Brownells Titanium 308 BCG vs JP LMOS with HP bolt

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jh2785

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Mar 29, 2021
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#1
I've got a new 6.5 CM upper on the way and I'm trying to save some weight and a little kick with a low mass BCG. I'm cross shopping the Brownells Titanium BCG and the JP LMOS with the high pressure bolt.

Brownells' 308 BCG looks like a ToolCraft product and in the DLC finish, which I've is super slick and is only 12 oz and I can probably get it for about $260 shipped.

The JP LMOS is pricier, a tad heavier (14.5 oz) but also comes with a high pressure bold that the creed might like better. I perceive the JP to be of higher quality and durability. Street prices are $450 - $480.

My concern is if I go the cheaper Brownells route to save some money and a little weight....... that I'll end up needing to put a high pressure bolt in it down the road ...... in which case......I'd prob just get the JP Rifles LMOS with the HP bolt for $450+ bucks.

Any thoughts on how they compare? Anyone used both?


Screenshot 2024-01-19 at 1.49.10 PM.png
 
#5
I have used the Brownells Ti 308 bolt carrier, no issues, with adjustable gas block.
I went light weight... with carbon fiber handguard, magnesium upper, titanium muzzle brake fluted SS 16" barrel, for a 6 lb 3 oz AR 10.
With a variety of handloads 155, to 208 eldm.
Even single loaded the 225 eldm...hot loads turn down the gas, but normal 155 to 179 SMK loads all run the same setting. So far it's handled every max load, without issue. Haven't used the JP product at all....but it's your dime, as they say.
 
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#6
I use to be really heavy in to 3 gun, like almost every weekend for years. I've seen almost a dozen JP bolts snap around the cam pin. Those were 223 not 308 bolts but I'd imagine it to be the same metal.
 
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#8
I just read Brownells "Guaranteed Forever" warranty, which allows me to return it at any point....and get credit for it. I may go ahead and grab the Brownells and just return if if I end up needing a HP bolt.
Screenshot 2024-01-19 at 5.25.35 PM.png
 
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#11
jh2785 said:
I just read Brownells "Guaranteed Forever" warranty, which allows me to return it at any point....and get credit for it. I may go ahead and grab the Brownells and just return if if I end up needing a HP bolt.
View attachment 8327290
Click to expand...
I actually used that guarantee once, when a major manufacturer tried to delay the return, to run out their 30 day return policy. I ordered their part through Brownells, and Brownells said sure return it...I did for a free replacement.
 
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#13
louu said:
I use to be really heavy in to 3 gun, like almost every weekend for years. I've seen almost a dozen JP bolts snap around the cam pin. Those were 223 not 308 bolts but I'd imagine it to be the same metal.
Click to expand...
Improperly heat treating 9310 is apparently common.
 
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#14
Redlion said:
Why not just buy a JP High Pressure bolt kit instead of the whole BCG if the Brownell's fails?

https://jprifles.com/1.4.7_Bolt.php?menu_select=HPbolts
Click to expand...
Well, I’m going to go with something low mass to save on weight and I wouldn’t mind if the recoil went down. I’ve got an adjustable gas block so if I’m gonna have to get that bolt anyway, I was considering going to the JP BCG (with HP bolt) route from the get-go.
 
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#15
Yes, a full mass bolt carrier is how it was designed and runs through a wider window, usually..easier..And a good recommendation for most.
But a light weight bolt carrier is very reliable if tuned correctly...and sometimes needed in certain applications. Like gaming, high rounds per minute, well above normal full auto fire.
Or just building an ultra light AR.
A shooters choice, you can have both...
 
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#16
Like I said , your dime, but I'd never pay JP prices. Toolcraft makes a .062 high pressure bolt too, same tool steel. I run them in alot in high pressure loads, no problem. Like 6.5 CM 150 SMK 2842 fps 24" AR 10 same load in the 24" bolt gun...
The Brownells Ti carrier in 308 16" is running 155 gr 2815 to 2900 in a 16", and 168 gr eldm 2756 fps with excellent accuracy in the 16" barrel ...obviously high pressure loads with that to bolt carrier as sent from Brownells.
Just saying all my ARs take the same pressures as the bolt guns...without going to JP.
The high pressure bolt does not allow any more pressure to be utilized, before the brass gives away. Not supposed to run high pressure bolts any higher than a non high pressure bolt....says so from the manufacturer.
The small firing pin dia will help with primer flow.. then you can get dual ejectors, I have tried all that. Its not needed unless you are having ejection problems, with your zippy loads. I almost never run nothing but high pressure loads...in everything.
Like I said, your dime, I do not care how you spend your money or build your gun...this is just my experience...for what it's worth. 2 cents or a dime for inflation.
You should build it, exactly how you want it, heavy and cheap, or light and expensive.
Maybe in between.
 
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#17
Toolcraft making "bolts" must be a fairly new thing? I spoke with their customer service a couple years back and they said that they only manufactured Carriers, not bolts.
 
#18
Redlion said:
Toolcraft making "bolts" must be a fairly new thing? I spoke with their customer service a couple years back and they said that they only manufactured Carriers, not bolts.
Click to expand...
Yeah they have their name on some other vendors work, like many...they do not manufacture everything in house. Not concerned with who makes it, as long as it works for me. Look at the typical automobile, Toyota on the car name tag, but many parts made in China...GM or Ford on the name tag, various vendors across the globe. Mostly just the way it is.
 
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#19
jh2785 said:
I’ve got an adjustable, gas block, even with that? It’s the superlative arms bleed off type.
Click to expand...

Yes for sure. Your basically making it to where you can run one load(as stated above where the guy said he hand loads). The pressure and bullet weight has to remain consistent or you will have to be adjusting gas for each different round you run. And it will be finicky. A gas block can't change the pressure; just volume.

Again, I would avoid light weight in an ar10 unless you are building a race gun or toy. Keep in mind you have to also consider your buffer spring and buffer in this....

I would go with the Rubber city set up, they are HP, nitrided, full mass, and you can also get one with an adjustable gas key.

Standard Mass AR-10 .308 Win+ Multi HP Calibers DPMS complete W/ Assist & Adjustable Gas Key - Welcome to Rubber City Armory

This is a complete AR-10/SR-25 DPMS style BCG with Blacknitride+ finish Carrier is fluted WITH FORWARD ASSIST and incorporates RCA's ADJUSTABLE billet gas key Bolt face is specifically machined to handle high pressure rounds. The firing pin is custom matched to this firing pin hole. Caliber...
rubbercityarmory.com rubbercityarmory.com

I shoot a 260, same and different :) the recoil is non existent. My reciprocating mass is 28.5 oz. My gun functions with factory ammo, hand loads, suppressed and not, all day.
 
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#21
Agree with guys above - all about what you want. I chose to build my rifle based on the projectile and velocity I wanted - and don't plan on running any other loads. With that load, it's reliable, low recoil, and is about 5.5 lbs before glass. But I'm sure it would be a dumpster fire if you handed me 10 different loads in the same mag. Reciprocating system is akin to picking bottom end components for a motor build...
 
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#25
FYI also my coating is more matte gray - yours looks shinier black, at least in the pic - unsure if they changed it at some point. Think I bought mine in late '22. If it's good Ti, can't see why we'd need a coating at all. Since lifetime warranty, maybe run it some more and see how it evolves?
 
#26
Chickentoast said:
FYI also my coating is more matte gray - yours looks shinier black, at least in the pic - unsure if they changed it at some point. Think I bought mine in late '22. If it's good Ti, can't see why we'd need a coating at all. Since lifetime warranty, maybe run it some more and see how it evolves?
Click to expand...
The bolts are steel, just the usual stuff.
The carrier is titanium.
Mine has close to a thousand rds, with nothing unusual.
It can be replaced with any bolt of your choosing, they are pretty much all identical made out if the same 2 steels from the same few factories, with the same heat treat and inspection. On CNC machines.
I'd just run it, it's working, the coating will wear. It's the steel bolt doing the job, not the coating. Just keep it lubed.
The titanium is great... but the aluminum carriers will wear once the anodized finish is worn off the carrier, the bolt is still steel.
 

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