RMW Extreme Build. It has begun.

[undeRGRound]

+1 on suppressors. Anyone have any info on the "Hearing Safety Act"?

Pablo, the firing pin will hopefully help.  Range Report soon?

I will not really look at a 10mm Carbine until there is a bigger Glock Mag available.
Do you know how the 1911 and Glock pistol conversions run?  I prolly have enough
toys for now, anyway     Gotta pay some bills first, then more ammo   

I will have a sweet 28 round HP 4595 if I get my butt into the shop!   

[Pablo]

I googled variants of bent AR firing pin. Causes and such. I got nothing. Some yahoos bend the back end of the pin with the hammer (doh)....mine is bent up front.

[mrpipesmkr]

The whole bent firing pin thing is new to me, Pablo !  I can see where it could happen but it seems to me that it would take a heavy strike from the hammer as well as a longer than normal firing pin to accomplish bending the pin.
  I have heard of guys shortening their firing pin slightly because it was long enough to cause primer perforations but I have no experience with this problem.  It would seem to me that your situation would call for a thorough inspection of the firing pin length, length of the bolt, depth of the well the firing pin runs in within the bolt, bolt face and length of the total unit when installed in the carrier. Common sense says that their can be variances in these measurements when the parts are machined. If you have enough variation in several of the parts it could lead to the total unit being out of spec enough to cause the bent pin and other problems.
  Since you have multiple AR's you shoul be able to get out the calipers and chart the variations you have in the parts you have available to measure.  You also might be able to get a diagram online which spells out the demensions and tolerances of the individual pieces.
   You would be looking for things that allow the pin to travel forward too much such as too deep a well in the bolt, or an accumulation of out of spec dimensions which lead to the same thing! I would also give the bolt face a good look.
  Also check out the hammer spring, you might need a less strong spring.
  Another spec to check out would be the "shelf" or ridge in the bolt carrier that prevents the firing pin from moving too far forward.

[GLOCK10MM]

Let me start by saying WOW. I am having very similar issues w/ both of my QC10/RMW ARs, one in .45 & one in 10mm. It gives me hope that w/ this info you guys are sharing I may get them to run reliably. I have had slam fires;  I have had one of them go brrrup for 3 or 4 rounds; constant failure to feeds, failure to extract, failure to eject?; my mags seem "loose" in the magwell....yea problems. I oiled them up (like an Irishman goin to the beach),cleaned the bolts,  changed mags, changed ammo, changed shooters & even had friends who are Colt armors look them over & try to run them (aka a smart person unlike me) to no avail. I spoke w/ QC10 who gave me some ideas but no luck. I emailed RMW & well that did not go well "it ran for me" 
So they both sit in my safe waiting for rust or the gov't to take them away. (I live behind enemy lines in the republic of new jersey)
I'm going to try the ideas you folks have shared & maybe sacrifice a chicken to the gun-gods & see what happens.

This is my first post, my name is Don, I am as mechanically inclined as Ray Charles. 

[Pablo]

For awhile, I thought I was the only one. But people have emailed and PM'd me on various forums with RMW 10mm issues. I can understand why and it gets a little weird.

I emailed RMW & well that did not go well "it ran for me"

I like Ron and he has helped me, I even sent my upper and mags back to him. Same response - "it ran for me". I basically gave up contacting him, yet I believe he would still try to help if I asked. That said, he has certain avid followers on AR-15 and other forums, who jump down the throats of people who speak up and say they are having problems (rather than actually helping)

I have come to the conclusion he is not lying when he says it worked for him. But perhaps something is different about his full auto lower, different hold on the magazine, different forces on the hammer coming and going, different buffer and spring.

I know for a fact the BCG is cheap junk compared my better AR's. My bolt rings were trash, my carrier is very rough inside and my firing pin was bent. I would say start there. A DI 10mm and really a .45ACP need ALL the help they can get. the BCG should be super free moving. I never had slam fires or full auto (hmmm bent firing pin??) - just saying.  Took me a little bit, but my BCG feels perfect now.

I received my Militec yesterday. Oiled up and ready to try. Perhaps this late afternoon.

[mrpipesmkr]

Hi Don,
  First of all, welcome aboard!  It great to have a forum where we builders of pistol caliber, DI operated AR's can compare notes and work the bugs out of our particular builds.
  I don't have any experience with the .45 AR, but some of the info I can contribute will probably apply regardless of caliber. The .45, of all the variants we all own, probably is the lowest pressure round with the largest bore and closest gas port and therefore is the hardest to make run properly.
  Of four of us who own these builds ( you, Pablo, SStewart and myself ) it appears that the two who are having the least problems ( SStewart and myself ) reload their ammo while you and Pablo appear to use off the shelf ammo of various brands.  I believe this is an important difference.
  Due to the fact that the gas ports on these weapons are located fairly close to the chamber, it is easy to see that a round that burns poorly creating a lot of carbon and crap is going to cause problems as that " junk" accumulates in the bolt area. Since pistol rounds in general operate at less pressure than the rifle rounds the system was originally designed for there is little opportunity for the gas and pressure to "self clean" by blowing excess build up out of the bolt. It seems that this build up is the cause of many of the problems you are experiencing, such as failures to feed and eject as well as slam fires.
  Also making your own ammo allows you to tailor it to the correct pressure curve and pressure to operate the action. This is important as too slow a build up in pressure will cause more unburned powder and debris to go into the gas port and slow down the action.
  Do you reload? If not, do you know anyone that does?  It seems that both SStewart and I reload and use the same powder ( Longshot ) and we are having the fewest problems by far. If you can't get reloaded ammo with Longshot, as I suggested to Pablo, you might contact Underwood ammo and see if they can provide you with a 180grain 10mm load powered by 9.6 grains or so of Longshot. Clean your weapon thoroughly, including scraping the tunnel in the bolt where the firing pin runs and see if the different ammo helps.
  You might try a healthy load of Longshot in .45 also. I'm not sure if Longshot works well in the .45 but it's worth a try. Again, Underwood may be able to supply .45 rounds also, I'm not sure.  Other clean burning powders might work in .45.  Also, using magnum primers may help by providing a quicker, cleaner burn.
  I have not had problems with carbon build up but have to admit that I generally clean mine after each heavy use.
   If you have read my post you know that my first QC10 lower had problems due to the fact that the magazine was too low in the magwell causing failures to feed. Quarter Circle 10 recognized the problem and exchanged my old lower with their newer one which holds the magazine in a higher, correct position. The difference was amazing and my failures to feed problems went away. You might contact them to see if you have an older lower and if so exchange it for the newer design.  They were great to me and exchanged the lower while paying for shipping both ways.
  The slam fire problems you are having has to be due to the accumulation of crap and carbon around the firing pin causing it to not move freely.  I keep mine fairly clean and have not had this problem. The Longshot powder appears to burn clean enough that I have not had serious carbon build ups to deal with.
  Pablo experienced a bent firing pin, probably due to carbon build up jamming the pin or a pin that was too long, so you might check yours to insure it is straight. Remember, there is no spring on an AR firing pin so it must fit loosely to prevent slam fires.
  I hope I have not bored you with this info as some of it is a re-cap. Try it out and let the board know how it works. I'm sure your problems can be overcome and a report on your experiences will help others!
 

[Pablo]

Great post (again) mrpipesmkr. I think we were both typing at the same time.

My only difference (of opinion) - is I believe (no evidence either way) is the way my firing pin is  bent, it's always been like that. Junk BCG.

That said, definitely some very subtle length differences, geometry, are involved. My near term goal is one chunk at a time. Get my BCG perfect and keep it super clean. The Militec is being baked on in the shop right now at 140°F. When I get my morning work squared away, I will get my brass out, set my press up and get some Longshot rounds loaded and hit the range. My days are a bit variable AND due to construction, the range is closed during day working hours. (Opens at 4PM and gets dark at 4:30PM!!!)

[Pablo]

I forgot to mention, I have loaded .45ACP with Longshot for my Camp Carbine and 1911's and SA XDS and other guns. It works, but it's not accurate at all until you go max book load. Which really isn't that hot, IMHO. So to get a .45ACP DI AR to run, you probably will have to go over book.

[mrpipesmkr]

Hey Pablo,
  Yeah, we must have been online at the same time!  I live in the Dallas- Ft. Worth metro area and was up early due to a few things I had to get done. I did my post and left but did not see yours until later.  I believe you are on the West coast so you must have been up late!
   Glock10mm (Don) seemed pretty frustrated with his build and I wanted to respond to his post before I was out and about this morning.
  As far as the bent pin goes I just assumed it must have happened when you were firing the weapon but you know what they say about assuming things. Since you have the pin to look at and I don't you are in a better position to evaluate what caused the bend.
  From your post I assume you did find some different measurements in your various bolt groups. Are these enough to jam the pin and cause it to bend?
  The mil-tech sounds interesting. Let me know if it works in terms of lubrication and keeping the bolt and pin clean. I do get a build up of carbon on the tail of the bolt but never enough to affect function.
  All I have left of my .45's is a set of dies. When I went to the 10mm I had to sacrifice a few things to finance my new interest.  I wish I was rich instead of good looking!  Anyway, your info on .45' s and Longshot should be helpful.
   I have not talked wit Ron for more than a month but he has always been patient with me and has helped with several problems. He is pretty busy but he will take the time to try and help with a problem. He is the one who figured out that my QC10 lower was out of spec as well as other customers he had, and contacted QC10 to convince them they had a problem. My new lowers are much better.
   I will say that I do notice a difference in the smoothness of my RMW lowers when compared to my .556 AR. The .556 is smoother but I attribute this to the thousand of rounds put through it, it is well broken in.
   So far I am generally happy with Ron's work but do not deny that I have had a few bugs to work out.  I usually talk to him on the phone rather than email and I think I get better feedback this way.
   Let me know how your trip to the range with the Longshot loads goes. I hope the factory ammo is the problem because that is an easy fix!
   

[Pablo]

I didn't get to do much gun stuff yesterday. Too much other stuff going on right now. Busy in a good way, but not enough long interludes to load ammo or go to the range.

[Pablo]

Went shooting at 22°F this AM. Fingers hurt a little at first, but it was beautiful at the range. Plus, I was the only one there, until another guy showed up. To my pleasure it was DAVE WORKMAN!!

So the 10mm AR...... It only had one type of feeding failure. This is actually progress!!

I only used Sig and Underwood. 180gr. Used three labeled magazines.

Zero ejection failures.

The ONLY issue, about 1 in 8 rounds is a partial chambering stop. The round was angled and hung, mostly ready but lodged and not entering the chamber fully. I need to see where and how it's hanging up. Happened exactly the same with Sig and Underwood.

[Pablo]

Took it down.

Hmmm.....wow the bolt is very gritty and tough to move. File for later.

Whitish powder puff debris all about. Not sure what to think about that. I shot 100 rounds, it's like one round didn't fully detonate. I've seen this white stuff in 357Sig, sometimes in .45ACP.

Cleaned it all up. A little grit on the bolt tail, but cleaned up nicely. Nothing remarkable.

So I took a round and with the upper alone (no BCG), dropped a round in. Hmmm, sorta hangs at the top were the case lip hits the upper chamber entrance edge. Hmm...a pretty hard stop. Thoughts?

[sqlbullet]

Sounds like a 1911 style "three point" failure. I am not familiar with this gun, but in the 1911 that indicates a need to clean the extractor install up and/or install stronger mag springs.

[Pablo]

Sounds like a 1911 style "three point" failure. I am not familiar with this gun, but in the 1911 that indicates a need to clean the extractor install up and/or install stronger mag springs.

I think different forces at work here. Extractor spotless.

Could be a mag issue.

If it was a .223 platform people would be talking about the feed ramp(s).

If the 10mm round entered the prechamber area at less of an angle it probably wouldn't jam....I think...

[mrpipesmkr]

Pablo,
  Sounds like some progress was made! Much better day at the range than you've been having lately! Do you attribute the improvement to the new militec lube or the ammo?
  I'm about convinced to follow your lead and try the Miltec lube using the recommended heat application. Been running both my builds with over lubrication for break in but I think there bath there now. The over lube tends to help with the break in but does trap powder residue in the action. I'm thinking your Miltec, properly applied, with a very light coat of oil over it may run the gun cleaner, attract lest carbon, and therefore be more reliable. I shoot both my builds yesterday and had few problems with either, two or three partial feeds that required the assist.  Usually this was with a full or nearly full mag.
  Now to your problem, which I have experienced also.  Don't know if I can clearly explain how it was happening in my 9x25 but will try.
  If you recall, the first lower I got from QC10 was not engeneerd right and held the mag too low in the well. This created the exact problem you are reporting. I looked at it and talked with Ron on the phone and he explained that with the mag so low the lugs on the bolt were only able to make partial contact on the round and this contact was only on the upper rim of the round. This partial contact in effect allowed the round to "flop" up and down, pushed by the mag spring as it went forward. So many times the round would hang up as it entered the chamber on the upper edge. The answer was to find a way to raise the round so more of the two bolt lugs would make contact with the round.  The lugs should contact the round further down near, or on both sides of the primer. This tends to keep the nose of the round pointing at the chamber.
  What I did on the old lower was alter the mag lips to raise the round higher in the mag to allow better contact. Because I could only raise the round so much without making the mag unable to hold the round this was only partially successful but did make a drastic improvement.
  My feeling, since your pretty close and only having a few miss feeds, is that raising the round will solve most of your problem, if not all. (Remember I cannot see your problem, only visualize it, so may be way of base). I would slowly close the bolt on a round and see where the lugs are contacting. If it's high on the round it is definitely at least contributing to your problem.
  If you've already spread the lips as far as possible and still hold the rounds in the mag then you need to find a way to extend the lips. I had thought of finding a small metal tube, similar to a ball point pen cartridge, slicing it down one side, slipping one of these over each of the lips and soldering them in place using silver solder if necessary. There may be other ways but that was all I could think of.
  I did also have some success by altering the slot where the mag catch rests in the mag. By cutting away some materiel on the lower part of the slot the mag would fit higher in the well. I had to add materiel on the upper part of the slot to keep the mag from slipping down in use.
  Anyway, my problem was solved when QC10 exchanged my old lower for the new one which held the mag and consequently the round higher.