Suppressor Bore Diameters

[1168]

I recently e-mailed Hansohn Bros to inquire about a comparison of identical suppressors with different bores I read that they were doing, and was given these two links in the following reply:

“Yes, you can see the results here https://youtu.be/3y87pu6wMYE and here https://youtu.be/jFkhg6TiTss

The Rex Silentium Viribus silencers are identical except for bore size.

Thank you

---
www.HansohnBrothers.com
540-748-8155”

I was asking because Rex Silentium will make a can in whatever length and whatever bore diameter one desires, not just .224 or .308. So I’ve been thinking about trying something oddball, like .284, because I’m an oddball.

In the videos above comparing .224 vs .338, it appears that there is no difference in at ear numbers, but a large difference in muzzle numbers. I’m sure the .338 was way less gassy. I would be curious how the numbers (particularly at ear) would look on two different rifles with gas adjusted for the individual cans. Perhaps they would still be about the same, perhaps not.

Anyways, I think most members here will find no surprises in these videos, but I thought y’all might find it interesting all the same. It is the only comparison with a meter that I am aware of using two cans of identical size and design with different bore sizes.

Merry Christmas, or Hanukah, or Kwanzaa, or Pagan Tree Festival, or whatever you celebrate! Stay safe, don’t drink and drive. That eggnogg is stronger than you think.

[Pappabear]

I am making a 30cal can and will bore it out to 338 dimensions because I like the cushion for baffle strikes and potentially gas issues. I run a Sig 338 can on 30cal guns all the time and find little difference in sound.

What does a good sound meter cost? I'd like to play around with such craziness.

PB

[Clint]

https://rexsilentium.com/MG7-K-Rifle...224-p148947022


Rex's published muzzle numbers show very good performance in the 224 short configuration, but dBs go up quickly when moving up in bore size.

The much longer 12 baffle MG10 in 308 shows about 3dB better numbers than the 6 baffle MG7 in 224.

One could conclude from this the design suppresses best with the tighter bore and more baffles help too.

We just ordered up a pair of MG suppressors.
#1 is a 6 baffle MG7 in 224
#2 is an 8 baffle MGX in 308

This will provide for an interesting comparison of back pressure vs suppression, although two variables are changed at the same time.

The plan is the 2 extra baffles will make up for most of the suppression lost shooting 556 through the larger bore, while allowing the flexibility to run calibers like 6.8 and 300BLK.

The extra 2 baffles add 2.6oz and 1" to the overall numbers.

[georgeib]

What does a good sound meter cost? I'd like to play around with such craziness.

PB

A sound meter that reads high enough to accurately measure sound pressures in the range of gun shots will be very expensive. Not sure exactly, but probably the best part of $10k. The ones that go up to a max of 140 db are in the $4-5k range.

Ouch. I know.

[1168]

What does a good sound meter cost? I'd like to play around with such craziness.

PB

They are very expensive, and from what I’ve read there are only two worth using at all. Ray from Thunderbeast posts on Snipershide, and would be a good resource to learn about this, unlike me.

https://rexsilentium.com/MG7-K-Rifle...224-p148947022


Rex's published muzzle numbers show very good performance in the 224 short configuration, but dBs go up quickly when moving up in bore size.

The much longer 12 baffle MG10 in 308 shows about 3dB better numbers than the 6 baffle MG7 in 224.

One could conclude from this the design suppresses best with the tighter bore and more baffles help too.
.

I suspect this is true of most or all rifle suppressors. Everybody says they don’t really notice a sound difference between their 224 and 308 cans, but the typical 308 can is longer and no one is shooting with their heads next to their muzzles. Does it matter? Maybe. Depends.

I’ve also watched more Silencershop videos than anyone should, and it does appear that this hypothesis holds up with other manufacturers.

Rex Silentium has a cool thing with the MG series. My MG7k is in purgatory, and I have not yet shot it, but the baffle design is clipped, and looks like what I would expect to see in a modern top end can. It looks like the larger diameter and tubeless body allow them to stuff more baffles per inch in there without sacrificing internal volume. I’ll have to fill it with water one day and see how much it holds compared to my M4SDk, which is about the same length, but neither tubeless nor oversized.

[Clint]

The other big takeaway from comparing dB numbers is that bore size has less effect on suppression as the overall length and number of baffles increase.

To put it another way,
with K cans bore size matters a lot,
but with jumbo cans, bore size hardly matters at all.

[markm]

it appears that there is no difference in at ear numbers, but a large difference in muzzle numbers.

In my opinion, the only numbers that matter are the numbers at the ear. Speaking from a centerfire rifle (not sub gun) perspective, Sonic crack is painfully loud in front of the can when you're near by, and far out-barks any wonderful Db reduction.

I’m sure the .338 was way less gassy. I would be curious how the numbers (particularly at ear) would look on two different rifles with gas adjusted for the individual cans. Perhaps they would still be about the same, perhaps not.

We've run over bored cans on a few set ups. Performance differences in gas volume, etc have been negligible. i.e. a 30 cal can on an AR-15 still adds gas and bolt speed, and doesn't seem to run significantly smoother/require a different port size etc. to optimize the configuration.

All in all. I definitely like an over bore can in almost every application because there's a little less back pressure/gas in the face, AND you get some margin for error if a bad round/bullet tries to hit your baffles/cap.

[Rogue556]

I definitely like an over bore can in almost every application because there's a little less back pressure/gas in the face

I can definitely attest to this.

I run a Surefire RC2 on my rifles. Using a buddies SF 300 SPS on my rifles, gas to the face is almost nonexistent by comparison. Sound at the shooters ear appears almost identical as well (probably due to the longer length making up for the larger bore diameter).

Of course you do pay for the blow back reduction in the form of weight and length, however.

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[markm]

I can definitely attest to this.

I run a Surefire RC2 on my rifles. Using a buddies SF 300 SPS on my rifles, gas to the face is almost nonexistent by comparison. Sound at the shooters ear appears almost identical as well (probably due to the longer length making up for the larger bore diameter).

Of course you do pay for the blow back reduction in the form of weight and length, however.

The thing I noticed too... was that the mini cans in the caliber matched bore diameter for .223 also were less gassy and no louder at the shooter position due to letting more gas pass through less baffles. (the exception being the Knights mini can which is pretty barky compared to the AAC mini 4).

[Clint]

Were these all fairly large/long cans?

We've run over bored cans on a few set ups. Performance differences in gas volume, etc have been negligible. i.e. a 30 cal can on an AR-15 still adds gas and bolt speed, and doesn't seem to run significantly smoother/require a different port size etc. to optimize the configuration.

All in all. I definitely like an over bore can in almost every application because there's a little less back pressure/gas in the face, AND you get some margin for error if a bad round/bullet tries to hit your baffles/cap.

This also makes sense.
Fewer baffles => lower back pressure.

The thing I noticed too... was that the mini cans in the caliber matched bore diameter for .223 also were less gassy and no louder at the shooter position due to letting more gas pass through less baffles. (the exception being the Knights mini can which is pretty barky compared to the AAC mini 4).