thinking of building a SIR systme upper. found that free float tubes can get really hot in extended fire. would a sir system be the same problem and what other benefits or drawbacks could this style upper reperesent. dont wanna go to the expense and effort blindly. thanks
- Thread starter marduk185
- Start date
Re: SIR systems
apparently no one has seen one of these mysterious chupacabra weapon devices, sure they exist?
apparently no one has seen one of these mysterious chupacabra weapon devices, sure they exist?
Re: SIR systems
The ARMS SIR system were the best thing going...10 years or so ago! Nowadays, they are just outdated and not as nice as more modern offerings from mfgs like Daniel Defense, Larue, etc. There are a host of reviews on these floating around on ARFCOM, M4carbine.net, etc. with addt'l info, but in terms of "drawbacks"...they are HEAVY, the lower portion of the system is polymer and is prone to cracking/coming lose in extreme temps (hot and cold), and the rail sections that are attached to the lower polymer portion are also prone to coming lose.
As to your "plans" for the SIR...I think that you'll find that under prolonged fire, any AR-15 or other AR in general will heat up like crazy. Perhaps the best solution (other than not shooting extended periods of time unless you have to in comps, etc.) is something like one of the JP Heat sinks...see here: http://www.jprifles.com/1.4.5_hs.php
The ARMS SIR system were the best thing going...10 years or so ago! Nowadays, they are just outdated and not as nice as more modern offerings from mfgs like Daniel Defense, Larue, etc. There are a host of reviews on these floating around on ARFCOM, M4carbine.net, etc. with addt'l info, but in terms of "drawbacks"...they are HEAVY, the lower portion of the system is polymer and is prone to cracking/coming lose in extreme temps (hot and cold), and the rail sections that are attached to the lower polymer portion are also prone to coming lose.
As to your "plans" for the SIR...I think that you'll find that under prolonged fire, any AR-15 or other AR in general will heat up like crazy. Perhaps the best solution (other than not shooting extended periods of time unless you have to in comps, etc.) is something like one of the JP Heat sinks...see here: http://www.jprifles.com/1.4.5_hs.php
Re: SIR systems
I'm not a fan of anything made by ARMS. There are many better manufactures out there... larue, american defense mfg...
I'm not a fan of anything made by ARMS. There are many better manufactures out there... larue, american defense mfg...
Re: SIR systems
I've always liked the ARMS SIR ,owned two.one major drawback I saw was the zeroing of back up irons or acog scope. The acog and irons were taken all the way to one side maxed out on windage to zero at 100. Longer ranges were affect too,I think that it had to do with mis aligned rail ,the way the sir is made i guess.
I've always liked the ARMS SIR ,owned two.one major drawback I saw was the zeroing of back up irons or acog scope. The acog and irons were taken all the way to one side maxed out on windage to zero at 100. Longer ranges were affect too,I think that it had to do with mis aligned rail ,the way the sir is made i guess.
Re: SIR systems
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body">The ARMS SIR system were the best thing going...10 years or so ago! Nowadays, they are just outdated and not as nice as more modern offerings from mfgs like Daniel Defense, Larue, etc. There are a host of reviews on these floating around on ARFCOM, M4carbine.net, etc. with addt'l info, but in terms of "drawbacks"...they are HEAVY, the lower portion of the system is polymer and is prone to cracking/coming lose in extreme temps (hot and cold), and the rail sections that are attached to the lower polymer portion are also prone to coming lose.
As to your "plans" for the SIR...I think that you'll find that under prolonged fire, any AR-15 or other AR in general will heat up like crazy. Perhaps the best solution (other than not shooting extended periods of time unless you have to in comps, etc.) is something like one of the JP Heat sinks...see here: http://www.jprifles.com/1.4.5_hs.php </div></div>
To add to what ORD said above, the ARMS SIR systems were the best when they were one of the ONLY rail systems available (KAC, ARMS, PRI). Now its a whole different story.
The only thing I buy that is ARMS is the bipod mount for the harris. ARMS #32. That might be changed with the introduction of Larue's integrated throwlever LT706 or the Atlas.
Also the older ARMS SIR handguards had a polymer plastic bottom section (not sure if they changed this now) which I did not care for and the "riser" created by the sleeve that attaches to the upper receivers flat top is something that I want to negate in my AR's. It is also something that isn't needed with the abundance of scope mounts available now for the AR family of rifles.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body">The ARMS SIR system were the best thing going...10 years or so ago! Nowadays, they are just outdated and not as nice as more modern offerings from mfgs like Daniel Defense, Larue, etc. There are a host of reviews on these floating around on ARFCOM, M4carbine.net, etc. with addt'l info, but in terms of "drawbacks"...they are HEAVY, the lower portion of the system is polymer and is prone to cracking/coming lose in extreme temps (hot and cold), and the rail sections that are attached to the lower polymer portion are also prone to coming lose.
As to your "plans" for the SIR...I think that you'll find that under prolonged fire, any AR-15 or other AR in general will heat up like crazy. Perhaps the best solution (other than not shooting extended periods of time unless you have to in comps, etc.) is something like one of the JP Heat sinks...see here: http://www.jprifles.com/1.4.5_hs.php </div></div>
To add to what ORD said above, the ARMS SIR systems were the best when they were one of the ONLY rail systems available (KAC, ARMS, PRI). Now its a whole different story.
The only thing I buy that is ARMS is the bipod mount for the harris. ARMS #32. That might be changed with the introduction of Larue's integrated throwlever LT706 or the Atlas.
Also the older ARMS SIR handguards had a polymer plastic bottom section (not sure if they changed this now) which I did not care for and the "riser" created by the sleeve that attaches to the upper receivers flat top is something that I want to negate in my AR's. It is also something that isn't needed with the abundance of scope mounts available now for the AR family of rifles.
