Comparison Chart of Major AR Brands

[Charles Daly]

How did you get an AR15 LMT bolt? Did it come with the gun or you bought it separately.

The "F" may actually not be a mark as some don't mark them. what's more important is that it is the correct height. I'll make a change to the chart to be more clear when I repost it next.

The "F" should be in the forging. It is not marked later when machining.

[rob_s]

The "F" should be in the forging. It is not marked later when machining.

I understand that. The point is that there are some that are not marked that still meet the spec (as well as the reverse, actually).

sometimes this chart is a curse. People obsess about color of inserts and markings on bases rather than whether or not they have proper extraction and correct front sight height.

[Charles Daly]

I understand that. The point is that there are some that are not marked that still meet the spec (as well as the reverse, actually).

sometimes this chart is a curse. People obsess about color of inserts and markings on bases rather than whether or not they have proper extraction and correct front sight height.

Thanks for clarifying that.

Your's must be a labor of love. Do others pester you as much as I do over this?

[AllAmerican]

They do list a semi-auto bolt carrier group. Just not sure why someone would opt for one. I take it you bought a complete "built" upper from someone with a BCG, rail, charging handle, etc?

Well I bought a brand new upper from a guy that lost his job. He bought it new and I got the original packageing, and it still had the check off tag attached to the FSB.... It came as a whole unit, from a dealer in Tennesee.
What do you think? There is a mark on the FSB that could be an F but it is a little rough. I am more concerned with the BCG. The gun does have a top rail a LMT rear tact sight. Are the BCG's marked in any way??

[RogerinTPA]

Hey Rob_s,

Why aren't the ADS, Knight SR-15 and Magpul ACR rifles included on the chart?

[Shihan]

Rob, I hate to bug you to, but...
On the LMT line it says M16 bolt, with MPI, HPT, Shot peened bolt, etc. Is that for the AR15 bolt also? That is what my upper came with. I did notice that the carrier key was staked really good.

Also can you tell me where the "F" mark is located on the FSB???

Thanks for your time!

LMT's FSB's are the correct hight but are not marked.

[Shihan]

Rob anyway to enlarge to chart? Witht the new format it would make it easier to read.

Thanks

[12131]

Hey Rob_s,

Why aren't the ADS, Knight SR-15 and Magpul ACR rifles included on the chart?

Why should the ACR be included? It's different animal. Moreover, it's not even out yet.

[AR15barrels]

The "F" should be in the forging. It is not marked later when machining.

NO.
A2 front sight base forgings are all the same.
It's how they are MACHINED that makes them different.
Bases destined to be installed on flattop carbines will often be machined 0.040" higher and be stamped "F" to designate as such.

There are NOT different forgings for the two different heights.

[AR15barrels]

People obsess about color of inserts and markings on bases rather than whether or not they have proper extraction and correct front sight height.

Eactly, they don't understand WHY they should have some feature so they just fret about technicalities...