Beginning LR-308 build first purchase

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JayBeeKay

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Okay - So I am not familiar with AR type builds, But I've wanted one and I've been attempting to be as thorough as I can be, when it comes to doing my homework prior to ordering.
So I believe that I will begin with getting a barrel and bolt - Shown below in attached pix.
If I do it this way - What am I going to end up regretting, if anything?
The same company offers 20" barrels as well, and I'm undecided on that part.

IMG_20200317_140644_415.jpg IMG_20200317_140726_944.JPG


BTW I am interested in the .358 Win chambering because I have another rifle chambered that way so I have plenty of ammo.

As Always - Thanks for any and all input :) !
 
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Any reason you're choosing .308 as a long-range caliber? There are a couple of really good smaller calibers (6mm ARC and 6.5 Grendel) that are designed for the AR 15 chassis. Lighter gun, cheaper to shoot, at least as accurate and comparable or longer effective range. The AR15 chassis will probably be cheaper to build, too. The BC of 6mm and 6.5mm are better than 30 cal.
I built a Grendel several years ago, it's a fun rifle to shoot and extremely accurate. I've had it out to 1125 yards.
DSC00790.JPG DSC_0341.jpg DSC_0361 (2).jpg

Whatever you decide to go with, I'd go with a 20" barrel at least. If you're interested, I'll give you the build details of mine.
 
IMHO... be sure to look around / Google search a Large Frame AR in .358 Winc.

Great round and all that.. but I am slightly concerned about the ammo, with its fatter bullet , feeding and capacity in a magazine designed for .308 sized bullets.

I don't remember hearing about issues... but just to be sure, double check.

Is there a muzzle brake available ?

Also, If you don't know... Large Frame AR's do not have a common "Mil-Spec" guideline like a AR15.

So, that means not all parts interchange across the "board". Parts like bolt catches, mag catches, takedown and pivot pin sizes ( and actual positions ) even hand grips, uppers and lower dimensions incompatible between brands, high and low tang heights... etc..

Point is... buy from 1 manufacturer, to save yourself a headache.. trying to make sure all your parts work together.

Also, in my experience.. most all large frame AR barrels tend to be "over gassed" , gas port is "oversized" to assure function with a wide range of ammo, cheap and good, and filthy conditions, but that also means pretty harsh recoil from the BCG being cycled needlessly fast ... and end up benefiting from an Adj. GB ... so buy a hand guard that has ample room for the Adj. GB.

Benefits from a quality Adj. GB, are well worth the added cost.

Next... what stock are you wanting to use ? ( there are separate "patterns" in the carbine stock dept. )

I could go on and on... this is in no way trying to discourage you. Just offering help, prior to any frustration, Lol

Any questions.. any, we will try to answer them.
 
Thanks for the advice
There's one thing that I've had second thoughts about already. And that's the bolt carrier.
I like the concept of the side pull bolt carrier, made by PSA.
I'll give some thought to the 6.5, but I'm leaning toward the bigger bore of the .358 for numerous reasons, only one of them being that I have a .358 rifle already and I'm used to it and the .308 as well.
1000+ yd range is very impressive though!

I appreciate the input - Things that I figure out before ordering will lessen overall frustration
 
A 16” 358win would be a dandy. Admittedly, I’d look closely at other options in a lighter AR-15 instead of an LR-308, but if you need an 8lb maul with a short handle, a 16” 358 will certainly do it. I’d personally order a midlength gas 18” and use an adjustable gas block, but only because I never can quite find a happy balance with 16” carbines.

Methinks @bangswitch was confused by “LR-308.” Understandably, it appears he inferred “long range 308” as your intended use and cartridge, rather than the LR-308 model. Unfortunately, I suppose we need a new moniker for LFAR’s of the high rail DPMS pattern, since DPMS is no more, and since AR-10 doesn’t aptly describe them either - and of course, because nobody seems to know what LFAR means.
 
What bfoosh was talking about was sort of the point I was trying to make. If you've never built an AR gun, starting with an AR10 can be a challenge because of the lack of interchangeability between manufacturers. The AR15 can present some similar issues, but as long as you stay with milspec parts, any brand of one part will fit any brand of another part, so you can mix and match to get the best stuff. Given the ease with the AR15 chassis, I was just suggesting a couple of outstanding cartridges that have been developed for it.

If you're set on the .358, I'd suggest a longer barrel than 16"; at least 20" to get as much velocity as you can, and if you're using this for long range, how far are you talking about? The bullets offered for .358 don't have that great a BC, so performance is going to suffer beyond 500 yards or so. The heavier bullets will be limited to 2500fps or less in an AR, most likely; the lightest available is a 180grain and you might get 2700 fps with a longer barrel. You'd be better off using the .308, frankly.

Edit: just saw varminterror's post, he's right; I assumed long-range rifle. I haven't been very interested in the AR10 , or whatever the popular name is for the larger-than-AR15 is., for the reason's I mentioned about interchangeability of parts.
 
bangswitch said:
What bfoosh was talking about was sort of the point I was trying to make. If you've never built an AR gun, starting with an AR10 can be a challenge because of the lack of interchangeability between manufacturers. The AR15 can present some similar issues, but as long as you stay with milspec parts, any brand of one part will fit any brand of another part, so you can mix and match to get the best stuff. Given the ease with the AR15 chassis, I was just suggesting a couple of outstanding cartridges that have been developed for it.

If you're set on the .358, I'd suggest a longer barrel than 16"; at least 20" to get as much velocity as you can, and if you're using this for long range, how far are you talking about? The bullets offered for .358 don't have that great a BC, so performance is going to suffer beyond 500 yards or so. The heavier bullets will be limited to 2500fps or less in an AR, most likely; the lightest available is a 180grain and you might get 2700 fps with a longer barrel. You'd be better off using the .308, frankly.

Edit: just saw varminterror's post, he's right; I assumed long-range rifle. I haven't been very interested in the AR10 , or whatever the popular name is for the larger-than-AR15 is., for the reason's I mentioned about interchangeability of parts.
Click to expand...

I understand what you're saying.
It's a different level of challenge than the AR-15s.
I may opt to go with the smaller gun, but I'm examining the options.
Thanks for your input on the 20" barrel. My .358 BLR has a 20" barrel and I'm going to be chrono-ing handloads for that this spring, sometime.
Originally I wanted a BAR in .358 ... But there's not one in production, and to have one customized would be costly.
I'd say 300 yd max for the .358 with about 250 yd being max for practical applications, such as hunting.
But I'm thinking that If I really start getting into long range play, I may swap barrels for a smaller caliber based upon the .308 case.
Our local range has targets @ 300yd max, though.
 
bfoosh006 said:
IMHO... be sure to look around / Google search a Large Frame AR in .358 Winc.

Great round and all that.. but I am slightly concerned about the ammo, with its fatter bullet , feeding and capacity in a magazine designed for .308 sized bullets.

I don't remember hearing about issues... but just to be sure, double check.

Is there a muzzle brake available ?

Also, If you don't know... Large Frame AR's do not have a common "Mil-Spec" guideline like a AR15.

I could go on and on... this is in no way trying to discourage you. Just offering help, prior to any frustration, Lol

Any questions.. any, we will try to answer them.
Click to expand...

Why DO I want a .358 AR?
It's partly because the .358 has capabilities that other chamberings don't do as well.
And by the time I'm finished researching this, I may decide against following through with this.
But I took an interest in that chambering as a hunting/range/survival cartridge, and I have discovered that in a lever action rifle, with the right bullets, I could feed 158 gr handgun ammo with a charge of shotgun powder and it would deliver subsonic performance, that is better than a .30 cal would be (unless someone buys very expensive bullets)
So for about 16c/shot I can play around with the same subsonic bullets that I'd be using in a survival situation.
I won't know if there would be enough gas pressure to operate the bolt on a semi auto, til I tried it out, but operating it manually would be an option with an adjustable GB.
And then, of course, there are the usual jacketed hunting bullets for playing with or hunting that cover the upper range of the power spectrum.
Right now my .358 lever is my favorite rifle, just for the versatility of that chambering. But if an AR .358 worked out, that could be my favorite ! :D WHEE!!!
 
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JayBeeKay said:
But I'm thinking that If I really start getting into long range play, I may swap barrels for a smaller caliber based upon the .308 case.
Our local range has targets @ 300yd max, though.
Click to expand...
I'd highly recommend a 7mm-08. 162's at 2700 fps, or 175's at 2600 fps; both have G1 BC's better than .650, and G7 better than .325.
My local club range is also limited to 300 yards, but I've heard the other local club just acquired a bunch of land on the downrange side of their range and have plans to extend to maybe 600 yards. I have to drive a couple of hours to get to a place where I can shoot 1000, so I don't get to go as often as I'd like.
I'd like to get another long-range gun, but it will probably be a bolt gun rather than a semi, something like the RPR or Savage Stealth or Precision. 6.5 CM has been my goal, but now looking at either 6mm CM or maybe the 7mm-08 if available.
 
bangswitch said:
I'd highly recommend a 7mm-08. 162's at 2700 fps, or 175's at 2600 fps; both have G1 BC's better than .650, and G7 better than .325.
My local club range is also limited to 300 yards, but I've heard the other local club just acquired a bunch of land on the downrange side of their range and have plans to extend to maybe 600 yards. I have to drive a couple of hours to get to a place where I can shoot 1000, so I don't get to go as often as I'd like.
I'd like to get another long-range gun, but it will probably be a bolt gun rather than a semi, something like the RPR or Savage Stealth or Precision. 6.5 CM has been my goal, but now looking at either 6mm CM or maybe the 7mm-08 if available.
Click to expand...

Long Prarie Gun /Archery Club?
It sounds like the same thing that's going on at our local range

... Thinking 7mm/08 as well
 
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For 0-300 yards, I wouldn’t complain at all with a 358 win. Might take a little more doing than a flatter shooting cartridge, but 300 yards isn’t long range. If you have another 358 and prefer commonality, it’s a fine option.

A short 358win for hunting with a 24” 7-08, 6, or 6.5 Creed upper added later for long range plinking isn’t a bad combination - assuming you have interest in and the space for long range plinking.

For hunting at 0-300, I’d personally rather have a 338 Fed or 358 Win in a 16-18” tube and a lightweight upper. I’m nothing if not a long range fetishist, but it’s apt to say a long range rifle simply isn’t warranted for 0-300yrd hunting.
 
You have made quite a few good points for going with the .358. I like that round more than any of the others mentioned so far.

Mainly because no one has mentioned .45 Raptor....
 
earlthegoat2 said:
Mainly because no one has mentioned .45 Raptor....
Click to expand...

If the Raptor becomes SAAMI standardized, things might change. I say “might” there because it’s still a high recoil cartridge in a heavy rifle, really only bringing value for hunting - and hunting is a dying sport. None of the heavy hitters we’ve discussed here, or anything like them, will ever enjoy mass popularity. But standardization would certainly help the Raptor. Lots of speed and lots of violence - hard to complain about what the Raptor can do. It’s just a matter of wanting one bad enough to carry an AR-10 at all, burn that much powder, and tolerate a limited pool of brass, barrels, and dies.
 
I've got a handful of 358 Win rifles, two of which are LR308 pattern semiautos. One of them was built using a McGowen barrel, and the other using an X-Caliber barrel. The McGowen barrel was delivered with an undersized gas port, but I fixed that pretty easily. (I should not have had to, but there it is..) Both shoot well within the limitations of the chambering and the shooter (me). I've built both using the Aero (DPMS high tang) receiver sets.

A few random thoughts :

- I built the LR308s in 358 Winchester initially to share ammo with my 358 Win 'woods guns'. To make that really feasible, consider making the barrels of the same length between platforms; I've found that it's easier to come up with a 'standard' reasonably-accurate handload for all of the rifles when they share a common barrel length.

- Chasing expensive brass out of the AR10 can get old, but it's the price that you will pay for shooting an esoteric chambering. I'm sure that you already know this, but 358 Winchester brass is a seasonal run; buy it when it's available and stockpile it.

- A lightweight 358 Winchester isn't much fun at the bench, but it does put a wallop on whatever it hits.

- If I could do it over again, I'm not sure that a 450 Bushy wouldn't be the best place to start. It's far easier / cheaper to build a lightweight AR15 than AR10, and the difference inside of 250-300 yards isn't so dramatic as to render one vastly superior over the other.
 
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Here's another question, because when I call for info there is a long hold or a robot voice and no call back.
PSA has a bolt carrier that I like , but not the barrel... I like that side-pull feature they offer.
KAK has the barrel.
So PSA says - In their online ordering site - Send the barrel to check headspacing, and correct if necessary.

If the headspacing on the bolt/barrel assy need correcting, which part do they machine to correct it? The barrel or the bolt?

I'm wondering this because if I opted to later get a longer range .308/7mm/6.5 barrel there could end up being complications if the bolt face was machined to match my first barrel.
Any thoughts on this?

I should be calling the dealer, but phone tech help is not a high priority at these places.

Thanks
 
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rbernie said:
I've got a handful of 358 Win rifles, two of which are LR308 pattern semiautos. One of them was built using a McGowen barrel, and the other using an X-Caliber barrel. The McGowen barrel was delivered with an undersized gas port, but I fixed that pretty easily. Both shoot well within the limitations of the chambering and the shooter (me). I've built both using the Aero (DPMS high tang) receiver sets.

A few random thoughts :

- I built the LR308s in 358 Winchester initially to share ammo with my 358 Win 'woods guns'. To make that really feasible, consider making the barrels of the same length between platforms; I've found that it's easier to come up with a 'standard' reasonably-accurate handload for all of the rifles when they share a common barrel length.

- Chasing expensive brass out of the AR10 can get old, but it's the price that you will pay for shooting an esoteric chambering. I'm sure that you already know this, but 358 Winchester brass is a seasonal run; buy it when it's available and stockpile it.

- A lightweight 358 Winchester isn't much fun at the bench, but it does put a wallop on whatever it hits.

- If I could do it over again, I'm not sure that a 450 Bushy wouldn't be the best place to start. It's far easier / cheaper to build a lightweight AR15 than AR10, and the difference inside of 250-300 yards isn't so dramatic as to render one vastly superior over the other.
Click to expand...

Thanks for bringing that up. That information is very useful.
My woods gun is pretty light and has a 20" barrel. That is one reason I'm leaning toward the 20" barrel for this project.
Also; It would be great to go to the range and have something in .358 that has a system for dampening recoil.
 
OK - I'm following along
A couple other questions: What is the purpose of the forward assist?
And what disadvantage might there be in disabling it in favor of a side charging handle?

Thanks for taking the time to help out
 
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JayBeeKay said:
OK - I'm following along
A couple other questions: What is the purpose of the forward assist?
And what disadvantage might there be in disabling it in favor of a side charging handle?

Thanks for taking the time to help out
Click to expand...


The forward assist was supposedly used to chamber a round when the gun failed to go full into battery. In the field it was typically used when the rifle had been submerged; the bcg was partially opened to drain water from the barrel, then the fa was used to return the bolt to battery without allowing it to slam shut and being noisy.

There is a downside; when the gun jams, it's possible that using the forward assist to try to seat the round may not only fail to do so, it may make a jammed gun a really jammed gun and in combat, that's a disaster. At the range, it means you might need a gunsmith to fix it .... or atleast more intensive care than can be done at the range.

Some people believe the f.a. causes more problems than its worth. I'll with hold my opinion on that for now.
 
Hey Gentlemen
Thank you for all the assistance so far.
So what I'm gathering is that with .308 builds, if you don't buy stuff from the same manufacturer, it's a crapshoot whether it will be compatible.
But for myself I just may have no choice but to roll the dice, because for one thing I want to get an 80% lower.
Secondly, The components that I wish to use aren't produced by the same companies.

So here's what I'm gathering;
Gen 1 - I'll go with that, because for a first build it's confusing enough that it's a .308, why add to the confusion...
The barrel and bolt are critical as matched components for headspacing purposes, so they should be purchased together from the same company.
There may be some variation on the upper parts - BCG and such

So anyhow - What I'm thinking is (for lack of other choices) I might buy a Gen1 barrel and bolt, and then purchase the bolt carrier separately because I want a side mounted cocking handle.
Would that be a reasonable choice?
Or would it be smarter to get a BCG assembled and then send the bolt in to the place where I get my barrel, for headspacing?
I really would prefer to buy from the same company, but I'm just not seeing what I want from a single seller.

Here are the features that I am trying to adhere to and hoping that I don't get into trouble;
80% lower
.358 Win chambering
Side cocking

So that seems like there might be some feasiblity to it - But, that's just on paper.

Comments ?

Thanks - Stay healthy
 
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JayBeeKay said:
OK - I'm following along
A couple other questions: What is the purpose of the forward assist?
And what disadvantage might there be in disabling it in favor of a side charging handle?

Thanks for taking the time to help out
Click to expand...

A forward assist is descriptively named. It allows the shooter to manually assist the rifle in feeding the cartridge forward into the chamber.

When everything is as it should be, an FA is an unused feature. Quite frequently, however, things end up finding a way to NOT be as they should be. I have a couple slick sides, and I don’t turn my nose when folks ask me to build slick sides for them, but frankly, circumstances in the field dictate that I use my FA’s just frequently enough that I strongly prefer to have them on my rifles, and further, that I recommend them on any rifle (especially for a reloader who doesn’t use a small-base die and want along brass life).

Fixed, reciprocating side chargers have the same advantages as an FA, but with the slight disadvantage that the charging handle/rod/knob will happily slap anything in its path with exceptional vigor, which can cause considerable pain, mild injury, and of course, a firearm malfunction to boot. Non-reciprocating handles lose the FA function, and only operate functionally the same as a standard rear port charging handle - BUT - they won’t ever slap you in the fingers. Admittedly, I’m not a fan of fixed/reciprocating handle side chargers. The knob digs and snags when I carry it, I end up slapping my fingers fairly frequently (any frequency is too frequent, really), and there’s simply not much novelty in the design. Much akin to stabbing a screwdriver through an oil filter in lieu of a strap wrench or cap wrench in my view.
 
Thanks for clarifying those things, Varminterror
I have to re-examine my original reason for wanting the side charger, considering that I reload.
It actually simplifies the build to use the std equipment.

There are so many decisions to make here, it's beginning to feel like lunacy and at this stage I'm looking for ways to simplify it.
 
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