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wisdom of the crowd - ocharry - 02-16-2023
hi guys...im new here...well i been here a lot just reading and a lot more as of late
trying to figure out what if anything is going on with my ar grendel
so to begin...it seems to have an ejection problem...i built this rifle almost a year ago and from the beginning i kinda thought it was under gassed....18" RLGS...i started with a h1 buffer and standard spring...and it was denting the case mouth on ejection and it would do some other things..sometimes not eject..catch a case in the ejectin port..flip one bacwards in the chamber laying on the mag....but it locks back on last round..and is a soft shooter
so i changed to a standard carbine buffer and...i though i had it fixed .....but noooo...it raised its ugly head again...but the case mouth dents are smaller but still there...first round out the other day it jamed it into the front of the ejection port...center of case mouth smashed into the front radious of the ejection port
so i have been reading here for about a week on other issues you guys are discusing and from what i am gathering the 18"RLGS is not optimum for the 6.5 grnedel...volume thing im thinking....kinda think i should have went 20" at this point....i got a 223 that is a twin to this rifle...18"RLGS i built too and it runs like a sewing machine...so has to be something with bigger cal going on.. less volume of gas in the barrel..and short dwell time...yeah im paying attention here fellas
anyway after doing all the reading and seeing what port sizes were or should be i took my rifle apart and here is what i have
took the forearm off and checked for leaks...no sooty spots that i could see..i looked with a good light and i was looking for anything leaking...poop.... nuttin
well i know now...must be a too small gas port or i got the gas block out of alignment...so off it comes....hmmmm...shadow on the barrel says that the gas block was lined up pretty dang good...almost perfect center...so i checked gas port size.... .096 thou goes in but .098 thou does not....so its probably in the .097 thou range... so i check gas tube in gas block alignment...that looks good too..dang that should be working pretty good me thinks....so...poop again
so i checked out the bolt carrier and gas key is tight and staked good...hmmm...no signs of leaking here either...well you know...poop...im running out of things to look at and to maybe fix...other than taking the gas port out to maybe .100+ in size...and i can put it in the mill and do that pretty easy...but i really dont want to unless i have to...but i will no problem
i kinda get too that the 18" RLGS runs better with a can...i really dont want to do that...i like the 18" thing really well... balances well for me and it just fits and feels good....shoulda went with a 20"...lol....hind sight is ALWAYS 20-20
so i ordered a linier compensator...just a cheap one to test out and see if i can get a little more dwell time outa this thing....kinda like maybe a 19" barrel...lol...you know just a little more push back...keep the stuff in there just a tad longer...
i really believe this rifle is right on the ragged edge and just a small nudge could get it over the edge of running ...i dont really want it on the edge i want it to run and run good
i want this gun to be a coyote gun and maybe a deer gun too...i want it to run with 120gr bullets....and maybe a sprinkling of 95gr bullets but those seem to be the real problem child....the problems do seem to show up more with the lighter bullets...
the gun wants to shoot.....and i want it to run good which so far has not happened...but i know it can be a runner...because it has shown me it is a shooter.....it does everything else good...feeds.... loads...locks open....just these pesky ejection things.....they gota go
well there you have it....i think i have covered it pretty well for you all to git in here and tell me your thoughts and where to go....careful !!!!! i have been told where to go a lot...lol...im talking about where i should maybe go with my rifle...lol...or maybe a fix to look at
i think the gas port is ok...but if i need to, i will open it up...but that would be my last option i think
OK....wisdom of the crowd ...i need some input from you fellas and gals if any.....i am a sponge and my ears are open and my mouth is shut...unless you ask a question of course
THANKS
ocharry
wisdom of the crowd - LRRPF52 - 02-16-2023
If you legitimately dont have any leaks, I would open the gas port to .1094 (7/64 bit) after checking that you have an efficient bolt carrier.
Test the bolt and carrier if the carrier with collapse on its own weight vertically, after telescoping the bolt forward.
If it fails that, test it without the cam pin the same way.
Especially with 95gr and shorter, youll tend to see short-stroke malfunctions with 18 RLGS because there isnt enough dwell time. This is particularly true in cold weather as well.
Insert a dowel in the barrel to prevent you from blowing all the way into your rifling, or set a mechanical limit with your tooling when you drill out the port.
Run your bit so that you dont tear a large burr out of the downside of the port. Carbide bits work well at certain speeds for this if youre more meticulous, but it can be done with a hand drill too.
wisdom of the crowd - grendelnubi - 02-17-2023
I also have an 18" RLGS and found that in the colder months, running 129 grain ABLR projectiles with AR Comp, I would intermittently experience a short stroke condition. I was also having the bent case mouth's, similar to what you have observed.
For me, after opening the adjustable gas block 1 turn, both issues went away. I also have been running the 90 TNT with 8208 powder with no observed issues even before adjusting the gas block.
It sounds like to me you have a good understanding of what is going on. Now just need to increase the gas and see if it corrects the issue.
wisdom of the crowd - Klem - 02-17-2023
ocharry,
Dings from ejected cases hitting the receiver deflector is normal in this calibre. The case is relatively short and flicks it all the way around on exit. The solution is to cut a couple of coils off your ejector spring, so it is flush with the bolt face when relaxed. There are threads on this, and I recommend you do some homework before snipping. A replacement spring is only a couple of bucks so a non issue as far as risk is concerned.
Doing this may or may not help with other issues like jamming due to a reflected case. It will certainly clean up the dings and you can then more clearly see what's left to fix.
wisdom of the crowd - montana - 02-17-2023
If the bolt holds open on the last round, I'm questioning if it is under gassed.
Some times a tight chamber can effect ejection. Can you place a factory cartridge in the chamber with slight pressure and then tip the barrel up and the cartridge fall out without sticking in the chamber?
If you push your ejector in and out on the bolt, does it stick?
Do a gas ring test.
Do you have a bent firing pin cotter key?
Do you have excessive powder residue and carbon in the fire control group?
Do you have a rubber O ring in the extractor? Especially with the Grendel, a rubber O ring will create too much tension on the extractor..
If you remove the ejector and insert the ejector pin in it, does it swivel freely without sticking?
Remove the extractor, insert the case rim into the extractor and see if it is a tight, snug or loose fit..
Remove the extractor and ejector and put the case into the bolt face, does it insert easily or is it tight??
It could be the extractor..https://www.youtube.com/watch?v=kMrMUyyWV0k
On another note, I'm not saying yours is, but I have seen over gassed rifles behave just like your rifle..
wisdom of the crowd - ocharry - 02-17-2023
sorry for the delay fellas...i only have this thing on in the morning
OK, so i guess i will start at the top..LRRPF52..yes i have done a bolt test...it is a new bolt from areo and it will hold its self up....i took it apart when i got it and checked it out cleaned and oil and checked head space...everything looked good about it
grendelnubi...i am working on loads right now....i was working on them last fall and then deer season came and i just got back to it....so it is colder now than it was the last time i had it out playing....i want to have a load that works with a 95gr vmax and a load with a 120-120+ gr bullet....so i am working with the sierra 120gr pro hunter right now....i got a good load worked up with the 95gr bullet...well if i can get it to cycle reliable.... for the record my gun has a midwest industries low pro gas block, the three screw model...so it is wide open all the time
Klem..i think i have figured that the dents are a given for this cal from what i have read..and i think i am over it...would be nice if it didnt happen but if it does it does is where im at...as for the spring...i got lots of spare parts ad springs and like you said they are sheap if i screw one up...so i will clip one and see what happens...down in the low teens here so it aint happening today...lol
montana...i have not checked the chamber... but i will....i guess if i have a sticky chamber it could maybe cause or contribute to some of this stuff...i did take the extractor apart when i got the bolt and it does have the o ring under the extractor with the spring and little rubber piece in the middle of the spring...pretty stiff i thought and the corners of the extractor it self are pretty dang sharp...it does leave marks on the rim and the rim is kinda snug fitting in the notch on the extractor.....hmmmmmaybe i should give that thing a polish...kinda like slicking up the extractor on a 1911....the ejector was fine last time i looked at it i dont think it is sticking but i will check it again....along with a chamber check with a cartridge...gas test on bolt is good...stands up just fine...i dont think i have a bent cotter key but i will check that too...i did the swivel thing on the extractor when i got the bolt ..while i had it apart to do the head space check...it spun around on the pin just fine...also i did check the extractor when i had it out and like said the thing is kinda sharp and i think i remember it was kinda tight in the rim of the case...i didnt check the case head in the bolt face but i will ...i am gona take it apart and do all of these checks again.......well i started with a H1 buffer and i now have a standard buffer in the gun....and i have been thinking... i do get into trouble doing that from time to time...but i was thinking i may have went the wrong way.....the gun has never not locked open...even with the H1 buffer...so i have a H2 buffer in the mail on its way along with a couple of new springs.....also i want to say here that theis rifle only has about 100 rounds down the pipe....and i have read where they need 200+ to get running smooth....but i will say the think is slicker than greased owl poop.....like it is riding on bearings in there.....so yes i want to try the liniare comp to see if i can get more dwell and i also want to try a H2 buffer ...just for grins.....lots of stuff to check and try before i open the gas port up...i just happen to have a .1065thou reamer from the old days ....but like i said i want this thing to run... so there is no second guessing it when we are down range...so what ever it takes i am gona make it run
thanks guys....anything else i need to look at???
ocharry
wisdom of the crowd - BluntForceTrauma - 02-20-2023
I like that you're checking everything carefully and not rushing into anything. LAST thing you want to do is open the gas port if it's locking back. Gotta be something else.
1. DOES it lock back on your 95gr load? If it does, I don't think it's the gas system. You said the carbon ring from the gas block is centered on the gas port hole, so that's good.
2. You mentioned it could just not be broken in enough with only 100 rounds on it. Go to 200 before get getting serious about altering parts.
3. What I'm really thinking is extractor.
a. Is there too much oil in the extractor claw groove causing the extractor to slip off the rim randomly? Did I read it wrong or did you say it's sometimes leaves a case unextracted in the receiver? If so, that sounds like an extractor slippage, which says oily or not enough tension but it DOES have an O-ring. Hmmm....
b. With a bone dry extractor claw, try with and without the O-ring. (I've only found them necessary on 12" CLGS; others find them not necessary at all experiment with this.
c. Try a completely different bolt and extractor? (If you don't have one, I can send a loaner.)
wisdom of the crowd - ocharry - 02-20-2023
BluntForceTrauma,
thanks for the complement....i was (retired now) and have been a trouble shooter my whole life...when i was working i would notice my coworkers would always be fixed on what was happening at the problem spot..i found that if i looked up stream most of the time it... the real problem was happening there and manifesting at the wreck sight ..lol...so i still look up stream when i am working a problem
yes it locks back with the 95gr loads.. it has never not locked open on an empty mag on any load.... as for altering parts i think the 200 mark is what i want to do, but i am planning on doing some part swaps with things i have and are coming in the mail this week... as to the extraction thing...it has always pulled the case out of the chamber....sometimes it doesnt get out of the port...i have had stove pipes and extractions out of the chamber but laying on top of the mag and cause a stoppage by jaming it into the extention...and once in a while it will flip a case around backwards and leave it laying on the top of the mag...and then i will get one that trys to get out..lol.. and it will jam the mouth of the case into the front of the ejection port....kinda like it is cycling to fast for things to happen, the bolt is moving to fast ...i dont really know how to explain that move it makes ...again montana touched on the over gassing thing and i have thought that too....so i will explan the plan of attack.. .lol
as for this one....well i took the rifle apart yesterday and did the chamber test thing montana talked about....i did it with 4 different loads..2 new factory brass loaded rounds 1 steel cased new round and a couple of my reloaded rounds...since i set the shoulder back .005 on auto loaders i thought that would be a good check also...they all fell out when i tipped the barrel up..so that is a go
i took the bolt apart and checked it out... i have noticed the rims of the cases do show marks from the extractor...so i slicked it up a touch...but other than that the case slips into the counterbore of the bolt just fine...ejector looks fine...i might try the spring clip Klem talked about to soften the ejection a touch but the face of the bolt was dry and clean...no brass slivers or anything that looked out of place
i just got a H2 buffer and i have a H1 and a standard...i have ordered a linier comp and a springco reduced power buffer spring...right now the rifle is set up with a standard buffer spring and a 2.96oz buffer...so when the rest of the stuff gets here this week the plan is to put the comp on and see if i get a bump in dwell time...it was just a thought and a cheap thing to try....if not then i plan on putting the H2 buffer in...and if that dont work i will leave the H2 in and change to the reduced power spring...if that dont work i will go to the H1 buffer and then to the standard buffer ...since i have polished the extractor i want to try that and maybe take the o-ring off and see what that does for the dents and clip the ejector spring to see if i can get the dents to go away.......if all of this fails then it will find its way to the mill and the .1065 #36 carbide reamer is going to make a bigger hole in the barrel....BUT that is the LAST resort...the barrel has a .097thou gas port in it now... and i just cant believe i can not find some happy place to make it run with both a 95gr bullets for varmints and a 120 gr bullet for deer sized game...although the 95gr could work for both as well as the 120gr bullets could work that way too...i just like to have more than one option
i do have a new bolt group, but for the life of me i cant see a thing wrong with this one...but i can toss the new one into the things to try bucket after the head space is checked ...i like redundancy ...old saying 2 is 1 and 1 is none
oh and i love the chase...trouble shooter thing i think..lol
so that is the chase plan for right now...unless you guys got something else i need to test or try....as soon as the rest of the parts and stuff gets here that is the plan
ocharry
wisdom of the crowd - LRRPF52 - 02-20-2023
A .094 gas port is standard for RLGS 20 barrel, which has ideal dwell time for most loads.
20 Grendels run very smoothly with that port.
An 18 RLGS Grendel with .094 is on the edge of having sufficient dwell time, and will cross over that edge as the temps dip in the winter or at night/early morning.
This is why at least 2 companies have been making Intermediate Length Gas port locations on 18 Grendel barrels.
wisdom of the crowd - ocharry - 02-20-2023
LRRPF52...
this barrel has a .097" port in it now...while it may be on the raged edge of running..and i believe it is....i think i can tune the mass of the bolt and buffer and spring to get it to run...i agree with you it does seem to run more ugly when it is colder outside...or in lower temps...like i said when i last had this thing out plying with it it was in october last year and it was warmer then than now and i thought i had it fixed....but with the cold temps now it is acting stupid again...so temps for sure are in the mix
so when all the stuff gets here the testing will start...i like all the ducks to be on the table when the smoke clears, so i know where they are
and i wil keep you guys in the loop..i hope you dont mind
ocharry
wisdom of the crowd - BluntForceTrauma - 02-20-2023
ocharry Wrote:i took the bolt apart and checked it out... i have noticed the rims of the cases do show marks from the extractor...so i slicked it up a touch
I'm still fixated on the extractor. If the corners of the extractor are too sharp, it can hang onto the brass longer than it should and pull it back into the receiver. This would argue for not shortening and weakening just yet the ejector spring. My opinion is you're on the right track by filing down those sharp fangs. I'd "defang" it and try shooting it again before doing anything else drastic. Focus on that one variable before muddying the waters changing other variables at the same time.
As I mentioned, I can always send a loaner bolt that's already "defanged" from the factory.
wisdom of the crowd - ocharry - 02-22-2023
BluntForceTrauma...
do we have something going on with the forum..keeps telling me it is unsafe..never had this problem before...so i have to jack around to get here..and then it probably wont let me post this...
anyway i did some checking around and found a couple of videos about grendel extractors...and what i found was going on kind of interesting..i did polish the corners on my extractor the other day but i did not check to see if it was hanging on the rim...so i took it apart again and checked that and the cases came right off ...no hangy or clingy ....but i went ahead and "defanged" it any way and then polished it back nice and shinny and slick...just a touch nothing fancy and it did seem to help just a little i think....so im not real sure that was or is a problem but it is a place to start and i only do one thing at a time anyway so i know if i am headed in the right direction and what finally needs to happen or what i did when the thing starts working
i found your web sight and i put a couple of grendel extractors and a bolt in my cart...i have no problems having extra parts and i dont have any extra extractors for this anyway......lol....you got any coupons...lol ...yeah i can be a tight wad these days...any help is ALWAYS appreciated
i do appreciate the offer to lone me a bolt to try, but i dont mind buying some parts from you guys...and i like having spares layin around
my compensator came yesterday..i took the thread protector off and put it on the barrel...looks ok i guess...i really dont care for the big stuff hanging on the end of my barrels but this is kinda small and really dont look to bad...i think i can live with it if it will give me a dwell bump to help out..it will stay on the barrel
so it may be a couple days before i can check this extractor thing out...it is raining like a cow pi$$in on a flat rock here and is supposed to be this way all day .... so we will see....lol....I'LL BE BACK..lol
ocharry
wisdom of the crowd - ocharry - 02-22-2023
BluntForceTrauma and LRRPF52...says you guys are administrator and moderator.....guys i tried to send a PM to BFT and im not sure if it went through...and i am having trouble getting on the forum this morn...i thought i was having a problem so i had my pooter swept and it seems the forum certificate is not valid..expired or something...lots of hoops to get things to work....and get past to get on
just thought somebody should know and maybe check it out...and if you already know sorry for the redundancy
ocharry
wisdom of the crowd - Old Bob - 02-23-2023
ocharry Wrote:BluntForceTrauma and LRRPF52...says you guys are administrator and moderator.....guys i tried to send a PM to BFT and im not sure if it went through...and i am having trouble getting on the forum this morn...i thought i was having a problem so i had my pooter swept and it seems the forum certificate is not valid..expired or something...lots of hoops to get things to work....and get past to get on
just thought somebody should know and maybe check it out...and if you already know sorry for the redundancy
ocharry
ocharry, I had the same problem this morning. My Bitdefender virus protection was warning that this forum's url had potentially unsafe websites attached. I have a bypass I can use to get by the warning if I deem it safe enough. When I logged on a few minutes ago, the warning was gone & my log on was normal.
wisdom of the crowd - vaguru - 02-23-2023
Still showing unsafe for me. unvalid certificate
wisdom of the crowd - ocharry - 02-23-2023
well this morning i am still getting the red triangle and the not secure and red https whith a line through it in the browser line...but i didnt have to jump through the hoops like yesterday...was a real pain...my pooter guy was on it when i called and had him do a sweep...i thought i had caught a bug..lol...but he said that wasnt it...he said it was on the forum side ..thats why i ran it up the pole here...he even tryed the web sight on his pooter to verify and it did the same on his pooter...i love them guys that do the sweeping for me...if there is a problen they will find and fix it...been with them for about 8 years i guess....pulled me out of the ashes more than once i tellya...lol
i can do a lot of things....but pooters aint one ofum...if it aint working i better git somebody in here cuzz it aint gona be purdy if i try to fix it....mans gota know his limitations..lol
ocharry
wisdom of the crowd - ragrendel - 02-23-2023
As stated previously, it's a server/site issue. Invalid certificate so HTTPS will not work. A workaround is using HTTP which isn't secure. That's why your PC/device says unsafe. You either prompt through to access unsafely via HTTP, or you can add the site URL to the browsers trusted list. That should bypass the prompts to continue via unsafe HTTP. Those are temp fixes IMO and not a true fix. I prefer to just live with the prompts until the issue is fixed and HTTPS works. But up to you obviously...
wisdom of the crowd - BluntForceTrauma - 03-03-2023
Any update on this ejection issue?
wisdom of the crowd - ocharry - 03-04-2023
not yet...weather has been terrible cold and windy and yesterday it rained all day...
but i did spend the day in the load room putting together ladder rounds to test with ...95gr hornady bullets and some sierra 105gr bullets...christmas colors...red and green tips everywhere
i am ready to get at it as soon as the weather stops being stupid...
i am lucky though..i dont have to go anywhere to test..i got 450yrds right out my back door..
i want to try and do some function testing tomorrow...im really hoping the extractor work i did fixes this thing
i got the bolt and extractor from you thursday i think it was...nice looking stuff..THANK YOU ..fast shipping too..so there is that to try also...if my defang and polish job dont work out
so yeah i want to get after it...just been unable to get back to it...but i will
ocharry
wisdom of the crowd - ocharry - 03-05-2023
ok guys here it is..went out yesterday and did some function testing and today did some ladder work..so here goes and some interesting results
yesterday it was really windy but i thought it would be a good day to do some funtion test...so i stood in the driveway to do this so i could see exactly what the brass was doing.....
1st round. 1 load in mag only thing changed was the extractor defanged and polished...ejected at 2:30-2:45 ...bolt hold open...hmmm
2nd round. 1 loaded in mag and i added the 2.3" linier comp...case ejected at 1:30-2...hmmmm...really
3rd round. 1 loaded into mag and ...i added an H2 buffer...case ejected at 4..bolt locked open...hmmm
4th round. 1 loaded into mag...same set up as round 3...case ejected at 4 almost exactly in same spot as round 3...bolt locked open...i really wasnt expecting what i got here...but today i ran with it
everything i did was 1 thing at a time added to the previous set up
it is a little windy today too so i moved the target out to 75yrd insted of 100
i shot 35 rounds of verying flavor and the gun ran great...not one hiccup .....but it was about 55-60* today ...i want to try this set up at a colder temp...maybe in the 20's...i hope we get a day or two to try this out..but i did make it a point to run some of the 95gr loads and they ran perfect too...not a thing to complain about ejected and locked open on everything i shot today...so i dont know what to say here...was it the extractor?? or that i added the comp?? i will say i think the comp did give me more gas to deal with...it showed in the ejection angle...that is the only real things i changed, except for the H2 buffer and i really didnt expect the bolt to lock open with it but it was showing over gas to begin with....and it was not showing that before....all the loads were the same for the test.. and the H2 put the cases right where i wanted them to be...very consistat toady
also i will say that the gun really likes the sierra 105 blitzking and AR-COMP....wow it reaaally like that combo...and the AR-COMP was showing good groups with the sierra 120 pro hunter bullet too....maybe the comp on the barrel changed the harmonics of the barrel to the good, and bumped the gas up for a dwell bump...not sure, but i tell ya that 105 made a little pencil hole for 5 shots...gona put some of them together again to make sure it wasnt a fluke ...the 120s did good too with a nickel or maybe a little less size group....was a good day..and i needed some trigger theropy...rifle ran really good and got some dang good groups
i was really surprised at the results i got and how the rifle ran..it never missed a beat...so we shall see if it was fluke today or not and a run in some cooler temps is on the plate
ocharry