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Posted: 2/22/2004 8:00:46 PM EDT
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I just put together another RRA lower (using RRA parts kit) and while testing the selector switch, it got stuck on fire. Removing the grip and spring, it seems the detent is caught up inside. The selector is fixed on fire (at least it can shoot!), but obviously this sucks. I've never had this happen to me before. Any ideas on how to get the detent out? I tried "pounding the lower on some wood" to see if it would work its way out, but no such luck. Thanks! -DE |
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Seems to be a theme with RRAs of late. You should be able to tap the selector switch with a no mar until the selector starts to rotate and cams the detent down. You'll want the switch halfway between FIRE and SAFE. In that position the groove in the selector is shallowest. Once you have the detent out of engagement with the selector you can remove the selector and drive the detent out from the top using a pin punch. Penetrating oil will help. Others have had luck with heating/cooling the part. |
| Take off the grip and remove spring than wiggle selector and tap on recvr, the detent should come out eventually. I don't know why RRA can't get these parts right it has been a PIA with every RRA lower and parts kit I have ever put together. To me it's a combo of shitty selector switch with too deep detent and the detent counterbore to deep and tight in recvr so the pin sticks up too far or just plain sticks .. |
| I had the same thing happen with my RRA lower. So have others recently, so you arent alone. What I did is tap out the selector, and use a precision screwdriver to push the selector detent out. I ordered a new detent, and it now works fine, so in my case I believe the detent was too fat for its hole. |
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You can send it back to RR as it appears this dimension is out of spec. If it were mine I would try this first: Strip any plastic parts off the receiver Use some brake cleaner to blast the area clean Put the receiver in a toasteroven set at 325 for 30 to 40 minutes (lower temp than is used for the resin-coatings) Wear gloves and remove the receiver from oven Lightly spray some penetrating oil in the hole Give the bottom of the receiver near the hole several smart raps with a wood hammer handle, and try wiggling the selector at this time. The aluminum should expand more than the steel detent and it may well be enough to get it to move. Good luck |
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Well, I got it out this evening. Used a plastic-faced hammer and popped the safety selector a few times until it moved between fire/safe. Gave the top of the receiver a few strikes, tapped out the safety selector and used a rollpin punch to push out the detent. It was stuck in there pretty tightly - either the detent is too wide or the hole is too narrow. I took a detent from another parts kit and it slipped in fine with enough play to move freely so I'm thinking it was the RRA detent that was too wide as opposed to the receiver being out of spec. Inspecting everything, the receiver is fine, some scratches on inside of the safety selector hole on the right (nothing externally cosmetic). The safety selector has a tiny divot from when I cammed it out. I filed it down and while not completely smooth, it's smooth enough to function properly. I may try to file down the detent to see if I can give it some more space. My other RRA parts kit has the same-sized detent so maybe it's a bad batch? I think I should send an email to RRA. Thanks for everyone's help! -DE |
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I have checked the last 20 detents from RRA they are to spec, the selector groove sucks in a couple of the selectors in lower parts kits from RRA that I have on hand. Contacted RRA they said if there is a problem call for a Return Authorization number and they will replace slector. I checked my last four stripped lowers and they are the correct depth and diameters in the detent area. As a side note the Star safetys are perfect (their invest cast molds) the standard are the ones with some questionable grooves. Rob |
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Quoted: Put the receiver in a toasteroven set at 325 for 30 to 40 minutes (lower temp than is used for the resin-coatings) Given that the aging temperature to bring 7075 aluminum to the -T6 temper is 250F, this would be an exceptionally stupid thing to do. 40 minutes at a temperature of 325F would result in significant overaging of the alloy, lowering the strength of your receiver. |
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Ouch, [url]http://www.mtbreview.com/files/data/250.html http://www.63xc.com/scotn/alumin.htm http://www.omegaresearchinc.com/Publications/volumeFive.htm[/url] 6061, Normal processing. 1. Weld -- again TIG or MIG are the choices. 2. Solution heat treat. 30 minutes at 980 F. Quench in water or water/glycol (no option for mist or air), keeping quench liquid at 100F or lower. 3. Align. Again, you want to do this as soon as the material is quenched, max of 8 hours. The more you wait, the harder aligning becomes, and the greater the residual stress that gets locked in. This can make the material less resistant to fatigue failure. 4. Delay. At least 72 hours at room temprature. 5. [red]Artifical age. 8 hours at 350F.[/red] ---------------------------------------- Heat treatment involves two distinct stages, solution heat treatment and ageing. In the first process the material is heated to temperatures between 800 and 1000 °F for a number of hours, then quenched to room temperature. [red]The second process, also known as precipitation hardening, is usually done in an oven -- bake at 250 to 350 °F for eight to 36 hours.[/red] ----------------------------------------- [red]In the case of artificial aging or precipitation hardening, the previously solution heat treated and quenched parts are subjected to elevated temperatures (instead of room temperature) in the range of 225-375 deg. F over extended periods of time (4-24 hours).[/red] The precipitants formed and grown here are more controlled and substantial in nature, resulting in higher mechanical properties as compared to naturally aged conditions. ETA, welcome to Tshooting BattleRife.[wave] |
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Thanks for the welcome, Tweak. I don't normally spend a lot of time here, but CanadianGunNutz.com has been down for days, and I am crawling all over the internet, looking for new ways to waste my time. In the case of toasting one's AR receiver, the biggest problem is the uncertainties. A few minutes, or even hours, at 325F, wouldn't do that much damage. It would, in fact approach the properties of a T73 temper (225F for 8 hrs. + 325F for 24 hrs), which has a tensile strength of 67 ksi, only about 10% less than the T6 temper, and still well above the physical strength of a cast A356-T6 receiver. BUT, toaster ovens are a horribly imprecise affair, and who knows what the real temperature was? Worse, they are heated by resistance elements that get up to cherry red heat (>700C). If you set a matte black receiver a couple of inches from a glowing element, radiation heating is going to produce local surface temps that are well in excess of the 325F air temperature, producing local softening. Anybody who tries this will likely end up with a receiver that has the dreaded T? temper. |
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The entire receiver is one large heat sink, spot heating would occur if the receiver were resting on the heating element, not likely if some distance away, especially resting on a pan (ir block). The AR lower is not a highly stressed part, they are made in plastic also. It is far more important that the annodizing be preserved for wear resistance on the soft aluminum receivers. Some have recommended drilling (which removes the annodizing)the undersized holes. I prefer to get the stuck part out and polishing the detent till it has enough clearance to work. The "bake at 350 degrees" is used as a refinish on GI upper and lowers according to John Norrell (a major supplier of Moly Resin products). |
| That pretty much word for word says what the back of the KG guncote moly teflon caoting said, right down to the dry fire testing and application process, except I believe now that I remember the KG stuff curing at 325 degrees, as I said, I ran a tad lower than whatever number was on the can, so I doubt I hurt the temper any. It's just a stupid EA reciever anyway[:D] |
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Putting the lower in a freezer will result in a difference in contraction rates between the steel pin and aluminum lower without the danger of applying heat. When assembling a kit, try fit all pins, springs, what-have-you before assembly so that you can identify and remedy any problem parts and have a better chance of removing any parts that may stick. |
| One word of caution when spraying penetrating oil on a hot part. Some types of penetrating oil such as WD 40 have been known to flash off when sprayed on a hot part. I would try to find either a high flashpoint oil as an alternative or spray canned air on the steel part to try to shrink it. |
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Is taping it out an option? I've got the same problem, but it is stuck behind any temperature change remedy. Suggestions? Is this a fairly recent rash of out of spec pieces, and is RRA replacing them if you bought them through a 2nd party? Thanks for any help guys. |
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My thought was to drill it out (I guess Tap isn't quite the right word). The safety detent is so stuck I don't see another way around it. I'd like to drill a very small hole and then try and pull it out. As for the size of bits and such, I'll leave that up to a friend who will drill it out at his shop. I just don't want to hand it over to him if this is a bad idea. Thoughts? |
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grunt11m, You will need a 1/32 punch to remove the detent pin out of the receiver. The selector can be worked back and forth to slightly lower the detent pin to clear the groove in the selector (to pull it from the receiver). Just put a few drop of CLP in the bottom of the detent hole, then the selector sides. Let the oil set for a while, then if needed, use a punch on the selector lever to gently work the selector back and forth. One small tap one way, then the other way, then back, then forward. No sharp/large blows, just let the selector detent high points in the grove slowly work the detent pin back in the hole. Once the selector is out, use the 1/32” punch to punch the detent pin back down and out of the receiver. Once the detent is out, chase the detent holes with the correct size drill bits, then spin file the detent to the correct size. Also, if the game plan is to able to remove the selector without removing the pistol grip, you will need to size the detent pin from the step section up so that is the correct length to allow the selector to escape out of the selector grove in between the save/fire position. P.S. Im flying down to Houston of Sunday and will be there for a few months. If you need help, and close to the Houston area, drop me a IM and we can get together. |
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Dano523, Thanks for the detailed advice. I will certainly give that a try before doing anything more drastic. Glad to see this site has such knowledgable and helpful people. I'll let you know how it goes on this thread, and add anything ingenious my buddy might come up with if that doesn't work. |
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Well, I said I'd update you, so here goes. It's been repaired, at the expense of one Safety Selector. Had to drill it out (or at least watch my buddy drill it out). Replaced the Safety Selector and purchased a new (properly sized) safety detent. Works like a gem now. Thanks to RB Precision for helping me out, and replacing the parts for free, they are definitely my go-to people from now on. |
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