SCAR vs AR; A detailed look...

[Hootiewho]

I think the 7 lug AR bolt and its short cam track is a result of having to use gas rings around the bolt, which is a point of friction.

In order for the expanding gas to be as efficient as possible in cycling the BCG, you design a rotating bolt with the shortest lock/unlock distance.

From my understanding, the LMT Enhanced carrier has a more drawn out cam pin track, which would give the pressure just a little bit longer time to drop and the case to shrink back down just a little more before extraction. This, to me, is a better solution for the AR. Grant has been saying this for a while. Obviously the Enhanced LMT works fine. So maybe it is not so important that the unlock distance be so short?

That was one of my points with the Scar, is how much of an increase in time you have with the Scar over the AR in the time to unlock the bolt and extract the round.

[Hootiewho]

This is an awesome review. It is quite surprising how much heat these things can generate. Including the ACR in this mix would have been cool. I think I prefer the ACR over the SCAR.

Hey, if anyone does have an ACR in upstate SC/NE GA and would like to get together I'd be very interested in doing this. Same for any of the following:
KAC SR15E3
HK416
The new KAC SR25 carbine
maybe even the AUG
LWRC .308

I plan on doing this with the Scar 17s when mine comes in later this fall, and the main rifle I'd like to see it compared to is the new SR25 Carbine. Shoot me an email if anyone is interested.

[VA_Dinger]

Wow, this is one hell of a thread. It has an incredible amount of information and raw data. It is certainly one of the finest SCAR threads to be found anywhere on the Internet.

I know Hootiewho and is a very well trained shooter and extremely knowledgeable on firearms.

For anybody who has purchased a SCAR or is thinking about it this thread is a "Must Read" in my opinion.

[Ned Christiansen]

Hoot, that is awesome data. I love technical reading that is presented well such as this (but that's a huge dose and I'm gonna have to take it in two parts ).

I see a lot of conventional wisdom and widely accepted perceptions backed up by real numbers-- and a few things debunked..... truly fascinating, thanks for all the hard work!

I missed Dean's article on the sights, but the one rear sight I checked dimensionally, I found that the 1/4 turn on the thread had been compensated for in the large aperture location.

[GLOCKMASTER]

What an awesome post Chad with a ton of great data.

[C4IGrant]

Very nice!



C4

[SGTMAJ]

Great data. Im going to have to read this 4 or 5 times before I can digest it all. Also seeing the weight differences of the moving parts bolt carrier group vs operating rod and bolt I can see why optics and lasers are getting pounded to death on the SCAR and companies had to do redesign to accomidate them.

[QuadBomb]

Thanks for doing the work Hootiewho. I've been wondering for quite a while if the AR's method of running hot is an inherent problem.

[RAM Engineer]

Now if we could just get factory short barrels and spare parts for the SCAR...

[Yog]

Spare SCAR parts are available. I've ordered them months ago and they are now in my possession. No problems at all.

SCAR barrels are made in Belgium. Tell gov.org how stupid their laws are that prevent importation of gun barrels. It's not FN's fault.

http://fnforum.net/fn-scar-16s-explo...st-t21344.html

Joel N.
"Yog"