Chassis forearm design silliness

[Eric B.]

Lately I have seen chassis-style stocks with tubular forearms so large in diameter that the scope must be mounted on an elevated rail.

This elevation then requires that the adjustable cheekpiece also be raised very high. Fine, I suppose, if you're only shooting offhand but what about prone shooting?

Drake Industries seems to have been one of the first to do this. The Army's XM 2010 chassis also suffers from this, being a Drake stepchild. Thankfullly others (Barrett, Colt, DTA) have seen fit to have more reasonable forearm diameters.

<span style="font-weight: bold">PRAY TELL,</span> why are some of these forearms so large in diameter? What the hell must be attatched to the forearm that requires such great clearance from the barrel??? If it's a barrel attatchment collar nut then engineer a better way.

I remain, Waiting To Be Enlightened, yr hmbl & obd'nt svn't

 

[Captain Kirk]

Re: Chassis forearm design silliness

Its the latest craze, honestly I got bit by the bug recently and almost picked up a AX chassis, I have owned a handful of AIs and AICS chassis but the forend tube and scope height reuired with the AX was what made me change my mind. The JP chassis seems to be one of the few that has the tube offset lower, which is a good feature when you want to keep the scope height low.

http://www.jprifles.com/1.2.6.1_AMCS.php

 

[Super-X]

Re: Chassis forearm design silliness

I just sold a JP mor-07 with the tube. The tube was not centered around the barrel but offset to the top of the barrel. So the scope was still quite low. My problem was again prone shooting. The tube was so high up compared to a traditional stock and I really had to reach. Plus no fore end rail for a hand stop... AICS incoming.
The whiskey 3 chassis or McRee's would have been a better choice for me.

 

[DeSnifter]

Re: Chassis forearm design silliness

So people don't mistake them for a huge barrel when playing Modern Warfare and Black Ops. Not to mention a small tube doesn't do midnight digital camo justice.

 

[Eric B.]

Re: Chassis forearm design silliness

OK, so I guess I'm not paranoid after all (just a bit schitzoid - "The Voices" told me to write this post).

I'm happy to see, since others have this problem too, that I'm not just a Grumpy Old Man.

Perhaps, once reason takes hold among buyers, that the market will correct this problem.

 

[Mirnyx]

Re: Chassis forearm design silliness

The issue you describe is a product of creating a near continuous top rail for mounting things. Some companies execute the design better than others but you can blame the government, they requested the feature.

 

[lencomatt]

Re: Chassis forearm design silliness

The higher the scope gets to zero it at say 200 yards would bring the scope adjustment almost all the way to the bottom so you have more up adjustment, at least that's my thought. If you are trying to stretch every last meter of the bullet you need lots of elevation.

 

[Killer Spade 13]

Re: Chassis forearm design silliness

Because it looks so freakin tacti-kool . . .

The more zombie-killin it looks, the better it must be!!!

 

[Captain Kirk]

Re: Chassis forearm design silliness

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lencomatt</div><div class="ubbcode-body">The higher the scope gets to zero it at say 200 yards would bring the scope adjustment almost all the way to the bottom so you have more up adjustment, at least that's my thought. If you are trying to stretch every last meter of the bullet you need lots of elevation. </div></div>

Don't mean to correct you, but scope height has nothing to do with internal adjustment. If you run a canted base which gives you more internal adjustment it lowers or "tips" the front objective bell lower and closer to the barrel, or fore-end in this case.

Kirk R

 

[Mike0341]

Re: Chassis forearm design silliness

my scope sits higher than most people prefer (I used a US Optics AR quick detach base) and i shoot in the prone all the time without any comfort issues. maybe some are more prone to being uncomfortable than others. others who have shot my rifle have not complained about being uncomfortable while in the prone.

 

[PowerstrokeOBX]

Re: Chassis forearm design silliness

One good thing about a forearm is the barrel creates less mirage from the heat when its super hot(at least from my experience).

 

[slowkota]

Re: Chassis forearm design silliness

I always heard that you want the scope as low as possible to the barrel???

That just gets thrown out the window when its a high dollar rig eh? lol

 

[seanh]

Re: Chassis forearm design silliness

Why? It's cool looking and maybe you'll look like some special ops guy at the range.

 

[SPfeiffer]

Re: Chassis forearm design silliness

doesn't seem any higher than tall rings on a flat top AR

 

[ddavis]

Re: Chassis forearm design silliness

There is really no disadvantage with an adjustable cheek piece. Your cheekweld/face in relation to the scope is the same as it would be with a traditional stock and a low mounted scope. The adjustment allows for this. The only downside is that you must compensate for the 2.5" scope over bore offset like you do with an AR at close ranges.

 

[Wheres-Waldo]

Re: Chassis forearm design silliness

For a few reasons it is suggested that your scope be mounted as low as possible.

1. We have all seen the guy at the range with see-thru rings and a chin-weld instead of a CHEEK-weld. That's inconsistent and can be mitigated by mounting your scope low to permit good cheek-weld.

2. All other factors being equal, when comparing two identical set-ups with the only difference between the two being scope/bore height, when significant elevation is dialed into the equation, any cant unintentionally put into the rifle by the shooter will result in a larger wind deflection the greater your scope/bore distance is.

It seems like one chassis in particular has been called into question here... The AIAX Chassis, so lets consider...

The AX Chassis is based on the AX Rifle...

The AX, along with many other chassis style OEM rifles are designed to be modular. As stated by Mirnyx, a continuous rail at whatever inclination is a design feature built into these.

Not a bad thing...