Noisy load !

[cookoff013]

even though a shotgun is a self contained unit, not like a CF bullet. i think its due to the residual pressures / gas volume equilibrating to outside pressures. my experience is only on shotgun. i do get what the other poster is saying ie different pressures / same burn rates etc. but the peak pressures are just that, the maximum recorded pressure upon firing. it is not total volume of gas produced.

i like my subsonics high pressure, and low speed. it gives ultra reliability. the only way i get high pressure and low volume of gas is with ultrafast powders (in 12gauge). i even did a 21gram subsonic load but pressures were seriously low (but consistent).

the mod on a shotgun are chambers to bleed off gas / knocking off the residual pressure from the peak chamber readings. now this will vary because depending on A, the original pressure of the load and B, the gas bleed off rate. shotgun silencers are really huge, but then shotguns burn anywhere between 15grains to 40 grains of powder.

reading a burnrate chart is like the equivalent of reading the daily mail. utterly pointless. (i stand by that statement whole hartedly) especially when different calibre, different cases, different MAP are brought into the picture.

[Parabuteo]

So let me get this straight.

A gun went bang.

Blimey....who knew?????!!!!!!!

(sorry, the title tickled my inner chimp)

[Black Beard]

I think it is about the difference in energy between the gas exiting the gun and the gas after it has expanded in to the outside air. This energy moves the rest of the air about and you hear the pressure wave.

A smaller charge of faster powder will have a lower exit pressure than a larger charge of slower powder, even though they have the same peak pressure or exit velocity of the bullet. The peak pressure doesn’t matter, it is the exit energy of the gas. The energy of the smaller charge of gas at exit is lower, which makes less noise.

A mod lets the gas expand and cool, which transfers energy from the gas in to the metal work and the air in the mod. This makes the energy/time (= power) of the gas exiting the mod lower so the noise level is lower. In particular, the initial peak of noise is smoothed off. If you put oil or water in to a firearm mod (if it is designed for it!) this cools the gas even more and the mod works better until all the fluid is gone.

This only applies in subsonic loads. If they are supersonic then the energy lost by the decelerating bullet has to be taken in to account as well. You can do this from velocity-distance curves for the round. But if the exit velocity of 2 bullets are identical, it doesn’t matter if you are just doing a comparison. The same amount of energy is lost from both bullets so the difference in noise level is down to the exit power of the gas.

[Eligus]

So let me get this straight.

A gun went bang.

Blimey....who knew?????!!!!!!!

(sorry, the title tickled my inner chimp)

Don't you realise that some of us who post on here are absolutly serious and pedantic and can't stand any attempt at humour!!!

Seriously though, it all seems very complicated, a bit beyond me!

I only noticed because I was using up the last of my H110 before starting on the Lilgun otherwise I would have been no the wiser as to the difference. The Lilgun does have a deeper bark even with smaller loads but the bullets go where I point them.

[Parabuteo]

Don't you realise that some of us who post on here are absolutly serious and pedantic and can't stand any attempt at humour!!!

Seriously though, it all seems very complicated, a bit beyond me!

I only noticed because I was using up the last of my H110 before starting on the Lilgun otherwise I would have been no the wiser as to the difference. The Lilgun does have a deeper bark even with smaller loads but the bullets go where I point them.

Its one of lifes oddities with hand loading.

Seemingly small changes can cause real issues (or make massive improvements) whereas what seems like a big one wont show.

I would say that as long as there are no pressure signs, and the rifle is going well, accept it.

It may even be that you were in a different location. Walls, roofed firing points, fat git next to you.....they can all change the perceived bark.

You would not believe the racket a 223 makes when you stick a brake/compensator on it. I have becoem an outcast since getting my bradders beastie!!

[Eligus]

There are so many variables in hand loading I don't think it's possible to eliminate them all.

I've just recieved some Sierra Hornet bullets in 40 and 45gr (ordered about 4 months ago) so I'm about to start loading to test them. Going to use Lilgun powder, we'll see how they compare with Hornady.

[223AI]

You would not believe the racket a 223 makes when you stick a brake/compensator on it. I have becoem an outcast since getting my bradders beastie!!

I would after shooting next to you & yours at the firing point

[Parabuteo]

I would after shooting next to you & yours at the firing point

Tart.....I love the bark of a BAR15 in the morning...it winds up wingebags!!!!

[223AI]

I would after shooting next to you & yours at the firing point

I said I would believe it not that I didn't like it, I'm not a leather clad TR shooter yet, guns go bang that's why you wear hearing protection!

Don't think anyone would last long at the BBS shoots if breaks bothered them to be honest I just need to get a gun I can put one on

[dodgyrog]

I remember vividly clearing an indoor range with my pal shooting a tricked up compensated S&W 686 .356 revolver in a Practical Pistol comp at Leicester.
There was dust coming down from the rafters.
Plugs in ears and ear muffs JUST protected our ears.
Oh what fun!!!!
Bunch of poofs shooting these days - .22 rimfire hurts their ears!

[angrybear]

I noticed at the weekend that the rounds with the 36gn barns grenades were a lot, lot louder than any of the other 30/35/45gn, I put it down to "one of those things"

[Eligus]

Same powder/load?

Could just have been them tumbling over as they came out of the barrel !!!

[Parabuteo]

I said I would believe it not that I didn't like it, I'm not a leather clad TR shooter yet, guns go bang that's why you wear hearing protection!

Don't think anyone would last long at the BBS shoots if breaks bothered them to be honest I just need to get a gun I can put one on

Totally agree B. I was there at the last brake debacle. To add insult to injury my lot complained about the club next door using one, I felt quite embarassed really, I offered to shoot next to him as I could not care less.

They are less "Brakes" more "Compensators" on the BARs. They work though. Its odd watching the firing line because you really see the flash against the baffles of the brake.

Should have meself a play with a Chey-tac this weekend.....that might bark a bit.

[223AI]

Totally agree B. I was there at the last brake debacle. To add insult to injury my lot complained about the club next door using one, I felt quite embarassed really, I offered to shoot next to him as I could not care less.

They are less "Brakes" more "Compensators" on the BARs. They work though. Its odd watching the firing line because you really see the flash against the baffles of the brake.

Should have meself a play with a Chey-tac this weekend.....that might bark a bit.

I know what you mean I noticed the flash with Bomag's on Sunday.

Chey-tac...... Nice, .408 or .375, either way its going to be a noisy load!! Over what distance?

[angrybear]

Same powder/load?

Could just have been them tumbling over as they came out of the barrel !!!

36gn was 11.5/12/12.5gn

35/45gn were both 11.5gn,
30gn @ 13.7gn.

By the time they hit the 36gn were tumbling, judging by the irregular shape holes.

Mute point as I'll never use the useless things again