Do silencers change a rifle's preferred load?

ObiWanKannoli said:

This topic drives me a little crazy.

Speaking strictly about bolt action rifles:

Suppressors can impact a rifles accuracy and precision regardless of load.

Why? Barrel harmonics change dramatically. In some very rare instances you might need a change in charge if you have any exceptionally high back pressure can.

Long, skinny, fluted barrel with a heavy steel can now hanging off the end? Yeah, you're going to see a huge POI shift and likely some degradation in groups.

Thick profile, short barrel with a titanium can on the end? You might notice no difference at all.

My 20" 300 PRC with a 9oz titanium can has absolutely no change in accuracy or precision between can or no can.

A change in load could solve the issue, but it's important to note the distinction in cause and effect here.

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Carbon wrapped barrel, 300 RUM with a Ti can, fingers crossed. Did you see signs of pressure? I know I'm already on that jagged line.

I looked at this issue a different way:

1) Will I ever buy a new rifle?
2) Will I ever try new bullets?

if the answer to either of those is "yes", then I am going to do load development anyway. Therefore, adding a suppressor is really no different than buying a new rifle or trying new bullets.

Personally, I first start with powders and bullets that have a very good reputations for accuracy and research to see if there are "known good loads" for my cartridge. After that, I use the Optimal Charge Weight Method for load development. Using the preceding approach, I can have the load developed, confirmed, and the rifle zeroed in three range sessions or four at the most.

Granted, I don't shoot beyond 600 yards and I am satisfied with a sub .8 MOA group. I also don't worry about 100 fps in a velocity.

Sorry for the somewhat long winded and slightly off-topic answer, but many "challenges" in life can be mitigated by viewing the issue in a different light; i.e., don't worry so much about load development; embrace and improve your load development process.

I can only speak to my own experiences, of course.
Bought my first can (30 cal) two years ago (1 year wait sucked). I have used it on a 300BO AR and my .308. I've learned two things. First being is that my POI shifted 9 MOA when I pulled the break and put the can on my Savage 10. Second being is that it's like driving a really nice truck. Once you have used it, you won't want to go back.

If you decide to use it on your bolt system, use direct thread and just leave it after you do your load development. It's just easier in the long run. Direct thread will keep your position of the suppressor the same (more or less) every time you take it on and off for cleaning. I wanted to go this crazy route of buying muzzle devices that would make swapping between the two rifles easier, but my POI would shift every time I took them on and off, and not a little bit. It was a hard lesson to learn after a couple hundred dollars later. DT is also better because they like to loosen after several shots. Check it frequently. I also bought a pair of high temp grill gloves with silicone grips and a rubber belt wrench to tighten/remove it. Carbon buildup can make it difficult to remove. Depending on the material, they take a fair time to cool down.

You'll buy more, don't you worry. It's nearly as addictive as buying firearms itself. I have three now. The .22LR one is laughably quiet on the 10/22 and the pistol (sr22). Bought my first big boy pistol can (.45 cal) this summer. Now I'm considering buying another 30cal or maybe one that will cover up to .338 should I decide to get one. The $200 "could I have this daddy" tax is a pain and they are still pricy as hell, but I think of all the accessories I've bought for my rifles, this one is the most beneficial one I've ever used.
Sorry for the word salad and do enjoy suppressor use!

Helpful links:
Plug in your rifle info and go…

Subsonic load data from Hodgdon. I haven't played with it yet, so take that with a grain of salt.

WA Coyote said:

I've never seen a load shoot worse through a suppressor than it did through a naked barrel, and that's over a fairly large sample size.

I've also had a fair number of loads shoot slightly better through a suppressor than they did pre-can.

I've certainly never had to create an entirely new load for the suppressor.

Admittedly, I tend to run shorter stiffer barrels (18-22"), so that could have some bearing on the results.

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Ballistic High Speed did a video on this topic, sort of. The visual of a bullet exiting a barrel @ 200,000 and 600,00 fps. Some rounds clearly get a little push from the expanding gas cloud as and/or after it exits the barrel. The suppressed rounds are significantly different. His reaction at the ends of shooting some of the firearms is pretty funny.

haftime said:

Looking to purchase my 1st silencer and am wondering if you have had to change a rifle's favorite load? POI shifts I expect but starting over for several rifles has me spooked. What are your experiences with old handloads and adding a suppressor?

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I just placed a supressor on our 8th rifle. 2 are gas, 6 are bolt. 556, 6mmCreed, 22250, 300wm, 300wsm, 270, 308. All the bolts I handload except 6mm, just not there yet. I first added ASR brakes to them all then adjusted the load to account for the change. Usually within a grain, not a lot of change there. Then we added the suppressors. All had a POI change, usually within 2.5 inches and mostly elevation. None of the loads were affected by the supressor. 4 have been to 1000+ before and after the supressor with the same loads. I just purchased a 22 supressor yesterday, can't wait to get it shooting.

"Long's theory" is legit imho. In the RF world we call that SWR aka Standing Wave Ratio. It's the ratio of transmitted power vs reflected power. It's a deep subject that I won't claim to fully understand. Physics is physics... the waves that form and travel down the barrel reaches the end and does what? It reflects back and interferes unless the timing of the wave is in the Goldilocks zone (just right).

From the PDF

Long's theory boils down to this: The ignition of the powder charge creates pressure that sends a shockwave down the barrel, to the muzzle and back again, in a repeating fashion much like the plucking of a guitar string. This ignition stress shockwave can and will move the steel enough to cause a distortion in the bore diameter. Subsequently, when the bullet engages the rifling, a second force — the swelling of the barrel ahead of the bullet — starts to travel toward the muzzle. According to Long's sound theory, if those two waves collide when the first wave is affecting the muzzle, the groups will open up as if the crown were out of round. If you can find the load with which the two waves are separated, the group size will indeed shrink.

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I run tuners and tuner/Brakes on several barrels. Very, very small adjustments not only changes the group size, but the impact. I have barrels that once a brake is installed, the barrel does not want to shoot well(5/8"), and vise a versa. This is a humbling sport.

FEENIX said:

Yes, as with anything else, YMMV. I have a couple of loads that only have the POI shifts but not the group size; I get lucky occasionally. For another load, I had to tweak them. In short, it is best to do load development with whatever muzzle device you use. Good luck, and have fun with your new toy.

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You are spot on.

It's a fact of physics that the gas being discharged from the barrel once the projectile leaves the pipe is traveling and expanding much faster than the bullets flight. This is exacerbated by the "hose nozzle" effect of boat tail bullets allowing gas to pass the bullet before the base even clears the muzzle.

Essentially, a bullet has to fly through its own prop wash of expanding and igniting gasses in the first couple feet of flight. I believe this is why we often see videos of projectile yaw during that first few feet too. With a suppressor, those gasses are peeled off as the bullet goes through the baffles in the can, making for a much cleaner exit and exponentially less external forces on the bullet.

Gundog74 said:

I have a 300 PRC and a 338-378 that I've started running cans on. These rifles are different in every aspect possible. I load for both. Both shot little low and little left. Other than that they are good.
It's possible your will shoot differently, but IMO the cans are definitely worth the effort of a new load.

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I have experience the same with my 6.5 Creed 6.5 PRC. I haven't seen any accuracy problems what so ever.

This is one of the best videos of a suppressor.

med358-boise said:

I looked at this issue a different way:

1) Will I ever buy a new rifle?
2) Will I ever try new bullets?

if the answer to either of those is "yes", then I am going to do load development anyway. Therefore, adding a suppressor is really no different than buying a new rifle or trying new bullets.

Personally, I first start with powders and bullets that have a very good reputations for accuracy and research to see if there are "known good loads" for my cartridge. After that, I use the Optimal Charge Weight Method for load development. Using the preceding approach, I can have the load developed, confirmed, and the rifle zeroed in three range sessions or four at the most.

Granted, I don't shoot beyond 600 yards and I am satisfied with a sub .8 MOA group. I also don't worry about 100 fps in a velocity.

Sorry for the somewhat long winded and slightly off-topic answer, but many "challenges" in life can be mitigated by viewing the issue in a different light; i.e., don't worry so much about load development; embrace and improve your load development process.

Click to expand...

Stop that you make to much sense, can't have that here!

The clear suppressor vid is eye opening.

SED is my favorite YouTube channel. The supersonic baseball cannon is freaking AWESOME!

Boss Hoss said:

Absolutely it will most likely change the POI because it completely changes the harmonics of the barrel, in addition a suppressor can also change velocities and corresponding pressures.

Since you asked this question and even for others this is a pretty good synopsis and when shooting 1kBR it is all about the details if you want to get wood.

Ballistics: Understanding Barrel Harmonics and Accuracy

"Barrel harmonics refers to how a barrel whips, torques and contorts. The idea of accuracy is simply a set of repeatable barrel harmonics.

gundigest.com

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"Absolutely....it will most likely "......
Is that the same as..."Without a Shadow of doubt...maybe" ?