GRA Posted June 1, 2015 Report Share Posted June 1, 2015 That 0.030" is locking you up. 30-thou. So is it his bolt, or the machining of his upper receiver? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted June 1, 2015 Report Share Posted June 1, 2015 So is it his bolt, or the machining of his upper receiver? Why are you asking me? You never listen to anything I say, you just make your smart remarks. I suggest you get your parts in, and you figure out your rifle on your own. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 1, 2015 Report Share Posted June 1, 2015 Why are you asking me? You never listen to anything I say, you just make your smart remarks. I suggest you get your parts in, and you figure out your rifle on your own. 98 .... you just don't appreciate honest questions. I'm sure you'll get over it. Maybe not as soon as I get the rifle built, but you'll get over it. :)) Quote Link to comment Share on other sites More sharing options...
GRA Posted June 1, 2015 Report Share Posted June 1, 2015 Bob I just checked my upper and lower together with the BCG and charging handle in place. Slid a 20 round mag in and it locked as expected. Fire control group is not installed. Buffer system not installed. Pulled back on the charging handle and the bolt would not clear, did the same thing you described. We both have the same upper and BCG. We have different barrels. My calipers are nowhere to be found yet I'll get another set tomorrow if I get home in time and I'll take the same measurements. Hopefully my wrench will be in by Wednesday (and it will be the right wrench) and I'll get mine together and see what happens. Meanwhile, please let me know what turns out with your friend's weapon when you compare. Sorry to hear about the setback. Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 1, 2015 Author Report Share Posted June 1, 2015 The difference is that without the hammer installed, my BCG will move back and lock with the bolt catch (I exercised it a few times and it will catch) using the charging handle. You indicate that yours binds without the fire control group installed which, frankly, sounds even worse. Without the hammer installed it operates normally, although without the hammer it obviously does not go bang. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 1, 2015 Report Share Posted June 1, 2015 I agree. We'll see on my end in a day or two. Let me know how your visit to your friend goes. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted June 1, 2015 Report Share Posted June 1, 2015 98 .... you just don't appreciate honest questions. I'm sure you'll get over it. Maybe not as soon as I get the rifle built, but you'll get over it. :)) I sure won't help you with anything, though. If you were on fire, I wouldn't piss on you to put you out. My opinion. Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 2, 2015 Author Report Share Posted June 2, 2015 Well, just for the hell of it, I decided to take the stock trigger out of my AR-15 and swap it for the Geissele G2S that I had in the ST-10. Damned if both don't work as they are supposed to! Apparently the Geissele sticks up just a little too high, or is too stiff for the BCG to ride over it on the charging backstroke. Since the stock fire control group has a few hundred rounds under its belt it is a little looser and is OK in the big brother. I have a MechDef trigger on order (was too late to get in on the buy at the beginning of April but it sounded good) so I will try that when it gets here. Thanks all for the suggestions, I certainly appreciate it. :banana: Now I can see if it will go bang! :auto: Quote Link to comment Share on other sites More sharing options...
GRA Posted June 2, 2015 Report Share Posted June 2, 2015 Great job Bob. Got me breathing a sigh of relief here. I planned on building mine with the Spike's .308 LPK for starts so I'm sure the fire control group will work just fine. Nice to know our BCG(s) will work also. How about the bolt catch ... how did that troubleshooting turn out? Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 2, 2015 Author Report Share Posted June 2, 2015 No problemwith the bolt catch after I exercised it a bit. Working fine now. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 2, 2015 Report Share Posted June 2, 2015 Thanks for the update. Please let us know how it performs at the range. <thumbsup> Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 2, 2015 Author Report Share Posted June 2, 2015 I will. I am also in contact with AIM Surplus and they are checking to see whether the depth (.968" in front of the gas key) and distance (2.25") from the front to where the slope begins are within spec for this manufacturer. The BCG appears to be very well made so that is a good thing, but if it is out of spec and limits my choices on fire control groups, or puts unnecessary stress on other components, I need to exchange for one that is within spec. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 2, 2015 Report Share Posted June 2, 2015 The BCG appears to be very well made so that is a good thing, but if it is out of spec and limits my choices on fire control groups, or puts unnecessary stress on other components, I need to exchange for one that is within spec. I agree. My plan is to build with the basic Spikes LPK first then later move on to a Timney or something similar. If my BCG will not allow me to do that then I need to look in to another unit. If so I'll be shopping with my calipers in hand this next time around. I should have some new calipers tonight. I got to be up early tomorrow so if I can't check my BCG(s) tonight I will get to it tomorrow. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 2, 2015 Report Share Posted June 2, 2015 The BCG appears to be very well made so that is a good thing, but if it is out of spec and limits my choices on fire control groups, or puts unnecessary stress on other components, I need to exchange for one that is within spec. I agree. My plan is to build with the basic Spikes LPK first then later move on to a Timney or something similar. If my BCG will not allow me to do that then I need to look in to another unit. If so I'll be shopping with my calipers in hand this next time around. I should have some new calipers tonight. I got to be up early tomorrow so if I can't check my BCG(s) tonight I will get to it tomorrow. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted June 2, 2015 Report Share Posted June 2, 2015 I will. I am also in contact with AIM Surplus and they are checking to see whether the depth (.968" in front of the gas key) and distance (2.25") from the front to where the slope begins are within spec for this manufacturer. The BCG appears to be very well made so that is a good thing, but if it is out of spec and limits my choices on fire control groups, or puts unnecessary stress on other components, I need to exchange for one that is within spec. Bob, there's only one thing wrong with what you're doing, as far as seeing if your BCG is in spec. There is no defined set of plans, or design specs, on a 308AR. Chances are, AIM is gonna come back to you and say, "It's perfect! We contacted the manufacturer, and what you gave us matches their design drawings exactly!"... That is one of the hazards in building a 308AR. There is no Technical Data Package to follow, no set specs. Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 3, 2015 Author Report Share Posted June 3, 2015 Bob, there's only one thing wrong with what you're doing, as far as seeing if your BCG is in spec. There is no defined set of plans, or design specs, on a 308AR. Chances are, AIM is gonna come back to you and say, "It's perfect! We contacted the manufacturer, and what you gave us matches their design drawings exactly!"... That is one of the hazards in building a 308AR. There is no Technical Data Package to follow, no set specs. I understand. The folks at AIM; however, appeared to be very concerned that there was an issue. It also may be that the Spike's lower has just a little less depth than the "normal" DPMS 308AR (I guess I should call mine an ST-10) and because of the stiffness of the hammer on the Geissele FCG that it just will not depress sufficiently for the BCG to ride over it. I was going to test with another 308 BCG but my friend's rifle is a piston unit and the BCG is different so we could not swap. With the FCG installed that I took out of the 15 it cycles just as it should, no feel of any obstruction. What can I say. AIM is outside of Cincinnati and I am a Pittsburgh native. They might want to get back at me for years of the Steelers kicking Bengal butts, but then they may be honest folks as are many of us from western PA and Ohio. Apparently they are located very near Faxon and the rumor is that Faxon uses their BCG (hell they may make them) to check their barrels. The BCG goes into battery beautifully and headspaced perfectly so if they tell me that it is within their design spec I think I can live with it, particularly if the drop in from MechDef sits just a bit lower than the Geissele. Based on what I see it may be a while before that gets here but if it works I will have great triggers in both rifles. In any case I do hope to get out Saturday and see if it goes bang. I did put a JP adjustable gas block on it and the gaps in the rail give me perfect access to the adjustment so if it runs I can tune it and will feel a whole lot better no matter what AIM says. Thanks for the advise, really appreciate it. I do hold you and others on this board responsible for the virus that has me ordering reloading equipment and supplies! <thumbsup> Quote Link to comment Share on other sites More sharing options...
GRA Posted June 3, 2015 Report Share Posted June 3, 2015 Just got back with a new set of calipers. Bob I'll get my BCG(s) out tomorrow and take the measurements you specified and post it up here. If I have time, I'll also do photos. I'm tempted to measure out the Spike's upper and write it all down so when I go to the gun show this coming weekend with my calipers I'll look for some .308 BCG(s) and other uppers and see how they all compare. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 5, 2015 Report Share Posted June 5, 2015 Been a long week. 12-14 hr. days everyday except Tuesday. No time to do anything. Did you get anything resolved on your end Bob? Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 6, 2015 Author Report Share Posted June 6, 2015 Sounds like a regular week for me. Hope to get to the range tomorrow. With the AR-15 fire control group everything seems to work normally so we will see. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 6, 2015 Report Share Posted June 6, 2015 (edited) COOL ... let us know how it went "bang" :)) Edited June 6, 2015 by GRA Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 7, 2015 Author Report Share Posted June 7, 2015 OK, back from the range. The new rifle ran like a champ. I put 40 rounds downrange with no failures of any kind. The BCG locked back on empty as it should. The trigger was not particularly kind as it was the old AR-15 rather stiff trigger, but I was able to get the glass sighted in and able to put 3 rounds within 1 inch using some remanufactured ammunition for Freedom Munitions at 100 yards. I also ran the AR-15 now sporting the Geissele G2S, which is a very nice trigger. I can't wait until I get the MechDef trigger I have on order to see if it will work in the ST-10. First impressions are that the Faxon barrel is a very accurate barrel and my guess on the setting for the JP adjustable gas block was about right. Shells were ejected at about 4 o'clock very consistently. Picking up the brass was easy as it was all in the same place. Before leaving I rang the steel at both 200 and 250 yards. By the way I am very pleased with the two Leapers (UTG) 8x scopes I mounted, a 2-16x44 on the 308 and a 1-8x24 on the AR-15. Big smile in place as I separate the brass so I can finish reading the manuals and get started on the reloading bench I have set up. :banana: <thumbsup> Quote Link to comment Share on other sites More sharing options...
Rsquared Posted June 7, 2015 Report Share Posted June 7, 2015 You bastard! <laughs> Good to hear that things are workin out. Quote Link to comment Share on other sites More sharing options...
GRA Posted June 7, 2015 Report Share Posted June 7, 2015 OK, back from the range. The new rifle ran like a champ. I put 40 rounds downrange with no failures of any kind. The BCG locked back on empty as it should. The trigger was not particularly kind as it was the old AR-15 rather stiff trigger, but I was able to get the glass sighted in and able to put 3 rounds within 1 inch using some remanufactured ammunition for Freedom Munitions at 100 yards. I also ran the AR-15 now sporting the Geissele G2S, which is a very nice trigger. I can't wait until I get the MechDef trigger I have on order to see if it will work in the ST-10. First impressions are that the Faxon barrel is a very accurate barrel and my guess on the setting for the JP adjustable gas block was about right. Shells were ejected at about 4 o'clock very consistently. Picking up the brass was easy as it was all in the same place. Before leaving I rang the steel at both 200 and 250 yards. By the way I am very pleased with the two Leapers (UTG) 8x scopes I mounted, a 2-16x44 on the 308 and a 1-8x24 on the AR-15. Big smile in place as I separate the brass so I can finish reading the manuals and get started on the reloading bench I have set up. :banana: <thumbsup> This is indeed great news. Elated that this finally got up and running. You put in a lot of effort and it definitely paid off, even without FedEx's assistance ... LOL <thumbsup> <thumbsup> Thanks for the information on the scopes. They seem to be quite popular but I've never fired with one. I'm wondering now about the Geissele trigger group that set you back. Do you think the particular trigger you bought might've been for the "DPMS high", and that is the reason it did not work (referencing your previous post regarding high vs low) ... ??? Let us know how the MechDef trigger performs. I've still got a week to 10 days on my build at minimum. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted June 7, 2015 Report Share Posted June 7, 2015 Do you think the particular trigger you bought might've been for the "DPMS high", and that is the reason it did not work (referencing your previous post regarding high vs low) ... ??? A trigger doesn't have a damn thing to do with DPMS upper receiver profiles. Not sure if you're aware of that - it looks like you think one would affect the other. Quote Link to comment Share on other sites More sharing options...
EngrBob Posted June 7, 2015 Author Report Share Posted June 7, 2015 98 is correct, there is no difference between low and high with regard to triggers, that refers to the rail height (at least I have never seen any indication of there being a difference in triggers in anything I have read or heard). At this point I suspect that it was simply a combination of a BCG that is a little deeper than some others plus the hammer being very stiff on the Geissele trigger due to the hammer spring. Based on some measurements it was hanging up right at the point where the slope changed going down to the firing pin. It may well be that when the Geissele is broken in that it will have sufficient play to allow the BCG to ride over it. At this point, the Geissele runs beautifully in the 15 and I am more accurate with it (the trigger is important to me because I am VERY right handed and VERY left eye dominant so trigger control is very difficult for me using my left hand). I am counting on the MechDef trigger I ordered. If that doesn't work I will need to get a better trigger in the ST-10. I am OK with the old trigger shooting off a bipod like today, but standing is a bit more of a challenge. Quote Link to comment Share on other sites More sharing options...
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