I am sighting in my new 7mm-08 Mossberg Patriot rifle for 200 yard zero. The scope is Sightron Big Sky 3x9 with hunter dot reticule. The trouble is erratic fliers with lighter bullets. I am firing 5 shot groups at 200 yards with 120 gr Sierra prohunter and 139 Hornady interbond bullets with unacceptable results.
I have hunting accuracy of 2.5 to 3" groups at 200 yards with Hornady 154gr SST bullets over imr4064. I prefer 120 or 140 weight bullets for deer.
Problem is with the lighter weight bullets. 3 or 4 shots are within 2 inches but there is always 1 or 2 fliers 3 to 4 inches from the group. The fliers are usually horizontal in nature. The barrel is completely free floated and all bolts and screws are tight. It is 20" bbl and does heat up. The 120 Sierra prohunters over imr4064 or h380 are averaging 6 inch groups for 5 shots. The groups with Hornady 139 interbond bullets average 5" for 5 shots at 200 yards.
Your thoughts?
Don't bother with adverse comments about Mossberg. I really like the feel of this new rifle with wood stock.
I don't know anyone here who likes Mossberg centerfire rifles. However, I've seen Vortex scopes that are chit, right from the get go. Here's a list I tend to check when looking for a good consistent shooting rifle:
1. Is it properly glass bedded?
2. Are you using a "proven" scope.
3. Scope mounts and rings secure and loc-tited. Screws aren't too long to cause issues.
4. Mag box isn't binding up.
5. Both locking lugs in contact.
6. Good clean trigger with appropriate pull wt.
These are just basic mechanicals I look for, not including bore condition, chamber condition, crown, and proper twist rate for bullet you are using.
If you are getting horizontal "flyers", it sounds like your barreled action is skating around in the stock or maybe the scope is garbage. Chances are, it's both..
