Ok Gents- need help & advice.
Had a 20" rifle built by a local 'smith back in March I think. Took it to range next day, slow fired 60 rounds to check function, hung up a couple times in chambering, but was ok otherwise. Rifle was put in safe until 4JAN21.
You can find all the details of the rifle in the Custom forum under the title After 5 Years…the Precious.
So, had first class Match Ammo, several different brands of mags, from 10,20 & 30 rounds…all mags have been vetted in two other rifles for years.
Here is what happened. Upon first loading the first mag…failure to chamber, bolt lacked about 1/2 inch or so closing. Hit forward assist, closed bolt…CLICK. Took out the round, small indent on primer. This happened 3 times in a row.
Took out the National Match bcg…cleaned it thoroughly, then rifle would fire. BCG felt very sluggish. Was a cold windy day, and at this point was lubed with Ballistol after cleaning the bcg.
Several more FTF & FTF after this with several known mags & Match ammo from IMI & Black Hills.
So, ruling out mags & ammo…Im think the bcg is the culprit, but dont know how or why. I cannot give out accuracy results yet, due to the windy conditions of the day and my frustration at the moment with the gun.
So- advice & opinion needed here ,and thanks very much in advance.
UPDATE 10FEB21:
PROBLEM SOLVED.
Installed a David Tubb 42 coil Chrome Silicon recoil spring in rifle.
Hit the range this morning…rifle functions & runs now like a scalded ape. Did about 25 lock back tests on about 8 different type of mags…100%.
Chambered & fed 100% with 150 rounds. Threw all brass into a ballcap size area at 4:30 using MEN193.
Really tested the rifle as much as I could & am now satisfied that it was a weak, or simply not strong enough RS to run the bigger, heavier NM bcg. Recoil was brisk and snappy, chambering was very solid. So, I am happy now to move on to next step of accuracy testing- which I will report back on here whenever that happens.
To ALL who helped & made suggestions & ideas…except that one asshole in Texas…THANK YOU so much.
SHOUT OUT TO SOTAR-THANK YOU SIR!
Only downside to the todays range trip is I broke the FP on my Gen 4 G19…thats my main carry/SD gun too. Praise God it happened on the range…less than 50 rounds in. Got others to use while new FP’s come in.
No sir…no gauges. BUT…the rifle was professionally assembled & Mike at Criterion personally headspaced the bolt to the barrel, for what thats worth.
TOM…could be, but Ive never felt an AR this sluggish. Im really concerened to NM bcg is gonna have to go, but Ill wait & see. So far, the rifle has under 100 rounds.
While you haven’t much to do, do this til you pass out:
Regularly lube the bcg and charge / dry fire a zillion times. Make sure the small gas rings remain wet. Every 25-30 or so remove the bcg and check for wear of its externals and within the upper.
With the lower, lightly lube the trigger assembly. Dry fire it a zillion times while either holding the hammer during movement or padding the rcvr where it would impact to prevent damage to the aluminum.
Hopefully, sooner rather than later, you’ll notice a difference. If you do, execute a grin and keep doing for about another 10 minutes on each assembly.
The highest level of success can be achieved while doing this watching Bevis and Butthead or most any other funny cartoon.
Remove the bolt from the carrier. Put the carrier back in and then check for excess drag pulling it back over the hammer. If the hammer can’t cock back fully it drags hard on the carrier.
If I had an AR professionally assembled, I’d spend very little time trying to fix it myself. He built it, so he (or she) should find the problem.
Since you should have at least one spare complete BCG, that’s as far as I’d go with troubleshooting. If your spare BCG allows the rifle to run, then the problem will have been identified.
By your post (and the other one) this is a Young “National Match BCG.”
You do know there is no United States military or industry standard for National Match anything for the M16 and AR-15, correct? You bought into Young’s snake-oil marketing. Their web site even states their carriers are NOT mil-spec.
Your other thread says you’ve got a BCM bolt in the carrier, so I’m going to assume (yes, I know about ass out of you-and-me) that something may be causing a sluggish interference-fit between your bolt and carrier. Does this have standard gas rings or a MacFarland coil? Is the bore of the bolt carrier under-sized? Is your parkerized bolt tail polished to fit the carrier bore hole? Did you lube it well? Did you break it in (parkerized bolt finish against chrome carrier bore)?
Does the gas tube bind on the gas carrier key on closing?
Ok Gents, thanks for all the info- Ive got some bcg’s to check rifle with. Let me try to do this & Ill get back to yall.
Sinister- didnt so much “fall” for it, as I researched it here & elsewhere for a year or more, even talked to a well known 'smith in Ohio that makes NM rifles for the USMC…he uses them. I was just trying to buy, what I thought, with my limited knowledge & money, to be the best bcg for accuracy. I am gonna get to work on this and post back here when I can,maybe today, but soon. Oh yes, yes, it is a Youngs NM. With standard BCM rings.Was lubed well & clean. Gun as of right now has under 100 rounds. the other questions I dont know.
Bamashooter…yep…Im in Huntsville. Bullet & Barrel did the assembly.
Thank yall again.
UPDATE: Went ahead & stayed in today to look about this.
So, cleaned the rifle thorough…Marine clean. BCG was cleaned, and to whatever knowledge I have, inspected.
One reason I wanted the Youngs was the Hardchrome coating. Cleans up easy & nice. Without the BCM bolt in, put it in with the Fortis Hammer CH and check for gas tube alignment-perfect. Was also smooth otherwise- NO hammer drag at all.
Next, installed bolt…was not too tight, felt like it ought to. Lubed it a tad and worked it awhile-fellas it feels smooth like it ought to.
NOTE: Im NOT hung up on keeping this carrier if its the problem. But without SOTAR’s expertise & gauges…aint no way I can tell good from bad. Next thing to do, is use different bcg’s at the range…whenever that may be. But Ill definately do that.
Im gonna take the advice given and from time to time keep working the action awhile in mean time.
1168- I have seen that video. Id already long bought mine.
One odd thing about the bcg. I sent the bolt to Criterion for headspacing. Mike said “they couldnt headpace it to several barrels they tried because the bolt was too small.”. So, He GAVE me the new BCM bolt & headspaced it for FREE.
Id love for SOTAR to get ahold of this thing just to see if its right or wrong inside.
So, thanks again for help & suggestions- keep any ideas coming.
I agree, AR’s just pretty much work, shouldnt need to be broken in or messed with as long as everything is in spec.
The rifle did hand cycle more smoothly it seemed, today. The lube had in fact gummed up since March…but I cleaned the bcg well and it stil did it after a few more rounds. When I test fired it in March, I slow fired two mags, checking for eveything. It hung up then, a couple times, but all rounds fired amd cases looked & look, perfect.
It was very sluggish at the range, it was cold, but my other AR’s ran like scalded cats, so it wasnt that.
Im gonna try to troubleshoot this thing, as a learning experiance mostly. MAybe in fact this one DOES need a break in, as suggested.
Ive got two ToolCraft carriers Ill try with the bolt next time, agan, whenever that may be.
Thanks for chiming in brother.
I agree with Andy, above. The BCM bolt was/is headspaced to your barrel and extension by the barrel manufacturer. If you have ANY other plain bolt carrier (commercial or GI) I’d use your known bolt and a carrier you know works in other weapons.
The alternate carrier shouldn’t affect headspacing at all.
Thank you sir. Could it be that the bcg just needs broken in? It would be the first time of me seeing that- but then again Ive never owned or ran a NM bcg, either.
Does FTF in the context you used it mean failure to feed or failure to fire with the small indent in the primer you wrote about? I have seen countless SPR builds with super light triggers cause this. If you are referring to a failure to fire I’d be interested in what a standard hammer spring does.