Geissele 16” CHF Barrel:  A Quick Look




Here’s a quick look at some of the specifications of Geissele’s 16” cold hammer forged barrel. The barrel has a taper profile similar to that of barrels from Black River Tactical and Hodge Defense.  Geissele has returned to finishing their barrels with a phosphate finish, instead of a black oxide finish. The 16” Geissele barrel has a stripped weight of 1 pound, 12.0 ounces. This is the same weight as a stripped Colt 16” government profile barrel.

Colt 16” barrel



Geissele 16” barrel . . .



Hodge Defense 14.5” barrel . . .



Black River Tactical 14.5” barrel . . .



This barrel has a 5.56mm chamber and the chamber and bore are chrome lined. The barrel has a 1:7” twist.  A Colt reference bolt closed on a 1.4646” head-space gauge. The bolt did not close on a 1.4666” head-space gauge.  Geissele’s website states that these barrels have been high pressure tested and magnetic particle inspected.






The barrel extension has M4 feed-ramps and the extension is marked as such.  Note the wick in the bore, ala how Colt barrels used to be shipped.





The gas block journal has a diameter of 0.750”.  The journal has a length of approximately 1”, so you won’t be able to use a traditional A-frame front sight base with this barrel.  The gas block journal has a single dimple contralateral to the gas port.





This barrel has a mid-length gas system. The gas port has a gauged diameter of 0.062”.  Yes, you read that correctly; 0.062”.  For comparison, a Larue 16" mid-length barrel has a gas port diameter of 0.082".









The threaded portion of the barrel has a relief-cut at the bottom of the threads.  A straightness gauge dropped cleanly through the bore and a muzzle device.








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While conducting pre-assembly checks, I inserted one of my match-grade hand-loads into the chamber of the Geissele barrel. The cartridge did not fully seat in the chamber and the bolt would not close on the round.  I then checked the match-grade hand-load in a SAAMI 223 Remington minimum spec LE Wilson cartridge gauge.  The cartridge slipped easily into the gauge and fell freely from the gauge.

Next, I repeated all of the above steps using a round of factory-loaded M193.  As before, the round did not fully seat in the chamber of the Geissele barrel and the bolt would not close.  The factory-loaded round also slipped easily into the LE Wilson gauge and fell freely from it.

For the next step, I again placed the factory-loaded round in the chamber and forced the bolt into battery. I then removed the bolt (which had the extractor removed) and the factory-loaded round would not fall free from the chamber.  I was unable to pull the round from the chamber with my fingers, so I tried mortaring the barrel, but the round still remained stuck in the chamber.  I had to insert a cleaning from the muzzle end of the barrel and tap the rod to get the stuck round out of the chamber.

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Other reports of problems with Geissele barrels . . .


geissele super duty fails to eject, fails to lock bolt back


four geissele barrels fail to extract part 1

four geissele barrels fail to extract part 2


16" geissele barrel won't cycle



Having to Mortar brand new 11.5 URGI part 1

having to mortar brand new 11.5" URGI part 2


geissele 16" barrel short-stroking

problem with yet another geissele 16" super duty


geissele super duty won't reliably chamber rounds


geissele barrel won't cycle reliably part 1


geissele barrel won't cycle reliably part 2


geissele 11.5" won't cycle reliably without a suppressor


geissele gas port size issue


geissele barrel won't even unlock



geissele 14.5" URGI live round has to be mortared out of the chamber


brass stuck in chamber, loose barrel nut


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Awesome, looking forward to the accuracy report

Looks delicious.

“. The gas port has a gauged diameter of 0.062”.  Yes, you read that correctly; 0.062”.”

This is interesting, looking forward to your report.

It's been a minute since I looked at port sizes. More like an hour. Is that a bit smaller than the norm for midlength? Less gassy would be nice.

I have one of their new 11.5 barrels from the same style you have. I have been very impresses with it. It’s only had a few hundred rounds through it.

Yep, that is pretty small by about .010 on average from other barrel brands in that size/gas length

Depending on how long the G intermediate gas length is, they didnt want a customer to source their own gas tube for it. I think there are 2-3 different 'intermediate' gas tube lengths depending on the company.

Cool ??

OST

The tab cut out for Gas Blocks was a great touch and the tight port sizing is a great step forward. These will be nice suppressor hosts and soft shooters.  

The packaging job was absolutely impeccable from Geissele on these barrels.

Apologies for the potato-quality photo


[img]

@stolenheron

Is that a 16" barrel?  When did you purchase it?

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Not that it matters, but that phosphate is gross.

In for throat photos.

Tagged

in for the upcoming shooting review regarding the gas port size

Very interesting.

I just got in a 12.5" midlength with a custom gas port size of 0.062". Wondering if it'll cycle.

Topic Moved

I think it looks great in stolenheron's photo

I'm glad to see these barrels hitting the market.  

Last year I was given a tour of a machinery manufacturer, and they were close to finished building the forge for these barrels, getting ready to deliver the forge to Geissele.  They did a demo for us; we watched it turn out a barrel blank, and then we inspected the blank.  

I hope these live up to the anticipation.

Very interested in how it runs with that size as well.

Definitely in for throat and gas port pix!

Yes it is a 16. Received it this month.  Won't be building it out for a while though.

I am quite excited to see the rest of the  CHF CL line released.

And yes, the phosphate finish actually looks great. It is quite uniform on my sample. I will keep the exterior lightly oiled though.

Have you gauged the gas port on yours?

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super stoked some mod moved this to where nobody will read it. It's not as though you actually contribute to the site or your posts are worthwhile or anything..

Words stollen…

Anyway, I’d love to see someone else with proper pin gauges check another 16” barrel. Just out of curiosity.

In for more great Molon info.

Did you get the 12.5 from Geissele?   I dont see thay size on their website.

That phosphate finish looks like it is pretty thickly applied.

Ditto.

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Looks pretty ashy to me.

Would that be bad though? A CHF CL should negate any worries really. No?

Are you asking if the exterior finish of the barrel will affect the performance of the barrel?

Before Geissele pulled gas port specs from their website, I could have sworn they had 0.072" posted for the 16" mid-length barrel.

Bill recently posted in another thread they pulled the numbers off the website because the barrels being sold separately would have different specs than the barrels that come in their complete URGs. He specifically mentioned the 16" barrels because the complete 16" URGs would have Geissele-length gas systems, and the barrels sold separately would be mid-length gas systems to make things easy for home builders. He never followed up though, and the gas port specs haven't been added back to the website yet.

I have not. I do not have a pin gauge set handy, but I was told (as your post demonstrated) it gauged at .062 as well.  The port is very tight (just by eye balling it) compared to the hodge 14.5 midlength I had recently.

G overprices their rails and triggers yet compared to the rest of the market these barrels seem like a good value with near perfect specs. I may have to order an 11.5 when they come in stock. Thank you for sharing these pics.

For comparison, a Larue 16" mid-length barrel has a gas port diameter of 0.082".




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I wonder if these have a tapered bore similar to a Hodge FN or Diemaco CHF barrel to make them more accurate. I also wonder how that small gas port will cycle with lower powered 223 stuff.

.082" is on the large end of the mid-length size spectrum. I have a 16" Daniel Defense 16" mid-length that came with a .072".

Pretty sure that is marketing speak to get the fanboys to pay more. The Hodge is decent per Molon, but not enough to justify the expense over a Criterion or Colt. Looking forward to Molon's accuracy eval on this Geissele barrel. https://www.ar15.com/forums/AR-15/Hodge-Defense-14-5-Barrel-Accuracy-A-Quick-Look/118-769904/
https://www.ar15.com/forums/AR-15/Criterion-CORE-Barrel-Accuracy-Evaluation/118-767754/

No, a tapered bore is legit. There’s a reason that a hand lapped rifle barrel will get more lapping in most of the barrel than the last couple of inches. The first sub minute ten shot group I ever fired was with an FN CHF barrel.

Different maker. Also I gauged the port over the weekend and found out it was 0.070 rather than the 0.062 I requested and they said they gave me.

It's super smooth suppressed though, so I won't complain or send it back. Probably could have gotten away with a smaller port and carbine buffer but it's straight up silky with an H2. Worked out OK I guess.

A copy/paste of a response from Monty at Centurion:

The bore gets slightly smaller as it moves to the muzzle end of the barrel.
I did not come up with the concept and it is not new. So why have you not seen taper bores in the AR platform before?? Probably because using hammer forged barrels is a fairly new thing in the AR rifles. Taper bore is something that is only realistically done by the hammer forging process. The mandrel that is used to put the rifling in the barrel is slightly tapered and this leave the tapered dimension in the barrels as the forging machine beats the blank around the mandrel.
So what does it offer you? Taper bore gives you a slight boost in velocity over a non-taper bore barrel and it help negate any potential accuracy issues caused by chroming the bore since it is not always a consistent thickness.
Taper bore does not extend the life of the barrel our barrels last longer because they are hammer forged and made from a different spec material that was engineered for machine guns. Hammer forging work hardens the material and the chrome is thicker than a normal barrel. The barrel steel is the same used on the MAG58, 240, M249, MK46, and MK48 machine guns it is also the same barrel material and process used on the 1/2moa sniper rifles FN won the FBI contract with and that are still in service. The FN SPR sniper rifles use hammer forged hard chrome lined taper bore barrels to get ½ moa accuracy and this is the same barrel specs and processes I have done to my barrels.
So who else uses this?
Obviously FN, who has the time, money, and resources to do the research to find this type of barrel steel and proof out this type of process and specs. FN hands down manufactures the best machine guns in the world and there isn’t even a close second in this field there isn’t even any two companies you can combine that has as much institutional knowledge as they do in making beltfed machine guns.
HK also taper bores their hammer forged barrels for all their rifles.
So why do I use it?
Well I didn’t really think much about hammer forging and taper bore before I was sent to work doing combat systems development and operational testing for SOCOM. There I worked on several weapons programs one that used these barrels on one of the rifles we were testing. I got to observes millions of dollars worth of R&D and testing that was done and got to see hundreds of thousands of rounds run through these weapons and got to see firsthand that these barrels did indeed last allot longer and on a whole shoot better than standard button rifled barrels that were chrome lined. The difference was significant and I wondered why the hell no one made these barrels for the M4/AR rifles so I figured I would bring them to market myself. I have over 20 years of service and have shot out plenty of M4’s in my time and can with full confidence say this is a improvement I’ve seen it first hand.

Thanks
Monty

Thanks for posting that TGWLDR, great info.

Good info, thanks! However, the sample of one testing by Molon shows that the tapered bore for Hodge doesn't give it an accuracy edge over Colt or Criterion, which are both less expensive.

The OP's results are not in question.

"A sample of one testing" vs "There I worked on several weapons programs one that used these barrels on one of the rifles we were testing. I got to observes millions of dollars worth of R&D and testing that was done and got to see hundreds of thousands of rounds run through these weapons and got to see firsthand that these barrels did indeed last allot longer and on a whole shoot better than standard button rifled barrels that were chrome lined. " is an apples/oranges comparison though.

Also, the tapered bore or "squeeze bore" as some call it is not a design feature " to make them more accurate" as another poster stated above, rather a trait inherent to the CHF process.

Glitch.

Are all CHF barrels inherently tapered? Or does it require a special mandrel do it?

I probably should have been more specific in my response. My response was more directed at Hodge being more accurate due to a tapered bore. Hodge has "huge" demand and little supply as well as higher prices and supposedly top quality. I'm not saying he stuff isn't nice or doesn't function well, but I'm in the camp of his prices are higher due to hype. If he claims his barrels are more expensive (and more accurate) due to the tapered bore, I was just trying to show that there are more accurate, quality barrels out there for a better deal. A tapered mandrel may very well add to the cost of production for a tapered bore, or his specs for the manufacturer, but I don't see the benefit in the linked tests based on price.

I'd like to know this as well. It's gotta be an incredibly fine taper which I imagine does make the manufacturing of the mandrel more costly.