Jgun

I know this is an old thread, but I don't see that an answer was ever posted as to the difference between the PRI .936 gas block and the DPMS SASS gas block measurement. I see that Doc posted that the DPMS has .125" space betwwen the two bores, If it's of use to anyone, the space between the .936 bore and the gas tube bore on the PRI is .065"

Very resourcful of you, I'll be eager to hear how the gun runs for you, please take the time to post your range results.

Impressive!, Can you tell me how you selected your starting dimensions for the parts? Did you take some rough measurements from a commercially mfgd setup? What about your spring and the bolt carrier, what parts are they and where did you source them? Did you modify the gas tube hole in your upper, installed any bushing, or does the piston just pass through the unmodified hole?

Since these aren't freefloat handguards, am I correct in assuming that you need the fixed front sight,handguard mount in order to use these? Also wondering, aren't the different lengths, carbine,mid,rifle actually different for 5.56 as compared to 7.62?

I was just making a poor attempt at humor. What I was implying was that you were going over into competition/ game gun territory. Please don't pay any attention. I'm as impressed as many others, that you've been able to lighten a large frame AR to sub 7lbs stripped. As you say, if you build the basic gun to this weight, and add weight with optics and other accessories, it will not present much of a problem to take them right off when desired, while on the other hand, if your stripped gun weighs a lot due to barrel/rail/stock, thats not going to be a practical option. I've never hunted with an AR, and have not found myself walking long distances with them so I'm not really able to appreciate what the 2 or 3 lbs will mean to you after a day of walking with it slung over your shoulder while carrying a pack.

Thats pretty good, but I think your cheating with that CF FF tube. In it's present state yours is 1-1.25 lb lighter than this one. Funny thing, after building this, I put together my 14.5" .308 carbine, and that one, which weighs 10 lbs, handles better IMO than this. I think the short barrel helps, but I've got a heavier stock on it and it seems to balance better off hand, when shooting on the move. This one with the longer barrel and lighter stock feels a little front heavy to me, maybe once I add a long range optic it will balance better. Of course, I'm not carrying any of these for long distance so my observations are probably different than someone that has to carry one of these for a living.

Sounds pretty straightforward. I'm glad that you will have both (eventually) to give a first hand comparrison. I'm going to be especially interested in what you find to be the bullet drop and max accurate range of the two (out of your length barrels obviously). I've never found the 7.62X39 to be all that accurate, but to be fair I've never shot anything but mil ammo out of AK's, so that's probably not representative of the level of accuracy that the rd is capable of. I've read some postings comparing the two, but it will be enlightening to hear it directly from a source that we can trust. Good luck with it.

I forgor to ask, Is your 300BLK finished? If so, I will be interested to hear your side by side accessment of the merits, faults of each. Do you know how many rds you'll be getting in a mag?

Just for my education, can you remind me what parts in the lower need to be proprietary to the 7.62X39, or is it just in the upper? Am I correct that you need barrel, BCG and upper receiver to be 7.62 X39 specific? What about the buffer/spring ?

Can't wait to hear how this one runs for you, Good luck with the build.

Thats pretty impressive, if it works out to be accurate, that's between 1.5 and 1.75 lbs lighter than my lightweight 18" build. better not leave it laying on the bench unattended on a windy day or it may blow away. By the way what rail are you using?

I'm not sure if I would be inclined to attribute 10" groups to that .0035" clearance. I think a bad chamber/barrel is a more likely explanation, but if you rule that out and are still concerned about the upper/barrel extension clearance, you can easily cut a piece of .0015" stainless shim stock (available from MSC or McMaster Carr) and wrap it around the extension to remove virtually all the clearance. You could also consider the lapping if you wanted, but I really doubt that alone could cause the kind of groups your talking about. I think you should take a close look at chamber/ammo. By the way, even if the warranty is void due to the recrown, I'd still give the MFG a call just to inquire about it. If they value their reputation, they may be willing to take a look at it anyway, and if the problem is due to their work they may do the right thing, there are some really good people running some of these companies.

Dis regarding the lrgal issue, I think that you might find that a 30 rd mag of .308 is kind of unweildy. I sticks out pretty far, not to mention the fact that 30 rds of .308 has some weight to it. It can really effect the way the gun feels when your shooting on the move. And there's the reliability issue to consider. 30 rounders don''t have as good of a track recored when it comes to reliability. I'ts really not much effort to hit the mag release and slap in another mag. I have not heard of a DPMS lower that will take the FAL mags. my research only turned up the preban Knights and DPMS as options.

Slidefire works when you hold forward tension on the gun and when it recoils it will recock and fire the gun. There is no modification to the trigger mechinisim or the gun. If you practice, you can do it by holding the gun loosely with no modifications, with a standard stock, I think I saw someone once show how you could do it with a paper clip and rubberbands. But since this is all external, there is no modification to the gun. Short of the feds outlawing rapid firing a semi auto weapon, I don't know how they will be able to outlaw it, although I'm sure there are people that would like to do it. I don't think it's really a practical way to have FA capability anyway, more like a parlor trick IMO. I've fired FA weapons and a gun with the Slidefire stock and there really isn't as much similarity as you might think. I find the fact that you have to maintain forward pressure at all times to shoot FA makes it difficult to shoot the gun effectively. Maybe with more practice, I only tried it once?

There is an underlayment that is produced by a german company called Schluter, that allows your foundation to move independantly from the stone/tile. If I recall correctly, they guarantee full reimbursement for any cracks that occur when this underlatment is installed according to the Mfgs specs. Good stuff http://www.schluter.com/4087.aspx

None of you even mentioned what a day of tile work does to your back. Those days are over for me.

I'm curious, do you mean your gas tube or your gas block? I'm trying to understand what you mean by the tube loosening up, are you saying the roll pin that retains it in the gas block came out?

I'm thinking it should be easy to determine, just run some ammo with bullets that aren't brass coated. If you still find gold colored shavings it must be coming from the cases. As others have posted, I think a gun with a tight chamber will be an asset to you if you like your gun to be accurate. If, on the other hand, reliability under adverse conditions is the priority, the POF's tight chamber may be something of a liability to you. I, also, think you should run it really wet, and put a few hundred more rds through it (after figuring out where the shavings are coming from) before sending it back. I think you'll find that it becomes more reliable when you keep it wet. By the way, if your gun is tight to begin with, it may become somewhat more forgiving about ammo later on.

WOW 40lbs! I'm thinking that you'll be able to just pull the trigger on this one without even having to brace it against your shoulder. at that weight it probably won't move much under recoil (what recoil ?) And you can forget about hollywood using it, I doubt most of the actors would be up to the task of weilding a 40lb gun for very long. If you've got a match quality gun under that housing I'm thinking your going to be getting some good groups with something as stable as that.

It really is very cool looking! I know that weight wasn't a consideration when designing this, but do you know what the completed gun weighs? I'm also thinking that you need to make some type of housing that disguises the receiver, that way everyone that sees it will think it's some revolutionary new firearms design. As Blue mentioned, I think that if you make some complementary housing for the reciever and post pictures, you may have Hollywood calling you to order some to feature in the next big Sci Fi film.

I had not heard of the practice of setting up your gas impulse at the minimum setting to operate unsuppressed and then just leaving it there to shoot with the can, then again, as stated above, I can't have one so it's more of an intelectual pursuit than for any useful purpose, when I read about them. I will be interested to hear how that works for you. A couple of things do come to mind. If you set it for minimum reliable cycling with one load, You may have to stay with that if you don't want to be adjusting the GB for different unsuppressed loads, and from what I've read some guys like to have both supersonic, and subsonic loads for suppressed operation, so that might require some further adjustment. I would definitely make sure that you have access to that set screw. By the way, on mine I took a small (tiny) nut and got myself a longer set screw that protrudes from the side of the GB enough so that I can thread the nut onto the set screw and tighten it against the side of the GB in order to make sure that the screw doesn't move and effect my adjustments. I've also heard from people, that the Gas Buster charging handle is a really good idea for a suppressed AR.

I'm not able to have suppressors in my state, so I have not researched this very thouroughly, but, I think DPMS or Armalite, make an adjustable gas block for one of their .308 guns. I have no idea if they are .936 ID or if they mount with the two set screws or not. I'm thinking that you may have no choice but to go with the PRI or use a low pro non adjustable GB. I was just offering the opinion that a screw adjustment type GB is not ideal for use on a rifle where you plan to switch back and forth from suppressed to non suppressed regularly, but based on your parameters it may by your only option, short of fabricating something of your own design, or possibly trying to modify a non adjustable low pro.

I have the PRI adjustable GB on my 300BLK. I know that you said yours needs to be .936, so it is not the exact same one as mine, but as far as I know, there isn't another adjustable GB on the market that's as small as the PRI, let alone being smaller, so what I'm getting at is that, if the PRI won't fit under the rail, I can't think of any other that possibly could. Since your asking about whether it will fit under the MA TEN monolithic rail, I'm guessing that your rifle length gas system will locate the GB under the rail, Are you sure about that? If so, you would be forced to make some type of access hole in order to be able to adjust the gas impulse. I'm also not sure if the set screw adjustable gas blocks like the PRI would be the ideal choice for a suppressor. I think you'd get better results with a gas block that has 2 or 3 settings like the Noveske switch block or equivilant.

When your boss is near by You need to start mumbling to youself about those voices in your head telling you to eliminate all the evil people. You may find that your schedule suddenly becomes very open.

What exactly are the restrictions in your state that make the pre ban stuff so desirable that the prices are so high?