Making a Muzzle break for the FX M3

[Lewis]

What recoiling canceling device is used in the second video? It looks to be very effective.

 

[thomasair]

It was an experiment. It was a donut shaped brass weight that slid inside the shroud on Teflon over the barrel. The muzzle blast blew it rearward.

It worked great…but it did not help me “see” the pellet in flight….which was the purpose of the experiment.

Mike

 

[Lewis]

Sounds great. I would have thought it would help to see the pellet in flight. Did it effect accuracy +/-?

 

[qball]

Here’s a 12 fpe FT gun held in sitting position….one with a barrel shroud, and one with a recoil canceling device. Slow motion. Somewhere I have a muzzle brake video too…and it’s somewhere in between the two shown.

Muzzle brakes significantly reduce recoil even in 12 fpe guns tuned to a 1.25 fpe/cu in level.
Mike

I had similar or slightly better result by simply adding a 39 oz scope(+5oz rings) on mine, also at 12 FPE.

I shot @motorhead’s 20 FPE version with his custom valve and it is unbelievably settled or basically dead, even more so than mine with over 2 lbs of extra weight. It is also unbelievably quiet with just the shroud, dead give away of a superbly efficient tune. My 12 FPE gun with same exact shroud is SIGNIFICANTLY louder compared to @Motorhead's gun which has almost twice the power.

 

[OldSpook]

I will just have to agree to disagree with that....I have seen high speed photos showing a air rifle when fired with a moderator installed and the turbulent cloud of air is still prevalent....in my opinion a moderator does not have enough volume to completely capture enough of that turbulent air to completely eliminate it........and....you know what they say about opinions......

=) Yep, everyone has one.

I think you are right. It would take a very large moderator to completely eliminate that puff of air or some very carefully designed and tested baffles. Here is what I think is happening in the case you mention. First the puff exits the muzzle and the pellet follows it. If there is a stripper positioned just so it will scrape off that puff of air and clean up the path. In the case of a stripper it is problem solved and job done. In the case of a moderator there is nowhere for that puff to go. You can redirect it but you can't remove it. It adds a bit to the pressure spike inside the tube but it isn't the real problem because you have stripped it off and it is behind the projectile. The projectile is now somewhere down the tube and the gas behind it is expanding into the moderator and building up pressure. That pressure front travels faster than the pellet and will overtake it if it remains in the moderator long enough. Timing becomes very important. You could build something which improved accuracy with one tune and made it much worse with a different tune on the same gun. With worst case timing the pressure front and the pellet meet at the exit of the moderator. With best case timing you manage to slow that pressure front down enough and keep the pellet path short enough so that the pellet exits the tube before the pressure spikes and blows out the exit of the moderator. You are trading suppression for accuracy if you get it right.

We are not really in disagreement here. Just looking at the problem from different angles.

NOTE: To place the time frame we are discussing in context, it takes about 0.00044 seconds for a pellet exiting the muzzle at 900 fps to traverse the length of a moderator that is 120mm long.

 

[DBlue]

=) Yep, everyone has one.

I think you are right. It would take a very large moderator to completely eliminate that puff of air or some very carefully designed and tested baffles. Here is what I think is happening in the case you mention. First the puff exits the muzzle and the pellet follows it. If there is a stripper positioned just so it will scrape off that puff of air and clean up the path. In the case of a stripper it is problem solved and job done. In the case of a moderator there is nowhere for that puff to go. You can redirect it but you can't remove it. It adds a bit to the pressure spike inside the tube but it isn't the real problem because you have stripped it off and it is behind the projectile. The projectile is now somewhere down the tube and the gas behind it is expanding into the moderator and building up pressure. That pressure front travels faster than the pellet and will overtake it if it remains in the moderator long enough. Timing becomes very important. You could build something which improved accuracy with one tune and made it much worse with a different tune on the same gun. With worst case timing the pressure front and the pellet meet at the exit of the moderator. With best case timing you manage to slow that pressure front down enough and keep the pellet path short enough so that the pellet exits the tube before the pressure spikes and blows out the exit of the moderator. You are trading suppression for accuracy if you get it right.

We are not really in disagreement here. Just looking at the problem from different angles.

No problems here.....as you and I and anyone else that has experimented with tuning rifles and trying various barrel devices, know, that there is no exact science involved and no one device that's going to be a cure all for perfect accuracy, just too many variables at play. I've got several trash cans full of failed devices that I have made over the years...I can definitely tell you lots of things that don't work....LOL

 

[bigHUN]

I am a fan of airstrippers and I have several, modified some of them.
My take is that helps shaving off the air in front of pellet/slug. Imagine a 700 liner or barrel full of air need to empty ... I can confirm that the pellets speed is 20-30 fps higher with an air stripper.
I have these, and I just got a new one that I started testing this week.
The important is a hole gap to bullet, also the distance from muzzle to cone edge.

 

[qball]

No amount of tuning removes that puff of air which PRECEEDS the exit of the projectile from the bore. Agreed tuning makes an enormous difference. It might be that there is more going on here than you have considered? I have exceptionally experienced shooters testing my strippers. They are reporting the accuracy of their otherwise exceptionally well tuned and maintained rifles does improve when one of the strippers we are working on is installed. I don't have any knowledge about your experience shooting competition so I won't argue with your opinion but that is what I am being told by the guys doing the tests. I have not personally tried to prove what they have told me because I don't have time to spend a bunch of time on an indoor range.

The puff of air precedes the projectile is called blow by and usually is very little and projectile and barrel combo specific. Generally a standard land and groove barrel tends to have that while smooth polygon barrels have less. Sometimes even pellet skirts do not fill all the way to full depth of grooves and obviously slugs are much worse, I've recovered pellets with only marking from lands but not grooves.

I'm not saying air strippers don't work, I'm saying it's for that possible last 1%. However to have air stripper work properly then you can't use a moderator which is a huge no no for me, noise is why I don't like shooting PB. An air stripper inside of a moderator would be ideal compromise/solution but unless someone has the ability to do custom work it's really not feasible/practical as the stripper needs to be fairly close to the muzzle plus bore size tolerance has to be very tight to be effective.

Back to my original point of focus on the tune first, an efficiently tuned gun will have very little muzzle blast/report. My Impact and Crown shooting at 70-80 fpe are pretty quiet with just my 3D printed moderators. However the muzzle report changes significantly if the tune is jacked up. Even the great Tedholdover has mentioned to use our ears when tuning in one of his tuning how to videos.


Muzzle break for recoil control is a separate lengthy discussion.

 

[OldSpook]

The puff of air precedes the projectile is called blow by and usually is very little and projectile and barrel combo specific. Generally a standard land and groove barrel tends to have that while smooth polygon barrels have less. Sometimes even pellet skirts do not fill all the way to full depth of grooves and obviously slugs are much worse, I've recovered pellets with only marking from lands but not grooves.

I'm not saying air strippers don't work, I'm saying it's for that possible last 1%. However to have air stripper work properly then you can't use a moderator which is a huge no no for me, noise is why I don't like shooting PB. An air stripper inside of a moderator would be ideal compromise/solution but unless someone has the ability to do custom work it's really not feasible/practical as the stripper needs to be fairly close to the muzzle plus bore size tolerance has to be very tight to be effective.

Back to my original point of focus on the tune first, an efficiently tuned gun will have very little muzzle blast/report. My Impact and Crown shooting at 70-80 fpe are pretty quiet with just my 3D printed moderators. However the muzzle report changes significantly if the tune is jacked up. Even the great Tedholdover has mentioned to use our ears when tuning in one of his tuning how to videos.


Muzzle break for recoil control is a separate lengthy discussion.

Ok, you and I will just have to disagree on a lot of this.

I am NOT talking about "blow by". There is practically no blow by in an airgun because the pellet obturates and seals the barrel. The puff of air is the air pushed out of the barrel by the pellet as it accellerates down the barrel. That volume is easily calculated. It is the radius of the caliber squared times the length of the bore and in a longer barrel can be quite substantial. For example in an 500mm barrel of 5.5 caliber. That volume is almost exactly 3.75 CC. It of necessity is traveling at the same speed as the pellet (something like 600 mph) as it exits the muzzle and is quite turbulent. That air is in front of the pellet, and is slowing down rapidly. The pellet has no other path than through that cloud unless that air is stripped. How much benefit there is, could be measured by laborious testing and a bunch of math. Feel free to do that and prove it for yourself. Then you will be speaking with some authority about how much difference it makes. I can't so... worse than that I am just going to trust the guys who are shooting the test moderators. They like them a lot. How much, "And the little air strippers... they are incredible! Stupid, crazy, STUPID accurate!!!!" So I dunno bud, you and I are going to have to disagree about how well they work. That's not a problem for me and most likely no problem for you as I know you to be as humble a man as I am...

As for having a stripper "work properly then you can't use a moderator"... again there is a trade off there between accuracy and moderation. The stripper DOES work inside a moderator. That is what we have experienced. It is a tougher problem to crack. Timing becomes a real issue and (I will repeat) that means even a gun's tuning can make the whole system fail. I don't believe bore size is as critical as you believe it to be. You can build a $200.00 stripper and it should work better than a $20.00 stripper. That does not mean the one does not work. It means it cost 90% less and you have traded one design criteria for another. The CUSTOMER then decides if it works well enough for his purposes.

I do think the shooter should be aware that the moderator can totally screw up his tune, especially if the pellet and that pressure front formed inside the tube meet at the exit end of the moderator. If that happens ES goes up and accuracy goes to crap. So the shooter should make sure his rifle is shooting well and then attach the moderator. He should at that point double check his accuracy BEFORE he does anything else. If the accuracy is still there he is golden and can tweak his tune. If it isn't he will know the moderator is degrading his accuracy and can either adjust his tune or try a different moderator.

Now if you come back and tell me you have a degree in mechanical engineering, some serious math credentials and you've been winning matches for 20 years I promise I will take everything I have said back. OK? (Naw, I won't but it sounds good) Meanwhile, let's you and I respect each other's opinion and experience.

 

[qball]

Ok, you and I will just have to disagree on a lot of this.

I am NOT talking about "blow by". There is practically no blow by in an airgun because the pellet obturates and seals the barrel. The puff of air is the air pushed out of the barrel by the pellet as it accellerates down the barrel. That volume is easily calculated. It is the radius of the caliber squared times the length of the bore and in a longer barrel can be quite substantial. For example in an 500mm barrel of 5.5 caliber. That volume is almost exactly 3.75 CC. It of necessity is traveling at the same speed as the pellet (something like 600 mph) as it exits the muzzle and is quite turbulent. That air is in front of the pellet, and is slowing down rapidly. The pellet has no other path than through that cloud unless that air is stripped. How much benefit there is, could be measured by laborious testing and a bunch of math. Feel free to do that and prove it for yourself. Then you will be speaking with some authority about how much difference it makes. I can't so... worse than that I am just going to trust the guys who are shooting the test moderators. They like them a lot. How much, "And the little air strippers... they are incredible! Stupid, crazy, STUPID accurate!!!!" So I dunno bud, you and I are going to have to disagree about how well they work. That's not a problem for me and most likely no problem for you as I know you to be as humble a man as I am...

As for having a stripper "work properly then you can't use a moderator"... again there is a trade off there between accuracy and moderation. The stripper DOES work inside a moderator. That is what we have experienced. It is a tougher problem to crack. Timing becomes a real issue and (I will repeat) that means even a gun's tuning can make the whole system fail. I don't believe bore size is as critical as you believe it to be. You can build a $200.00 stripper and it should work better than a $20.00 stripper. That does not mean the one does not work. It means it cost 90% less and you have traded one design criteria for another. The CUSTOMER then decides if it works well enough for his purposes.

I do think the shooter should be aware that the moderator can totally screw up his tune, especially if the pellet and that pressure front formed inside the tube meet at the exit end of the moderator. If that happens ES goes up and accuracy goes to crap. So the shooter should make sure his rifle is shooting well and then attach the moderator. He should at that point double check his accuracy BEFORE he does anything else. If the accuracy is still there he is golden and can tweak his tune. If it isn't he will know the moderator is degrading his accuracy and can either adjust his tune or try a different moderator.

Now if you come back and tell me you have a degree in mechanical engineering, some serious math credentials and you've been winning matches for 20 years I promise I will take everything I have said back. OK? (Naw, I won't but it sounds good) Meanwhile, let's you and I respect each other's opinion and experience.

If it works then it works, some guns are impossible to get efficient tune due to the valving and hammer with out the ability to custom make parts for. I will stand by my statement of the tune is everything first and foremost and strippers are for last 1% or bandaid for the bad tune. Most quality guns are perfectly accurate with a good tune without air stripper, otherwise how did we all live all these years.


The muzzle break/stripper OP listed for is for a M3 or impact, impact is known for the ability to fine tune to be extremely efficient so an airstrip per isn’t really needed. RMAC last year was won by a crown with no air stripper, pretty sure last few years were all won by guns with just a regular moderator. 25-50 meter bench rest is where air stripper can help with the last 1%.

Regardless, we can agree to disagree. I have an engineering mind and curiosity but in the end this is all entertainment and zero interest in comparing sizes.

 

[bigHUN]

My latest stripper