Question for you all.
This is in regards to a Thompson center compass in 7 mm 08. I have not been able to get this thing to shoot groups for anything (I’m talking 6-10 inches sometimes..). I’ve tried a bunch of different brands of ammo, as well as a wide range of weights. Now, I wanted to test the chamber, because I have checked everything else on the gun including swapping scopes and rings, pulling the action, etc. I wanted to check the chamber because I heard another person with a Compass had a very badly cut chamber.. With a $250 rifle, who would be surprised.? Now I will jump into the details and relevant facts.
I wanted to test the jump of the bullet to the lands vs the factory ammo. I had a box of 139 gr Hornady sst ammo, half shot. I took a case (shot out of this rifle) dented the mouth a little to retain the bullet, colored the bullet with a sharpie, and seated it in the brass. I then chambered the round gently and got a COAL measurement of 2.8945 after the round was pushed back into the case as it contacted the lands. I then measured the factory SST round and got 2.7670. . I added a little more tension to the neck of the fired brass, colored the bullet, and ran the test again, and got 2.8950 (so fairly consistent).
The difference in factory COAL (2.7670) and the round I colored and pushed the ogive to lands was about .2185 inches. Does this seem like the chamber might be cut a little funky? Does anybody have any other suggestions that I should take a look at? This is pretty much the last thing I can think to look at before I print this shipping label and send it back to Smith & Wesson.
I am pretty much entirely unexperienced gunsmithing and evaluating a chamber, so any feedback or advice is a big help.
Also I can’t reload the round that long, won’t fit in mag.
This is in regards to a Thompson center compass in 7 mm 08. I have not been able to get this thing to shoot groups for anything (I’m talking 6-10 inches sometimes..). I’ve tried a bunch of different brands of ammo, as well as a wide range of weights. Now, I wanted to test the chamber, because I have checked everything else on the gun including swapping scopes and rings, pulling the action, etc. I wanted to check the chamber because I heard another person with a Compass had a very badly cut chamber.. With a $250 rifle, who would be surprised.? Now I will jump into the details and relevant facts.
I wanted to test the jump of the bullet to the lands vs the factory ammo. I had a box of 139 gr Hornady sst ammo, half shot. I took a case (shot out of this rifle) dented the mouth a little to retain the bullet, colored the bullet with a sharpie, and seated it in the brass. I then chambered the round gently and got a COAL measurement of 2.8945 after the round was pushed back into the case as it contacted the lands. I then measured the factory SST round and got 2.7670. . I added a little more tension to the neck of the fired brass, colored the bullet, and ran the test again, and got 2.8950 (so fairly consistent).
The difference in factory COAL (2.7670) and the round I colored and pushed the ogive to lands was about .2185 inches. Does this seem like the chamber might be cut a little funky? Does anybody have any other suggestions that I should take a look at? This is pretty much the last thing I can think to look at before I print this shipping label and send it back to Smith & Wesson.
I am pretty much entirely unexperienced gunsmithing and evaluating a chamber, so any feedback or advice is a big help.
Also I can’t reload the round that long, won’t fit in mag.