I think I got lucky with my initial baffle spacing and what I can achieve with a 1.5" OD and 8 baffles. I took it out today and tested it on my 54r Mauser. Everything is 316 stainless but the first two baffles which are 17-4.

I don't have a good decibel meter and I hesitated to take the one I have along but as my buddy said, "comparison is comparison, just don't believe the numbers". I checked a couple shots through my Rugged Surge then a few through the form1 and the form1 seemed quieter. Nothing to get excited about but it lays the groundwork and gives me feel good about my first form1. I wish there were better meters available that didn't break the bank.



Here's a short video clip of a few shots today: https://www.youtube.com/watch?v=uPmK2OByBUQ

Quick question.

Are the baffles/spacers in the photo in the same order where you got better sound reduction?

If so, I noticed that one of the spacers is longer more towards the middle of the stack.

Which would also correlate with my earlier findings from rearranging my baffles to have a larger chamber toward the middle as more of a secondary expansion chamber to allow for better expansion as the gasses are starting to lose some of their initial momentum.

The spacers are laid out in the order the rifle was shot in the video. I was pleased with the way it shot and sounded.

John A. wrote:Quick question.

Are the baffles/spacers in the photo in the same order where you got better sound reduction?

If so, I noticed that one of the spacers is longer more towards the middle of the stack.

Which would also correlate with my earlier findings from rearranging my baffles to have a larger chamber toward the middle as more of a secondary expansion chamber to allow for better expansion as the gasses are starting to lose some of their initial momentum.

Excellent observation that is rarely considered.

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Good stuff there Holes!

Here's a question regarding POI for you more experienced builders. My 54r mauser is dialed in with my form 1can and shoots well. Yesterday I wondered where it would shoot without the heavy stainless can so I took it off and fired a couplr shots. The groups were 3" lower. Not what I expected at all.

Barrel harmonics, a silencer bore that isn't perfectly concentric, and/or asymmetrical baffles are likely why.

fishman wrote:Barrel harmonics, a silencer bore that isn't perfectly concentric, and/or asymmetrical baffles are likely why.

I think I need to check it out on another rifle to see if the shift follows the can rotation on the flash hider. It might be an interesting experiment. I've experienced no issues with accuracy, it's just that I expected the shift to be upward from lack of weight hanging on the end of the barrel.

Well it's like Fishman said; barrel harmonics can play funny games with POI when changing the weight dramatically. Every barrel moves during the shot, while the bullet's still in there. It's not a simple matter of the weight dragging the bore down. It could easily be that taking off the heavy can dramatically increased the cycling of the barrel's whip, causing it to go through a full up-down motion before the bullet crests the crown. With the can on it might only be going halfway through that cycle during the same timeframe, so the muzzle's pointing upwards when the bullet leaves and results in a higher POI. Watch a few videos showing barrel harmonics in very slow motion. It's an eye opener.

Yes, I've made a few of those high speed videos myself. My favorite is the PSL barrel whip video. I might drag the camera back out if I find out the bullet isnt following the can rotation. I have another rifle in 54r made with the same barrel to get a comparison from.

Have you chrono'd your loads, w/ and w/o the suppressor attached?

Looks awesome!

How did you go about engraving the tube?

I don't have a chronograph yet, I've just started thinking about getting one. There ought to be a good sale around the end of November. I've only ever fired my standard target loads through the cans.

I marked the can on my CNC mill.

I found a flash hider that when screwed onto the barrel of my Mosin held the form 1 can almost exactly 180 degrees of rotation from where it was on the Mauser. After a lot of fooling around with the scope to get the rifle sighted in I finally got down to business with the good reloads.



The top two groups are with the can, the bottom group was with the can removed so something else must've gone wrong the day I had it on the Mauser and the POI shifted. I didn't change anything in the can so I need to pull the Mauser back out and try it again.

My Mosin:

54r.....Mauser? Come on, you can't just casually toss that out and then withhold pictures. That's just unkind.

jlwilliams wrote:54r.....Mauser? Come on, you can't just casually toss that out and then withhold pictures. That's just unkind.

Here's a glamor shot taken just after the paint had dried. It wears a different scope now:



It's a 98 Mauser action with a mis matched bolt I bought at a gun show. I bought the barrel blank from McGowen. Who knew that a Mauser box magazine held 3 54r's? The stock is highly polished aluminum with a translucent red paint over it.

Long story short, I spent a couple years building 54r rifles (both bolt action and SA's) when the ammo was cheap. When I wasn't building I was trying to get cheap surplus ammo to shoot MOA like half the posters on the internet claim their rifles shot. Then I started reloading to show that the rifles really were sub MOA capable with good ammo. Next came a bet that I couldn't get a Mosin action to shoot as accurately as the Mauser action and I built the green one. Same barrel blank and same ammo shoots exactly the same. I'm toying with the idea of making another 54r using an Arisaka action I picked up in a trade, in fact it's sitting on the desk next to me waiting to be blueprinted.

That's pretty cool.

Holescreek wrote:I found a flash hider that when screwed onto the barrel of my Mosin held the form 1 can almost exactly 180 degrees of rotation from where it was on the Mauser. After a lot of fooling around with the scope to get the rifle sighted in I finally got down to business with the good reloads.



The top two groups are with the can, the bottom group was with the can removed so something else must've gone wrong the day I had it on the Mauser and the POI shifted. I didn't change anything in the can so I need to pull the Mauser back out and try it again.

My Mosin:

Where did you find that buttstock? Looking for something similar for my 6mm Remington in a Mcrees Precision billet stock.

I make everything.

T-Rex wrote:Have you chrono'd your loads, w/ and w/o the suppressor attached?

I bought a Magnetospeed V3 and took some rifles out to the range today. It was way too cold (for me) to enjoy a day at the range. We went to the 200 yard range because we can usually get it all to ourselves but the cold wind seemed to be blowing right up the lane at us. I noticed a couple of interesting things from the data. The first cold bore shot from every rifle was slower than the following shots. I guess that makes sense because the steel will expand as it warms up.



I'm way to new at using a chronograph as a tool but I thought is was noteworthy that my buddy asked about the second shot in his string (shooting .223 from a Savage 12FV). His second shot had dropped 1/4" lower than the other 4 in his group. Upon reviewing the data his second shot was 14 fps slower than the average of the other 4 shots. I wouldn't think that small amount of difference would have mattered. Group size from the Mosin varied as well. My series 2 shots through the form1 can netted a .752" group. The series 6 five shot group was 4x larger, could be because I let the Mosin sit for 30 minutes while we shot the .223's.

From what I see, your first shot, in the first string, is the only slower round. In fact, the third chart's first shot is the fastest. I've never used your chronograph, but I have a F1 Chrony and the first shot is to ignored as it is a calibration shot, for the unit. Also, a clean barrel, an oiled barrel, and a dirty barrel left for a while, can all have adverse affects on the first fired round.

As far as the temp of the barrel, it's opposite of what you might think, not that it works like this in reality. What I mean is two-fold. The first part is that if the barrel did heat-up and expand, it would cause lower velocities as there'd be less friction from bullet to bore. The second part is that the bore of even a hot barrel will only expand in the hundred-thousandths of an inch range. Far too small a change to make appreciable differences. What typically happens, with a warm barrel, is it increases the temp of the gunpowder in the chamber. This will absolutely have a positive increase in muzzle velocity. On cold shooting days, I'll put my rounds inside my jacket to keep them warmer.

The suppressors definitely helped control muzzle velocity, though. Your ES and SD were much lower with cans attached.

From what I see, your first shot, in the first string, is the only slower round.

My fault, I should have specified the first shot from each individual rifle, not the first shot in the individual strings.

Youv'e done truly amazing work with those guns.

Thanks! It's a lot more interesting/fun to build them unconventionally.