I shoot all of my ar15/10's suppressed. I am running h3 buffers in all to slow it down and most have adjustable gas blocks. Is there any downside to a h3 or any benefit to a lighter buffer if the rifles run fine with an h3 suppress or unsuppressed?
- Thread starter flyfisherman246
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If it works then dont change it. You never mentioned barrel lengths. That is the most important factor to what buffer you 'should' need. H3 is a heavy buffer that is usually best for 14.5 and under barrels when running a suppressor. 14.5 and over the H2 will work just fine suppressed or unsuppressed. Refer to the Geissele chart below. I have found it to be pretty accurate. I also run their buffer's and springs though.
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dave is on the hide as well, can’t remember his user off hand though.
I’ve been playing around with this as a winter project and I’m not sure if I fully agree with this. I have a 16” PWS w/ can, and stock, it ships with an H2 buffer. Even with the gas port at the highest setting (or maybe it’s lowest, I’m still trying to wrap my brain around this), the system is still quite over gassed. I tried an H3 and it really smoothed the system out, and I’m going to try an H4 on my next range trip.
Though more mass is moving, if the lighter buffer is slamming back to the tube, I think recoil could be higher with a lighter buffer.
* my understanding and experience is subject to change
Why does JP market an ultralight carrier system? How do 3 gunners set up their rifles for rapid follow ups?
Let me add that if your system is overgassed with a light buffer, then going to a heavier buffer will smooth it out. But, reducing the amount of gas in the system with a good adjustable gas block- using the light buffer- will give you a lighter recoiling gun than adding a heavy buffer with the greater amount of gas.
Changing the buffer will necessitate a change to the gas setting on the adjustable gas block the OP says he has on his gun. If his gun is running how he wants it to run, then I wouldn't change it. But, he should be able to get a somewhat lighter recoiling rifle with a lighter buffer, but it is a system change- not just a part swap.
Changing the buffer will necessitate a change to the gas setting on the adjustable gas block the OP says he has on his gun. If his gun is running how he wants it to run, then I wouldn't change it. But, he should be able to get a somewhat lighter recoiling rifle with a lighter buffer, but it is a system change- not just a part swap.
This. If a gun has an adjustable gas block, I see zero reason to use an H3 buffer. The same rifle should be tunable for a C buffer or at most an H, for the same function and less movement at the shot. There is a really good reason some guys use light weight carriers and buffers.
I’ll add some further thoughts to this. First off, I’m personally running a PWS gas piston system with adjustable gas block. There are 4 gassed settings (1-4) and a fifth setting that passes all gas and thus disables the semi-auto function. At the 4th setting, the setting that releases most of the gas possible, with a suppressor and hotter loads, I’m still over gassed. I feel the buffer slam and my ejected cases are fairly smoked. Increasing the reciprocating mass (moved from a stock H2 to H3) lessens this, and smooths out the felt recoil of the rifle. I’m suspecting moving to an H4 will allow for use of some of the other gas setting on the adjustable gas block.
The other way this can be dealt with, if one’s system allows is opening up the gas port more and lightening the loads. At that point, if there’s room for tuning, then lightening the reciprocating mass can be beneficial.
Again... I’m still learning, so this is subject to revision.
The other way this can be dealt with, if one’s system allows is opening up the gas port more and lightening the loads. At that point, if there’s room for tuning, then lightening the reciprocating mass can be beneficial.
Again... I’m still learning, so this is subject to revision.
That is an issue of a poorly matched "selectable" gas block on your rifle, and does not reflect what an adjustable gas block on a normal DI AR15 does. Your issue is specific to that rifle, and unfortunately you're pretty much at the mercy of the manufacturer or trying to swap buffers. That kind of thing is one good reason not to go with a piston system; if it was a DI system you'd have a huge selection of gas blocks to choose from that are able to restrict the gas as much as you need.
I’m not sure I’d go to the extent of describing this as “poorly selected”. Just different ways to approach solving the problem; and yes, piston systems have a different set of things to tune. I’ve run DI guns with fully adjustable gas blocks (like JP) and I’ve run several different piston systems (Ruger and LWRC). PWS recommends and provides the parts to tune a system accordingly, and does recommend moving to an H4 buffer (from the stock H2) when running hot loads and a suppressor
Also, adding mass is something done by several of the national level shooters at my club. It was explained as a method to increase dwell time. Heck, obe of our clubs top competitive long range shooters was explaining why many of them are starting to use not only heavier buffered, but heavier BGCs for the sake of pushing 80gr bullets out to 1000y. Thus I’m experimenting and sharing some personal experience.
I think there’s a few approaches you can go with AR’s.
Standard gas port, standard weight bolt and h1-4 buffet to get it just right.
Example being my 18” SPR build with a cold weather influenced gas port, standard bolt and B5-H3 buffer- its a sweet shooting rifle and reliable in any conditions or ammo but no gamer gun.
Gamer gun with gamer gas port, light bolt and buffer.
Super smooth and fast shooting.
Is it going to be reliable in reality cold weather or when filthy or with any ammo?
I’m doubtful.
It’s all about compromises.
Standard gas port, standard weight bolt and h1-4 buffet to get it just right.
Example being my 18” SPR build with a cold weather influenced gas port, standard bolt and B5-H3 buffer- its a sweet shooting rifle and reliable in any conditions or ammo but no gamer gun.
Gamer gun with gamer gas port, light bolt and buffer.
Super smooth and fast shooting.
Is it going to be reliable in reality cold weather or when filthy or with any ammo?
I’m doubtful.
It’s all about compromises.
Never heard of a "gamer gas port", but most gamers do use AGB's..........................
And that's what the AGB's are for...................fine tuning a given setup & being able to tweak it on demand as circumstances may change.
On every Di gun that I own (double digits) that have an AGB, I run carbine (3 oz) buffers or lighter with either a full weight BCG or a reduced weight BCG, with never more spring weight than a standard Sprinco white spring.................never don't work, never.
On other guns w/o an AGB, then I will use an H1 or 2 buffer & a different spring as needed for that particular gun.
Never don't work either.
MM
And that's what the AGB's are for...................fine tuning a given setup & being able to tweak it on demand as circumstances may change.
On every Di gun that I own (double digits) that have an AGB, I run carbine (3 oz) buffers or lighter with either a full weight BCG or a reduced weight BCG, with never more spring weight than a standard Sprinco white spring.................never don't work, never.
On other guns w/o an AGB, then I will use an H1 or 2 buffer & a different spring as needed for that particular gun.
Never don't work either.
MM
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My gas port on my SPR barrel is .104.
The two guys I know doing 3 gun I believe are running high80’s low 90’s with the same length and rifle gas.
both those rifles are incredibly smooth shooting.
I can guarantee that heavier buffers (and BCG's) increase recoil. I've done quite a lot of testing swapping stuff around, and the effect is quite pronounced.
Buffer and BCG weight contribute to reliability. Increasing the reciprocating mass will help a dirty gun function longer before it quits due to accumulated crud. You pay the price for that with increased recoil.
Buffer and BCG weight contribute to reliability. Increasing the reciprocating mass will help a dirty gun function longer before it quits due to accumulated crud. You pay the price for that with increased recoil.
I use heavier buffers in both 5.56 mid-lengths and 7.62 rifles. They seem to help keep the sights on target by reducing perceived recoil, and help to extend brass life.
.103-.105" is pretty normal on 18-20: rifle gas. I have a new 18" WOA on the bench that measure .105"
Smaller than that on the same barrel would be a special size.........................my mid-gas & intermediate gas 18" barrels are .093-,096".
You can get your .104" port rifle gas gun to shoot very smooth & soft too with the right combo buffer & spring & an AGB; I've gone as low as 2.1 oz on the buffer, light BCG & a Sprinco spring one step softer than standard (yellow), with an AGB, works fine when tuned correctly.
Gas flow to the BCG is gas flow to the BCG, whether you get it from a smaller gas port size or by using an AGB, the end result is more or less the same as far as recoil perception & muzzle movement goes..
MM
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I didn't say "poorly selected". I said you have a "selectable" gas block (as opposed to screw adjustable like most DI gas blocks) that is poorly matched to the rifle. If you have to go up to an H4 buffer because the gas block can't restrict or bleed off enough gas, the block is poorly matched to that application; it won't do the job it's intended to do. When the gas system is tuned right, there is no reason to use a buffer that heavy, and it is a disadvantage. Not all manufacturers do this stuff right, and some of the popular names do some goofy stuff.
The dwell time argument is a common one, but somewhat misleading as well. (Also it's not increasing dwell time, it's delaying unlocking; not the same thing.) Delayed unlocking is important, but you get that by restricting the gas flow with a standard carbine buffer too. Heavy buffers are not unique in that regard.
Refer back to my earlier analogy of driving your car with the throttle to the floor.
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If a race car/motorcycle's shock compression valving is too firm you don't handicap the car and add weight to to accommodate poor valving, and if the rebound valving is excessive you don't increase spring rate and compromise grip to accommodate poor valving... you change the valve stack pressure curves. Less is more IMO.
Any extra heavy buffers (9 to 10 oz) were designed for guys like me, obsessed with shooting the heaviest bullet as fast as they can out of a AR.
I’m finding out that QuickLoads is your friend (and enemy) when it comes to reloading for an AR10/LR308.
With my 45 Raptors, I’m at the point where an Extra Heavy buffer (9-10oz), Tubbs Flatwire, and a standard weight BCG, are the only way to get the gun to operate when launching a 250 grain bullet at 2600-2700 FPS. A rifle gas system, or a +2 rifle, is also a must have when using longer barrels, due to dwell time.
Now that I’m getting into reloading for my (2) 6.5 Cm AR’s, I’m finding that the more I push the envelope...the more I need a Extra Heavy Buffer...and wish I had a +2 Rifle gas system, on my 22” and 24” 6.5 CM barrels.
Using QuickLoads, it shows you that even with the same barrel length, the bore/load pressure is much higher in a 6.5 Cm than a 45 Raptor.
BUT...I’m shooting a 250 grain bullet at 2650 FPS in the Raptor, and a 140 grain bullet at 2850, in the 6.5 CM.
What I’m seeing between the 6.5CM and the 45 Raptor, is that dwell time and unlock time are my 2 greatest variables to account for.
Here’s the challenge I’m facing... using (2) Xanthos guns (lightweight), using Titanium BCG’s, and JP-SCS or Armaspec buffers...
In the 6.5 CMs, the titanium BCG’s, along with the JP-SCS/Armaspec, the guns can be tuned pretty good with standard Hornady loads.
But with reloading, a lot of that goes out the window.
With reloading in the 6.5 CM, (yes, for speed and accuracy...ok but I’m looking for speed mainly...
the barrel pressures at the gas block increase. And the unlock time SEEMS to decrease. And what is fixing it?...extra heavy buffers and full weight BCGs.It’s to the point now, that when it comes to reloading for an AR10/LR308, the +2 Rifle gas system, should be a pre-requisite..and a +3 Rifle would be even better
Because when it comes to reloading for speed (yes, and accuracy) with the 6.5 CM in the AR platform, the rifle gas system is difficult to tune for.
Rifle +1 or +2 with an adjustable gas block are your friends in the AR platformAny extra heavy buffers (9 to 10 oz) were designed for guys like me, obsessed with shooting the heaviest bullet as fast as they can out of a AR.
I’m finding out that QuickLoads is your friend (and enemy) when it comes to reloading for an AR10/LR308.
With my 45 Raptors, I’m at the point where an Extra Heavy buffer (9-10oz), Tubbs Flatwire, and a standard weight BCG, are the only way to get the gun to operate when launching a 250 grain bullet at 2600-2700 FPS. A rifle gas system, or a +2 rifle, is also a must have when using longer barrels, due to dwell time.
Now that I’m getting into reloading for my (2) 6.5 Cm AR’s, I’m finding that the more I push the envelope...the more I need a Extra Heavy Buffer...and wish I had a +2 Rifle gas system, on my 22” and 24” 6.5 CM barrels.
Using QuickLoads, it shows you that even with the same barrel length, the bore/load pressure is much higher in a 6.5 Cm than a 45 Raptor.
BUT...I’m shooting a 250 grain bullet in the Raptor, and a 140 grain bullet in the 6.5 CM.
What I’m seeing between the 6.5CM and the 45 Raptor, is that dwell time and unlock time are my 2 greatest variables to account for.
Here’s the challenge I’m facing... using (2) Xanthos guns (lightweight), using Titanium BCG’s, and JP-SCS or Armaspec buffers...
In the 6.5 CMs, the titanium BCG’s, along with the JP-SCS/Armaspec, the guns can be tuned pretty good with standard Hornady loads.
But with reloading, a lot of that goes out the window.
With reloading in the 6.5 CM, (yes, for speed and accuracy...ok but I’m looking for speed mainly...
It’s to the point now, that when it comes to reloading for an AR10/LR308, the +2 Rifle gas system, should be a pre-requisite..and a +3 Rifle would be even better
Because when it comes to reloading for speed (yes, and accuracy) with the 6.5 CM in the AR platform, the rifle gas system is difficult to tune for.
.104 is bigger than I would want for an 18” barrel but it’s common. .093” is the largest I would want in a 20” or really even an 18”.
I had a 17” .093” rifle that functioned great with 5.56 but got sluggish with 223. Adding a two baffle low backpressure moderator made it cycle like an unsuppressed gun. A buddy does 16.5 rifles with an OPS 12th model and .077” gas port.
You only need an AGB if your gas port is the wrong size. It’s only advantage is that it’s cheaper than R&D.
I had a 17” .093” rifle that functioned great with 5.56 but got sluggish with 223. Adding a two baffle low backpressure moderator made it cycle like an unsuppressed gun. A buddy does 16.5 rifles with an OPS 12th model and .077” gas port.
You only need an AGB if your gas port is the wrong size. It’s only advantage is that it’s cheaper than R&D.
Aaaand that's why you are having to use heavy buffers in it now.
Heavy buffers were primarily designed to delay unlocking in applications where people don't want to or can't tune the gas system correctly. Tuning the gas system is still the better option when possible. It doesn't matter if you want to shoot weak 223 ammo, or "the heaviest bullet at the fastest speed" as you put it; the gas can be tuned correctly for either one without resorting to really heavy buffers.
It's your rifle, but IMO it's a crying shame that you've taken a Xanthos with a Ti carrier and installed a heavy buffer and full mass carrier, instead of adjusting the gas to match your loads. That's like driving around in a Ferrari and holding the brakes down the whole time to control your speed.
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News flash - there is no perfect gas port size to work with every load and rifle configuration. If you and I have the same barrel, I might choose to use a powder like Lever that produces more gas, and you might choose Varget. My barrel will need a smaller gas port to be perfect. Or maybe I'll choose to use the same ammo as you, but also use a suppressor; I'll need a smaller gas port.
This idea that gas adjustment is only necessary if you bought junk is ignorant BS.
Absolutely.............
And running a Ti BCG & then adding huge lead sledgehammer for a buffer defeats the purpose of the Ti BCG in the 1st place.
If one wants a light BCG, then generally the direction would be with a (relatively) lighter buffer with tuned gas, ie an AGB...............all with the objective of reducing felt recoil.
Going with a light BCG & a heavy buffer + a larger gas port shows a basic lack of understanding the system.
MM
I’m using a full size BCG, and the 9 oz buffer with the 45 Raptors
With the 6.5 CMs, 24” barrel rifle gas barrel, and reloads, I’m learning that the 9oz buffer is required with the Titanium BCGs, or I have problems and trashed brass...
What would you guys recommend I use in my 24” 45 Raptor barrels?
How about the 24” 6.5 CM with rifle gas, pushing 140 ELDs at 2850?
Factory Hornady 6.5 CM with 140 ELDs are right at 2750 FPS..
No worries about unlock time with reloads?
With the 6.5 CMs, 24” barrel rifle gas barrel, and reloads, I’m learning that the 9oz buffer is required with the Titanium BCGs, or I have problems and trashed brass...
What would you guys recommend I use in my 24” 45 Raptor barrels?
How about the 24” 6.5 CM with rifle gas, pushing 140 ELDs at 2850?
Factory Hornady 6.5 CM with 140 ELDs are right at 2750 FPS..
No worries about unlock time with reloads?
Most of the little differences are lost in the noise by the time you have a port that works in the cold. Just pick a pressure and stick to it. Once you realize wolf is essentially a different and inferior caliber, you don’t need it to work with everything.
I agree...tell that to Christensen...
20” .260 Rifle +2 JP Full Mass BCG and SCS with superlative arms AGB. Shoots Prime 130’s around 2775 suppressed and unsuppressed.
All of your problems with those setups and your need to use heavy buffers are because your rifles are overgassed. Use some sort of gas restriction (adjustable gas block, or other methods) to control the gas and you can get rid of the heavy buffers. Adjust the gas to work with the loads you want to shoot.
It's a real shame to use a 9 oz buffer with a Ti bolt carrier; you've completely unbalanced an otherwise well set up rifle and adding weight to an expensive light weight carrier doesn't make any sense.
No. LOL.
You really seem to be stuck on this idea that there is one port size that will work for everything. It's wrong. There are many ways to set up an AR, and the resulting gas system needs vary a lot.
A perfect example of that is Earnhardt's rifle with the Ti bolt carrier. A lightweight bolt carrier needs less gas (i.e. either a smaller gas port or a correctly adjusted gas block, which are both the same result); he's adding buffer weight because he doesn't have the gas adjusted right. That's not a small difference, it's the difference between functioning correctly and not.
Your idea of setting up a barrel with the perfect gas port size does work if you're building a whole system and selecting a gas port size for one particular load. I've done that with several barrels I've made for rifles that will only ever shoot one thing; those rifles are tuned perfectly for that load and that action setup because I worked up to the right gas port size using that ammo in that rifle until it was correct. However, that's the exception, not the rule, and most end up a little overgassed for a standard setup and ammo, and can be severely overgassed with certain combinations of action parts, ammo, and suppressors.
That still doesn't mean your gas & recoil system is optimized...........................
MM
.875 would be the standard for a 6.5
Port size?
Your talking gas block size
Heavier reciprocating mass can cause a kinda funky nosedive between shots .
I still usually lean to heavier buffers than light. With my creedmoor even with an agb I was getting more brass damage than I liked. Going to a xh buffer took care of it.
There's no one gas setting or port size that's perfect for every load and suppressor but it seems like going heavier on the reciprocating mass makes the gun less finicky than going lighter.
I still usually lean to heavier buffers than light. With my creedmoor even with an agb I was getting more brass damage than I liked. Going to a xh buffer took care of it.
There's no one gas setting or port size that's perfect for every load and suppressor but it seems like going heavier on the reciprocating mass makes the gun less finicky than going lighter.
So there is a lot of miscommunication on here about how a heavier or lighter buffer will change the amount of recoil. The only thing that will change that is tuning the gas coming back into the system. A fixed gas port gun will have the same amount of recoil with either a C or an H3 buffer.
HOWEVER, changing buffer weight CAN change how you distribute that recoil over the duration of the operating cycle. A heavier buffer means more weight moving rearward but will slow the speed of that moving mass thereby lessening the secondary recoil impulse that occurs when the moving parts bottom out in the rear of the rifle and transfer their remaining energy to your shoulder. If you have ever shot a semi rifle that seems to give you a sharp slap on the shoulder even when you are holding it tight then you have experienced that sharp secondary recoil when the moving parts reach their rearward most point of travel. Many AK rifles are a good example of this.
A heavy buffer will also increase dwell time as noted above. If you are trying to save and reload brass this may help you as it makes your ejection of the brass less violent.
It is important when choosing a heavier buffer to make sure that the rifle will still cycle. Load one round into the mag and shoot it to confirm that the rifle locks open. If it doesn’t your buffer is too heavy. Also take some chilled rounds to the range with you in a cooler with ice/dry ice. Shoot these as most bulk ammo uses ball powder and will exhibit lower pressures with decreased temps. Where I live we can see temps below zero all the way up to above 100 so it is very important for me to check that my rifles will function in all situations.
Any questions please PM. I just switched my main gun from a C buffer to an H3 and it smoothed out beautifully and ejects consistently to the 3 o’clock.
HOWEVER, changing buffer weight CAN change how you distribute that recoil over the duration of the operating cycle. A heavier buffer means more weight moving rearward but will slow the speed of that moving mass thereby lessening the secondary recoil impulse that occurs when the moving parts bottom out in the rear of the rifle and transfer their remaining energy to your shoulder. If you have ever shot a semi rifle that seems to give you a sharp slap on the shoulder even when you are holding it tight then you have experienced that sharp secondary recoil when the moving parts reach their rearward most point of travel. Many AK rifles are a good example of this.
A heavy buffer will also increase dwell time as noted above. If you are trying to save and reload brass this may help you as it makes your ejection of the brass less violent.
It is important when choosing a heavier buffer to make sure that the rifle will still cycle. Load one round into the mag and shoot it to confirm that the rifle locks open. If it doesn’t your buffer is too heavy. Also take some chilled rounds to the range with you in a cooler with ice/dry ice. Shoot these as most bulk ammo uses ball powder and will exhibit lower pressures with decreased temps. Where I live we can see temps below zero all the way up to above 100 so it is very important for me to check that my rifles will function in all situations.
Any questions please PM. I just switched my main gun from a C buffer to an H3 and it smoothed out beautifully and ejects consistently to the 3 o’clock.
I don't understand how a heavier buffer will increase dwell time. Unlocking time, yes, but isn't the bullet already out of the barrel & your pressure at zero by then? How can the gas travel ¾ the distance back down the barrel length (gas tube) before the bullet makes it like 4" & is gone?
I thought dwell time was the amount of time from when the bullet passes over the gas port, and allows gas into the gas tube/action, to when the bullet exits the barrel.
So therefore dwell time doesn't change unless the gas port is moved
So therefore dwell time doesn't change unless the gas port is moved
... or the end of the barrel is moved, haha!
Correct, dwell time is the time between the gas port being pressurized and the bullet exiting. However, note that the bullet is moving at 2500-3000fps and the gas is moving at 4500-5000fps. That’s why porting and buffering matter, increasing the amount of gas and time it takes to pressurize against the piston and move the carrier.
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