A few questions on parts:

I, through extreme luck, was able to get a phenomenal deal on a stripped LMT monolithic railed upper (12inch) and a 5.56 LMT barrel (16 inch). I was assured that sometime in the future I’ll get another phenomenal deal in a stripped LMT lower. So guess who’s now in the slow process of doing an AR build?!?!

I’m not in any great hurry to get this thing together. When a deal comes up, I’ll grab the parts. I already have an AR, so again, it’s not like I'm in an “I need this right now” situation.

Any of you who have an LMT with the fully railed upper, or have used one know that they are HEAVY! One hell of a great gun, accurate, reliable as they come, but HEAVY!!! So I'm going to try to shave off weight with parts. My primary concern on this build is RELIABILITY, then weight. Function over fashion.
I'm looking at Titanium parts. Dust cover, forward assist, takedown pins, castle nut, buffer tube… Flash hider - I’ll make that decision when I get there. The barrel comes with one. Buttstock & pistol grip are probably going to be Daniel Defense. I know the buttstock makes a difference when it comes to weight. The bolt & BCG are going to be LMT as well.



Are all Titanium parts created equal? Is one company better than the others? Any companies that I need to stay away from or take a serious look at? (DS Arms is one of the places that I'm really looking at now)

What about trigger mechanisms? Can I go with all titanium or should I go with something else? I know about Timney, ALG & Geissele’s are about the best “drop in’s”, but would an all titanium trigger kit work too? What parts are an absolute “NO GO” when it comes to titanium?

The two single biggest places to shed noticeable weight in an AR are the barrel and the hand guard.


In my opinion, the weight out front is the weight you feel.

As such I don't see much advantage in titanium replacements for the assortment of small parts that are available. Not for what they cost anyway.....

I don't know on ARs, as I've only built them with standard parts. But we did some similar experimenting with racing mx bikes, where every pound you can get is an advantage.

We added up all the hardware we could afford - within reason - to see what the savings would be. With changing out the rear sub-frame, both axles, handlebars, and all external hardware (bolts nuts washers) on non-moving parts, we came up with like 2 lbs of savings. This is on a bike that weighs 219 lbs (dry weight).

So for roughly $1200 invested in the parts (this was in the late 90s) on a $4600 bike, we would shave less than 1% of the weight compared to the same parts in aluminum.

Basically we figured out if I could avoid one mud-hole in practice, and eat two fewer burritos during the week, we could save more weight and have less stink in the truck on road trips as a bonus.

Maybe a step the pros or factory racers could afford to take, but definitely not worth it for privateer efforts.

In short, I agree with IndianaBoy. The headache and expense is not worth the marginal weight savings.

Titanium - it turns out - is also more brittle than aluminum. We found out in racing that on fixed parts (think exhaust pipes, hardware), that matters very little, but on stressed parts (think handlebars and sub-frames) it can be a huge disadvantage. I am not knowledgeable enough in metallurgy to know why this is so - but I'm sharp enough to listen to my betters who tell me it is the case.

Going that route, you're going to shed more weight from your wallet than your rifle.

I do not know of any commercially produced titanium trigger groups. Titanium is light, but it can also be brittle.

IMO, there is no point in going titanium given the parts you already have. Going with titanium in the small parts that are commercially available in titanium will not significantly lighten your rifle.

If you want a lighter rifle, get a 14.5" pencil profile bbl.

quote:

Originally posted by LDD:
I do not know of any commercially produced titanium trigger groups. Titanium is light, but it can also be brittle.

IMO, there is no point in going titanium given the parts you already have. Going with titanium in the small parts that are commercially available in titanium will not significantly lighten your rifle..

Between this and what CAS said is kind of what I was hoping against.

quote:

If you want a lighter rifle, get a 14.5" pencil profile bbl.

The price on the standard barrel & railed upper I got was way too good to pass up on. Good thing is, I can always get just a new barrel from LMT. 2 screws, and it's changed.

I'm in total agreement with LDD, you are going to shave a couple ounces, but not enough to cause a significant difference given the weight of the barrel and upper receiver.

You could buy high quality regular parts (LMT, BCM, DD,COLT) and a gym membership :-).

Yeah, accept that this is NOT going to be a lightweight rifle. Maybe even put a heavier stock on it to better balance the heavy barrel/rail. After you build this one, odds are you're going to be building another one at some point, so you can always make that one a lightweight rifle.

Have you looked at the Colt AR6720? Going to be challenging to get one as light as that.

I have several LMT MRP's. Very reliable and accurate rifles. About the best thing you could do on that platform is to get the MRP Slick upper or have the upper rails machined off and get the barrel contoured.
Personally, I'd keep it as is and shoot the hell out of it. If you want a light weight AR build one, don't try to start heavy and go light.

Agree with the others. There are several grades of titanium. With different attributes. It's expensive to machine so you are going to spend a lot.

VSeven does a bunch of Titanium parts.

But you may save a few ounces on take-down pins, castle nuts, and etc. But barrel & handguard are where you can trim fat if at all.

quote:

Originally posted by Expert308:
Yeah, accept that this is NOT going to be a lightweight rifle. Maybe even put a heavier stock on it to better balance the heavy barrel/rail. After you build this one, odds are you're going to be building another one at some point, so you can always make that one a lightweight rifle.

This is good advice.

Part of the reason why I like the Magpul UBR is that it balances some of my rifles out.

So wait...
You guys are telling me to just forgo the Ti parts, and go with a standard build.

THEN...

Start another build that's ALL LIGHTWEIGHT.

Damn, this hobby is starting to get expensive!

That sounds like the best answer.

(and by "best" I mean stupidest, most expensive answer, the one we'd all choose.)



The thread did remind me of a magazine article many years ago where the writer pointed out the irony of many hunters who would go to great lengths and great expense to shave a 1/2 pound in weight from their rifle, only to take to the field 20-30 pounds overweight themselves.

Depending on the barrel profile, you could get it dimpled to shave weight.
Plus, it looks cool...

http://modernserviceweapons.com/?p=3068

http://modernserviceweapons.com/?p=3582


tp

quote:

Originally posted by cas:
...

The thread did remind me of a magazine article many years ago where the writer pointed out the irony of many hunters who would go to great lengths and great expense to shave a 1/2 pound in weight from their rifle, only to take to the field 20-30 pounds overweight themselves.

Well that weight is WAY harder to remove...