20 caliber build

[bodhisafa]

Came across a lot of 55gr Bergers in 20 caliber and would like to build a 20 Grendel or 20 BR.

Has anyone on here have any experience with either caliber ...advantage disadvantages?
Suggestions?

I already have a 6GT and other bigger calibers so looking for something light and fast for varmints.

 

[Redvanes]

Man that sounds like a fun build! Those 55s are impressive!

 

[BurnOut]

FWIW, I couldn't get them moving all that fast out of a .204 Ruger. 3300-3400 or so. At that point, the drop and drift were damned close to 39-40gr pills around 4000 (but obviously with more energy). I figured that the 55s would make for a good 'yote load, but for my uses (prairie dogs), the 39-40 grainers are more explosive on target.

 

[steve123]

Could be that the person that sold you the 55's had the same problem I did.....

I had a 20x47L wildcat, well actually I still have the barrel, dies, etc. Anyway the 55's starting disintegrating mid air before 300 rounds were through the rifle. It was a Krieger barrel and when I called to explain they wouldn't do anything about it. I did have the 55's cranked out to 3830 fps but it was only a medium load in the rifle from what I could tell, and well they shot so well at that speed for a couple hundred rounds that I was happy until.... I tried to keep the barrel clean and throat maintained - blah, blah....

From what I understand if you get minimally invasive rifling it might help prevent the jacket from seperating from the lead core. Also I think 5R or polygonal would help too. Don't let the barrel get hot, keep the speeds reasonable, etc. I'd call Bartlein, get their advice, and order accordingly.

For whatever reason the 40's at 4100 fps (a light load) worked fine in this same barrel after I abandoned the 55's??? Honestly for 500Y and in this is good enough for me.

Personally if attempting the mantra of higher BC, going fast, and having low recoil for varmints, I'd rather use a 22 caliber sending 75ELDM in whatever case floats your boat.

I'd rather neck down from 6mm than 6.5mm so I'd pick the 6mmBR, but 22PPC would be even easier to neck down.

 

[steve123]

BTW the neatest 20 cal cartridge I've ever seen is one that I bought into a couple years ago. It's a 20-221AI. With 18.1 grains of H4198 it sends 32's at 3750 fps in a 21" barrel. Extremely low recoil, low noise, can fire many rounds before the barrel heats up, long barrel life, and components are cheap. By far my favorite medium range varmint cartridge! What a joy to shoot it is! If you don't mind those 55's going 3200 fps or so it'd work for those bullets in a 8-9 twist.

 

[bodhisafa]

BTW the neatest 20 cal cartridge I've ever seen is one that I bought into a couple years ago. It's a 20-221AI. With 18.1 grains of H4198 it sends 32's at 3750 fps in a 21" barrel. Extremely low recoil, low noise, can fire many rounds before the barrel heats up, long barrel life, and components are cheap. By far my favorite medium range varmint cartridge! What a joy to shoot it is! If you don't mind those 55's going 3200 fps or so it'd work for those bullets in a 8-9 twist.

Steve 123,
Are you suggesting I abandon the 20 Grendel project and choose a different case and bullet combination ?

 

[Halfnutz]

Check out the woodchuck den.

Todd Kindler has a book called "The Terrific Twenties" He has info on the 20 Lapua BR, Not sure on the 20 Grendel as it is not listed as such in the index. Good book with case dimensions and some load data as well as history etc.

Berger only does a limited run on the 55gr IIRC. I emailed them a while back about data for 20 practical. I only have 54 of them to play with so they are low on my load development list.

 

[Halfnutz]

Per the email from Berger, the 55s are available on a limited basis through Graf & Sons.

Kindler's book claims the 20BR will push them to 3700+ and recommends a 24-28" long barrel with a 1-9 twist, and load them slightly into the lands.

 

[Halfnutz]

20 Grendel is the 20 Titan?
31gr of RL15= 3760fps (max load).

Sounds like a fun project. Keep us updated.

 

[supercorndogs]

BTW the neatest 20 cal cartridge I've ever seen is one that I bought into a couple years ago. It's a 20-221AI. With 18.1 grains of H4198 it sends 32's at 3750 fps in a 21" barrel. Extremely low recoil, low noise, can fire many rounds before the barrel heats up, long barrel life, and components are cheap. By far my favorite medium range varmint cartridge! What a joy to shoot it is! If you don't mind those 55's going 3200 fps or so it'd work for those bullets in a 8-9 twist.

It takes me 27g of WC844 to get the 32 around 3700 in my 18" 20 tactical. About the same story, zero recoil, not as economical on powder, but making brass is a breeze. 26 was around 3600 and put 10 unless than inch. I will chromo again once i get a couple hundred rounds through it.

 

[bodhisafa]

20 Grendel is the 20 Titan?
31gr of RL15= 3760fps (max load).

Sounds like a fun project. Keep us updated.

yes the 20 titan is his version of the 20 Grendel.
Not sure which of the two cases would be best.

I spoke to black hole bullets and they recommended the 20 BR as it gives “more ““options”

The 20-221 fireball looks interesting however that case needs a unique bolt/action to work properly.

 

[will67]

221 fireball is the same case head as .223

 

[bodhisafa]

221 fireball is the same case head as .223

Correct what I have read is the position of the extractor needs to be at a certain clock face in order to eject correctly....someone else may need to chime in on this one.

 

[tydex21]

Correct what I have read is the position of the extractor needs to be at a certain clock face in order to eject correctly....someone else may need to chime in on this one.

I have a 20-221 Fireball aka a 20 VARTARG and didn’t have to do any modifications from the original setup which was a 223 Rem. Btw, I freaking love that cartridge.

 

[Mike Casselton]

Correct what I have read is the position of the extractor needs to be at a certain clock face in order to eject correctly....someone else may need to chime in on this one.

It's more related to the position of the ejector.

If you build something based on the PPC/Grendel case, CZ 527 or the Howa mini will feed and eject properly.

Check out Saubier dot com

 

[Travis224]

I had all the components from a 224 valkyrie build, so I had a reamer created and made a 20/224 valkyrie. With the 40s, I'm running at an even 3900fps, if imagine 55s would be 3300-3500fps as a guess. I was impressed at the drop at 1k..or lack of.

 

[will67]

I'm running a 20 VARTARG on a Bighorn TL3. Extraction and ejection aren't a problem but I still need to work on a good magazine. I put it together the last time we had a shortage and all you could find was 20 cal and 50 BMG. It's a blast out to 500 yards and is easy on powder.

 

[chevy_man]

I'm a fan of the 20 practical. Mostly because brass is damn near free and it is easily adaptable.

 

[bodhisafa]

If I decide to go with Grendel vs the BR case.

Would I need certain features to extract and eject the Grendel case ...like a Sako extractor and mechanical ejection for 100% reliability?

what action manufacture is recommended?

 

[BurnOut]

If I decide to go with Grendel vs the BR case.

Would I need certain features to extract and eject the Grendel case ...like a Sako extractor and mechanical ejection for 100% reliability?

what action manufacture is recommended?

I would think that a good starting place for your build would be a Howa mini action in Grendel or 7.62x39 (same face diameter). They really are slick little actions that run very well.

 

[RTH1800]

Lot of good advice above.
I have extensively shot 20 Tac, 20/250 and .204 R.
I have extra 20 Cal barrel blanks Krieger 8 twist iirc. if you want one. .204 is great with 55 grain Berger.

 

[steve123]

Steve 123,
Are you suggesting I abandon the 20 Grendel project and choose a different case and bullet combination ?

I learned the hard way to not push the extremes, 3 times now in different combo's of long bullets in various cartridges and some at higher speeds like my 20x47L, it always seems to bite me in the rear later on and I think I've got that out of my system. Man, it can get expensive to find out my cool project didn't work out like expected, so I had to figure out alternatives to getting around the problems.
If for some reason you have problems with the 55's you can use the 40's like I did. Since I had problems with the 55's I sold them but I've read of others not having any problems. Would I try the 55's again??, NOPE.

Just an FYI, I've shot my 20-221AI out to 675Y, and often at 421Y, it's not bad at all at 421Y except for wind drift but at 675Y it's silly.

I think it comes down to the distances you have in mind to shoot too in the context of use on varmints with a 20 cal. 300Y and in 32's are great, to 500Y the 40's, 500Y+ I'd want to build a 22 cal using 75-80gr because of those higher BC's. I had problems with the Hornady 88gr in my 223AI so I went to the 75 ELDM which worked out well but getting hard to hit stuff by 800Y in the wind. Ended up selling it to a friend because I like my 6mmBR so much more.

The easy button for me was just using my 6mmBR past 400Y, I use my 105gr load which has very low ES and hitting the 4" head of my 2/3 IPSC isn't hard at 800Y. Heck I have a pic of 1.5" vertical for 9 shots at 1000Y with it!!!

The chances are if you took my Bartlein suggestion and kept the velocities down with the 55's you'd be fine but IMHO you are nevertheless taking a chance with these bullets?????

 

[Lost_Phil]

I would look at the 20 and 22 Nosler. It has the same bolt face as 223 and they are the same length. There is also a 24 Nosler that fits the same bolt face as well.

 

[bodhisafa]

I would look at the 20 and 22 Nosler. It has the same bolt face as 223 and they are the same length. There is also a 24 Nosler that fits the same bolt face as well.

Thanks for the suggestion, I am locked in on using Lapua brass.

 

[bodhisafa]

If I am understanding the neck down process correctly ....I can purchase a 6 ppc and a 22 ppc seater die to begin the step down process of a 6.5 Grendel case with the final step being a 20 Grendel FL die. ???