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cjd3
27 November 2017, 18:54
So after two outings to the range, I am happy with the sound of my Revolution 45. I am not a big fan of the splash back. I am just assuming this is just going to be an issue with with any pistol suppressor. Its minimal with my SparrowSS, but a lot from my .45. Is this a case of bigger bore, more back pressure, more particulate face dusting? I've fired in both full and K config from my XDm, and it's pretty much the same.
Thanks guys.

Uffdaphil
27 November 2017, 19:27
Not sure it is comparable, but my Revolution 9 is not bad at all either long or K config on a G19 or P226. On the blowback AR9 it’s intolerable - like shooting over a smoke grenade.

Something different enough about .45ACP to explain the difference?

alamo5000
27 November 2017, 21:29
I will take a stab at this. I may have to put my nerd hat on.

My Revolution 9 has minimal blowback. It does have it but it's not so bad. The host is a 226 most of the time. I have gotten dusted before but I have noticed that if I use certain store bought ammo I get dusted a lot more (relatively speaking).

If you look at the load data for various rounds...for example I used Titegroup as a sample powder for both calibers.

For a 147 grain subsonic 9mm load at the listed max on Hogdon's site it has a CUP of 27,500. The listed velocity is 929 FPS.

For a 230 grain 45 ACP round with the max load the CUP is only 17,000. Velocity is 855 FPS.

If you don't know the difference between CUP and PSI read this: http://bulletin.accurateshooter.com/2014/10/cup-vs-psi-whats-the-difference-in-pressure-measurements/

It's basically two ways to measure chamber pressure.

I had a conversation with some of the Griffin guys here before and they said (I can't remember exactly) but some or all of their cans are pressure driven. At a certain pressure they perform at their maximum efficiency. I don't know if this applies to their pistol cans or not.

I would however be willing to bet a dollar that those drastic differences in pressure make the difference right along side ammo choices.

I would think the Revolution 45 would have less back pressure all around which leads me to ask what kind of ammo you are using?




Is this a case of bigger bore, more back pressure, more particulate face dusting?

I think getting dusted in the face is part ammo and part host. I would think the overall back pressure on a .45 ACP would be less.


Not sure it is comparable, but my Revolution 9 is not bad at all either long or K config on a G19 or P226. On the blowback AR9 it’s intolerable - like shooting over a smoke grenade.

Something different enough about .45ACP to explain the difference?

I have a Revolution 9 and I have only shot it on a 226 and a CZ75. Both cases it wasn't bad at all. I haven't shot it on anything else.

The 9mm can should in theory have more back pressure but on the AR9 I would wonder again what kind of ammo you are using? If it's just smokey it makes me curious if the round/powder/host combination has anything to do with it? I obviously don't know but if the barrel is longer it makes me think that the smoke could be trapped in the barrel longer due to more dwell time? And then with it being a blow back gun the bolt would open with all the gas still trapped and not having enough pressure to blow it through the can by the time the bullet gets there.

On a pistol the pressure on the end of a 4 inch barrel is one thing but on a longer barrel all that smoke is contained and seems to be released when your bolt blows back.

This makes me curious now. I wonder how these things work...I am curious to see what other people come up with. That is my educated guess though.

Uffdaphil
27 November 2017, 21:49
I’m using the same 147 & 158 grain on both platforms. 4-5”pistol and 8” AR. I suspect all of the obnoxiousness is due to the AR blow back in longer barrel venting a higher volume of gas through less diffuse, more compressed escape paths - ejection port and CH. At least that is my theory.

alamo5000
27 November 2017, 22:19
I’m using the same 147 & 158 grain on both platforms. 4-5”pistol and 8” AR. I suspect all of the obnoxiousness is due to the AR blow back in longer barrel venting a higher volume of gas through less diffuse, more compressed escape paths - ejection port and CH. At least that is my theory.

8" AR barrel+7.6" of suppressor... that's almost 16" total. In the K it might be what? 2 inches shorter?

I am with you that the timing of the gun with limited venting options, when that bolt blows back, that might be happening before the gas can escape in other means.

I think you are on to something.

cjd3
28 November 2017, 18:27
Thanks for the input guys. I just reassembled the Revo in long configuration, so naturally, the baffle stack came out and was given a quick clean. There was a lot of particulate matter in there that I am assuming is unburnt Accurate #5. From my Nosler load book, I'm getting somewhere around 864 FPS using 9.1 grains behind 185 Nosler CCs. I've been shooting it dry, and I can only assume that if I shoot it wet, the splash back will be just wetter, and it won't encapsulate the particles better in the can.
While it is uncomfortable, It's manageable with eye pro. I'll just shot the lot, and find a cleaner burning powder next go around.

alamo5000
28 November 2017, 19:50
Shooting a can wet as far as I know is 'designed' to cool the gas more than otherwise. Your muzzle boom is a result of hot gasses being instantly exposed to relatively cool ambient air. It won't have anything to do with back pressure.

Former11B
1 December 2017, 07:57
First things I always ask:

What is the host weapon?

Tried other powder? Something faster like Titegroup? I use TiteWAD (#5 on the list) for .45ACP. I know #5 is recommended in their load data but there may be a better option that’s not so dirty or one that generates less blowback. FYI #5 is 41 on burn rate chart

alamo5000
1 December 2017, 08:48
Here is a chart for reference. (There are several so I just picked one that can be referenced if need be so we are all on the same page)

https://www.loaddata.com/articles/PDF/Burn%20Rate%20Chart%20(New).pdf

I have been using Hodgdon Universal for quite some time and it has worked perfectly fine. It is slower than Titegroup by a lot but still a lot faster than #5. At least in 9mm it seems to have a complete burn and it's clean. I think that's partially due to it being a flake type powder. I have been using that powder for quite a long time but I figured I would give Titegroup a try too.

At least my theory is with spherical powders they can get compacted down more so your primer blast doesn't get in between and light everything up. With those little disks of Universal though, even though it's slower than some other options the primer pop lights everything up because it can get into the air space in there.

Basically with that powder (Universal) I have found very little left over or unburnt powder in my suppressor.

cjd3
31 December 2017, 14:43
First things I always ask:

What is the host weapon?

Tried other powder? Something faster like Titegroup? I use TiteWAD (#5 on the list) for .45ACP. I know #5 is recommended in their load data but there may be a better option that’s not so dirty or one that generates less blowback. FYI #5 is 41 on burn rate chart


Here is a chart for reference. (There are several so I just picked one that can be referenced if need be so we are all on the same page)

https://www.loaddata.com/articles/PDF/Burn%20Rate%20Chart%20(New).pdf

Thanks for the follow ups guys.

The host weapon is my xDM. I have some left over Bullseye that I am going to try, plus they have some in stock locally (can only get local because, Alaska). The only problem, I need to pull 450 some bullets to re-reload. At least they are primed. Naturally, I'll test some first, before going pull crazy.

alamo5000
31 December 2017, 19:00
The only problem, I need to pull 450 some bullets to re-reload. At least they are primed. Naturally, I'll test some first, before going pull crazy.

Wow. Pulling 450 bullets? Not me. Just shoot em.

Joelski
1 January 2018, 06:21
Wow. Pulling 450 bullets? Not me. Just shoot em.Choot 'im, Limabet! [:D]

Sent from my SM-G930P using Tapatalk

cjd3
13 January 2018, 16:44
I pulled 10 rounds, and reloaded them with 4.5gn of Bullseye. What a difference! Almost zero splash back, and it ran pretty well. However, I defiantly need to add more crimp to my bullets since they are setting back in the mag. I also picked up a SiCo barrel for a Beretta 92fs, it did well too with the 9mm load I have worked up for it. But I do need to get some high sights for it. Can sighting is tough. Thankfully it's a newerish one that has replaceable sights.

Still gonna pull a couple hundred rounds since I'm cheap.

Former11B
13 January 2018, 19:15
I pulled 10 rounds, and reloaded them with 4.5gn of Bullseye. What a difference! Almost zero splash back, and it ran pretty well. However, I defiantly need to add more crimp to my bullets since they are setting back in the mag. I also picked up a SiCo barrel for a Beretta 92fs, it did well too with the 9mm load I have worked up for it. But I do need to get some high sights for it. Can sighting is tough. Thankfully it's a newerish one that has replaceable sights.

Still gonna pull a couple hundred rounds since I'm cheap.

What bullets again?



I taper crimp to remove the bell; as hard and as much as I shoot I don’t have that issue...how much flare/bell are you applying? Do you seat and crimp at the same time? I use plated bullets 99.999% of the time and doing the seating and crimping separately keeps the plating from being damaged.

N If you over crimp you might experience pressure and accuracy issues as well.


Latest batch: 100ct 124gr Xtreme plated HPs over 3.4gr Tite Group

4809

cjd3
13 January 2018, 19:25
What bullets again?
Nosler CC 185. I am putting enough flare in to seat, as little as possible, but not too little that it starts to cut the copper base (Sometimes I get little copper horseshoes). I am a big fan of the LEE FCD. I ran into problems seating and crimping early on with .223, but not anymore. When I crimp, it just enough to smooth the round to it plunks in the chamber. I'll do another test with varying crimp. I've been doing it with half turns which Lee says is a light crimp. So I'll probably do a few batches at ¾ and 1 turn at various charges. See which one is happiest and doesn't get set back. I've been getting my bullets from Shooters Pro Shop when they are on sale.

alamo5000
13 January 2018, 20:31
I pulled 10 rounds, and reloaded them with 4.5gn of Bullseye. What a difference! Almost zero splash back, and it ran pretty well. However, I defiantly need to add more crimp to my bullets since they are setting back in the mag. I also picked up a SiCo barrel for a Beretta 92fs, it did well too with the 9mm load I have worked up for it. But I do need to get some high sights for it. Can sighting is tough. Thankfully it's a newerish one that has replaceable sights.

Still gonna pull a couple hundred rounds since I'm cheap.

Glad the big part of the original problem is solved. Getting peppered in the face sucks.

mustangfreek
15 January 2018, 01:57
I never liked AA#5 when I tried it in 9&45 while not suppressed I have noticed other powders and such are just more Smokey, dirty and everything.

My favorite powder for 45 has been bullseye and of lately cfe pistol..although tried wsf as it’s by far the best all around powder I’ve used in 9mm, but 45acomwasnt quite good enough to bother

Try belling a little more then you have been just to see, in 9mm I’m ocd enough that .356 bullets make me tighten it up a little from the .355 size..lol