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Post by HMC710 on Oct 17, 2010 10:53:17 GMT -5
Calculating out different heavy buffer arrangements. Getting some interesting numbers. Taking measurements of the buffer tubes, buffers, and springs. Our prototype Max Buffer is 7.5 oz. Adding Tungsten could get it over 11oz.
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Post by HMC710 on Oct 19, 2010 6:06:22 GMT -5
Made a heavy buffer w/sliding wgt inside on the roll pin. Didn't pick up any wgt but will see if we get some dead blow effect. Need to do some more measurements to make sure my slider hits the back of the buffer tube. Just took some more measurements and analized the buffer movement: It reminds me of the 7th grade physics experiment with 2 basket balls, one on top of the other dropped at the same time. The ball on top accellerates up when they hit the ground. If I had to guess, I would say this is what happens with the tungsten wgts in a std buffer. The durometer of the nose acts as the spring to send the wgts forward. Got some harder ejectors on order for the blow back adapters and an extra power spring.
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Post by HMC710 on Nov 6, 2010 9:10:05 GMT -5
Got the new hardened ejector sample in and mounted today. Will test things out this afternoon along with some buffers and see what happens. Field reports coming in ok so we hope the new ejector will work out fine and we can get some adpaters made. Update: Tried out some heavy buffer & springs and did help smooth things out on the Tok blow back.
New ejector is a shade too tall so will have another sample cut and check it out.
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Post by HMC710 on Nov 20, 2010 13:01:19 GMT -5
Updated ejectors came in yesterday and fitted them to a couple of blow back mags and they cycle just fine. Have not tested them yet out in the field. Between being swamped at work and trying to get a couple hrs of deer hunting in here and there, there is just not enough daylight. Looks like I need to get that test chamber finished......
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Post by HMC710 on Nov 21, 2010 12:13:31 GMT -5
Tested the new blow back adapter ejectors on the Tok upper. Ejectors are still a bit high, but we can work with that to get these orders out. Function was good after some adjustments. We are reviewing the prints and making some machine adjustments to handle the thicker material and the added roll pin. One thing that is very noticable in the blow back is the variation in recoil. Using a heavy spring and H3 buffer helps, but the variation in the surplus is definately noticable. Did not get a chance to play with other buffers.
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Post by HMC710 on Dec 8, 2010 7:42:22 GMT -5
Got a call from the company making our new ejectors. Needless to say, they have not been made yet. They promised they would get right on them and get them out.....
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Post by HMC710 on Jan 1, 2011 18:15:09 GMT -5
Modified a couple adapters for the new ejectors. Didn't run any new adapters yet, powered up machine and got electronic error. Have not dug into it, but we did lose power 6 times in December.... hopefully just a glitch.
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Post by HMC710 on Jan 11, 2011 6:54:32 GMT -5
Maybe not a glitch. Reset boards & components and ran half a cycle......faulted out. Will start swapping jigs over to other machine.
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Post by HMC710 on Jan 12, 2011 20:25:02 GMT -5
Pulled and cleaned the Y drive and Praise the Lord, we are making chips on the Blow Backs. TMAR's next.....
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Post by HMC710 on Jan 13, 2011 12:25:23 GMT -5
New ejectors fitted and ready for live testing!
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Post by HMC710 on Jan 16, 2011 10:05:39 GMT -5
Live fired new ejectors and tweaking just a bit. Building a new jig for the ejectors and may play with the feed ramps on adapter a bit. Still having control issues on machine so working on a new program for the other machine.
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Post by HMC710 on Feb 8, 2011 7:03:05 GMT -5
Built a new jig for the ejectors and looks good so far. The blow backs have been hanging back here for way too long. Got a few of them machined and doing assembly. Added some minor changes to the mag catch portion which we are doing to all adapters. Adding a clearance cut to speed up assembly.
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Post by HMC710 on Feb 28, 2011 7:55:13 GMT -5
We have some blow back adapters out in the field and I got a call Friday from a customer in the Upper 1. "Tim, man, I wanna tell you, this thing runs like top, I could not be happier! When can I get some more?" He has the version just before we changed and beefed up the ejectors. I asked him how the ejector was holding up and said he had to file it a bit for clearance and tighten it down once, but works just fine. Our new ejectors are even stronger and we changed the roll pin, so we are glad to get these reports. Thanks for the call and it was great talking with you again!
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Post by HMC710 on Mar 14, 2011 6:29:08 GMT -5
Got a chance to run a bunch of ammo through the blow backs this weekend and I am very pleased with the results. I swapped out the stock and put in a rifle buffer system and that smoothed things out a bit. I didn't have my max buffer with me or I would have tried that also. The blow back is still not as smooth as the gas systems, but much better for me with the longer buffer spring. There were no clearance issues and the ejection was great with the new ejectors. Looks like its time to heat treat the jig and bend up some more.
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Post by HMC710 on Oct 17, 2011 7:08:41 GMT -5
Wow, March 14th.... time flies. Was discussing blow back systems with sub sonic loads the other day so I dug out the blow back upper and our modified Max buffer. I had some Unique reloads that wouldn't cycle a gas system so started off with them. Poof, poof, poof, hmmm, those must be some light loads because this thing is smooth. Single loaded some sub stuff and again, very smooth. And the sub rounds would function in a blow back system with the loads I had. The heaviest bullet was one of the solid brass baubles I had turned on the lathe, 147gr if I remember. I took the upper off for cleaning and realized that this was using the modified Max buffer. Could that be the reason for smoothing things out? Loaded up a mag of surplus and went back out and sure enough, there was a noticeable difference in the cycling action. I had a 16" brl on my pistol lower, which used to be harsh to shoot in blow back. The best luck I had was with a 9mm buffer in a rifle stock. Even with the original Max buffer, it was still rather rough. Looks like some more testing is going to be required with the modified Max buffer and see if this is real or imagined, but there is definitely a noticeable difference for the better.
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