View Full Version : Managing an overgassed AR.
castanagajt
07-27-11, 10:32
Online, many people talks as the AR system is overgassed and the port size from the gas block, the barrel and through the gas tube affects the behavior of the platform.
My question to you is if i were to use an ar side vent, a compensator, can it drop the force of the gas when the bolt carrier group goes back?
http://www.weaponoutfitters.com/products/ar-gas-vent
The weight are now going to be an H3 buffer (in the lower.), full auto carrier was needed. The heavier springs don't help any, infact, made it worse. The last part I want to do is buy an adjustable gas block since it is 120.00. If I can avoid that, I will.
__________________
Dude, what kind of AR are you running? Manufacturer(s)? Barrel length? Ammo?
We need details :)
castanagajt
07-27-11, 11:29
Dude, what kind of AR are you running? Manufacturer(s)? Barrel length? Ammo?
We need details :)
The barrel is a Yankee hill machine 20 inch barrel, using a Rock River arms front sight base. The F-marked iron sights type. rifle length gas tube, ammo is Wolf 7.62x39 122 gr. FMJ.
Bolt carrier group is a Fail Zero Full auto, carbine spring, carbine 6pos buffer tube with now an H3 buffer. on testing it was an h2 buffer, and an 6.5 HSS slash heavy buffer, better result was a spikes ST-t2 buffer.
Straying a bit out of my lane but overgassed with a 20" barrel and rifle length gas tube? Are you sure? Seems to be like you're going the wrong way with the buffer and you would want to go lighter (carbine buffer) instead of heavier with rifle length gas
What kind of malfunctions are you seeing?
ETA: Just noticed its a 7.62x39 upper so I'm not sure how that changes the game in an AR. My guess is Grant or IG will be along shortly and can give you much better insight than I.
castanagajt
07-27-11, 11:57
Straying a bit out of my lane but overgassed with a 20" barrel and rifle length gas tube? Are you sure? Seems to be like you're going the wrong way with the buffer and you would want to go lighter (carbine buffer) instead of heavier with rifle length gas
What kind of malfunctions are you seeing?
ETA: Just noticed its a 7.62x39 upper so I'm not sure how that changes the game in an AR. My guess is Grant or IG will be along shortly and can give you much better insight than I.
The rifle is having a failure to fully extract and then the bolt catches the next round and is trying to push the new round to the chamber about 10 of 20rounds but not consecutively, more like sporadically. I did try to go lighter by using a semi auto carrier and has jammed even more than it did with a Full auto carrier. I figure with a yet lighter buffer it will do the same as it has with the semi auto carrier.
i hope i can get some assistance too.
Straight Shooter
07-27-11, 12:28
I was thouroughly castigated by a couple on here when I mentioned what I had done to my LMT carbine to slow down its very overcharged cycling. It was like Id called one member here's mother a whore or something. I reckon your just supposed to live with it/like it,thats the impression I got, but its not what I did. I added a heavier buffer/spring,and it helped me a lot. Gonna add an even heavier buffer soon, and try that out.
GET RID OF THE STIFFER AFTERMARKET BUFFER SPRING -- IT IS PROVIDING RESISTANCE TO THE OPERATING CYCLE.
No, neither this vent or a compensator will have an effect on the pressure to the BCG. The BCG is moved rearward (and bolt forward)by the gas pressure via the gas tube. A more comprehensive explanation can be found here (http://www.ar15barrels.com/prod/operation.shtml).
Gas blowback occurs in the upper receiver. This comes from the chamber, the bolt carrier (notice the little holes on the side of the carrier?) and a minor amount from the gas tube (vast majority the latter is captured via the gas key). The gas will exit via the ejection port and the charging handle areas. All the vent does is redirect this gas away from your face if you seal the CH using RTV (or use a PRI Gasbuster CH). A suppressor will significantly increase the amount of gas pressure to the system and, consequently, increase blowback.
I'd recommend that you figure out the problem with your rifle before you invest in alternative solutions such as adjustable blocks as it is very unusual for an unsuppressed rifle-length gas system to experience excessive gas pressure. Further, adjustable blocks are a PITA and the adjustment screws often work their way loose. Definitely ditch the aftermarket spring first and go back to the standard carrier. Check the extraction with a snap cap by hand cycling the action. You may have a faulty extractor or extractor spring. If this is the case, get the extractor spring upgrades from BCM (http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm).
Additionally, your gas port may be out of spec, but I'd start by looking at the above first.
EDIT- I missed the part about this being 7.62x39. Most of the above holds true except for my statement re: unusual for a rifle length to experience excessive gas. Many 7.62x39 ARs have host of issues, some due to the gas port size and problems with bolts, e.g., ejectors and extractors.
Good luck. Let us know what you find.
Online, many people talks as the AR system is overgassed and the port size from the gas block, the barrel and through the gas tube affects the behavior of the platform.
My question to you is if i were to use an ar side vent, a compensator, can it drop the force of the gas when the bolt carrier group goes back?
http://www.weaponoutfitters.com/products/ar-gas-vent
The weight are now going to be an H3 buffer (in the lower.), full auto carrier was needed. The heavier springs don't help any, infact, made it worse. The last part I want to do is buy an adjustable gas block since it is 120.00. If I can avoid that, I will.
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elephantrider
07-27-11, 13:16
To answer your first question, I doubt that side vent forward assist will bleed off extra gas and reduce operating pressure on your bolt. That forward assist is mainly for reducing gas blowback to the shooter's face. I got all of that from reading the product desription.
As for addressing your apparent overall function problem, I'm not even sure where to start with diagnosing a 20" 7.62x39.
You might want to ditch the carbine stock system in favor of a rifle length stock.
Would like to add, that if you determine that the rifle is overgassed after addressing the issues recommended in this thread, try an LMT enhanced carrier before you consider an adjustable gas block. This carrier has additional gas vents added to reduce the pressure to the carrier and bolt. You don't need the entire BCG- just the carrier. You could easily sell it here for near what you paid. Heck, I'll buy it :p
I'll be the first to admit I know jack scheit about 7.62x39 AR's, other than they traditionally have proven to be unreliable.
I agree with sinister that I would use a standard buffer spring. I would also be tempted to either but a rifle stock on there or possibly look at an A5. But, I honestly wouldn't dump alot of money into the platform.
Do you have specific reliable info on the barrel you have being overgassed? Contact the manufacturer to see what buffer and spring they recommend first.
Put one round in the mag and shoot it, check to see if your bolt is locking to the rear. See if the empty case is extracting and ejecting properly.
What problem are you actually having in specific?
castanagajt
07-27-11, 16:28
GET RID OF THE STIFFER AFTERMARKET BUFFER SPRING -- IT IS PROVIDING RESISTANCE TO THE OPERATING CYCLE.
True. I had the best result with a stock m4 carbine spring.
castanagajt
07-27-11, 16:44
Would like to add, that if you determine that the rifle is overgassed after addressing the issues recommended in this thread, try an LMT enhanced carrier before you consider an adjustable gas block. This carrier has additional gas vents added to reduce the pressure to the carrier and bolt. You don't need the entire BCG- just the carrier. You could easily sell it here for near what you paid. Heck, I'll buy it :p
Hey all, might as well share you some 7.62x39ar15 knowledge.
The concept was to use the 20inch rifle length in hopes to increase the dwell time and drop the chamber pressure. Everything I have seen on the 7.62x39ar15 was shorties to m4 platform with 16inch barrel and the luck was probably worse than mine.
When I pulled the charging handle all the way back the carrier key is almost inside the buffer tube so I figured that the port holes will once again line up the AR gas vent once again as it has with the open ejection cover and it will be one last ditch effort to drop the pressure.
You guys can be right, by then it will be too late to make a difference as the Bolt carrier group about finished its cyle to push the new round in.
the feeding issues will be from the 223 barrel extension, I have yet to hear about a 7.62x39ar15 barrel extension. The fix is I broght in the upper to Bentwood gunsmithing to widen out the barrel extension and drop the m4 feed ramps on the lower receiver lower.
to help the bolt to extract the spent round I will have Bentwood gunsmithing to do a chamber polish on it.
I have on c-product 7.62x39 ar15 magazine as well. The front side needs to be ground down lower as the tip of the bullet knocks on that front side each and every time. I have found USA 7.62x39ar15 magazines as the best. As we speak I am waiting on USA 10rd 7.62x39 magazines to come in.
Funny, that you mentioned about the LMT Enhanced bolt carrier as i got off the phone at 8:30am in the morning hahaha Las Vegas time and ordered it from LMT, themselves.
I remembered a couple weeks back I talked to LMT technical staff and they said that if I was in the area, they would let me borrow one but, I dont live that close. They did say that they want me to perfect my 7.62x39 m16 with their LMT Enhanced bolt carrier and give them a call to tell them my findings. LMT do have a few of their 7.62x39 bolts left which was intended for another sales brand company, and they do have a 7.62x39 in the drawing boards.
I am hoping that enhanced bolt carrier will help, if not it is time for the adjustable gas block.
the A5 it seems like an idea, but, I am not familiar as how it will work or what it wil do. Care to share some light?
Man you all I do appreciate the help.
constructor
08-07-11, 12:19
First things first, shoot the rifle with only the cartridge in the chamber, mag in but no other cartridges in the mag.
Does it lock back? if not you are not getting enough gas so don't add a stiffer spring or heavier buffer.
Is the fired case being extracted from the chamber? Is it being ejected out of the port? If the answer to either of those is no you have an extractor problem or the chamber may be rough and the case sticking to the chamber walls.
...The bolt is moved forward by the gas pressure via the gas tube...
This is a myth
castanagajt
08-09-11, 22:41
I called my gunsmith today, and he did not start working on the rifle.
The work that needed to be done is polish the chamber, drop the M4 feed ramps lower on the lower, and enlarge the barrel extension and straighten the feed ramps. I assume that is what needed to be done with the 300Blk out and the 7.62x40WT.
The Franken mags has a tendancy of getting too weak on the 16 to 20rds and will not feed. So,my little brother bought six 10rd. USA magazines for it so we can try the bolt hold open. By the way thank you for the idea.
Tomorrow, I should be getting that LMT enhanced carrier from the UPS delivery man. As suggested prior by some of you that it shold expel more of the excessive gas and slow down the cycle
When we identify the problem and fix the problem with the 7.62x39 AR15. I promise that I will let LMT technical department, and that I did it with some of the kind people from M4Carbine.net who gave insightful suggestions. That would save them 100s of hours in reserch, production costs and materials.
I am still delighted my little brother chose this round. It is teaching me alot about the operation of the M16, M4 platform. Thank you to the moderators for keeping my thread clean.
This is a myth
Care to add any relevant information to refute?
Care to add any relevant information to refute?
In order to push the bolt forward, the pressure inside the expansion chamber of the BCG must be greater than the pressure inside the bore. The most the pressure in the expansion chamber will ever be is equal to the bore pressure
In order to push the bolt forward, the pressure inside the expansion chamber of the BCG must be greater than the pressure inside the bore. The most the pressure in the expansion chamber will ever be is equal to the bore pressure. Also, the greatest amount of force inside the BCG is being used to move the BCG rearward
I was referring to the collective motion of moving the carrier rearward, and consequently the bolt forward, due to pressure fed by the gas tube. That is, the bolt does not more forward until the carrier moves. As I understand this, once the bolt moves rearward the pressure in the BCG is greated than the bore pressure (?)
In order to push the bolt forward, the pressure inside the expansion chamber of the BCG must be greater than the pressure inside the bore. The most the pressure in the expansion chamber will ever be is equal to the bore pressure
B.S.
The bolt does not go forward.
The carrier moves to the rear, with nothing to resist it but its own inertia and the the buffer spring.
I was referring to the collective motion of moving the carrier rearward, and consequently the bolt forward, due to pressure fed by the gas tube. That is, the bolt does not more forward until the carrier moves. As I understand this, once the bolt moves rearward the pressure in the BCG is greated than the bore pressure (?)
What I am defining as forward movement is forward movement within the barrel extension. There has been a claim made that the gas pressure pushes the bolt forward to assist in the unlocking. This is incorrect.
As the bolt carrier move rearward, the volume of the BCG expansion chamber increases which in turn decreases pressure. (This decreases the pressure of the entire system, including the bore.) The bolt does not move forward to unlock. It turns. The turning is from the mechanical interface of the bolt cam and the carrier cam slot. There may be a bit of slack that lets the locked bolt have a small amount of fore and aft movement but this slack is taken up by the expanded case.
The bolt carrier moves rearward and the residual pressure is bleeding off (the bullet has cleared the muzzle and traveled several feet before the carrier begins moving) and more gas is bled off when the bolt rings wipe past the carrier vent holes. From there it's the momentum of the carrier and spring pressure that works the action (Perhaps a bit of assist is given by the residual pressure). As you can see, the gas pressure inside the expansion chamber of the carrier is never greater than the pressure in the bore
B.S.
The bolt does not go forward.
The carrier moves to the rear, with nothing to resist it but its own inertia and the the buffer spring.
That's what I said. The explanation why is-
In order to push the bolt forward, the pressure inside the expansion chamber of the BCG must be greater than the pressure inside the bore. The most the pressure in the expansion chamber will ever be is equal to the bore pressure
What I am defining as forward movement is forward movement within the barrel extension. There has been a claim made that the gas pressure pushes the bolt forward to assist in the unlocking. This is incorrect.
As the bolt carrier move rearward, the volume of the BCG expansion chamber increases which in turn decreases pressure. (This decreases the pressure of the entire system, including the bore.) The bolt does not move forward to unlock. It turns. The turning is from the mechanical interface of the bolt cam and the carrier cam slot. There may be a bit of slack that lets the locked bolt have a small amount of fore and aft movement but this slack is taken up by the expanded case.
The bolt carrier moves rearward and the residual pressure is bleeding off (the bullet has cleared the muzzle and traveled several feet before the carrier begins moving) and more gas is bled off when the bolt rings wipe past the carrier vent holes. From there it's the momentum of the carrier and spring pressure that works the action (Perhaps a bit of assist is given by the residual pressure). As you can see, the gas pressure inside the expansion chamber of the carrier is never greater than the pressure in the bore
Good explanation, thank you.
The work that needed to be done is polish the chamber, drop the M4 feed ramps lower on the lower, and enlarge the barrel extension and straighten the feed ramps. I assume that is what needed to be done with the 300Blk out and the 7.62x40WT.
We use standard M4/extended feed ramps on the 300 BLK and 7.62x40, I don't know if Wilson did anything to the barrel extensions when they got them.
This might help with a feeding problem but you described an extraction, ejection, or short stroke problem.
The bolt is pushed forward when the piston is under gas pressure, but it does not move forward.
...The bolt is pushed forward when the piston is under gas pressure, but it does not move forward.
This is also true when the system is at atmospheric pressures. Without explaining the scientific principle, the statement is confusing.
Yes, the bolt is being pressed forward. It's also being pressed rearward by the same pressure. When subjected to 1 Atmosphere, the entire surface of the bolt, the carrier and the surfaces of every part of the carbine is being pushed by approximately 15 psi. So even when the pressure is only atmospheric, it could be said the bolt is pushed forward as well. As the pressure is equalized, no work is performed (nothing is moved).
When the system is charged by firing of the cartridge, the same principles apply. (However, the increase in pressure is limited to those surfaces exposed to the increase. All others remain at atmospheric pressure.)
When the cartridge is first discharged, all the pressure the bolt experiences is on the bore side. The majority of the the thrust vector on the bolt is rearward with a tiny amount of forward thrust (or push) from the atmospheric pressure that is found in the expansion chamber before the bullet clears the gas port to allow it to be charged by the expanding gases. Once the gases reach the expansion chamber, the forward thrust on the bolt will increase with the increase in pressure. So in this respect, yes the bolt is pushed forward, but no work is done as the bolt is not caused to move.
To go deeper, the push does cause movement of the bolt as there will be some displacement at the molecular level likely involving the laws of chaos and quantum mechanics, and will be a localized phenomena.
For our purposes, it is simply that- The pressure inside the bolt carrier does not move the bolt forward
What I am defining as forward movement is forward movement within the barrel extension. There has been a claim made that the gas pressure pushes the bolt forward to assist in the unlocking. This is incorrect.
Ohhh, I see what you mean now. Sorry 'bout that.
For what it's worth, I agree with your assessment 110%.
castanagajt
08-11-11, 10:12
We use standard M4/extended feed ramps on the 300 BLK and 7.62x40, I don't know if Wilson did anything to the barrel extensions when they got them.
This might help with a feeding problem but you described an extraction, ejection, or short stroke problem.
The bolt is pushed forward when the piston is under gas pressure, but it does not move forward.
I went to see Matt Babb, my local gunsmith at Long Mountaint Outfitters/ Bentwood gunsmithing of Las Vegas, NV. He said that the m4feedramps from YHM are right for the 30 caliber.
As for the tips of the bullets hitting low, it is the angle of the feed lips of the magazine. The franken mags are too soft and can easily be changed unwantedly because of the material used for it.
I will hope i can use 10 rounder USA magazines.
To be honest with all of you, I felt like I was thrown under the bus on this one. I wanted him to polish the chamber, extractor, etc. but he just went to the back and gave back the rifle and my other 7.62x39 7.5inch upper.
Looks like I am on my own on that one and I will teach myself to polish the chamber and lower the feedramps.
I did get the LMT enhanced bolt carrier, yesterday and none of my bolts I had laying around will not fit in it. I even took out the gas rings on one bolt to see if that may be the problem. No, the gas rings were never the problem. It was the internal diameter of the carrier is too small.
I called LMT and they were professional about it so I have to send it back.
As for the 7.62x39 lower I guess it is best that I spend the money for an MGI 7.62x39 lower with interchangeable magwells for more than $500.00!
For now, maybe I will see if the H3 buffer helps cycle the weapon atleast, check for the BHO too.
bleaman225
08-11-11, 10:37
This is also true when the system is at atmospheric pressures. Without explaining the scientific principle, the statement is confusing.
Yes, the bolt is being pressed forward. It's also being pressed rearward by the same pressure. When subjected to 1 Atmosphere, the entire surface of the bolt, the carrier and the surfaces of every part of the carbine is being pushed by approximately 15 psi. So even when the pressure is only atmospheric, it could be said the bolt is pushed forward as well. As the pressure is equalized, no work is performed (nothing is moved).
When the system is charged by firing of the cartridge, the same principles apply. (However, the increase in pressure is limited to those surfaces exposed to the increase. All others remain at atmospheric pressure.)
When the cartridge is first discharged, all the pressure the bolt experiences is on the bore side. The majority of the the thrust vector on the bolt is rearward with a tiny amount of forward thrust (or push) from the atmospheric pressure that is found in the expansion chamber before the bullet clears the gas port to allow it to be charged by the expanding gases. Once the gases reach the expansion chamber, the forward thrust on the bolt will increase with the increase in pressure. So in this respect, yes the bolt is pushed forward, but no work is done as the bolt is not caused to move.
To go deeper, the push does cause movement of the bolt as there will be some displacement at the molecular level likely involving the laws of chaos and quantum mechanics, and will be a localized phenomena.
For our purposes, it is simply that- The pressure inside the bolt carrier does not move the bolt forward
Contributing nothing here but... nice post!
castanagajt
08-11-11, 11:58
Contributing nothing here but... nice post!
Hehehe It is a great post. We all can learn something from this thread.
I have never heard of an issue with fitting standard diameter bolts to the LMT carriers. Did you try a 5.56 bolt? Further, the putative issues with your chamber may affect extraction, but as Todd pointed out, reworking/polishing the feedramps would address feeding, not extraction.
I'd recommend abandoning this mess.
I went to see Matt Babb, my local gunsmith at Long Mountaint Outfitters/ Bentwood gunsmithing of Las Vegas, NV. He said that the m4feedramps from YHM are right for the 30 caliber.
As for the tips of the bullets hitting low, it is the angle of the feed lips of the magazine. The franken mags are too soft and can easily be changed unwantedly because of the material used for it.
I will hope i can use 10 rounder USA magazines.
To be honest with all of you, I felt like I was thrown under the bus on this one. I wanted him to polish the chamber, extractor, etc. but he just went to the back and gave back the rifle and my other 7.62x39 7.5inch upper.
Looks like I am on my own on that one and I will teach myself to polish the chamber and lower the feedramps.
I did get the LMT enhanced bolt carrier, yesterday and none of my bolts I had laying around will not fit in it. I even took out the gas rings on one bolt to see if that may be the problem. No, the gas rings were never the problem. It was the internal diameter of the carrier is too small.
I called LMT and they were professional about it so I have to send it back.
As for the 7.62x39 lower I guess it is best that I spend the money for an MGI 7.62x39 lower with interchangeable magwells for more than $500.00!
For now, maybe I will see if the H3 buffer helps cycle the weapon atleast, check for the BHO too.
castanagajt
08-11-11, 12:36
I have never heard of an issue with fitting standard diameter bolts to the LMT carriers. Did you try a 5.56 bolt? Further, the putative issues with your chamber may affect extraction, but as Todd pointed out, reworking/polishing the feedramps would address feeding, not extraction.
I'd recommend abandoning this mess.
You heard of it now. The LMT enhanced carrier does not fit any of my 5.56 bolts. The bolts do fit on all of my 5.56 carriers. So yah, a defect from LMT.
castanagajt
08-11-11, 22:46
Got it so feeding was not the problem, no point for me to polishing the chamber. Why quit? Pretty close in ironing out the bugs. I didn't say this was ever the go to gun. We did it to learn how the AR system works and that is all we wanted since the beginning.
After a couple of hours I finally got the C-products magazine how I wanted it witha triangle file.
The AK has no feed ramp at all. The round goes straight in and into the chamber.
I had to drop the front part of the magazine probably a 1/4 inch until I can see the whole round visible when I am looking infront of the loaded magazine.
There were these reinforcement tabs that reinforces the feed lips that makes the round stuck and changes the directions inward so I filed as much material off as deemed necessary.
the C-products magazines are not too bad, more robust on the top part than frankenmags, the angle is all right, easy to strip, the follower is pretty good too.
Tomorrow, I will test this rifle out with my little brother. What we are doing different than last time:
1. Replaced the Spikes ST-T2 buffer for a Rock River Arms H2 buffer.
2. We are now going to use six USA 10 round magazines but only fill it to nine rounds a piece.
3. Test out my modified C-products magazine with probably 15 rounds in it.
4. We changed the buffer spring with a brand new CMMG carbine buffer sping.
5. We are also going to try a CMT H3 buffer.
the ammo is Wolf.
The AK has no feed ramp at all. The round goes straight in and into the chamber.
It's called a bullet guide in an AK. Some have individual ramps but most have one chamfer across the front.
http://www.k-var.com/shop/product.php?productid=16321&cat=281&page=1
castanagajt
08-12-11, 16:37
After you posted that picture. I went and grabbed my Arsenal SGL-31 and saw that same bullet guide on it.---This always has been my go to gun. That, and my Norinco SKS. Besides, the point.
We went shooting today and the problem was the feeding. The bullet tip hit too low or it hit square on the middle bump of the barrel extension.
So my gunsmith was wrong and I was right all along. I do have to modify the barrel extension. i was thinking of a scallop style like a bulldozer type but extend the scoop on to the m4 feed ramps on the lower receiver. Pretty much the same look as that bullet guide you have posted up.
The USA 10rd. were all duds.
The best magazine was the modified C-Products magazine that I did a day earlier. The round enters out straight, exactly how I wanted it.
After that, the barrel extension just throws everything out of whack.
Until, I can get that feeding part, I then can move on to the other things like playing around with the buffer weights.
I will send back the LMT enhanced full auto carrier too soon.
Well, time to put down the firearm project and pick up my car project this time. Thanks all, I will revive this thread again in the near future. Until then, I will try to keep an open mind and learn about these AR15, m4, m16,CAR15, etc.
If the bullet tips are hitting too low you can adjust the angle of the feed lips. Basically bend them up slightly at the front so the rounds feed with the bullet tips higher.
castanagajt
08-13-11, 18:56
You are right on that one Todd K.
That idea worked on the franken magazines. Namely, the G-Tech and the Scherer magazines. That does work.
I am going to adopt the new C-products magazines and probably the ASC magazines some day.
Unfortunately, the barrel extension is a big problem for this particular rifle. If it were a 5.45 it will probably be fine.
Whenever I get around to working a couple of spare barrel extensions and polish them up and try the rifle out again with a couple of my designs I am thinking of. By all means, I will revive this thread again.
Thanks again Todd K.
castanagajt
08-16-11, 01:46
The first thing was last minute preparation, I stripped a cheap 7.62x39 bolt for the black insert and extractor spring because I knew it is brand new and stuck it in the MGI bolt.
I brought the C-products 30 round magazine.
A franken magazine of assorted winchester and Yugoslavian rounds. I cannot tell the difference in looks since I was in a hurry. Besides, they were both brass and shoot about the same.
30 rounds used for Bolt hold open.
I started off with the H3 buffer and it did a bolt Hold open 7 of 10 times using one good USA 10r round magazine.
Fixer's Rock River Arms buffer is up and I got 9 of 10 rounds bolt hold open with the same USA 10 round magazine.
HSS Heavy buffers buffer, It fired perfectly just 1 of 10 bolt hold open.
Since I had the best of luck with the Rock River Arms 9mm buffer why not keep using it.
The test with 73 rounds.
The Franken magazine shot 24 of 25 Yugoslavian rounds.
The C-products magazine shot 17 of 20 Wolf rounds.
the USA 10 rounder shot all 10 rounds.
The wolf box on its own. I loaded that one with 9 rounds (I had a bad feeling of this one,) of the other USA magazine, it will not seat properly. It had two Wolf duds on the first nine from the box.
(I ran the two Wolf duds again on the other USA 10 round magazines and indeed, they were duds. So that is 7 of 9 wolf rounds working. The duds are excluded from the test. making 7 of 7.
The second set of 9 rounds from the same wolf box had two jams. It was because the nose of the bullet hit too much to the left and missing my extended feed ramps, These rounds were on the lower part of the follower. 7of 9.
The last two rounds of the box went off, just right. It was loaded in my C-products magazine.
Home time.
Soon after I got home I extended the feed ramp and re-contoured the barrel extension. hopefully, I did a great job, and it was better than before. I tested two of three USA 10 rounders and they were junk. so I rechecked my C-products. Those fed perfectly in a lab rat experiment.
67 of 73 success. 0.9178 or 91.78% success rate.
Before it was a consistent 2-3 of 10 rounds that worked and now it is about 9 of 10 success rate, I will keep that.
Most of these parts are bought here in town. We tried to keep our money in this town.
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