Will there be any significant velocity loss going from a 22" bbl to a 19" bbl???
I currently shoot reloads using IMR 4451.
It's a gun I shoot with a surpressor on it, trying to make it a bit more user friendly.

Perry

20 to 40 fps loss per inch.

Maybe.

Very rifle, barrel and load specific.

My free advice: Don't cut it.

What Use Enough Gun said.

Not sure what user-friendly means; the .257 is a mild-mannered cartridge, and the noise from the report is readily controlled by plugs or muffs.

Rather than chopping the barrel go for a smaller more compact suppressor. Over here in the UK many use moderators (as we call them) and standard practice is to remove them when not using and storing. Left on when a rifle is stored all the acids etc from burning powder, which get caught by moderator) fall back down into barrel ad can cause all sorts of damage.

There is a temptation to constantly take mods apart. Don’t, especially those made of aluminium. The threads are pretty fine, and once they have been gunked then hard to reassemble and very easy to cross thread. This leads to mod letting go on firing. Much the best is just give them a good tap to let the gunk fall out. And then put them somewhere warm so any moisture is driven off quickly.

How far do you shoot and how much velocity do you want to lose. Consider those, and chop away.
I, personally, want my barrels to be 25 inches, and I would never use a suppressor/moderator, whatever.
Guys here want them, because they just allowed them in this state. No other reason.

I'm not sure you'd actually lose anything.

quote:

Originally posted by Lamar:
I'm not sure you'd actually lose anything.

Well, I am. Any reduction of length of a given barrel will reduce the muzzle velocity of any bottlnecked, high intensity cartridge. The earlier guess of 20 to 40 fps per inch is a reasonable ballpark estimate. As with any cartridge or bore, just how much depends on the relative burning rate of the powder, the condition of the bore, and maybe the phase of the moon.

Anyway, if you can live with 50 or 100 fps less velocity and it is worth the trouble and expense to have a shorter barrel, then pay your money and take your choice.

As for me, I hunted with the guide's 24" barrel .270 with an 8" suppressor mounted on it in Africa and didn't find it handicapping in any significant way.

By the way, the longer barrel results in less muzzle pressure which makes for less blast for the suppressor to suppress -- and moving the muzzle blast that much further from your ears enhances the efficacy of the suppressor. Just as with an unsuppressed barrel, chopping the barrel will have the effect of making the rifle louder than it otherwise would be.

quote:

As for me, I hunted with the guide's 24" barrel .270 with an 8" suppressor mounted on it in Africa and didn't find it handicapping in any significant way.

Have done the very same thing. I also have a SilencerCentral Banish338 9" suppressor that fits 8 of my threaded barrels. Most of them are 24" barrels.

It depends on how much you're carrying the rifle round, if you have to backpack around with it then people cut the barrels shorter over here to accomodate the suppressor. But otherwise, keep the velocity. Speed kills. Especially in things like the .257 Roberts, .243 etc.

quote:

Originally posted by perry:
Will there be any significant velocity loss going from a 22" bbl to a 19" bbl???

Perry

Yes. A Bob makes good use of every bit of 22". A 19" bbl would be better suited to a shorter case with steeper shoulder and faster powders.

Many years ago I handled a Winchester pre64 M70 in 257R that had been rechambered to 257WBY....and the barrel cut to 20"

My .257 Roberts wears a 20" barrel - I get 2800 fps with a 117 gr. SGK.

I can't see 19" being that big a deal...but a fair bit of muzzle flash and blast.

quote:

Originally posted by perry:
Will there be any significant velocity loss going from a 22" bbl to a 19" bbl???
I currently shoot reloads using IMR 4451.
It's a gun I shoot with a surpressor on it, trying to make it a bit more user friendly.

Perry

From your comments it seems you already have a suppressor on your 22" barreled 257R rifle? If so is it a muzzle forward suppressor or one that screws to the muzzle with a portion of the suppressor coming back over the barrel and a portion forward of muzzle?
These are the suppressors to use, not those that all unhandily hang forward of the muzzle.

I use a 7mm WSM rifle with an 22" barrel fitted with a 13.5" long suppressor (w built in stainless brake) which has 8.5" back over barrel and 5" forward of muzzle. Chronographed factory ammo shows velocities for 140gr (@ 3230fps ave.) and 160gr (@ 3008fps ave.) bullets, a bit better than factory advertised MV's so nothing lost in the shorter barrel for this rifle/cartridge combination anyway.

My pocket knife is that long! cutting to 19" has nothing to add to a rifle but feel, and thats a good reason I suppose,

I would not go beyond 20 inches, past that you pay a small price in velocity, always seemed the turning point.

22" alway seemed to be ideal for me..a nice compromise anyway.

Id solve your problem by cutting off the muzzle brake. I fail to see the need for a brake in a 257 Rooberts. its all but recoilless but you may have a medical reason or ?? but you have room to shoot mild loads and still equal a 250 savage or 243..