Why the big 20s?

[Tommie]

Velocity loss, would a short barreled 204 be similar velocity to a 20 Br?

It will be suppressed all the time and to fit in my gun rack in the truck barrel will be 20” or shorter.

I guess what kind of velocity should I expect from say a 18” 20 br with a 40gr or 55gr

Personally I’d just do a 204 with a barrel that length. Especially with a suppressor.

 

[Skattergun]

Personally I’d just do a 204 with a barrel that length. Especially with a suppressor.

That’s kinda what I’m thinking, still curious what velocities guys were getting around a 20” barrel

 

[Gabe22BR]

3650- what I’m at on 21”

 

[RegionRat]

In my 204 Rugers, when I use the same ammo in different length bbls, it works out to about loss of roughly 40 fps per inch of bbl for the 40 VMax. YMMV

ETA: That 20" idea for the truck gun would still be outclassing all but the hottest 223 loads and still carry more downrange energy due to the higher BC.

 

[Gabe22BR]

In my 204 Rugers, when I use the same ammo in different length bbls, it works out to about loss of roughly 40 fps per inch of bbl for the 40 VMax. YMMV

My findings as well w/ select powders…

 

[L.Sherm]

I guess what kind of velocity should I expect from say a 18” 20 br with a 40gr or 55gr

If your goal is to run the 55's at 3600, 40 around 3900 or more in a 20" barrel the 20BRAI. The BR case is way more conducive to running 39-55 bullets at that speed because of the neck length just like the PPC case otherwise one or other is gonna be down in the case or seated way out for maximum potential. Pick your goal and go with it. For Speed the BR case is hands down winner vrs 204 and pure raw accuracy.

 

[Lefty2506]

At 40 fps/inch, going from 26" down to 20" is going to cost you about 240fps, which is about the equivalent of loosing 75 yds of reach. I would imagine that most of the 20 cal cartridges are going to loose velocity with a 20" barrel, so the questions I'd ask myself are how much velocity will the BR (or BRA) case gain from a 20in tube compared to any other option you're considering, and is that extra velocity worth the cost of the more expensive BR brass and bullets (assuming you want to use something other than the 39gr bk, or 40gr vmax).

Personally, if I want more speed my first choice is to go with a longer barrel and then a bigger cartridge, but that's just me. There are plenty of things that would cause me to want to limit the barrel length. Cans and vehicles are certainly 2 of the things that are on that list.

 

[L.Sherm]

I've built 2- BRAI mine is 28" it runs 3730fps with the 55's were it shoots the best, I built another for a friend that he only wanted a 26" when I sid load development for him they both ran the same FPS essentially were they shot the best.
Going to a faster powder with the 39-40's would probably negate some of the FPS loss in a 20" barrel. I know a couple that have shot really well with 8208 in the 39-40's.
At the end of the day its really no different than any other cartridge short barrel vrs longer barrel

 

[Skattergun]

3650- what I’m at on 21”

Was that with 55 or 39/40?

 

[Dgd6mm]

I've built 2- BRAI mine is 28" it runs 3730fps with the 55's were it shoots the best.

 

[L.Sherm]

Was that with 55 or 39/40?

I'm pretty sure its with 55's

 

[urbanrifleman]

I'm still trying to figure out the math on that Berger 55. The Bc is .35? How does it have less drift? The 62 eldvt has a higher bc than that .395. The 62 eldvt explodes like a hand grenade.

 

[Larry Koch]

Go big or go home.

 

[Tommie]

I'm still trying to figure out the math on that Berger 55. The Bc is .35? How does it have less drift? The 62 eldvt has a higher bc than that .395. The 62 eldvt explodes like a hand grenade.

Berger originally listed the BC at .381 but changed the number at some point. With a MV around 3750 I’ve found the .381 number to be accurate. While that BC is lower than the 62 ELD-VT the higher MV cures some of the difference.

 

[Gabe22BR]

I'm still trying to figure out the math on that Berger 55. The Bc is .35? How does it have less drift? The 62 eldvt has a higher bc than that .395. The 62 eldvt explodes like a hand grenade.

Wouldn’t compare Hornady BC to Berger BC…
Best to figure out what your Hornady Bc is first….didn’t know they made a 20cal 62gr bullet..

Berger is conservative..or in my findings anyhow..

 

[Lefty2506]

I'm still trying to figure out the math on that Berger 55. The Bc is .35? How does it have less drift? The 62 eldvt has a higher bc than that .395. The 62 eldvt explodes like a hand grenade.

This was the thinking behind my original question. I've come to the conclusion that they are basically a wash. Its just a question of whether you want to spend a little more money on the 55gr Bergers to get less recoil, or save money on the lead but burn more powder and get more recoil from something like a 22xc, 22 Creedmoor, or 22-250AI. The consensus seems to be that the lower recoil is why folks are keen on going with a 20 and spending a little more on bullets.

 

[urbanrifleman]

This was the thinking behind my original question. I've come to the conclusion that they are basically a wash. Its just a question of whether you want to spend a little more money on the 55gr Bergers to get less recoil, or save money on the lead but burn more powder and get more recoil from something like a 22xc, 22 Creedmoor, or 22-250AI. The consensus seems to be that the lower recoil is why folks are keen on going with a 20 and spending a little more on bullets.

The 22bra with the 62 eldvt has been wonderful. It barely moves.

 

[L.Sherm]

I dont trust any B.C numbers untill I shoot them to find out for myself, that being said when I do put my Berger stuff into there Ballistic app it has been on or Damn close

 

[Tommie]

The 22bra with the 62 eldvt has been wonderful. It barely moves.

What velocity?

 

[urbanrifleman]

What velocity?

3470.