sbr ar 15 questions

[dewayne]

my son and myself are building father and son ar's and i have some questions. is thier any difference between a 7.5 upper and a 10.5 upper(other than the length) as far as function? do you need a different buffer or or gas block upper? are they dependable? any problem or things to watch for, any setup better than the other? how does it take to get the paper work back?

thanks
dewayne

 

[338Shooter]

7.5s have a pistol length gas system. They also tend to be finicky, at least more so than a carbine length rifle. I would go with 11.5" for an SBR. It is a really nice length.

Paperwork takes about 4 months.

 

[dewayne]

thanks for the advice

 

[tyromeo55]

My opinion..... For the vast majority of us, the primary function of the rifle is pleasure. All of them can be made to run reliably (some with more cussing then others) and once the paperwork is in hand, changing upper lengths is no big deal. so, I'd just get what you really want with one exception. If you plan on putting a suppressor on it then longer is quieter and less destructive to the can. Most manufacturers will not guarantee a their product out of anything less then 10.5

Me I digg the 10.5's

 

[dewayne]

thanks for the replies, this is my first ar build up. i started with a stripped spikes lower and put the spikes kit in it. i have the magpul grip and trigger guard. my son's is od green and mine is fde. i just didn't want them to look like all the others that is why i want to do a sbr. i would like to slience both of them at some point so thanks for the heads up.

 

[Ignored Member]

If you decide to get suppressors later on, make sure the manufacturer will cover them for use on a short barrel. Some won't warranty any if used on barrels shorter than 16"

 

[338Shooter]

I don't know of any cans that are only warranted on 16" plus. If there is such a thing, don't buy the silencer, it is probably crap. Most are 10-10.5+.

 

[Ignored Member]

Ok well I could be wrong on 16" but I am correct on some not being covered for SBR's and I agree that if it can't handle being on a SBR you probably don't want it.

 

[338Shooter]

If you're so sure about the second, then that nullifies the first. 16" is the cut off for SBR.

 

[Ignored Member]

Yes, thank you. I'm fully aware that 16" is the cutoff length for SBR. I do own one, as well as a suppressor.

I'm sorry I may not have gotten the exact length for suppressor warranties, my point in it was to do research to make sure the supressor you're buying will still be under warranty while being used on the particular length SBR the OP wishes to use.