31" Rimfire Barrel

[thedrifter]

So, I did some search and didn't find much anything on trusty google so I ask the professionals

What would the effects be of a 31" rimfire barrel in a light palma contour?
1. I would have a longer sight radius current 27"
2. likely a decrease in Velocity? longer barrel slowing the bullet down? maybe
3. Harmonic effects? negative or positive?

Goal: trying to mimic 308 Palma rifle, in Medium contour? both have same rifle stock.

Estimates for barrel weight
308 at 32" Medium Palma at 5.85lbs
22 rimfire 31" Light Palma at 5.84lbs

Just thinking out loud,
Cameron

 

[DR1586]

I went with a heavier diameter barrel and a bloop tube to achieve the same effect. I believe my Barrel is 25-ish inches finished length and 6" tube. Puts the sights within .5" of one another on the big gun and small gun.

 

[USMCDOC]

So, I did some search and didn't find much anything on trusty google so I ask the professionals

What would the effects be of a 31" rimfire barrel in a light palma contour?
1. I would have a longer sight radius current 27"
2. likely a decrease in Velocity? longer barrel slowing the bullet down? maybe
3. Harmonic effects? negative or positive?

Goal: trying to mimic 308 Palma rifle, in Medium contour? both have same rifle stock.

Estimates for barrel weight
308 at 32" Medium Palma at 5.85lbs
22 rimfire 31" Light Palma at 5.84lbs

Just thinking out loud,
Cameron

Use a shorter barrel and then put a bloop tube on it to achieve the sight radius

 

[watercam]

If you want to maintain the weight of a longer barrel you can make a David Tubb style version of a bloop tube with a piece of barrel stock but machined to maintain thicker walls with what ever sight relief cut you need. Optimal velocity comes at around 20" of barrel length. My 27" barrel cuts standard velocity ammo speeds to about 1000 fps from 1080.

 

[mgdietrich]

Nevius tried long SB barrels years ago, couldnt get the accuracy. I would not waste my time. Go 20-26, somewhere in there to get the balance you want an add a bloop tube if you want a longer sight radius.

all my rifles have the same sight radius, Palma, Any rifle and SB gun. SB is a 21" barrel, others both carry 30" tubes.

Just an opinion.

 

[thedrifter]

Thanks,
The longer barrels are really that bad for accuracy? I suppose I have just had better luck without the bloop tubes, I am trying to avoid those, the return to zero is better without a tube. That gets me shooting into the center faster, I guess Short and fat is the way to go.

So 24-25" with 6" or 8" tube should be a good combo, is there a popular preference diameter? i want to say my Annie has a .920" now, and if i go from 27" down to say 25" I should look at around .950" so estimate 4.8 lbs saves about a pound for a sight tube...

Sincerely,
Cameron

 

[6xcshooter]

31" barrel for a rimfire hmm? wonder if the bullet would be slower at the muzzle in a 31" compared to say a 20" barrel. 22 rimfire doesn't have a lot of powder to push it. The extra drag on the bullet in the barrel would slow it down?

 

[mgdietrich]

I have a 1" diameter, 21" long. I was trying to get the weight farther back. .92 is normal Ahg diameter, I would probably just go with that and decide on whatever length you want. If your Bloop tube wont return to "0" easily, then there must be something wrong. I have warner sights on mine, and my zero tracks. Bloop tube comes on and off everyday. Mine has a reference ring- Uptagrafft, but I believe the Bee Sting and Starik do something similar. Had an ESP before and that returned to "0" as well.

 

[thedrifter]

well, perhaps I should clarify what my return to zero was. It's not like I would be chasing the shot around the white all day. With the tube it was not uncommon to find myself in the wide side of the 9 ring, on say an NRA 50y target. but with the fixed front sight on a ladder its almost always in the 10 first shot. Maybe it was just the way I would put the tube on, I use a torque wrench and hold the same side every time, but who knows.

I have an Upta tube on my FWB 27" Benchmark, and that things a beast just WAY heavier and longer than my LR rifles that I am trying to replicate with this Anschutz.

Anyways, I have a Precise bloop Tube I've never used/installed and it uses a notch like the newer Upta design so Ill give that a closer inspection and see what barrel diameter it was for and go from there. Down side would be unable to use a ladder on the Anschuz Tube. I could switch out for a Houle Tube... but that's another discussion. and would require turning down the muzzle end (not Ideal).

I suppose this answers the original question but I was really looking for some hard data why longer would not work.

 

[BenPerfected]

Some say the longer RF barrels are harder to get lubed.
Ben

 

[swd]

31" barrel for a rimfire hmm? wonder if the bullet would be slower at the muzzle in a 31" compared to say a 20" barrel. 22 rimfire doesn't have a lot of powder to push it. The extra drag on the bullet in the barrel would slow it down?

31" is definately slower than a 20" or so barrel in a 22 LR.
The ballance of bore friction vs expansion is leaning towards the friction side winning. Just not enough powder.

 

[SBS]

Barrel time is more than twice as long as a .308, so much better follow through is required than with a .308 Palma rifle when not shooting off the bench. Sooner it gets out of the barrel (and still subsonic), the better. For whatever reasons, the BR top shooters have generally settled on the 24-26" barrels as the most accurate in the classes where the resulting weight permits it. Not that longer and much heavier barrels have not been tried; they seem to be harder to tune. Remember that in rimfire, we cannot load our own and can only choose brands and lot numbers to try to match the rifle's requirements for tuning. Tuners are used in RF BR shooting, but it adds weight and generally considerably more for heavier barrels.