User Panel
User Panel
User Panel
NC, USA
|
Posted: 6/1/2024 9:32:23 PM EDT
[#1]
Definitely an interesting thread .
|
|
|
CT, USA
|
Posted: 6/6/2024 1:01:48 AM EDT
[#2]
Updates - 120 more rounds fired. 1 blown primer.
Moved from H3 to H4 buffer. It's much much better in all regards. Less fouling, less recoil, very reliable. Groups are .6ish for most work right now. |
|
|
WLF
|
Posted: 6/8/2024 4:29:53 PM EDT
[#3]
Quote HistoryOriginally Posted By vectorsc: Updates - 120 more rounds fired. 1 blown primer. Moved from H3 to H4 buffer. It's much much better in all regards. Less fouling, less recoil, very reliable. Groups are .6ish for most work right now. I don't think 1oz of buffer weight is enough to be the difference between blowing primers and not. If it is you're still on the ragged edge. |
|
|
|
Posted: 6/8/2024 5:00:14 PM EDT
[Last Edit: lazyengineer]
[#4]
Quote HistoryOriginally Posted By vectorsc: Updates - 120 more rounds fired. 1 blown primer. Moved from H3 to H4 buffer. It's much much better in all regards. Less fouling, less recoil, very reliable. Groups are .6ish for most work right now. Now Im kind of curious what your round count on that barrel is up to already. The blown primer item is an issue. As a random thought, have you considered downsizing you ejector springs a bit? Blown primers don't actually "Blow" when fired, they can't. Yea yea, they loosen up, and are no longer held by the correct tension anymore when overpressured. But they fall out during ejection. |
|
|
|
CT, USA
|
Posted: 6/8/2024 8:51:40 PM EDT
[#5]
I think the H4 is getting it. Also, I have quite a few spent cases lol.
|
|
|
CT, USA
|
Posted: 6/9/2024 5:08:34 PM EDT
[#6]
Well today was the end. Blew another primer. That was the last stop in the Journey.
I'll be flipping the parts on the EE later. I'm sure someone will want some sfar spares and a barrel extension to convert. |
|
|
NC, USA
|
Posted: 6/9/2024 5:17:01 PM EDT
[#7]
I'm not going to assume so , did you ever fire the rifle before the mods ?
|
|
|
|
Posted: 6/9/2024 5:18:35 PM EDT
[Last Edit: lazyengineer]
[#8]
Quote HistoryOriginally Posted By vectorsc: Well today was the end. Blew another primer. That was the last stop in the Journey. I'll be flipping the parts on the EE later. I'm sure someone will want some sfar spares and a barrel extension to convert. Sorry to hear it. FWIW, this appear to be nontypical. Might I suggest just buying a new one in factory configuration, and aside from the necessary gas-block/handguard topic - just leaving it that way this time? Not trying to piss you off - honest suggestion not intended as a dig. I have been running reloads in mine, and some hot enough to mar case heads. In my experience an AR10 and 6.5 CM with multifired brass, will blow primers more easily than anything, especially with Hornady brass, and my factory condition (with replacement handguard) hasn't blown a primer yet. I kind of hope you do try again starting over anew (they're $905) as your tests are interesting and useful reads! The common denominator in your experience appears to be the ammo. If we lived closer, I'd actually try to get some from you to test in my own factory unit. (I'd trade you other ammo for it - not trying to scam free ammo - just really interested in this one) |
|
|
|
CT, USA
|
Posted: 6/9/2024 6:55:56 PM EDT
[#9]
Appreciate it. That said, I'm just running off the shelf new Hornady 147's right now. To make sure its not my massive lot of ammo doing it.
This journey started because it was blowing the primers in the factory configuration, too. My bet on all of this is its still an unlocking moment issue specific to 147's. Its not a pressure issue - or not a typical pressure issue. I can run it all day with the gas off and the primers look identical to my Sako bolt gun. That makes the chamber/barrel likely to be fine. The chamber was inspected to have good freebore and good geometry/headspace. I will go back to my original note. The Ruger BCG weighs 11.x ounces. The regular AR10 BCG weighs 18oz. That's 7oz. So I would have to have a 10oz buffer in the gun before the operating system weighed what a regular AR10 does AND those guns frequently need an H2 themselves to stop losing primers with 6.5 CM and a can. The ruger has dramatically more BCG venting than a typical bolt system, which probably helps a lot. Still, I'm $1500 into working these issues probably....and I'm not interested in kicking the can any further. Mostly ammo related. I think I may move on to experimenting with 6arc. |
|
|
WLF
|
Posted: 6/9/2024 9:56:48 PM EDT
[#10]
Quote HistoryOriginally Posted By vectorsc: Well today was the end. Blew another primer. That was the last stop in the Journey. I'll be flipping the parts on the EE later. I'm sure someone will want some sfar spares and a barrel extension to convert. Your barrel has very little value. Cut the muzzle back to 2" from the gas part and reshoot. You have dwell issues. |
|
|
CT, USA
|
Posted: 6/10/2024 12:02:06 PM EDT
[Last Edit: vectorsc]
[#11]
Quote HistoryOriginally Posted By ian187: Your barrel has very little value. Cut the muzzle back to 2" from the gas part and reshoot. You have dwell issues. And I was for sure surprised when +2 gas didn't get it. It's generally the answer for something like this. +2 gas is even more impactful than just reducing the dwell time with a chop job as the peak pressure impulse also drops by 15% and unlocking time is moved out by a very small amount. |
|
|
|
Posted: 6/10/2024 12:28:18 PM EDT
[#12]
Quote HistoryOriginally Posted By vectorsc: I appreciate this reply, and I for sure felt the same. However, my gun has custom modded +2 gas, which is pretty much exactly the same as your suggestion. And I was for sure surprised when +2 gas didn't get it. It's generally the answer for something like this. +2 gas is even more impactful than just reducing the dwell time with a chop job as the peak pressure impulse also drops by 15% and unlocking time is moved out by a very small amount. Quote HistoryOriginally Posted By vectorsc: Originally Posted By ian187: Your barrel has very little value. Cut the muzzle back to 2" from the gas part and reshoot. You have dwell issues. And I was for sure surprised when +2 gas didn't get it. It's generally the answer for something like this. +2 gas is even more impactful than just reducing the dwell time with a chop job as the peak pressure impulse also drops by 15% and unlocking time is moved out by a very small amount. Since it's write off anyway, try +3? Sounds like their 147 gr is very much turned for a bolt action, with really slow burn giving high P still, far out. |
|
|
|
WLF
|
Posted: 6/10/2024 12:33:29 PM EDT
[#13]
Quote HistoryOriginally Posted By vectorsc: I appreciate this reply, and I for sure felt the same. However, my gun has custom modded +2 gas, which is pretty much exactly the same as your suggestion. And I was for sure surprised when +2 gas didn't get it. It's generally the answer for something like this. +2 gas is even more impactful than just reducing the dwell time with a chop job as the peak pressure impulse also drops by 15% and unlocking time is moved out by a very small amount. Quote HistoryOriginally Posted By vectorsc: Originally Posted By ian187: Your barrel has very little value. Cut the muzzle back to 2" from the gas part and reshoot. You have dwell issues. And I was for sure surprised when +2 gas didn't get it. It's generally the answer for something like this. +2 gas is even more impactful than just reducing the dwell time with a chop job as the peak pressure impulse also drops by 15% and unlocking time is moved out by a very small amount. Respectfully, I am aware of your mods and my suggestion is in addition to the gas port location change. I am not surprised the port change isn't enough. Ruger added gas venting to the carrier in an attempt to mitigate the steep cam path and light weight carrier. The added gas port distance helps but you negated it with your ammunition selection. 147 ELDM uses an H4350 analog and is slow for cartridge class. Your ammunition selection is static so what else can change? Extend the port another 2", add buffer weight, or reduce the barrel length in front of the port. Your barrel is effectively worthless if you sell it now that it is modified soooo, start cutting the end off. Start at 18" OAL and work back. You'll need approximately 1.5" in front of the port if you want a threaded muzzle device. The static ammunition selection is the fly in the ointment. That gun in a +2 RLGS 18" 7-08 would be excellent. Your use case is very unique though. |
|
|
WLF
|
Posted: 6/10/2024 12:36:06 PM EDT
[#14]
Quote HistoryOriginally Posted By lazyengineer: Since it's write off anyway, try +3? Sounds like their 147 gr is very much turned for a bolt action, with really slow burn giving high P still, far out. That ammo is not only the very top of max pressure but also has slow burning powder. |
|
|
CT, USA
|
Posted: 6/10/2024 2:12:58 PM EDT
[#15]
Quote HistoryOriginally Posted By ian187: That ammo is not only the very top of max pressure but also has slow burning powder. I am likely going to try threading the inside of the bcg and putting in buffer weights to see what that does....Because I'm bored AF. |
|
|
|
Posted: 6/10/2024 2:49:25 PM EDT
[#16]
Quote HistoryOriginally Posted By vectorsc: All true. On a full size ar10 style gun I have no issues getting it back into acceptable pressure, but I think the SFAR op system is a bit too light for that. I am likely going to try threading the inside of the bcg and putting in buffer weights to see what that does....Because I'm bored AF. Quote HistoryOriginally Posted By vectorsc: Originally Posted By ian187: That ammo is not only the very top of max pressure but also has slow burning powder. I am likely going to try threading the inside of the bcg and putting in buffer weights to see what that does....Because I'm bored AF. I imagine a smaller gas port hole might help as well. I assuming you are running gas at 1? (Or did you toss the factory gas block?) |
|
|
|
CT, USA
|
Posted: 6/10/2024 4:16:25 PM EDT
[#17]
Factory gas block is tossed. New port is .086.
I'm at 7 or 800 rounds now troubleshooting. so more than the gun was worth LOL. |
|
|
|
Posted: 6/10/2024 4:54:22 PM EDT
[#18]
Quote HistoryOriginally Posted By vectorsc: Factory gas block is tossed. New port is .086. I'm at 7 or 800 rounds now troubleshooting. so more than the gun was worth LOL. I know! Honestly, the gas block is a lot better than people dis. Only issue is they didn't size the handguard right. If you have route to run it exposed (which you probably do at plus 2", I think it's actually a great gas block. It manages carbon locking better than many, and has a good span of an appropriate number of settings options. It's mildly oversized, but in some ways that's kind of a heatsink- I personally thinks it's the best gas block I've owned. |
|
|
|
WLF
|
Posted: 6/10/2024 5:16:43 PM EDT
[#19]
Quote HistoryOriginally Posted By vectorsc: All true. On a full size ar10 style gun I have no issues getting it back into acceptable pressure, but I think the SFAR op system is a bit too light for that. I am likely going to try threading the inside of the bcg and putting in buffer weights to see what that does....Because I'm bored AF. Quote HistoryOriginally Posted By vectorsc: Originally Posted By ian187: That ammo is not only the very top of max pressure but also has slow burning powder. I am likely going to try threading the inside of the bcg and putting in buffer weights to see what that does....Because I'm bored AF. Tubbs used to make a carrier insert weight. There are pictures if you Google it. Are you using an AGB in addition to the new smaller port. |
|
|
CT, USA
|
Posted: 6/10/2024 7:09:46 PM EDT
[#20]
A superlative job.
|
|
|
NM, USA
|
Posted: 6/11/2024 9:43:20 AM EDT
[#21]
Change ammo?
I'm a fan of the Federal 130 grain Berger Hybrid Tactical load. |
|
|
|
Posted: 6/11/2024 10:32:21 AM EDT
[Last Edit: lazyengineer]
[#22]
Quote HistoryOriginally Posted By badkarmaiii: Change ammo? I'm a fan of the Federal 130 grain Berger Hybrid Tactical load. Particular to OP, he was paid for a job via crates of this particular 147 gr ammo. So he has to fit the gun, to the ammo. It's a challenging ammo for a gas-gun. |
|
|
|
NM, USA
|
Posted: 6/11/2024 12:22:33 PM EDT
[#23]
Quote HistoryOriginally Posted By lazyengineer: Particular to OP, he was paid for a job via crates of this particular 147 gr ammo. So he has to fit the gun, to the ammo. It's a challenging ammo for a gas-gun. Gotcha. Sounds like a pickle. The extended gas system is cool. I'd use the 147s in a bolt gun or heavy AR and use the SFAR when weight matters. |
|
|
CT, USA
|
Posted: 6/13/2024 12:54:31 AM EDT
[#24]
Yeah i moved on to experiment with a proof barreled 6arc lmt.
Gonna go shoot that this weekend.  |
|
|
CT, USA
|
Posted: 6/29/2024 12:40:09 PM EDT
[#25]
Well, I'm an idiot and found something to try.
It got better the more buffer weight I added....then I was on Tacswap and someone had a smoking deal on this. 9oz here we come.  |
|
|
CT, USA
|
Posted: 6/29/2024 4:11:17 PM EDT
[#26]
Round 21 - started blowing primers. Again.
|
|
|
CA, USA
|
Posted: 6/29/2024 4:28:07 PM EDT
[#27]
Wow, never ends...
|
|
|
|
Posted: 6/29/2024 5:10:06 PM EDT
[#28]
Quote HistoryOriginally Posted By ian187: Respectfully, I am aware of your mods and my suggestion is in addition to the gas port location change. I am not surprised the port change isn't enough. Ruger added gas venting to the carrier in an attempt to mitigate the steep cam path and light weight carrier. The added gas port distance helps but you negated it with your ammunition selection. 147 ELDM uses an H4350 analog and is slow for cartridge class. Your ammunition selection is static so what else can change? Extend the port another 2", add buffer weight, or reduce the barrel length in front of the port. Your barrel is effectively worthless if you sell it now that it is modified soooo, start cutting the end off. Start at 18" OAL and work back. You'll need approximately 1.5" in front of the port if you want a threaded muzzle device. The static ammunition selection is the fly in the ointment. That gun in a +2 RLGS 18" 7-08 would be excellent. Your use case is very unique though. Quote HistoryOriginally Posted By ian187: Originally Posted By vectorsc: Originally Posted By ian187: Your barrel has very little value. Cut the muzzle back to 2" from the gas part and reshoot. You have dwell issues. And I was for sure surprised when +2 gas didn't get it. It's generally the answer for something like this. +2 gas is even more impactful than just reducing the dwell time with a chop job as the peak pressure impulse also drops by 15% and unlocking time is moved out by a very small amount. Respectfully, I am aware of your mods and my suggestion is in addition to the gas port location change. I am not surprised the port change isn't enough. Ruger added gas venting to the carrier in an attempt to mitigate the steep cam path and light weight carrier. The added gas port distance helps but you negated it with your ammunition selection. 147 ELDM uses an H4350 analog and is slow for cartridge class. Your ammunition selection is static so what else can change? Extend the port another 2", add buffer weight, or reduce the barrel length in front of the port. Your barrel is effectively worthless if you sell it now that it is modified soooo, start cutting the end off. Start at 18" OAL and work back. You'll need approximately 1.5" in front of the port if you want a threaded muzzle device. The static ammunition selection is the fly in the ointment. That gun in a +2 RLGS 18" 7-08 would be excellent. Your use case is very unique though. I suspect you are correct. I have a friend fighting the same issue with a full size AR-10 in 260. He is using a Proof Research barrel with a +2 gas system. He's getting pressure signs that are made much worse when using a suppressor. I have seen both 308 and 223 factory ARs sold with rifle gas systems on 16" barrels, so I suspect a 260 or 6.5 Creedmoor could do well with a +4 or more gas system on a 20+ " barrel which is probably closer to what most other gas operated rifles like the M-14, FAL, etc use. |
|
|
|
|
Posted: 6/29/2024 5:32:44 PM EDT
[Last Edit: lazyengineer]
[#29]
I guess the botled high pressure of the 147gr ammo with the slow heavy bullet amd slow burn high P powder, means high residual pressure as the bolt starts to move. During that extra dwell time. So the advise to start chopping barrel, may well be the way to go. The barrel has zero value to anyone else anyway.
I don't have any factory 147 ammo, so can't comment on if this is a universal SFAR problem with that ammo. I will say I have some rather warm 143 gr ammo with R16, that runs just fine. |
|
|
|
|
Posted: 6/29/2024 8:22:39 PM EDT
[Last Edit: lokifox]
[#30]
Wish I had caught this thread earlier.
To get top end 243 loads to run in my suppressed DPMS GII I had to create a mad scientist 13 oz. recoil buffer and pair it with a heavy spring. It was basically a useless POS until I did that. Buffer weight is my universal go-to when things don't play nice now. Especially when it involves overbore cartridges and suppressors (flow or traditional). |
|
|
|
|
Posted: 7/12/2024 6:34:47 AM EDT
[#31]
Very informational thread.
Interesting results. Sorry if I missed it, ( and I realize you have enough 147gr to stock a shooting team ) ... but what other ammo have you tried? I ask not because something else might work, but more because, if it pops primers that consistently. I hope that makes sense. |
|
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
