Hammer Forged Barrel vs. 4150CMV Barrel - QPQ Coated - MPI/HPT

[MegademiC]

Price aside, what are the main differences between these 2 barrel types?

Would one barrel be preferred for certain applications over the other?

Does the Hammer Forged Barrel have a longer life span (round count) as far as accuracy is concerned?

Whats the benefit of the chrome lining over the QPQ Coating?

https://www.bravocompanyusa.com/BCM-...s-11%20bfh.htm

vs

https://dsgarms.com/dsg-4001-0016
https://dsgarms.com/dsg-4001-0007

Manufacturing method is part of tge equation.

Quality of the final part is independant.

FN makes some sub moa hammer forged chrome lined barrels.
There are people making 1.5 moa ss barrels.

Everything else is in between.

There are a few threads about cr vs melonite.

[snackgunner]

Looking at the choices you put forth, I see that there is a $90 difference in price. Not being accusatory, but "cheaping out" is what the DSG seems like. The BCM is a hammer forged, chrome-lined barrel. It costs more, but there is a reason for that.

My personal opinion is that the modern wave of nitride/Melonited barrels is a cost-cutting, cheapskate way for manufacturers to make barrels. Don't get me wrong, I would readily take a nitride/Melonited barrel over an untreated one, but NEVER over a chrome lined one. Just my opinion and worth what you paid for it!

Dsgarms actually has these barrels on sale for $120

[BrigandTwoFour]

Please forgive any typos, I’m doing this on my phone.

If you’ve got some time, I wrote up a long and thorough article on the subject at my own site.

https://www.everydaymarksman.co/equi...rel-selection/

I started that article years ago when questions kept coming up here or with my friends. I hate to be that self promoting, but you genuinely might find it useful.

To hit some main points, though. Separate the barrel steel, rifling method, lining and manufacturer as independent factors. The first priority should be the manufacturer, because you’re not really paying for the others items as much as you’re paying for good quality control standards.Chrome is the long-time standard because it’s a known quality. It’s tough, wears consistently, and just works.

QPQ, like someone else mentioned, isn’t a lining. It’s a surface conversion process that makes the outer layer of the barrel (inside and out) harder and more corrosion resistant than chrome. So, potentially, you can do the process to an accurate barrel and make that barrel last longer without any sacrifice to accuracy. The trade off of the QPQ is that it’s less heat tolerant than chrome. Doing multiple mag dumps will harm the nitride and break down the lining faster. The other thing to be aware of is that nitriding/QPQ/whatever must be carried out at high temperatures. In fact, the temps it’s fine at are very close to the same temps used for stress relieving barrels, so it’s lossible to undo the stress relief done during manufacturing. That would turn an accurate barrel into junk. So good manufacturers have to get the temperatures certified by the nitriding facility.

It also matters if the manufacturer torqued the barrel extension before or after nitriding. If after, the extension must be torqued again since the process tends to loosen them. This is why paying for good QC is important. Like others said, some people look at nitriding as a cost cutting measure because it’s typically cheaper than chrome to perform. The added cost of good QC ends up evening out the price.

Regarding stainless barrels, they aren’t inherently more accurate because they are stainless. An unlined CMV barrel could be every bit as accurate as stainless. The difference is that the lower carbon stainless is easier to machine and more resistant to corrosion. That means a single shop can do everything in-house including rifling, profiling, polishing, and shipping it out. There’s no need for anyone else to get involved or alter the tolerances of the barrel.

Stainless also has different wear characteristics, as someone else pointed out. It shows less gradual accuracy loss until it hits a point where accuracy drops off very quickly. CMV has more of a gradual loss of accuracy from earlier in the barrels life. But we’re talking tens of thousands of rounds here. Most people are never going to shoot out their first barrel.

[vicious_cb]

Without even going into the differences between CL vs Nitride. You are comparing a no-name barrel, with no pedigree of what shop cut the barrel or what standards they hold, to BCM which is one of the most consistent mfg/dealers of parts in terms of quality.

At this point I wouldnt touch even the DSG barrel whether it was nitrided/QPQ/chrome-lined whatever. You can chrome-line, QPQ/nitride,polish a turd all you want. All you end up with is a nicer looking turd at the heart of your AR.

[Gunnar da Wolf]

I have a DSG “duty grade” 16” mid length upper on a rifle I put together as a beater. Its done three years of riding in the truck, three gun competition and being the rifle that always goes to the range. Probably a couple thousand rounds and cleaned sporadically, a half dozen brush strokes and a couple patches does the job nicely.
Last week I took the RDS off and slapped a 1.5-4 Leupold AR scope on it and it still shoots 1.5” 100 yard groups off the bench. It actually shoots as well as my FN Tactical Carbine that cost a lot more.
I’d have no problem buying another barrel from DSG.

[MSW]

From what I understand from an engineer who is an expert in steel & steel working, a hammer forged barrel is work hardened & theoretically will outlast a non-hammer forged barrel, assuming comparable rate of fire. Throat erosion, either from rapid fire (full auto) supposedly is responsible for “shooting out” a barrel. Adding a hard chrome lining helps prevent rust, corrosion & eases cleaning. The steel in steel case ammo isn’t hardened as much as the barrel. That said, i’m an ammo snob and can’t remember the last time I shot steel case in an AR, as I prefer brass for reloading & like Lake City. The only steel case ammo I shoot is in my AKM pattern rifle & Saiga.

Baikal, the makers of the Russian Arms that shoot steel case, uses hammer forged chrome lined barrels for their military. As you likely know, the Russians use steel case ammo, if that helps your decision process.

[everready73]

I believe DSG uses ballistic advantage barrels for their nitride ones. They are decent quality but still a budget barrel. If it is a range gun it will work fine. If more serious use I would go with the BCM

[lysander]

By durability I meant the number of rounds fired before throat erosion reduced accuracy to an unacceptable level.

The method by which the rifling is created is a factor, as well as how well it is implemented. I'm not going to guarantee the absolute accuracy of any of the below, as I've never worked in the barrel creating business.

Krieger's single point cut rifling is highly regarded. Some believe that this method allows for the most precise creation of the lands/grooves in the bore. There aren't many barrel manufacturers that use this method, likely due to the required time and therefore cost (and knowledge). If Krieger were to start using the button rifling process, while continuing their hand lapping and additional quality control inspections, these barrels will likely end up very close to the same precision of lands/grooves/smoothness as their cut rifled barrels. Some other company can also use the single-point cut rifling process to create absolute garbage.

Savage uses the button rifling process, in which a rifling/shaped cutting head (the button) is pulled through the barrel, likely many times to incrementally cut the grooves. Their barrels are also highly regarded, from a factory barrel perspective, even though the complete rifles can cost less than a Krieger barrel. The means by which the barrel is attached to their bolt action rifles is also important to the final accuracy of the rifle, but that's way beyond the scope of this AR-centric thread. They have obviously worked out the fine details of what it takes to use this particular process to create accurate rifling, as well as appropriate QC standards.

Inspection of the bore and the cutting tools is also important to ensure that the bore is as smooth and uniform as possible. If the cutting tool is beyond it's service life, and it is continued to be used, the rifling will continue to be cut, but not to the precision as is they were in perfect condition. Visual and mechanical inspection is important to ensure that the rifling was cut properly.

The bottom line is that the steel used, rifling method, lining/treatment process, hand or fire lapping, air gauging, visual inspection, etc all affect the end product.

I have no experience with DSG Arms, but my BCM hammer forged, BCM non-hammer forged, FN hammer forged, Colt non-hammer forged, etc barrels are all more accurate than would be considered acceptable in a bolt action hunting rifle 50 years ago.

I've read many many times that stainless barrels are more accurate than CMV barrels. This is most likely because stainless steel is easier to cut than CMV, therefore it's easier to do well...not necessarily a better material.

A few things:

1) Button rifling (as done by Savage and numerous other barrel makers) is done by pulling a "rifling button" through the bore once to cold form the grooves in the bore.

A rifling button (50 bucks on ebay, by the way):

See how its done here: https://www.youtube.com/watch?v=Eme6NaJIn7s

2) You can have a cold hammer forged barrel made from CMV steel, or any other steel you choose. The choice of steel makes a bigger difference than the method of rifling. The Germans in WW2 were making cold hammer forged barrels out of 1065 steel, not what I consider super high quality steel for small arms. A closely related manufacture method that is often lumped into CHF is "rotary swaging". This forms the interior of the barrel in the exact same manner as CHF, however the machines are simpler (and cheaper) so they cannot form the chamber or the exterior contours. I'll wager that most "CHF" barrels are actually made on a rotary swaging machine.

3) There is a forth way to get rifling into a bored hole, and that is with a single pass broach (see image below).


See how its done here: https://www.youtube.com/watch?v=j0ka827PpcQ

[Don Quijote]

You people overthink the most useless details.........tip of the hat to grizzman for trying to wade into this cesspool of misinformation and ignorance and set it straight.

I couldn't do it.