Jgun

besides the clearance needed to physically locate the tab, you need clearance on both sides of the upper in order to install the two long screws that actually secure it, through the nut, to the back of the rail. I had even thought about leaving it off all together considering that Armalite seems to get by alright with just the gas tube keeping the rail/nut from rotating.

I thought that was where you said you got it. As soon as you told me I contacted them and they were out of stock. This 300 stuff seems to be VERY popular. I'm sure things will settle down eventually and the brass will become more redily available, especially once people start shooting factory ammo in greater volume.

There are other considerations in trying to mix and match rails/uppers. The half moon retainer that LaRue uses, has clearance issues on many of the uppers, It doesn't fit the Mega or DPMS uppers without some clearance work done to the receiver( something I can't imagine anyone wanting to do) In fact LaRue even mentions it in their installation instructions. Fortunately, it did fit the Kaiser with no mods. I think that a custom nut might work with those other uppers if you were to use the Armalite SASS rail and adjustable gas block (something I'm thinking about for the next build) because, as far as I can tell, Armalite does'nt use that retainer.

I was getting 3" at 100 yds, but in my defense, I was really focusing on function testing the gun, and I was cleaning the barrel between each shot. I hope to go back out there soon with some match ammo and no distractions and see what the gun is really capable of. Of course I will still be handicapped by my poor shooting skill. Maybe I'll see if one of my more talanted friends will try it so I can see what it will do in the hands of a more capable shooter.

that was very perceptive of you caporider. I didn't think anyone would notice. I did in fact make my own barrel nut in order to be able to utilize the LaRue rail which uses a 1 7/16-18 nut, on the Kaiser receiver which has a 1 7/16-16 pitch KAC/DPMS pitch thread. I did it because I wanted the front of the rail to be even with the front of the rifle length gas block and the LaRue was one of the few that was the right length to accomplish that.

I used the polishing method with the electric drill to fit the .1555" oversize pins I ordered from KNS, in my MA TEN receiver. As stated by survivslshop, I found that I didn't have to polish them down the full length of the pin, mostly on the ends so they fit through the receiver without damaging the holes. I had no trouble mounting them in the drill, I just had to use my 3/8" drill vs the 1/2" that doesn't close small enough. If you have an electric drill that will tighten on a 1/8" drill bit you should have no trouble. The freezing idea sounds pretty good also. One final thing, if you do decide to polish your pins, you need to clean them thoroughly so there is no abrasive grit left or you will prematurely wear out your trigger/hammer/pin fit. Also if you polish them you have to make sure that they feel cold to the touch when you measure or try the fit, as they will measure about .001" bigger when hot than when cold to the touch.

You could take some fine emery paper and you can carefully mount the pins in the chuck of a variable speed electric drill. Wrap the paper around it and polish the pins slightly. You should finish with extra fine 1000 ,1200 grit paper for a smooth finish. Look at it this way, It would be far better to screw up and have to replace the pins if you decide the fit of the hammer and trigger is too loose, than to do any damage to the $600 receiver. The KNS non rotating pins aren't a bad idea either.

My barrel finally showed up this weekend. I mocked it up and pinned it to my Mega lower. I'm building this as a comp focused upper, so have chosen my parts with weight savings in mind. The gun as pictured weighs under 7 lbs empty without optic. I hope I don't regret the light weight barrel contour.

So, Now that my trigger came in, I finally got to the range to try out the Kaiser build this weekend. I had some function issues with it. Not sure if they are due to the gun needing to be broken in, or are due to the chrome DPMS bolt carrier. What I encountered was that the bolt wasn't locking back on an empty mag. when I examined the action I found, as compared to the Mega carbine with the Armalite bolt, that the Armalite moved back and forth in the upper with smoother and the bolt locked up with less effort. When I examined the bolt carrier, I found that the locking cam for the DPMS bolt was very stiff. Don't know if this is a matter of needing to break in, or a matter of excessive chrome on the carrier. Before stopping for the day I oiled the whole thing down internally so much that there was oil dripping off the gun. This seemed to improve the condition, but still not 100%. I'm going to clean the whole thing thoroughly and see if I can find any wear patterns indicating some clearance problems. I found that the recoil of this one was subjectively heavier than the other. Not sure if it's due to the lighter weight of the gun or a less effective muzzle brake. More testing will be needed.

I noticed that in the data you posted, Wilson used a 1 in 12 twist barrel. I'm not sure what effect that might have on the velocity, but it is my understanding that the longer twist may not stabilize the heavier bullets (I don't see any data on bullets heavier than 150gr) My barrel mfg told me that the 1/10 twist of the 300 barrel I ordered would not perform as well as 1/8, on bullets over 200 gr. Also, I can't own a suppressoer in my area, so I don't know much about this, but don't they like to use subsonic ammo with a can? If so, the added performace may not be of use if your loading subsonic for the supressor? One other thing I was thinking about. I see Wilson specifically mentions using modified Lancer mags (which I find to be top notch). I wonder if the Pmags can be modified in the same manner as the Lancers, in order to accomidate the 7.62 X40 rds? And I agree with you about it being a sickness, every time I start a new project I say to myself that this will be the last on, and that there's no other AR variation that I need, and then when it's finished (or even before) I've already come up with some other cal/barrel length/purpose gun that I think I need. I think what I really need is an intervention.

I just got an email from my barrel guy, says that my barrel has shipped. Gunstop has also emailed saying that the dies should be back in stock next week, so I may be able to shoot my own 300 pretty soon. I still haven't found anyone with the 300 AAC marked brass in stock, Survivalshop, where did you get yours

I guess this is for those people that aren't sure if they're a righty or a lefty! I have to assume that it requires a right hand or left hand bolt in order to eject in the desired direction, Wonder if they're planning an ambi bolt/carrier!

I have a friend that owns one of these and I've had the pleasure of shooting it. My impression is that it's a beautiful, well made gun, excellent fit and finish. I really like the side charging handle that doesn't cycle with the bolt, and the rail is very nice. The gun shoots better than I can, the only complaint I might have (aside from the price) is that it seems very heavy, even for a .308. It feels more like a bench gun than a field gun. I know I wouldn't want to have to carry it, along with ammo, for any distance in rough terrain. By the way, I believe you can get them for much less than the MSR price. I know my friend got his for under 3K.

I had not heard of this cal before reading this post, Not that I really keep myself up to date on these things. It sounds as though the 7.62 X 40 Wilson is very similar to the 300 Blackout which is 7.62 X 35. While cutting down my .223 brass to make 300 brass, I noticed that it could actually be cut down slightly longer while still using the .223 brass. Obviously the extra powder capacity in order to get greater velocity is a good thing. The only question for me is wether that small performance advantage is worth the added trouble and expense of having to have modified Lancer mags in order to accomidate the added cartridge length? I kind of like the ability to use the same mags for .223 and 300. The same thing applies to my .308's I don't have any Armalite platform .308's because I don't wish to have to have twice as many mags to shoot both KAC platform and Armalite platform guns. Have any members tried this cartridge? I'd be interested to know how the extra FPS over the 300 Blackout translates into real world performance in range and loger distance accuracy.

Robocop, I'm assuming that your building your 10mm with the Mega AR-15 rec set. I'm not familiar with the 10mm AR's, can you tell me what mags they use? Since you say your using a Mega rec set, am I correct in assuming that it will require either a lower receiver mag well block or the mags will have to be individually modified? I think that the 10mm is definitely a superior cal than either the 9mm or the .45acp for a pistol cal AR. That being said, I'm still thinking about an AR-45 build this year. Do you have contact info for Ron Williams? I'd like to discuss my possible project with him.

I'm looking for 2300 with a 150gr or 1800-1850 with the 175 and 180gr to make 320 PF (Power factor = bullet weight x velocity divided by 1000). Although I'm impatient about getting the upper put together, I'm prepared for the load development to be a slower ongoing effort for me. I still don't have the Foster dies and have no idea when they will get here. I'll be satasfied just to get the thing together and break in the barrel and start to see what kind of hits I can get at 200-300 yds with my friends ammo.

I'm trying to imagine what would make this a more desirable setup (for me) than a dedicated 5.56 gun and a seperate 7.62. If I could use any mil spec AR-15 upper on it, that would give me options to build the upper to suit my needs, But if the lower is built to accomidate 7.62, I'm thinking your going to end up with a heavier 5.56 gun than you'd get if you built a dedicated AR-15 type gun. And I'm guessing that if their 7.62 upper fit's the same lower that accepts reg mil spec 5.56 uppers, that has to mean that no other AR .308 upper will fit, which means your stuck with whatever Colt offers for 7'62 uppers, rails, barrels etc. Of course, if it's lighter than a full size, dedicated .308 AR type gun, that would be very desireable. Kind of like the ar15performance.com "ITS 12". Man the .308 AR scene sure seems to be developing rapidly these days.

SWshooter, I checked the website and spoke to someone at S&W. As you say, they tell me that they will refinish it for $250 and do any other work I require for additional cost. I think I'm going to send it to them as soon as I get the 300 upper together. I also have a NOS case colored target hammer I'd like them to install. You say that you were satisfied with the quality of the reblue, yes? By the way, good price on that model 25. I have wanted one of those in .45ACP for years but some other gun related purchase always seems to take priority. I bet it's a lot of fun in .45 colt.

Thanks for the idea. I'm going to give S&W a call. I'm guessing they won't give me a price without looking at it, so I'll probably wait until I have the cash allocated for it before sending it to them, but I'd really love it if they could refinish it as good as new. Then I'd have to go for a nice set of exotic grips.

Sounds as though you've pretty much covered the range of what can be expected from these powders/ bullets. And based on your results I don't think it's likely that any of them will get me to major power factor, even with the longer barrel. But, there's still hope for me, because I was able to speak to my barrel guy today. Although the barrel has still not shipped, He assures me that it will be waiting for me when I get back into town next week. He also tells me that, they are currently making power factor using 175 and 180 gr bullets. He promised to share the load data with me. In order to make the PF I will need to get 1800-1850 fps with those weight bullets. He also tells me that AAC is planning to offer ammo specifically intended for the 3 gun shooters, which will be guaranteed to make the PF without over pressure. You say that the recoil is minimal, I was also suprised when I tried the 300 how mild the kick was. It seems not so sharp as a .223. I can't help wondering how accurate my 300 will be with 180's I hear that the 300 doesn't shoot as straight as the .223, so I'm wondering if I'll have to deal with holdovers at longer range?

Yeah, they told me that due to a mixup the first one had the wrong twist. I was told that they have the corrrect blank now. If I have the time I'll give them a call this week. Good luck with your testing tomorrow. Hope you get good weather. I'm going to be in FL this week also. I hope to get lucky weatherwise myself.

Not sure where to post this but thought it would be of interest to the members. Apparently GA Precision is selling a direct gas impingment .308 AR based on the POF .308 AR lower and a matching upper that they say they get from POF. They call it the GAP-10. I haven't heard any evaluations on the gun but it looks pretty good. Kind of what I had in mind to do with a POF lower. www.gaprecision.net

I know how you feel I really have a fondness for those model 29's. I bought the one pictured, a while ago, used even though it wasn't in the best condition, because I really like the 5" barrel and unfluted cylinder. I'd like to have it refinished but I'm not sure who I can trust to do the job well enogh to satisfy me. Can any of you guys recommend someone good?

98Z5V, looking at Mega's web site it would appear as though the rail length on thier rifle length monolithic upper will work out to be just about 13". Although that method of measurement may not work on a monolithic because it may not end in the same place at the receiver end of the rail as a normal bolt on rail does. Based on my guns, A DPMS rifle length gas block location works out so that a 12.75 bolt on rail is around .1" short of the back of the rifle length gas block location, so I think the Mega monolithic rifle length upper would work out to around 12.85" rail length. On my Mega carbine, a 14" Noveske rail works out to be even with the back of the threads on the end of a Noveske 14.5" Afghan barrel. What I'm getting at here is that with the rifle length Monolithic upper you might not be able to go shorter than 13"-13.5" for your SBR without the rail covering the front of the barrel. I'm not sure how short you wanted to make it but if you wanted to go shorter you may have to go with the Mega mid length upper coming out soon. Imschur, You say you might be able to get info on these, Any chance you can find out the actual weight of the rifle length upper,lower set? I see that Mega lists 29.8 oz for the upper, and 29.8oz for the MA Ten rec set but don't, as far as I can see, list a weight for the complete Rifle upper/lower set.

I wonder if it will, in fact be a big enough problem to put him out of business?