I'd like to address the question by arguing its assumptions.
First, just how similar to the PRS/NRL (or any other match rifle) does the practice rifle need to be?
As far as dimensions and weight/balance are concerned; I think the rifle simply needs to be functional rifle of a similar action type, capable of delivering performance of a predictable and consistent level; not necessarily as accurate, but consistently accurate in a manner that reveals better/worse shooter performance.
As far as capabilities are concerned; it needs to allow practice at the individual tasks that will be encountered, in a manner that parallels the means employed in the actual contest. This means that if the ranging in competition is done via Mil Dots, then Mil Dot ranging has to be a component of the trainer; and other actually needed capabilities duplicated in kind.
Where chambering is concerned, the smaller, the better. I did a lot of experimentation with 22lr at distances out to 200 and 300yd. Quite honestly; beyond 75yd, performance is below what I would consider a reasonable analogue of centerfire rifle performance. It's tougher to hit the target, which we want; but consistency lags, and I have reservations about the entire concept. My way of finding relevance was/is based on effective BC and target MOA equivalence.
The difficulty with writing off the 22lr is that despite it's issues, I have yet to find a better means; and as long as the directly preceding sentence is adhered to, it's something to go by in improving performance.
I am not a fan of the Chassis system. That's probably my loss. I just don't really see the advantages as applicable to my needs. If thy stock offends thee, replace it with a chassis. I suspect, however, that if one doesn't; the the sky will still not fall.
As for balance, triggers, weight; my viewpoint may differ from the norm. I don't think it's necessary, and may not even be wise, to insist on the closest possible match between the two rifle systems.
It goes back to my most original belief regarding marksmanship skills The skills should match the rifle, and if possible any rifle, instead of the reverse. A true marksman should be able to encounter a rifle, indoctrinate themselves with that rifle, and either get its full potential, or be able to localize the source of any problem that prevents obtaining its potential.
In essence, the accomplished marksman is a generalist with skills that are flexible enough not to be hampered by reasonable variances in rifle setups. If that flexibility is absent or deficient, the marksman becomes a specialist whose skills limit their abilities to adapt to changing rifles, and likely, conditions as well.
So what would I do in response to the original question?
I'd go with the 22lr..., initially.
I wouldn't strive to totally emulate the contest rifle system, but I would include the pertinent features. Targets should be scaled according to the differences in projectile BC. If My match bullet has a BC in the .500's, I'd be assuming a 22lr BC in the .100's range, which I ballparked at about .140-.160.
That means that if I'm emulating a contest target being shot at 500yd, I'd be shooting the 22lr at 150yd in order to find a reasonable scale of difficulty. For 1000yd; 300yd.
If the contest target has an X ring of 1MOA at 500, or 5", then the 150yd target's X should be 1MOA as well, or 1.5". The X ring at 300 would be 3".
Is this a reasonable assignment of challenge? I'm sure I could get an argument about that. But we all start somewhere, we give it a SWAG, and that's mine.
Then, when stuff gets adjusted, worked, and becomes redundant; consider a .223; and try to avoid going overboard; and understand that A) the same BC relationship continues to exist, and that B) the BC's on the .223 are a whole lot closer to those of the Contest rifle. I've shot the .223 as my contest rifle quite a bit; just not in PRC/NRL.
As I age, I've grown a lot more accepting of the AR system. I like the .223 for things out to 600yd, and I'm bringing on the 6.5 Grendel as a swap out Upper for longer distance; I just haven't found the reasonable extreme distance yet. I have two Grendel Uppers, a 20" and a 24".
Greg
