There has been a LOT of development work on accurizing the M-1A for NM shooting but almost nothing done on the M99 for long range shooting, so you are pretty much on your own. Factors influencing accuracy on the M99:
- forend bedding; no practical way to free float it but work can be done to limit contact with the barrel.
- buttstock bedding; glass bedding the butt to the frame with minimal stress can help a little.
- trigger is....not a precision instrument and it can only be improved a little bit due to its design.
- perhaps the biggest shortcoming is the barrel; some are better than others but don’t expect what you have in your M1A match barrel.
- optics and load quality will of course have an effect.
I guess it depends on what you expect. Terminal velocity will be fine - similar to your M1A - but what kind of accuracy are you expecting? Will this be a target gun or a hunting gun? If you expect the M99 to come close to the M1A in accuracy, you will probably be disappointed. If you are shooting at a gong at 600 yards then you might be satisfied. It really depends on what will make you happy.
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