View Full Version : Configuration of buffer weights
So recently I decided to change a Giessle super 42 H1 buffer to an H2 buffer. After ordering the tungsten weight and popping off the rubber cap I discovered the weights were installed backwards from what Giessle recommended. Giessle recommend inserting the tungsten weights first followed by steel weights. The steel weights should be the ones touching the rubber bumper.
This got me curious and after popping off the rubber caps of a few more buffers from Aero, White Label Armory, and another that I don’t recall the brand I noticed every one had the weights backwards from what Giessle recommended.
Does it matter which way the weights are inserted for H buffers or am I overthinking this entirely too much. Is it possible that all these manufacturers inserted the weights backwards or that Giessle messed up the instructions they sent?
I have difficulty imagining it matters much.
Heavier weights go in first.
Okay, I'll be contrary.
The drawing for the H2 Buffer Assembly places the tungsten weights in the rear. . . .
I would split the difference and put them in the middle... just to be safe
dont_tread_on_me
03-27-22, 21:34
Does the Tungsten have a dead-blow effect at all?
That was my impression as well but how is it possible that 4 different H buffer from 4 different manufacturers placed the weights in incorrectly?
It leads me to believe maybe it doesn’t truly matter? I know I’ve ran some guns with the weights backwards and they ran fine. Maybe I’m just overthinking this but it just kind of bugs me that all of mine were backwards including the Giessle that came with specific instructions.
Okay, I'll be contrary.
The drawing for the H2 Buffer Assembly places the tungsten weights in the rear. . . .
Can you post a picture of this drawing? Finding any information on this online has been almost nonexistent. The only info I was able to find was a brownells video that placed them in the same way giessle recommended in the instructions.
I can't even remember what I've done before. Just get them in there.
bamashooter
03-28-22, 08:31
This will be fun. Definitely not. It doesn't matter one iota. Aside from the fact during the first nanosecond those weights are travelling forward.:jester:
Does the Tungsten have a dead-blow effect at all?
Yes, yes it does.
Can you post a picture of this drawing? Finding any information on this online has been almost nonexistent. The only info I was able to find was a brownells video that placed them in the same way giessle recommended in the instructions.
Nope, you'll just have to trust me.
Contrary to popular belief the drawings still belong to Colt.
This will be fun. Definitely not. It doesn't matter one iota. Aside from the fact during the first nanosecond those weights are travelling forward.:jester:
It only manners if you're shooting full auto.
Mysteryman
03-29-22, 07:45
It only manners if you're shooting full auto.
Can you elaborate as to why it matters for FA and what could or does happen if the weights aren't stacked properly.
Mysteryman
03-29-22, 07:46
It only manners if you're shooting full auto.
Can you elaborate as to why it matters for FA and what could or does happen if the weights aren't stacked properly.
Can you elaborate as to why it matters for FA and what could or does happen if the weights aren't stacked properly.
The weights are only there to prevent bolt bounce. Bolt bounce is only a problem in full auto as it disrupts the timing of the hammer falling on the firing pin.
In semiautomatic fire the hammer falls when the trigger is pulled again, which is long after even the worse bolt bounce has subsided. The since the weights sliding in the buffer serve no purpose in semiautomatic fire, the order in which they are placed is immaterial.
In full auto, it makes sense to put the heavier weights in the back, as the weights hit in succession, first the forward one, then the second one, etc. You want the impact force to increase, not decrease as a function of time.
Bolt bounce is only a problem in full auto as it disrupts the timing of the hammer falling on the firing pin.
I would argue that bolt bounce can be problematic in semi auto too. Bad bolt bounce could act like a bullet pulling inertia hammer on weakly neck tensioned ammo. It's possible that I could be totally wrong on this, but I've seen some slow motion video, and that was my first concern.
When you step up to the AR-10, bolt bounce with crappy buffers like HEAVYBUFFERS.com can be so awful that it's distracting. This is aftermarket nonsense of course, and not a real buffer. But an extreme example of a semi auto buffer still being important.
The weights are only there to prevent bolt bounce. Bolt bounce is only a problem in full auto as it disrupts the timing of the hammer falling on the firing pin.
Disagree with you there… being I’ve seen out of battery discharges due to that very thing you said only is a problem with full-auto.
Link related to 9mm ARs, but still occurring with semi-auto fire. Just because OOB is almost non-existent in a 5.56mm, doesn’t mean it is the same across the board. And with the push of 9mm ARs over the past few years… it is a fair argument.
https://blowback9.wordpress.com/2021/04/02/everything-about-the-ar9/#23
That being said, putting the heavier weight forward helps prevent that. Shy of “just because,” give me an argument where you’d see weight balance shifting towards the rear as a positive. Legitimate question.
Because even if you fire quick enough to send the hammer down when the bolt isn’t locked… you still end up with click/no bang and need to cycle the action. If running buffers like that reduces that chance (bolt bounce), why not?
Disagree with you there… being I’ve seen out of battery discharges due to that very thing you said only is a problem with full-auto.
You've seen a 5.56 AR fire out of battery? Or did you mean 9mm AR? It's physically impossible for the firing pin to touch the primer if the gun isn't fully in battery without some other mechanical failure.
You've seen a 5.56 AR fire out of battery? Or did you mean 9mm AR? It's physically impossible for the firing pin to touch the primer if the gun isn't fully in battery without some other mechanical failure.
Was talking about 9mm… pointed that out about 5.56mm in that post.
Was talking about 9mm… pointed that out about 5.56mm in that post.
Gotcha. yeah... 9mm is a whole other ball of wax. I was toying with a 5.7 upper in AR years ago. The horrible bolt bounce was the deal breaker.
Mysteryman
03-30-22, 04:46
The weights are only there to prevent bolt bounce. Bolt bounce is only a problem in full auto as it disrupts the timing of the hammer falling on the firing pin.
In semiautomatic fire the hammer falls when the trigger is pulled again, which is long after even the worse bolt bounce has subsided. The since the weights sliding in the buffer serve no purpose in semiautomatic fire, the order in which they are placed is immaterial.
In full auto, it makes sense to put the heavier weights in the back, as the weights hit in succession, first the forward one, then the second one, etc. You want the impact force to increase, not decrease as a function of time.
Just so I'm tracking. The tungsten weight is closest to the urethane plug, not closest to the bolt carrier.
Disagree with you there… being I’ve seen out of battery discharges due to that very thing you said only is a problem with full-auto.
Link related to 9mm ARs, but still occurring with semi-auto fire. Just because OOB is almost non-existent in a 5.56mm, doesn’t mean it is the same across the board. And with the push of 9mm ARs over the past few years… it is a fair argument.
https://blowback9.wordpress.com/2021/04/02/everything-about-the-ar9/#23
That being said, putting the heavier weight forward helps prevent that. Shy of “just because,” give me an argument where you’d see weight balance shifting towards the rear as a positive. Legitimate question.
Because even if you fire quick enough to send the hammer down when the bolt isn’t locked… you still end up with click/no bang and need to cycle the action. If running buffers like that reduces that chance (bolt bounce), why not?
If you are seeing out of battery discharges, you have an poorly designed bolt and/or firing pin, period.
In is a simple thing to design the bolt and firing pin so that the hammer can only hit it when in battery.
So my understanding was steel weight(s) go into the buffer before tungsten. Kinda like the alphabet, S before T. Gotta say though, my guess is that it matters about as much as putting the buffer spring in "backwards". ;)
So my understanding was steel weight(s) go into the buffer before tungsten. Kinda like the alphabet, S before T. Gotta say though, my guess is that it matters about as much as putting the buffer spring in "backwards". ;)
I have to go check mine! :jester:
And my cam pins!!!
Just so I'm tracking. The tungsten weight is closest to the urethane plug, not closest to the bolt carrier.
To my understanding and according to the instructions Giessle sent me with the tungsten weight I ordered, when you pop off the rubber bumper you insert tungsten weights first followed by steel. So for an H2 buffer you should insert tungsten, tungsten, followed by steel touching the rubber bumper. I just find it really strange that 4 different buffers I popped open all had the weights the exact opposite way.
Fwiw the other buffer that I could not remember the brand at the time of this post is a cmmg h1 buffer. So that’s Giessle, aero, cmmg, and white label armory that all sent me H buffers with the weights installed backwards. If you’re like me and it’s something that bothers you it may be worth the time to check your h buffers. I don’t think it really matters that much at the end of the day considering I ran every one with the weights backwards for years before discovering this and reconfiguring them.
Ned Christiansen
03-30-22, 11:29
There are so many 9's being made my so many outfits, and some of them "have issues" as they have not been carefully designed by people who understand all the little nuances of firearms (not saying I do).
One can pretty easily self-demo the fact that the original in 5.56 cannot fire out of battery by means of dropping the hammer on the firing pin. The hammer will drop with the bolt retracted a bit but it cannot contact the FP at that point. Further forward it might, depending on carrier design, but the FP cannot reach through the breech face with the bolt unlocked. Looking at just about any "repeater" design going back to before 1900, there will be found some manner of blocking the firing pin or hammer or both until the bolt is fully in battery.
On some of the myriad 9's out there it would not surprise me to find that many or even most will fire with the bolt say 1/8" out of battery. Since, again, standard AR design allows the hammer to drop with the bolt retracted-- all the way back to the point where the carrier rocks the hammer off the sear and holds it there-- simple blowback 9's, probably a lot of them will fire slightly out of battery.
To my understanding and according to the instructions Giessle sent me with the tungsten weight I ordered, when you pop off the rubber bumper you insert tungsten weights first followed by steel. So for an H2 buffer you should insert tungsten, tungsten, followed by steel touching the rubber bumper. I just find it really strange that 4 different buffers I popped open all had the weights the exact opposite way.
Fwiw the other buffer that I could not remember the brand at the time of this post is a cmmg h1 buffer. So that’s Giessle, aero, cmmg, and white label armory that all sent me H buffers with the weights installed backwards. If you’re like me and it’s something that bothers you it may be worth the time to check your h buffers. I don’t think it really matters that much at the end of the day considering I ran every one with the weights backwards for years before discovering this and reconfiguring them.
So, they would have been install the correct way, according to the drawing.
On some of the myriad 9's out there it would not surprise me to find that many or even most will fire with the bolt say 1/8" out of battery. Since, again, standard AR design allows the hammer to drop with the bolt retracted-- all the way back to the point where the carrier rocks the hammer off the sear and holds it there-- simple blowback 9's, probably a lot of them will fire slightly out of battery.
Given the power of 3-D modeling, it seems sad to me that such would be the case.
Mr Browning managed to design things properly without such aids.
For clarity; starting with an empty H Buffer-
Add 1 rubber washer, 1 tungsten weight, another washer, a steel weight, another washer, another steel weight, and then the plug?
Is that the correct orientation?
the AR-15 Junkie
03-31-22, 07:22
According to the drawing the 2 heavier tungsten weights go towards the rear or against the rubber bumper. This is an H2 (2 tungsten weights) and the 1 steel weight is up front.
https://i.imgur.com/cHLErrm.jpg
Thanks, but how can you tell from the drawing?
the AR-15 Junkie
03-31-22, 08:48
Thanks, but how can you tell from the drawing?
You look at the notes under the buffer. The 2 tungsten weights are labeled 1, and the 1 steel weight is labeled 3.
So, they would have been install the correct way, according to the drawing.
No they were installed backwards according to the instructions and drawings Giessle sent me
The youtube videos show installing the tungsten weights first. Opposite the drawing.
No they were installed backwards according to the instructions and drawings Giessle sent me
The youtube videos show installing the tungsten weights first. Opposite the drawing.
Hmmmmmm, Colt's approved drawing versus other people . . . .
I'll stick with the opinion of guys that designed the buffer in the first place. According to the little hexagon in the lower left hand corner, the order is an inspectable requirement.
Hmmmmmm, Colt's approved drawing versus other people . . . .
I'll stick with the opinion of guys that designed the buffer in the first place. According to the little hexagon in the lower left hand corner, the order is an inspectable requirement.
Totally agree.
What source do you recommend searching to get the correct information on these types of details?
Hmmmmmm, Colt's approved drawing versus other people . . . .
But it's YOUTUBE!!! :jester:
Totally agree.
What source do you recommend searching to get the correct information on these types of details?
The TDP.
The TDP.
....which us mere mortals can't access.
You seem to have access to it, yet you state that the TDP is still owned by Colt, therefore you work for Colt?
the AR-15 Junkie
04-02-22, 00:09
....which us mere mortals can't access.
You seem to have access to it, yet you state that the TDP is still owned by Colt, therefore you work for Colt?
go here for instructions on how to find and download the M4 and M16a1 data packages. Your Welcome!
https://www.youtube.com/watch?v=TeZLh4jiSlc&t=3s
go here for instructions on how to find and download the M4 and M16a1 data packages. Your Welcome!
https://www.youtube.com/watch?v=TeZLh4jiSlc&t=3s
Wow, thank you for that! Much Appreciated!
Is the slotted pin on the buffer a 1/8 x 3/4?
Hmmmmmm, Colt's approved drawing versus other people . . . .
I'll stick with the opinion of guys that designed the buffer in the first place. According to the little hexagon in the lower left hand corner, the order is an inspectable requirement.
The fact that the buffer weight stack is an inspection point leads me to believe it may be of import. Of course we don't know what the criteria is. Could be they are simply making sure it's rubber washer, weight, rw, weight,...
That's one problem with specs. If you don't have the complete narrative it can be hard to determine what items are critical and which are superfluous. Having been involved in spec writing a little here and there I have seen first hand that most things are included because it matters but there are occasions where details becomes spec just cause "we gotta put something here".
Without that narrative I would personally default to the spec unless I was presented with a very good argument to do otherwise.
joedirt199
04-02-22, 09:18
So make up some buffers with weights in different orders and shoot them to see if their is a felt or noticeable difference. Curious to see the outcome.
Carbine – If you ever experience issues with moving up in buffer weights you can always go back to this one to have your rifle run 100% of the time. It just might have more muzzle flip than you like.
H/H1 – We’re not adding a whole lot of weight moving up from carbine buffers to this one but it is possible for some carbine and mid-length rifles to have cycling issues with the added weight. However, if you’re using a factory built rifle it should be just fine as they come over-gassed enough to be able to handle it.
COLT, BCM, & SOLGW buffers are steel first and then tungsten just like the drawing. These use a 6061 aluminum body and a phosphate slotted pin.
VLTOR buffers are the opposite, tungsten first and then steel. The last steel weight is partially drilled for the biasing spring so that particular weight has to go in last. VLTOR uses a 7075 T6 aluminum body and a stainless slotted pin. The slotted pins are slightly under 1/8 x 3/4 and I don't know where to source them?
Is the slotted pin on the buffer a 1/8 x 3/4?
Seeing as the inner diameter of the action spring is 0.741 to 0.771, a 3/4 inch spring would be a bad idea.
And I'll wager that Colt's Buffer bodies are made from 7075 as well.
Seeing as the inner diameter of the action spring is 0.741 to 0.771, a 3/4 inch spring would be a bad idea.
And I'll wager that Colt's Buffer bodies are made from 7075 as well.
Do you know the size of the pin?
It is not a standard length pin. There is probably a drawing for it out there somewhere.
DWG B8448521 (19204)
0.720" long
If I were going to modify an existing pin, I would make it .695" long and have it flush to the buffer body.
It is not a standard length pin. There is probably a drawing for it out there somewhere.
It takes what - 2 seconds on a grinder to make one (that is a touch long) whatever length you desire?
No drawing should be 'required' with something this simple in my opinion.
It takes what - 2 seconds on a grinder to make one (that is a touch long) whatever length you desire?
No drawing should be 'required' with something this simple in my opinion.
Someone has already posted where to get an answer to questions like this. Simply letting it be known all of that is addressed on the drawings.
If you just pick up a standard pin and grind it likely it has the wrong finish if you didn't look at the print. Most standard hardware store pins I have seen don't have the mil spec finish.
Most standard hardware store pins I have seen don't have the mil spec finish.
Yup. Cause that non milspec finish could fail after swimming in the ocean with the rifle for a few months non stop and I could not personally stand for something like that.
:rolleyes:
Someone has already posted where to get an answer to questions like this. Simply letting it be known all of that is addressed on the drawings.
If you just pick up a standard pin and grind it likely it has the wrong finish if you didn't look at the print. Most standard hardware store pins I have seen don't have the mil spec finish.
The pin size is not on the drawing.
Yup. Cause that non milspec finish could fail after swimming in the ocean with the rifle for a few months non stop and I could not personally stand for something like that.
:rolleyes:
Its easy to mock, but there are probably reasons for the coatings and finishes where specified. For example, shit rusts if you look at it sideways in the coastal Southeast. Buffer tubes also seem to attract condensation internally in my experience, and there is a popular brand of spring that I tried a few of and had lots of surface rust unless I cleaned it and wiped it down all the time. Also had that problem with a first-gen Tubbs, but not the second-gen. How much rust would it take to matter? I have no idea. Or maybe the concern is galvanic something something, again no idea. But it is easier for me to trust the engineers rather than internet strangers that disagree and say “ dremel it; it’ll be just as good”.
With all that said, I’d have no hesitation grinding one in a pinch to use short-term. I already use oil on the pin when I install it. Chamfering the edge seems like a good idea if you go that route. Seems kinda Bubba, though, in a world where the correct part exists and is cheap as heck.
Its easy to mock, but there are probably reasons for the coatings and finishes where specified. For example, shit rusts if you look at it sideways in the coastal Southeast. Buffer tubes also seem to attract condensation internally in my experience, and there is a popular brand of spring that I tried a few of and had lots of surface rust unless I cleaned it and wiped it down all the time. Also had that problem with a first-gen Tubbs, but not the second-gen. How much rust would it take to matter? I have no idea. Or maybe the concern is galvanic something something, again no idea. But it is easier for me to trust the engineers rather than internet strangers that disagree and say “ dremel it; it’ll be just as good”.
With all that said, I’d have no hesitation grinding one in a pinch to use short-term. I already use oil on the pin when I install it. Chamfering the edge seems like a good idea if you go that route. Seems kinda Bubba, though, in a world where the correct part exists and is cheap as heck.
I definitely have to agree with you. The hardware store isn’t the best place to be buying parts for any AR15/M4/M16. This reminds me of when a friend bought some cotter pins from Lowes and tried using them as a firing pin retaining pin. To say the least they didn’t hold up for long at all and caused his rifle to fail.
Its easy to mock, but there are probably reasons for the coatings and finishes where specified. For example, shit rusts if you look at it sideways in the coastal Southeast. Buffer tubes also seem to attract condensation internally in my experience,
Exactly.
and there is a popular brand of spring that I tried a few of and had lots of surface rust unless I cleaned it and wiped it down all the time.
Exactly why I stick to mil spec/Colt buffer springs. People are nuts with the aftermarket nonsense.
Exactly.
Exactly why I stick to mil spec/Colt buffer springs. People are nuts with the aftermarket nonsense.
Yup. Colt extractor, ejector, and buffer springs are the best available, IME. And cheaper than much of the competition. I think there is a time and place for some of the others, but that time and place is much more rare than many seem to believe.
the AR-15 Junkie
04-04-22, 13:24
Yup. Colt extractor, ejector, and buffer springs are the best available, IME. And cheaper than much of the competition. I think there is a time and place for some of the others, but that time and place is much more rare than many seem to believe.
I 100% agree with you!
The pin size is not on the drawing.
Sure it is. A post above gives the drawing number. The drawing clearly states it is from a MS16562-130 pin to the listed length on the drawing. The pin is 1/8". If someone did not want to bother looking up the pin from the given number flip to the buffer body drawing that shows the hole diameter before finish. Add the called out finish thickness with the 1/2 finish thickness penetration into the material and half the thickness buildup which closes the hole up to .125" which is 1/8". It is all on the drawings.
Sure it is. A post above gives the drawing number. The drawing clearly states it is from a MS16562-130 pin to the listed length on the drawing. The pin is 1/8". If someone did not want to bother looking up the pin from the given number flip to the buffer body drawing that shows the hole diameter before finish. Add the called out finish thickness with the 1/2 finish thickness penetration into the material and half the thickness buildup which closes the hole up to .125" which is 1/8". It is all on the drawings.
What’s the length?
the AR-15 Junkie
04-04-22, 18:04
Anyone have a McMaster Carr part# for the roll pin?
Per BCM- 1/8 x 5/8 slightly shortened.
Per Sionics- 1/8 x 11/16
Per Vltor- 1/8 x 11/16
Per KAK- 1/8 x 11/16
Per Colt- they could not tell me the size, only the part# and offered to send me one.
Per FN- no response
Only BCM mentioned shortening the slotted pin.
McMaster Carr sells a Mil-spec phosphate 1/8 x 5/8 slotted pin.
They also sell a zinc plated 1/8 x 11/16 pin that is not mil spec
Anyone have a McMaster Carr part# for the roll pin?
But, but... It won't have the mil spec 'wonder finish' on it unless it comes from Colt!
:)
What’s the length?
In Table 1 in the middle of the drawing, the -2 pin, Dimension L.
And, McMaster pins have the correct finish, at least those that state they are made to MS16562.
There are only two non-standard spring pins in an AR/M16/M4, the one in the buffer we are discussing and the one that goes in the charging handle for the latch and in the forward assist for the pawl. All the rest can be sourced by googling the "MS16562-XXX" part number.
In Table 1 in the middle of the drawing, the -2 pin, Dimension L.
And, McMaster pins have the correct finish, at least those that state they are made to MS16562.
There are only two non-standard spring pins in an AR/M16/M4, the one in the buffer we are discussing and the one that goes in the charging handle for the latch and in the forward assist for the pawl. All the rest can be sourced by googling the "MS16562-XXX" part number.
Are you referring to this drawing?
67707
[QUOTE=prepare;3024245]Are you referring to this drawing?
Number 6 is the pin on that drawing and you use the chart to look up the print number for it. 8448521. He posted the print number in an earlier post. One important thing on that drawing you posted is the note for the orientation of the opening in the spring pin. It is even more wonderful than the finish.
[QUOTE=prepare;3024245]Are you referring to this drawing?
Number 6 is the pin on that drawing and you use the chart to look up the print number for it. 8448521. He posted the print number in an earlier post. One important thing on that drawing you posted is the note for the orientation of the opening in the spring pin. It is even more wonderful than the finish.
Finally I'm tracking. Thank you!
In Table 1 in the middle of the drawing, the -2 pin, Dimension L.
And, McMaster pins have the correct finish, at least those that state they are made to MS16562.
There are only two non-standard spring pins in an AR/M16/M4, the one in the buffer we are discussing and the one that goes in the charging handle for the latch and in the forward assist for the pawl. All the rest can be sourced by googling the "MS16562-XXX" part number.
That would be 3 non standard pins
This would be the correct part number for pin right?
https://www.mcmaster.com/97855A160/
That would be 3 non standard pins
No, only two non-standard parts, one part is used in two different places.
This would be the correct part number for pin right?
https://www.mcmaster.com/97855A160/
The correct part number for the buffer is 8448521-1, which is a modified MS16562-130 spring pin.
The -130 spring pin starts life 0.750" long and is cut down to 0.709" to 0.729".*
If you can't find a 8448521-1 pin, then the MS16562-129 (5/8" long), is the best you are going to do.
_________
* Actually, they just have their spring pin provider setup the machine that makes spring pins to make them shorter than standard and run off a day or two worth of production.
The correct part number for the buffer is 8448521-1, which is a modified MS16562-130 spring pin.
The -130 spring pin starts life 0.750" long and is cut down to 0.709" to 0.729".*
If you can't find a 8448521-1 pin, then the MS16562-129 (5/8" long), is the best you are going to do.
_________
* Actually, they just have their spring pin provider setup the machine that makes spring pins to make them shorter than standard and run off a day or two worth of production.
Thank you for the information.
In Table 1 in the middle of the drawing, the -2 pin, Dimension L.
And, McMaster pins have the correct finish, at least those that state they are made to MS16562.
There are only two non-standard spring pins in an AR/M16/M4, the one in the buffer we are discussing and the one that goes in the charging handle for the latch and in the forward assist for the pawl. All the rest can be sourced by googling the "MS16562-XXX" part number.
Is MS16562 a requirement for all the pins?
These are the only ones that meet MS16562 https://www.mcmaster.com/ms16562/
Is MS16562 a requirement for all the pins?
These are the only ones that meet MS16562 https://www.mcmaster.com/ms16562/
MS16562 is the specification that covers all tubular, slotted, spring pins. So, if it is a tubular, slotted, spring pin, it has a MS16562-xxx part number.
You might what to get a copy of TM 9-1009-319-23&P, it has all the part numbers of the parts.
Oh, and there are other places that sell spring pins besides McMaster . . .
MS16562 is the specification that covers all tubular, slotted, spring pins. So, if it is a tubular, slotted, spring pin, it has a MS16562-xxx part number.
You might what to get a copy of TM 9-1009-319-23&P, it has all the part numbers of the parts.
Oh, and there are other places that sell spring pins besides McMaster . . .
McMaster doesn't have this part number MS16562-121 the forward assist roll pin
They have plenty of pins that size, just not MS16562
McMaster prices are around $10 while the other places are over $150
McMaster doesn't have this part number MS16562-121 the forward assist roll pin
They have plenty of pins that size, just not MS16562
McMaster prices are around $10 while the other places are over $150
https://i.imgur.com/dUTVexT.jpg
Just tossing this out there because:
https://www.spirol.com/product/coiled-spring-pins/
McMaster doesn't have this part number MS16562-121 the forward assist roll pin
They have plenty of pins that size, just not MS16562
McMaster prices are around $10 while the other places are over $150
There are other places besides McMaster . . .
https://www.huyett.com/products/fasteners/pins/spring-pins/spph-125-0625?searchText=
https://www.aircraftspruce.com/catalog/pnpages/04-01715.php?gclid=CjwKCAjw9LSSBhBsEiwAKtf0n6BaIGBeuzhtOsNE85wD6wbSIWe3INe6OZN5SCqnOBMdBSF_jGKyXxoCqaAQAvD_BwE
https://www.145.aero/MS16562-121-p/ms16562-121.htm
https://aerobase.store/hardware/slotted+pins/MS16562-121
And if you don't want to spend $35 for 100 pins, you can just but one here. (https://www.brownells.com/rifle-parts/receiver-parts/forward-assist-parts/ar-15-forward-assist-roll-pin-prod97620.aspx)
There are other places besides McMaster . . .
https://www.huyett.com/products/fasteners/pins/spring-pins/spph-125-0625?searchText=
https://www.aircraftspruce.com/catalog/pnpages/04-01715.php?gclid=CjwKCAjw9LSSBhBsEiwAKtf0n6BaIGBeuzhtOsNE85wD6wbSIWe3INe6OZN5SCqnOBMdBSF_jGKyXxoCqaAQAvD_BwE
https://www.145.aero/MS16562-121-p/ms16562-121.htm
https://aerobase.store/hardware/slotted+pins/MS16562-121
And if you don't want to spend $35 for 100 pins, you can just but one here. (https://www.brownells.com/rifle-parts/receiver-parts/forward-assist-parts/ar-15-forward-assist-roll-pin-prod97620.aspx)
Are there any real differences between this https://www.mcmaster.com/98296A849 and this https://www.145.aero/MS16562-121-p/ms16562-121.htm?
In Table 1 in the middle of the drawing, the -2 pin, Dimension L.
And, McMaster pins have the correct finish, at least those that state they are made to MS16562.
There are only two non-standard spring pins in an AR/M16/M4, the one in the buffer we are discussing and the one that goes in the charging handle for the latch and in the forward assist for the pawl. All the rest can be sourced by googling the "MS16562-XXX" part number.
So the pin for the charging handle latch and the forward assist pawl are the same size?
What size do they start out as?
Are there any real differences between this https://www.mcmaster.com/98296A849 and this https://www.145.aero/MS16562-121-p/ms16562-121.htm?
Black oxide vs black phosphate.
If your dealing with quality spring pins, you are dealing with either ASME B18.8.2 or NASM16562 spring pins (tubular slotted). The two specifications are comparable in regards to strength, and quality. The major differences are B18.8.2 has more sizes available and the finish specified.
NASM16562 allows three types of finish, phosphate, cadmium, or passivated CRES. B18.8.2 does not specify any finish, allowing the purchaser to request any finish desired. Normally, for steel pins, that black oxide.
B18.8.2 also discusses beryllium copper spring pins.
So the pin for the charging handle latch and the forward assist pawl are the same size?
What size do they start out as?
MS16562-97
…the [non-standard spring pin] that goes in the charging handle for the latch and in the forward assist for the pawl.From what I can find, these are just a smidge longer than a standard 1/16” x 1/4” size roll pin: they’re supposed to be 0.257–0.277” long versus 0.235–0.265”. Apparently the same material thickness (.012”) etc. Any idea why someone went to the trouble of specifying a non-standard pin just for the sake of an additional 0.017” in nominal length? The allowed lengths even overlap….
I’ve tried buying these things from several vendors, and measuring them now, every one I’ve received is just a regular 1/16 x 1/4.
So the pin for the charging handle latch and the forward assist pawl are the same size?
What size do they start out as?McMaster doesn’t list the -97 pin (5/16”), but they do show the -98 (3/8”), so if you wanted to grind one down yourself to 0.267”, you could start there instead.
MS16562-97
Is this pin altered for both the pawl and the charging handle latch?
Is this pin altered for both the pawl and the charging handle latch?
Both the CH & FA use Pin, p/n 8448521-2.
Both the CH & FA use Pin, p/n 8448521-2.
Thank you again.
From what I can find, these are just a smidge longer than a standard 1/16” x 1/4” size roll pin: they’re supposed to be 0.257–0.277” long versus 0.235–0.265”. Apparently the same material thickness (.012”) etc. Any idea why someone went to the trouble of specifying a non-standard pin just for the sake of an additional 0.017” in nominal length? The allowed lengths even overlap….
I’ve tried buying these things from several vendors, and measuring them now, every one I’ve received is just a regular 1/16 x 1/4.
Because the FA pawl is under a fairly high load they needed to ensure that the pin actually spanned the gap. The pawl gap is 0.155" wide, and is you push a 0.25 long pin flush to the side of the plunger you are only engaging the tapered edge of the pin. You can have no engagement at all if the pin is at the short end of the tolerance.
If you use the -2 pin, you will always have engagement with the cylindrical portion of the pin.
The same is the case with the CH, and while not loaded heavily, it is softer aluminum.
Can you get away with a 1/4 inch pin? Yes, if you are careful to make sure there is full engagement on both sides. For production, it is better for both cost and quality to just make it so when one side is flush, you have adequate engagement.
Black oxide vs black phosphate.
If your dealing with quality spring pins, you are dealing with either ASME B18.8.2 or NASM16562 spring pins (tubular slotted). The two specifications are comparable in regards to strength, and quality. The major differences are B18.8.2 has more sizes available and the finish specified.
NASM16562 allows three types of finish, phosphate, cadmium, or passivated CRES. B18.8.2 does not specify any finish, allowing the purchaser to request any finish desired. Normally, for steel pins, that black oxide.
B18.8.2 also discusses beryllium copper spring pins.
Is phosphate superior to the ASME B18.82 finishes?
Is phosphate superior to the ASME B18.82 finishes?
Zinc phosphate is generally considered a better finish for resisting corrosion than black oxide. But, it is not like it won't rust at all.
But, like I said B18.8.2 doesn't specify any finish, so you can find B18.8.2 pins with a phosphate finish.
Because the FA pawl is under a fairly high load they needed to ensure that the pin actually spanned the gap. The pawl gap is 0.155" wide, and is you push a 0.25 long pin flush to the side of the plunger you are only engaging the tapered edge of the pin. You can have no engagement at all if the pin is at the short end of the tolerance. Thanks for the explanation. I just examined a forward assist, and I can see what you’re saying here.
My sample of Colt pins measure 0.725
67812
the AR-15 Junkie
04-12-22, 17:03
My sample of Colt pins measure 0.725
67812
Nice post, thanks for confirming that.
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