I have a Mossberg 100ATR in 243, (I know, it was a bet), with a 22", 1:10 twist barrel.
I tried 5-6 100+ grain bullets and none would group using several different powders, ( 4064, H414, W760, R17,4350, 4320).
I have been able to find loads in the past for other rifles I have, but this rifle is frustrating. A conversation with a competitive BR shooter, he recommended a 75gr FB bullet for that twist. That is a bit light for a deer gun. I'm not looking at superb accuracy but looking to put 5 shots inside an inch at 100yds.
The 75gr bullets did shoot the best group, but out of 5 shots, one will fly on me. Supposedly, this rifle has a Howa 1500 action. It does not like to get hot. When it warms up the groups open up to 2" (or more) @ 100yds. The trigger is heavier than any other rifle I have, and I have tried to adjust it to be lighter.
I have thought of just selling it and be done with it. Best group so far has been 1 1/4" groups with the 75gr or 85gr bullets. I think it's a deer gun with the 85gr Sierra Game King and 37.6gr 4320.
Changes I have made to this rifle:
- free floated the barrel, it wasn't clearanced at all
-Lightened the trigger as much as I could
-bedded the action
I have loaded bullets, ranging in weight from 105 - 75 in about every increment available from Sierra, Barnes, Nosler, Speer and Hornady using the above mentioned powders. So far, this has been about an eighteen month trial and error program. Boyd makes a stock and Timney has a trigger to fit it. My question, (I have already answered to myself is NO!), is this gun worth all the money for the trigger and stock to SEE if it helps it or just can it and use a Tika, Winchester Model 70, or a remington action build? I'm not sold on the 243 cartridge, this is the only one I have, and have a Savage 6.5 CM next to it.
What are your thoughts?