my factory brake and screwed it on, and same results at 100yds. When I originally developed the two loads, I had an idea where my lands were. I backed out .005" from jam, and both loads shot really good at that. When I would go to close my bolt on my original loads, the last little fraction the bolt close felt tight, and took just a tiny bit of pressure to close. This last session it closed smooth as butter, that's why I am thinking maybe my lands move a couple of thousands? Like a gentleman commented in this thread and from what I have gathered was telling me that a lot of barrels will change around that first 100-150 rounds, and than again around 1000 rounds. I think I am going to try .005" out and see what comes of it.
