Muzzle breaks.

[LB]

Fifty, I understood your point, and I was in basic agreement. While it is no concern of mine, what sort of gear is being used at the next table, in some cases, it is/can be, a major distraction. And, discourteous.

I'd like to see the blasters confined to their own area, and some of those muzzle breaks, well, they actually do **** me off, sometimes. Same as rapid fire commandos. You know what I mean. LB

 

[Mysticplayer]

Mr. "Horn", how a muzzle brake helps reduce felt recoil is by redirecting the exhaust gas from going straight forward. As we know from basic physics, every action...so the exiting exhaust gases 'rocket' the rifle towards your shoulder.

The higher the muzzle pressure and the larger the volume of that high pressure gas, the more rocket effect and thus more recoil.

A muzzle brake redirects the gases 'forcing' it to travel away from the boreline. This reduces the forward jet effect and voila, less recoil.

So for a single expansion muzzle brake, you want a small forward exit hole (gases don't follow the bullet forward) and lots of lateral holes so the gases have somewhere to go. Gas exiting at 50000PSI doesn't care if it goes through 4 or 50 holes as long as the surface area of the holes are the same. The larger the total surface area the better. Of course, there is a limit to that or else there is not enough metal to stay together. That is why a brake with a larger diameter is more effective. More surface area to put more holes in.

Now the baffle or multi chamber brake just repeats the process as many times as there are chambers. There will always be a percentage of gas following the bullet. That gas expands into the next chamber, is redirected, and less goes forward.

don't get any bright ideas of making a long multichambered brake. Because of recoil, that tiny hole your bullet is trying to shoot through will move and that leads to other 'recoil issues'.

When you make a baffle brake larger in diameter, you also provide a 'sail' that the gases hit. This helps to drive the rifle forward and reduces recoil. Just look at the Armalite 50 muzzle brake (or those found on the muzzle of tanks and artillery). One of the most effective muzzle brake. Very large surface area and multichambered. It also vents the gases backwards to drive the rifle forward.

I put a 3/4" single port into my 300RUM barrel. Just one big hole. It reduced the distance the rifle recoiled by 2/3's.

In magnum or overbore cartridges, a lot of powder is burnt for the cal so muzzle gas pressures and volumes are high. A lot of the recoil is from the rocket effect of that gas. This exiting gas makes a muzzle brake work more effectively.

One reason why a muzzle braked 300Win mag can have lower felt recoil then a muzzle braked 308 shooting the same bullet weight.

In large bore low pressure rds like the 45-70 and HG cartridges, there is little gas pressure to work the brake. Most of the felt recoil is from the leaving projectile. That is why muzzle brakes don't work for these type of cartridges and why porting is the most logical choice.

Reduces cheek slap in a rifle and bent wrists in a pistol/revolver.

Hope this answers your questions...

Jerry

[ 08-23-2004: Message edited by: Jerry Teo ]

 

[4ked Horn]

Quite nicely. Thanks.

 

[srhaggerty]

FiftyDriver,

This should probably be posted as another topic, but I am having a bit of a debate on which gun to get. I want to get the .300 UM, but everyone I talk to says it is not worth it compared to the regular mag. What is your take? Did a brake help out the recoil on the .300 UM?

 

[Fiftydriver]

Srhaggerty,

First off welcome to LRH, good to have you here.

I had one of the first 300 RUMs that came to central Montana and if you use factory fodder, there is really nothing impressive about the 300 RUM over other 30 cal magnums.

But since 99% of us here are dedicated handloaders, the 300 RUM as great potential as a handloaded round.

My load uses a 180 gr Ballistic Tip or the newer 180 gr Accubond loaded to a solid 3400 fps from the factory Rem 700's 26" barrel.

I use H-1000 and Fed-215 primers to get this velocity in the factory barrel. THis load shoots so well that I have had no reason to test other bullets or powders in this rifle.

Compare those numbers with anything else and you will see the 300 RUM out of a 26" barrel is quite impressive, even compared to a 30-378 Wby with will only beat it by 100 fps or so in a 26" barrel. In a longer barrel there will be a larger advantage for the larger round but not in a 26" pipe.

I have a whitetail hunt planned in Canada next season and by then my now tired factory barreled 300 RUM will be wearing a 28" Lilja #7 contoured Stainless barrel and I will be loading the 190 gr Wildcat RBT ULD bullet to I expect a bit over 3300 fps.

As far as what a break does for a 300 RUM. Well, I only use Holland Quick Discharge brakes because they are the best big game hunting brake available in my opinion.

Any brake works better the larger the case volume is and the smaller the bore is. These two things effect the level of muzzle pressure and this is what makes a brake work, muzzle pressure.

With the 300 RUM you have 100 gr capacity in a relatively small bore and the Holland QD brakes work great. My 300 RUM feels about like a 270 Win in recoil.

One thing to also remember, the effects of a muzzle brake will be more dramatic the lighter the rifle weight is.

THe heavier a rifle is the more momentum it gets under recoil. This makes it harder for the brake to slow the rearward motion of the rifle.

A light rifle will be slowed much quicker by a brake then a heavy rifle so teh effects of the brake will feel more dramatic.

Personally, I feel the 300 RUM is the best factory offered big 30 caliber magnum by far, will get some comments about that but for shear power and cost effectiveness, the 300 RUM stands alone in the field.

Good Shooting!!

Kirby Allen(50)