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Posted: 8/23/2008 3:13:52 PM EDT
I have a 10.5" upper with a Rock River barrel and CMT bolt/carrier. It ran fine with a KX3. I pulled the KX3 off and put my can adapter on it. Sold the KX3. I also have a 9mm buffer. The bolt was pretty dry and I didn't have any CLP with me. It cycled my American Eagle 55 gr. just fine. I tried to run Wolf polymer 55 gr. It would fire and eject but not load the next round. I tried this for 6 rounds and same result. I changed buffers to a standard carbine buffer. It fired the round but no ejection. The case was stuck in the chamber. I had to come home and push it out with a cleaning rod. What's the problem? I know Wolf is underpowered but I will not have a rifle that won't cycle it. One day Wolf may be all I have plus, I'm embarrassed to say, My department will only get us Wolf for training.
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I have no experience with RRA 10.5, only LMT 10.5. The gas opening has to be the right size for enough gas to get back to operate the BCG, no sure what RRA specs are. So here is what I would do first: It maybe that your buffer spring is too tight to allow full cycling. Just swap it out for a very used one from a 16in gun. If you compare them side by side the used one should be about an inch shorter due to compression. This should fix it. But it may also take 500 runs of hottest stuff you can find to break it in. |
| Sounds like it was short-stroking with the Wolf and 9mm buffer. It would eject, but the bolt was not travelling far enough to the rear to pick up a new round. Switching to the standard buffer may have caused an opposite result. The lighter buffer wasn't slowing down the bolt enough, causing it to extract a little too early, before the chamber pressure had time to drop. The result is a stuck case, or sometimes the rim will get ripped off. I would suggest trying either an H buffer or an H2 buffer and see what happens. Sometimes some trial and error is needed to get these things running right. I use the H2 in my LMT 10.5. Good luck |
He summed it up. PKfirearms has them for $30 and so does DSG. Shipping at DSG will be a a dollar cheaper($5.05 total) assuming that's all you buy. Both are great company's to deal with. PK DSG If you shopped the EE I'm sure you could get one cheaper. Also since you are a LEO you could probably get a discount from certain vendors. Can't really help on that one  Just out of curiosity, what ammo do you use in your RRA 10.5" while on duty? |
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You should take a look at this thread. jobrelatedstuff.com/forums/topic.html?b=6&f=23&t=199901 |
I got mine from Bravo Company. Price is about the same as the other vendors mentioned, just another option.
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Is this a consistent issue with the WOLF ammo. The bimetal case is notorious for breaking apart where the extractor latches on to it. I have seen this is numerous barrel lengths from 20's to 7's. Did the damaged case come out of the rifle easily with a push of a cleaning rod? |
| Yes, it came out with little effort. I'm not sure about the rim. I only had a small flat head scre driver at the range and tried to pry it out. I could have tore the case up myself. I did recharge the bolt several times but it still did not catch on the case. I'm running a defender o-ring in it. It ran fine when I had the pig break on it. I needed to put my can adapter on it. It was also running pretty dry. I was shooting my .22 at the range. I didn't plan or set up to put many rounds through the 5.56. Just wanted to make sure it cycled Wolf. Thats why I was so unprepared. Never again. I'll try it again tomorrow with a wet bolt. If it doesn't run, I'll change buffers. |
| Went back to the range today more prepared. Here's what I found. With the 9mm buffer or the standard carbine buffer, it short strokes with with 193 and Wolf. With the suppressor on it cycles both with a 9mm buffer and a carbine buffer. It ran fine with the Noveske KX3 I had on it but I sold it. I'm leery of trying to open the gas port up myself. I don't want to start buying parts just to see if they work. It's my work rifle and I got to get it running. I have an M4 I can fall back on until I do. Any ideas with what I found will be appreciated. |
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It short stroked with M193 and Wolf with the carbine buffer? Ok, we know what happened on at least one occasion while shooting Wolf with the carbine buffer. The extractor may have ripped part of the rim off. Or it just slipped over the rim. I'm assuming you have an extractor upgrade of some kind; extra power spring, Oring, Dring. It seems like the extractor has enough strength to pull the case out but the cycling action may be expending too much energy pulling the case out, do to the faster cycling rate a light buffer will cause. This causes the action to start earlier when the bore and chamber pressure are higher. With the 9mm buffer it's probably the opposite. The bore and chamber pressure has dropped too much because the cycle rate is slowed do to pushing a much heavier buffer back. There is a difference in weight of about 2.6 oz between those two buffers. Just about anyone who shoots an AR with 10.5" barrel will tell you they may take a bit of adjusting to get working with different types of ammo. I'd would try changing to an H and H2 buffer before messing with the gas port. If they don't work you can always re-sell them. As for both rounds working with the KX3 and the suppressor? I know very little about using a suppressor but I do know one result of using one. It can cause a lot of blow back and they may be why it's able to cycle all the way with either the 9mm or carbine buffer. I'm assuming the KX3 causes a similar effect. |
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I have a 10.5" LMT upper on my pistol lower that's still pretty new. Only 430 rounds through it so far. One thing that I noticed is when I shoot XM193, it has a tremendous fire ball coming out of the barrel. I have fired 5.56 75gr TAP also and there was very little flash at all. About the same as the flash of XM193 shot out of a 16 inch barrel with the same flash hider(I only have A2 hiders) That leads me to believe while shooting XM193 all that extra burnt powder is wasted energy. Entertaining at least With out knowing too much of the technical jargon, there is a chance Wolf and XM193 fired from a 10.5 inch barrel have similar velocities. They use different powders so the difference in burn rates could play a part. I've never seen a velocity report on 55gr Wolf shot out of a 10.5" barrel. I use an H2 buffer in the LMT to make it reliable with 5.56 75rg TAP. 100 rounds of the TAP with no issues(way too expensive and early to make any forgone conclusion). But I have had two instances of short strokes, once with M193 Prvi and once with 223 55gr Black Hills. To me it was expected. I bet with a lighter H buffer those two rounds may never have a short stroke failure. I will be testing that that once I get the chance. The buffers aren't cheap but they are easy to swap. |
| Well I guess if the buffers don't work I can sell them on the ee. I got the barrel from PK arms. I don't remember the spec on the gas port but he said it should be fine. Of course that was with the KX3. I'll give him a call Monday and see if he has an idea. Seems to know what he's talking about. |
did you try switching out the buffer spring with a used one? i know everyone suggests h2 buffer, but before I bought anything I would play around with the parts I already own. |
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It does not matter what buffer you use if you are not getting the gas you need to move the bolt back. All the buffer does is to slow down you cycle speed. It work with normal ammo and not with wolf because of the loss in port pressure. so if you open the port problem fixed. the KX3 changes the duration of the port pressure and some added back pressure. Adding a A2 rifle buffer would not make it work. If you are use a used spring and a car buffer it will work if the port size is right for the ammo you are using. My 10.5, 11.5 and 7.5 all work with wolf I sure hope your not using a can with wolf unless you don't like your can
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The burr is there untill the first bullet pass down the tube then it gone. Just clean the bore after you drill each time you will be fine. Wolf is under powered so you may have to drill it a few times. The 11.5 barrels are less ammo picky if you traded it off for a 11.5 your problems are solved.
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Drill out the gas port. Make sure you do not drill into the other side of the barrel. The barrel steel is rather easy to drill into. There is also a thread on here somewhere stating the proper port size for a 10.5" barrel but I cant remember where it is. Dont go with bandaid fixes, do it right. I have a 10.5" and I use a standard carbine buffer and it will feed anything. I have an 11.5" with an old style carbine buffer and a semi-auto carrier with the whole bottom rear cut out and it is perfectly flawless with any ammo. It originally was doing the same thing yours is untill I opened up the gas port on it. Do it right, dont spend a lot of money on stuff you dont really need. |
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