Ok guys and gals my gun is a complete aero precision with a new proof research barrel. The bolt is a complete 6.5 Grendel aero bolt. And sometimes when I close the bolt shut I have misfires it leaves a small primer mark on the primer and when I go to eject the case it stays in the barrel till I slam it again and hit the forward assist then it will come out and I’m getting bad marks on the rim of the the case head from the ejector claw wat is wrong with this thing it’s factory hornady 62gr eld-vt ammo or wat have I done wrong thanks in advance
Do you have wear marks on the outside of your extractor?
Might be that the extractor isn't properly clearanced for the larger case and is getting wedged, unable to completely snap over the rim. Stops the BCG from going fully into battery and doesn't allow FP protrusion for proper firing.
Q2, is it a Grendel/ARC extractor?
Might be that the extractor isn't properly clearanced for the larger case and is getting wedged, unable to completely snap over the rim. Stops the BCG from going fully into battery and doesn't allow FP protrusion for proper firing.
Q2, is it a Grendel/ARC extractor?
You can either hit the red outlined portion with a dremel or try a different 6.5 Grendel Extractor. The Rexus stuff has been great for me so far.
www.sixfiveoutfitters.com
SixFive AR15 Improved 6.5 Grendel / 6mm ARC Extractor
SixFive AR15 Improved 6.5 Grendel / 6mm ARC Extractor
www.sixfiveoutfitters.com So I did wat ya told me and I’m still getting the two marks on the case mouth I even checked to make sure I took enough off and put magic marker on there to c if it would rub off and it don’t but the marks r still coming up on the brass
One thing you might need to do is tune the extractor so there aren’t sharp corners to the lip.
There is no reason to have them, and part of the M16/M4 TDP has them relieved during the machining process anyway.
The after-market cranks out parts with a lot of corners cut, no pun intended.
My go-to bolts now are the Rexus bolts and extractors, though I have never had problems with a wide variety of bolts.
I’ve used several types dating back to 2009:
AA
AA Hard use (several samples)
Maxim from PF (many samples)
Monster logo bolts from forum group buy (many samples)
Rexus
There is no reason to have them, and part of the M16/M4 TDP has them relieved during the machining process anyway.
The after-market cranks out parts with a lot of corners cut, no pun intended.
My go-to bolts now are the Rexus bolts and extractors, though I have never had problems with a wide variety of bolts.
I’ve used several types dating back to 2009:
AA
AA Hard use (several samples)
Maxim from PF (many samples)
Monster logo bolts from forum group buy (many samples)
Rexus
I have 2 6 mm ARC s and both have Proof barrels. I have no such issues. I do not shoot factory ammo in anything, everything is handloads...even 9mm.
Try a different brand of ammo. The ammo and chamber my be a mis match, with headspace slightly too tight, or bullet seating slighy long. Hornady had ammo problems with the 6mm ARC when it came out, that wouldn't completely chamber on every shot...open the action and the powder is dumped into the chamber with the bullet stuck in the barrel...a mismatch between the ammo maker and the chamber, at least one is out of spec.
Try a different brand of ammo. The ammo and chamber my be a mis match, with headspace slightly too tight, or bullet seating slighy long. Hornady had ammo problems with the 6mm ARC when it came out, that wouldn't completely chamber on every shot...open the action and the powder is dumped into the chamber with the bullet stuck in the barrel...a mismatch between the ammo maker and the chamber, at least one is out of spec.
One of the things different with the .441” case heads is that the extractor has to snap over a larger diameter in dynamic range for proper function.
If the barrel extension has any bit of eccentricity to it after heat-treating, this can impede on the extractor lift and grind over those places LedZep highlighted. With the cartridge seated and the extractor already snapped over, you will not see the potential problem.
Bill A. talked about it as one of the early bugs he had to work through when determining the processes map for machining and heat-treating of components. Once those processes are worked-out, it’s not an issue.
A lot of the after-market companies never worked through these engineering challenges and just expected to be able to drop-in components and have everything function out of the gate.
I have not seen any extractor binding in those places on any of my Grendels over the years, but have seen it on someone else’s. I can’t remember whose it was, maybe a Satern 18” fluted barrel/bolt combo back in the mid 20teens.
De-edging the extractor lip corners will help prevent this as well since there is less required extractor lift to snap over the case.
If the barrel extension has any bit of eccentricity to it after heat-treating, this can impede on the extractor lift and grind over those places LedZep highlighted. With the cartridge seated and the extractor already snapped over, you will not see the potential problem.
Bill A. talked about it as one of the early bugs he had to work through when determining the processes map for machining and heat-treating of components. Once those processes are worked-out, it’s not an issue.
A lot of the after-market companies never worked through these engineering challenges and just expected to be able to drop-in components and have everything function out of the gate.
I have not seen any extractor binding in those places on any of my Grendels over the years, but have seen it on someone else’s. I can’t remember whose it was, maybe a Satern 18” fluted barrel/bolt combo back in the mid 20teens.
De-edging the extractor lip corners will help prevent this as well since there is less required extractor lift to snap over the case.
I had never seen it, but I wasn't on the Grendel case head diameter bandwagon until much later.
Interesting the an old problem is still around. That seems to be alot of runout and or heat treat distortion. Much of which can be controlled by alloys and heat treatment procedures.
Plus CNC machining when properly set up will have concentric threads, and the threaded broached extensions may be where most of the runout occurs.
I machine my own AR barrels from time to time, but never had an issue even with bushmaster .473" dia, bolt.
Dial the barrel in cut the barrel extension threads concentric to the bore, thread on barrel extension and check clearance for bolt lugs, chamber, and torque down, check headspace. If your math was correct your in tolerance.
Hope I never run into it, but if I do. I'll see if that idea works for me. Thanks.
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Any time a new PPC/Grendel variant is introduced and companies who were not dealing with it before jump on, there is the high likelihood that they will have to re-learn several engineering lessons the hard way.
This is also true with 5.56 NATO. Plenty of companies still can’t get that even remotely right because they lack the culture or commitment to demand even maxing the minimum from themselves. Mediocrity is now a high bar to reach.
With Grendel-based cartridges, the barrel extensions need to be cylindrical and not egg-shaped after heat treat. A potential problem is the processes and when you grind the feed ramps. Because 5.56 only has .378” case diameter, even eccentric extensions will not manifest the extractor binding as there is plenty of clearance.
Another thing unique to the .441” case heads is the binding on the side of the ejector. AA dealt with it by making sure the ejector was limited to a certain length. Competitive shooters who were shooting PPCs and Grendel posted that bulletin in AccurateShooter where they chamfered the ejector to prevent right side magazine presentation binding against the side of the case rim.
This is also true with 5.56 NATO. Plenty of companies still can’t get that even remotely right because they lack the culture or commitment to demand even maxing the minimum from themselves. Mediocrity is now a high bar to reach.
With Grendel-based cartridges, the barrel extensions need to be cylindrical and not egg-shaped after heat treat. A potential problem is the processes and when you grind the feed ramps. Because 5.56 only has .378” case diameter, even eccentric extensions will not manifest the extractor binding as there is plenty of clearance.
Another thing unique to the .441” case heads is the binding on the side of the ejector. AA dealt with it by making sure the ejector was limited to a certain length. Competitive shooters who were shooting PPCs and Grendel posted that bulletin in AccurateShooter where they chamfered the ejector to prevent right side magazine presentation binding against the side of the case rim.
One process I go through before I even think about installing a barrel is to check the chamber with 4 different dummy cartridges to make sure they chamber and fall out without effort. I also have a stripped bolt to make sure there is lock-up with a chambered round with known shoulder datum locations.
A lot of factory ammo is undersized so it will chamber, when talking about shoulder location relative to the base. There should not be difficulty extracting factory ammunition, or lands being jammed by the ogive.
Then I de-edge, blend, and polish the feed ramps. Grendel cases are fatter, so the feed ramps do well to be opened up a bit, or at least the sharp edges taken off them. I like BAT Machine extensions that are tumble-polished if you’re looking for a solution you don’t want to mess with.
A lot of factory ammo is undersized so it will chamber, when talking about shoulder location relative to the base. There should not be difficulty extracting factory ammunition, or lands being jammed by the ogive.
Then I de-edge, blend, and polish the feed ramps. Grendel cases are fatter, so the feed ramps do well to be opened up a bit, or at least the sharp edges taken off them. I like BAT Machine extensions that are tumble-polished if you’re looking for a solution you don’t want to mess with.
Anyway that it could be the plunger spring being to tough. Because with factory hornady 62gr eld-tv I’m getting slight ejector swipe Aswell as dented case mount. I have the gas turned down my ejection is right at 3:30. I am using a brass catcher but it was doing all this before I was using it anyway.
thanks a ton guys and gals
thanks a ton guys and gals
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If your extractor has the O-ring around it, take it off and see if the rim damage continues.
I remove O-rings from extractors as a rule because they were developed as a band-aid for a very limited range of early SOCOM Heavy M4A1 barrels back in the early 2000s, where many were reamed with tight chambers that caused extraction issues.
A lot of people in the AR world said, “SOCOM is installing O-rings in their M4s! We must replicate!"
I fell victim to it myself until I saw what was going on with chambering and said, “You know, I never really had extraction issues before this, so I’m not using these things."
I remove O-rings from extractors as a rule because they were developed as a band-aid for a very limited range of early SOCOM Heavy M4A1 barrels back in the early 2000s, where many were reamed with tight chambers that caused extraction issues.
A lot of people in the AR world said, “SOCOM is installing O-rings in their M4s! We must replicate!"
I fell victim to it myself until I saw what was going on with chambering and said, “You know, I never really had extraction issues before this, so I’m not using these things."
Something to try as I had a similar issue once..... I suggest to try a at least an H2 buffer. I fought that similar issue while trying to get my gas just right so the ejection angle would be at the suggested angle. Put a heavier buffer in and all is well.....go figure.
A stronger action spring will keep the bolt locked longer as well, because it fights carrier momentum.
Stronger action spring makes a lot of sense for a 30-34gr case capacity with a tiny bore. Residual bore pressure is higher for the same case capacity compared with 6mm and 6.5mm.
Stronger action spring makes a lot of sense for a 30-34gr case capacity with a tiny bore. Residual bore pressure is higher for the same case capacity compared with 6mm and 6.5mm.
This tells me you need more buffer weight.
1. Ejector swipe
2. Dented case
3. 3:30 ejection
Adjust your gas to where it stops wrecking the brass and tell us what happens.
Are you saying what's still happening is ejector swipes and the case heads being ripped off?
Did you ever manually cycle through a few rounds I may have missed it?
The case head is not being ripped off it is only getting mark on the side of the rim of the case from the extractor and it is getting slight plunger marks on factory rounds witch I wouldn thank would b to hot from hornady and yes I have Manually cycled a whole box maybe twice now and it’s still doing the same I intend to take off the rubber oring today and sees we’re that takes me
This sounds like a combination of problems. The extractor problem is separate from the early unlocking. Everything that @LRRPF52 about the bolt and extension. I only use AA bolts with Grendel cartridges and still need to smooth the extractor. I'd also want Proof to look at that barrel but, if you don't trim back the extractor corners the extractor needs more lift. If there isn't enough clearance in the extension the extractor can't move far enough.
No it doesn't, it very well could be the Aero bolt and every single extractor they make. Buy a complete bolt and firing pin from one of the vendors @LRRPF52 listed first, if that doesn't work call Proof. My preference is Alexander Arms for Grendel bolts, they are the source of Grendel.
Watching with interest
I’ve got my own issues with a 6 mm Creedmoor barrel that is walking not gonna comment on the manufacturer but it has been unknown issue, and the barrel sat in my safe for three years before I actually took it out and shot it so hopefully they’ll Stan behind their barrels
Yep I have talked with proof and they want so bad for my bolt to be the problem but I have ordred a brand new type 2 jp bolt kit witch they suggested and I’m gonna try this then if this don’t work they want me to send my bolt and barrel to them so they can try it well in my opinion this is a brand new barrel with problems so I think they should replace it but we will see to bad there warranty isn’t like vortex best in the business
It shouldn't come as a surprise Proof wants you to follow the terms of their warranty before they'll consider investing warranty labor and money in your parts build. People act like large frame ARs are the deep end of the AR pool. Well they aren't, Grendel is.
I have done everything they have asked me besides sending it in to them this is a brand new product everything on this gun is brand new and something is not right and I have swapped everything but the barrel so that tells me that’s the problem but I don’t know nothing to b honest
Your parts being new is not a criteria for them to be right. Maybe the barrel is the problem but Proof plainly states which bolts to use for their warranty. You chose the third tier bolt to go with the, arguably, first tier barrel. No shit Proof wants that changed first.
People have been shooting .224 AR /22 Grendel wildcats for the better part of the last 10 years without these issues though, so something is off here that others don’t typically see.
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