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Difference in MPA BA Comp action fitment

Brandon H.

Private
Minuteman
Jul 21, 2018
13
3
Plant City, FL
I noticed on MPA's website the MPA BA Comp chassis has a few different actions and I'm not sure what to order. I'm tossing between a Defiance Tenacity or a Bighorn Origin. Im after a chassis that could fit either. The MPA website says I can order the chassis in the following actions

Defiance XM
Remington Short Action (and Clones)

I though Defiance was a 700 clone anyway so what's the difference? Which would I choose that way either action would work? Looks that the Tenacity has the same short lug as the Deviant and I'm assuming that's the difference?

And yes I know I'm buying tires to a car I don't own yet, I'm torn on actions. Safety is a big thing to me and I'm not sure I'm sold on the BigHorn bolt shroud, any advice on the safest action also appreciated.
 
The Defiance XM actions are not a short action like the Bighorn. Their XM is an intermediate length designed for more reliability for cartridges 6.5PRC. The Medium length Defiance is the equivalent to other Short Actions.
 
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Just read it somewhere, something about the quick release release shroud assemblies not being as safe as a threaded one in a over pressure situation.
Any truth to that?
I’m sure ultimately there could be but not that I’ve ever heard of in practicality.

Get either. You don’t have a bad option.
 
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I guarantee plenty of people have gotten gonzo with a load and sneezed a case hard in a Zermatt without getting speared in the face.
It’s a non issue.
Lots of people fuss about nothing on the internet.
 
Thanks guys for the replies, it will def help me sleep better at night knowing i can go with either.

Now that I have The chassis answer from MPA, y'all help me choose which action 😆. Not to be one of those threads, but i considered all the common ones, APR, Axiom, Nucleus, Tenacity, Tac30, Origin, Atlas, and i think thats about it for the 1k and under range. I have it narrowed down pretty much to the Origin and Tenacity. One key for me is I want a barrel nut option for either one. I really like the Tenacity and one thing the draws me to it is the one piece bolt. But after all the research it seems like Most recommend the bighorn over the defiance. The floating bolt head doesn't bother me, but my savage already has that. I wont be beating my gear but I do plan on using it, and I head the defiance was held to tighter tolerances so dirt and dust being an issue for galling and not running smooth, where as the big horn shines. Most of these posts are from 2018, and things have changed.

is the tenacity still a good choice or will it be moody? I have spent hours researching, but i really just want something reliable, and smooth. The most bang for my buck. And i dont plan on switching calibers so the bolt means nothing to me.
 
I don’t think you could go wrong with either. Bighorn’s are renowned for their light bolt lift. A mate has a TL3 and that is lighter than his Impact but his only gripe is it binds if you put sideways pressure on it. Ultimately if the decision were mine I’d ask if I want a Pushfeed or CRF action. The Bighorns being CRF work well with BR variant cartridges. As far as I’m aware the Tenacity has the option for prefits as it has a guaranteed headspace, that’s why I have a Defiance Ruckus on order. Though I really don’t think you could go wrong with either.
 
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