.270 Velocities From an 18.5" Barrel?

R

Rob3

New member
Does anyone know what kind of muzzle velocity you can expect from a .270 WIN rifle with an 18.5" barrel?

A local shop has a Ruger RSI in .270 on sale for $699. I am seriously considering it since I have always wanted one in 308 but the prices have rocketed above $1,000 since Ruger stopped making them a few months ago.

I have been searching on Google and I have seen conjecture from 100 to 30 fps lost for every inch shorter than 24". This would put it somewhere between 30/30 and 30-06 velocities. Not very helpful. Some think it may be a flamethower that will burst your eardrums, some say not.

What do you think? Would faster, lighter rounds with fast-burning powder mitigate the short barrel or would it be the opposite? This would strictly be for hunting whitetails from less than 300 yards.
 
.270 is one of the calibers that looses a lot from shortened barrels. Worse than the velocity loss is the muzzle blast. A shot from a barrel that short is going to look like the space shuttle going off.
 
A friend of mine is a long time hunter and gunsmith. He absolutely adores .270 win and influenced me to get one. When I asked "what gun should I buy", his reply was short. Any gun you like as long as it has a 24" barrel! He then expounded a bit about powder burn rates, and muzzle flash that would most certainly come with shooting this caliber through a shorter barrel.

Now, I have some friends who do have .270's with 22" barrels. They lose 50-100 fps on their handloads from the published data.

IMO (worth every penny you pay for it) an 18.5" barrel in this caliber will not perform very well.
 
The velocity on most chamberings will change somewhere between .5%-1% for each inch barrel length changes. If you are expecting 3000fps from a load in a 24" barrel you should expect somewhere between 80-170 fps slower velocity from an 18.5" barrel. Not enough difference for any game anmal to ever notice at distances where ethical shots are being taken.

If you plan on shooting at ultra-long range you will see enough difference to matter. Muzzle blast will be a concern.

If you like the rifle buy it and go hunting.
 
The velocity on most chamberings will change somewhere between .5%-1% for each inch barrel length changes. If you are expecting 3000fps from a load in a 24" barrel you should expect somewhere between 80-170 fps slower velocity from an 18.5" barrel. Not enough difference for any game anmal to ever notice at distances where ethical shots are being taken.

If you plan on shooting at ultra-long range you will see enough difference to matter. Muzzle blast will be a concern.

If you like the rifle buy it and go hunting.
Click to expand...

Agreed. It will not be very efficient with the shorter barrel, but you will not notice a difference if it is a hunting rifle. Heck, the old Swedish M94 carbines had a 17" barrel and 6.5x55 is just as overbore as the .270. I say if you you like the rifle, go for it. Accuracy will not be effected, just velocity.
Regards,
-Dan
 
Thanks for the input guys. It wouldn't bother me to lose a couple hundred fps but I think I will hold out for the 308 that I really want. It just seems like it would be more efficient in this package.
 
I won't try to talk you out of a 308. A great round and one of my favorites, just make sure you do it for the right reasons. Don't confuse efficiency, with performance.

It is true that a 308 will be more efficent in a shorter barrel and will lose a smaller percentage of it's velocity. But traditional long action action rounds such as the 270, 30-06 and even the 300 mags start out with a lot more velocity. While they may lose a larger percentage of their original velocity from shorter barrels, they will still come out of a shorter barrel moving faster than the 308.
 


With a barrel that short, something like a 6.8SPC or a 338Fed is a better match.... I don't like 308 out of barrels much shorter than 21" (or 20 if it's a semi-auto) - too much muzzle blast.



-tINY

 
Thanks again guys. Jmr40, I was thinking along the same lines that a 270 from even a short barrel would still be just as flat shooting as a 308. When I looked at the gun again today I just did not like the looks of the long action with the short barrel. Don't try to make sense of it, it just didn't speak to me. I will continue to hold out in hopes of finding one in 308 for a reasonable price.
 
18.5" Ruger

What are the odds? I had a Ruger M77-II Mannlicher style carbine (is that the RSI? ) in .270 in my hands on Tues, 11May, and the asking price was $699 at a certain shop in E. Alabama.

Same trip I handled a Ruger #1 RSI in .270 in Johnson City TN, also in .270.

My comment to bamaboy was, "If either one of those was in .308, I'd buy it.!"
 
Rob3, Those are valid reasons. I personally like a barrel of around 20" as a minimum on most rifles, but understsand why others may want a shorter barrel. The concerns over lost velocity are greatly exagerated for most folks using a hunting rifle. For someone shooting at 1,000 yards they really need to squeeze every fps they can out of their rifles. On a hunting rifle, the way the rifle looks, and balances is the more important than a few fps either way.
 
I joined this forum because of this post even though it's a year old. I found it while searching for others experience with velocity loss in the 18.5 barrel.
More on that latter but i can tell you I have owned an RSI in .270 since 1986 and have shot many whitetail and mule deer with it since. I hunt every year with this rifle in eastern WY Black Hills, shots are close brush and oak to open fields with shots as long as you can see.
I have never once felt the rifle was not up to the task with any shot 300 yds and under. It's a joy to carry, fast to the shoulder, hits even a big mulie like a train and doesn't bark anymore than the various 30.06's in camp and much less than the boy's .270 Weatherby mag and .270 WSM. Muzzle flash? A bit but don't do much shooting at night...much.
I own, shoot, reload for, hunt with and collect many rifles and the RSI .270 is always my go to from deer to pigs to black bear to elk in timber.
 
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