How fast can 6.5x55 be run? And some Qs about muzzle brakes


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SprayAndPray
September 13, 2007, 10:32 PM
Talking the best/strongest possible case and a new premium rifle. 139/140grain projectile.
Is it possilbe to run those bullets at 3000fps or more? Maybe even 3200?

What would happen if you crammed in let say twice the amount of powder you should (dont know if thats even possible but lest say it is) in a case?

Will the case rupture? Will the rifle blow up?

I also got a (few) question about muzzle brakes, I doubt youll need on on a 6.5 swede but still. Lets say you have a recoiling power of 40J, how much can that possibly be lowered with a muzzle brake? (the most efficient, ideal muzzle brake that is)

What is the most efficient muzzle brake design today? First id like to say I dont know much about this (I just go with common sense), but it looks to me like the barrett type design seems efficient http://www.barrettrifles.com/pdf/Model_82A1_Exploded_View.pdf
diverting the gasses 45 back, but is a more "round", streamlined design better?

Like this one, Armalite http://www.50bmgstore.com/ar5050bmg-2.htm
is this design more efficient?

Also should the space between the baffles be the same all over, or should it be more distance for example in the middle or towards the end? Anything to gain with more baffles?

Ive been thinking about this for quite a while and wonder if this would work (imagine you look at the brake from above) http://en.wikipedia.org/wiki/Fan_%28implement%29 but with an angle of 90-100 (instead of that ~160 as in the picture), widest circular end away from the muzzle obviously. The internal design would be something similar to the armalite

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Jim Watson
September 13, 2007, 10:43 PM
The highest velocity I have seen for a heavily loaded Swede in a strong action is a 142 gr SMK at 2900 fps.

Results of a gross overload depend on the action. From pictures and accounts I have seen, if there is any exposed brass as with a Mauser or Springfield, it will likely blow the casehead and demolish the gun. If it is of the Remington fully enclosed casehead pattern, it can expand the bolt into the action or barrel breech and fuse the brass; leaving it both brazed and swaged in place. Sometimes the bolt can be beaten open and replaced, the barrel and receiver remaining usable.

I don't know much about the theory of muzzle brake design, the NRA won't let me use one. But I have read that the jet effect of powder gas can contribute 25% of the recoil of a high velocity or high intensity rifle. Supposedly impact of the gas stream against the brake baffles can generate a forward impulse reducing overall recoil by more than that 25%.

rangerruck
September 14, 2007, 12:26 AM
I would say in a modern built rifle, you could do it , easy, to 3000fps. I know I read somewhere, a dude, with a montana action he had built , was trying for 3200, but I don't remember how the story turned out. 3000 I would say is deff doable.

SCW
September 14, 2007, 12:38 AM
I don't know much about the theory of muzzle brake design, the NRA won't let me use one.

Jim, why does the NRA care what you shoot?

SprayAndPray
September 14, 2007, 12:49 AM
25%, is that depending on how many grains of powder is used in the cartridge? I mean bullet/powder ratio. Im thinking if the projectile is 150grains and the powder 50, those 50 can be diverted elsewhere than just straight ahead, 25%. Dont know if I understand this right tho. But still 25% is good I think.

Zak Smith
September 14, 2007, 01:00 AM
There was recently a thread analysing the effect of muzzle brakes. You can use the powder momentum and some ratio of brake effectiveness to calculate theoretical recoil abatement. Also note that the muzzle velocity of the powder/gas ejecta is substantially higher than the bullet MV.

USSR
September 14, 2007, 06:53 AM
We have several guys, including myself, who use the 6.5x55 in 1,000 yard F Class Competition. The general consensus is, with certain powders (RL22, MRP, and N560), 2950fps can be safely reached. Since this is the velocity that most 6.5-.284 shooter's run their loads at, there is no reason to go beyond that. There are several other powders that will yield 2925fps, and I typically run N160 at 2925fps out of my rifle. Please note: loads like this are to be used only in modern actions.

Don

golden
September 14, 2007, 07:35 AM
I have a muzzle brake on one of my rifles and like it. It really does cut down the recoil. I have shot 36 rounds of .280 REMINGTON in a lightweight rifle from the bench without pain.

A good muzzle brake can also improve your accuracy. Not all brakes do this, only ones like the BROWNING B.O.S.S.


The negative aspect of a muzzle brakes is the muzzle blast and noise go up for the NON SHOOTER. Usually the shooter does not notice this as they are directly behind the brake. Shooters in the next lane at a range will NOTICE IT IMMEDIATELY.
If you get a brake, be neighborly and shoot from a couple of lanes down from the next shooter if you can.

On the 6.5x55, why would you want to magnumize it? One of the great strengths of the 6.5 Swede is the gentle recoil. It is very effective on game at the low velocities of American ammo companies.

Jim

USSR
September 14, 2007, 08:30 AM
On the 6.5x55, why would you want to magnumize it? One of the great strengths of the 6.5 Swede is the gentle recoil.

Not really "magnumizing" it. The Swede is deliberately downloaded because it was originally chambered in the single lug Norwegian Krag rifle. Just bringing it up to normal operating pressure in modern rifles. When you are shooting at LR, high BC bullets and velocity are needed.

Don

Jim Watson
September 14, 2007, 09:02 AM
SCW,

I presume that the NRA does not allow muzzle brakes in Long Range shooting for the comfort and safety of the other shooters on the line. Or maybe they thought that reduced recoil would cause an equipment race and encourage people to shoot ever more powerful cartridges to try to beat the wind.

I don't actually know their reasoning, it's just The Rule.
Doesn't matter to me, I shoot F-T/R and my 13 lb .223 and 17 lb .308 don't kick much anyhow.

Friend of mine is looking hard at the Swede, he figures the long neck will burn more of the powder in the case and extend barrel life; which is notoriously short in the 6.5x284.

GunTech
September 14, 2007, 09:42 AM
If you load the 6.5x55 to 60,000 PSI, you can easily get 3400 fps with the Sierra 85gn HP.

slzy
September 14, 2007, 10:18 AM
i remember in the hey day of hot rodding 5.0 mustangs,people started using injectors from a 460. at this point,why not use the whole 460?

USSR
September 14, 2007, 10:45 AM
Friend of mine is looking hard at the Swede, he figures the long neck will burn more of the powder in the case and extend barrel life; which is notoriously short in the 6.5x284.

Jim,

Exactly why I went with the 6.5x55, along with the availability of Lapua brass.

Don

SprayAndPray
September 14, 2007, 06:05 PM
Is Lapua brass considered better than Norma? Whats the difference? How many times can you use the brass if loading it quite hot?

Jim Watson
September 14, 2007, 06:28 PM
I have not used any Norma brass in years. Lapua is very, very good.

Try to squeeze the last fps out of it and brass will be trashed in one or two loadings. To no purpose, a reasonably heavy load like USSR's in a strong action is fine to 1000 yards.

I begin to doubt you are serious or sensible.

USSR
September 14, 2007, 06:41 PM
SAP,

Norma brass in 6.5x55 is not great. It will not stand up to stiff loads like Lapua does, and does not have the consistency of Lapua either.

Don

SprayAndPray
September 14, 2007, 06:47 PM
Jim I was just asking..

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