RMW Extreme Build. It has begun.

[Pablo]

Mine still has the occasional feed glitch. I have become pretty masterful at manipulating the feed lips so magazine errors are limited. Partial feed errors are more common. The round goes about 75% in, and bolt stops. I do not know the cause of this.

[mrpipesmkr]

Pablo,
  I feel your pain! I went through the same thing and it is a PITA !  I put a stronger spring on the Mag release bar and that helped a little by keeping the mag more stable. But Ron also said to visually check to see if the two bottom lugs of the bolt were getting good contact on the round as they stepped it from the mag .  My problem turned out to be that due to a change in the design of the Glock mags the two bottom lugs of the bolt were making contact with the metal on the rear of the Glock mags. My mags set a little higher in my lower than Ron's did in his lower.  The lugs making contact with the rear of the mag was         " jolting" it just as the round was being fed to the chamber, causing the FF's .  I took a Dremel and small stone and ground just enough of the side lugs off to insure they cleared the mag. I did not shorten the lugs, just narrowed them by about 30%. They have to be long and strong enough to strip the round. This solved the problem for me.
  My experience may be different than yours because I use the Glock mags and your using the GG's I believe. But it would be worth visually checking it out.

[Pablo]

Good place for me to start. Thanks!

[mrpipesmkr]

Good luck Pablo.  Once it all comes together you'll fall in love with it!

[Pablo]

It is fun regardless. It would stop once or twice in a magazine of 32. I finally played with the sights. Great fun was had. Two clicks brought it exactly to the exact left side of the target where I was on the right. One click right and centered. Shoots and holds quite nice. Shot some steel at 200+ yards.........that's challenging!

Also it stove piped 2-3 times. Seems like would be bolt issues. It actually ran really well on light ammo, contrary to what Ron was thinking. But hot rounds didn't cause any issues. The SBR is so light now, I can really feel the difference in ammo.

[mrpipesmkr]

Damn Pablo, now you've got me wanting a 10mm SBR to go with my 9x25!  I need to give my bank account a chance to recover, but it's deffinately something I want.  You are absolutely right, these builds are about the most fun you can have at the range and that includes tweaking them to make them run. Just part of the fun and good learning experience also.  My 9x25 appears to be very accurate also. I think the long barrel and high rate of spin due to velocity does wonders to stabilize the short pistol bullets.  Have not had a chance to shoot mine over 100 yards yet but will soon.
  Reading your last post, something occurred to me.  The 9x25 does feed a little easier due to the smaller diameter of the bullet, this is true in rifle or pistol. But one thing I have become aware of in my 10mm pistols over time is how critical the overall length of the round is in feeding properly. Generally, the shorter you make the round, the easier they feed. This varies according to bullet styles and model of gun but is something I record for each load to avoid feeding problems.  Stovepiping is sometimes an indication of too much length on the round.
  It occurs to me that the same thing is probably true for rifles so I am wondering if you re-load and if you've experimented with O.A.L. Of your rounds? 

[Pablo]

Something occurred to me when I was cleaning the gun this AM. When the gun has a FTFeed (partially in chamber) and the round can go the rest of the way into the chamber (manually shake gun or feed assist) the trigger is NOT set. Would this not indicate a short stroke event which didn't latch the hammer? I feel when it happens so I don't pull the trigger prematurely but for sure when the bolt is closed the hammer is already released. Like I said this happens on average every 15 rounds or so, and does not matter - hottest or mildest ammo. I am at a loss as to cause.

[Pablo]

I agree how some 10mm guns are susceptible to very minor ammo differences. Other than some Underwood 200gr that had some interesting bullets that really didn't feed worth a darn in anything, the issues don't really seem to follow ammo type - and all my loaded ammo  is well with specifications and I am pretty anal. In fact I was shooting up a bunch of very HOT JHP 155gr ammo and it fed quite well, and to back what you say, it had more issues with 200 and 220gr factory ammo.

Also see my posts about my Glock 20L with very tight 6.2" 10mm Lone Wolf barrel (chamber) (oh and I have a 6" 9x25 barrel for the G 20 as well)

[mrpipesmkr]

Sounds like you may be short stoking. If you have the adjustable gas block you can dial it up a little to increase the stroke. If not, you might try over-lubricating your weapon until you get it broke in.  As a rule,on any new semi auto I buy I always use a lot of lubricant until the parts are broken in. My reasoning is that when the parts are new you are actually lapping off minute particles of metal as the weapon breaks in.  You want these to float off the mating surfaces to allow for the break in to create the smoothest possible surface.  Lube the rings on the bolt well and dry cycle a few times before firing and make sure the breaks in the rings do not line up with each other to cut down on gas leaking through them.  All this will help the weapon cycle with less gas. After break in you can adjust for minimum recoil.
  I will check out your posts on the lone wolf g-20 barrels. My experience is that the lone wolf chambers are much tighter and better supported than the stock Glock barrels. Full length re-size Every round or you can have problems with the rounds feeding into one barrel and not the other. It does not sound like your rounds are too large for the chamber since you can easily tap them in using the forward assist.  One thing you need to check with both re-loads and factory rounds is the area were they are crimped. Too much crimp can easily bulge the sides of the round just behind the case mouth and this can cause the kind of partial feeds you are experiencing .  Have fun!

[Pablo]

Interesting comment on the lube. Very interesting!

Being a lube guy, I think the same thing about lubing and break-in. So I figured I was past that step by now, so believe it or not this time I was running a bit dry - AND this AM when I took the upper off and tried to pull the bolt out - IT was stuck. Stuck hard. I cleaned the gun really well, and really lubed it well, even dipping the ring end of the bolt in synthetic (Amsoil) ATF (no VII's or polymeric thickeners). Wetted the rest of the carrier and such pretty well, bolt face dry.

Suspect my chamber is probably a bit tight. That's not helping.

Oh and you might also be onto something with thinning the lugs a bit.

Like any good problem - a combination of things!!

[mrpipesmkr]

Pablo, 
  My biggest wish is that my suggestions are helping, not hurting!  If so, I am happy.  And, let's face it, what I learn from your experience  will no doubt come in handy when I build a 10mm.
  Let me know how it turns out!

[Pablo]

Helping. So far good ideas. Wish I had a range in my yard to try it out with the ultra lubed bolt. It's the only variable I changed this time.

[sstewart]

Milli-tech lube helped my 12.5 inch 300 AAC AR cycle subsonic rounds, So it sounds like that could be helping you too.
208 gr. amax.  H110 I can't remember the exact powder load. It was a couple tenths below book max. Was definitely short stroking until I lubed it.
No suppressor is allowed in this state.

[Pablo]

Going wet this time!

[mrpipesmkr]

Pablo,
   How's your 10mm running? Did the lube help?