A "short" 20VT, or just light loads? For 50-200yd paper and steel?

[saber63]

Just as it sounds. I really only shoot paper and steel from 50-200 yards. Steel means I need to keep velocity below 3000fps at 50yards. Otherwise id go straight 20vartarg or 20practical.

Im also trying to minimize powder consumption. Barrel heat/wear/recoil etc... honestly... a 17hmr would work, but i want to reload it.

I started thinking a .17 but noticed bullet selection is limited. Lots of options 20 cal pills.
I have been kicking around a 6ppc build, and noticed .204 is %83 of 6mm... And the .378 case diameter is %86 of the .440... So lets make a %85 ppc!

And you get a 20VT but ~.159" shorter... Sooo could I take a 20vt barrel and shorten it? Or run a reamer shallow? Or am i stuck ordering a reamer?

I could start with a normal 20VT build with heavy pills and lighter loads, but ive read/heard that under filling cases tends to be inconsistent/other issues. Could i run a full fill of a slower powder? To get velocity down to 3000-3200 fps? But this would be less efficient in terms of powder use...

Ill admit i ran across another form member showing some short 20VT brass (.100 and .150") when google searching... but I never saw a build, or load data etc... as to if it actually worked....

If this goes anywhere it would likely be on a howa mini action or a rem700 clone like a solus.

Thanks!

-Levi

 

[snert]

Run Blue dot. Read Calhoune's "To Bee or not to Bee" article.

 

[snert]

To Bee or 223, That is the Question

 

[snert]

800X is no longer made. However, he wrote an article about using Blue Dot. I would assume if you hit his website it is still there.
I have used Unique in a 222, 220 Swift to run reduced loads safely and there is no reason the same math could not be done with a 20VT. I only suggest that you fire the case full power, then neck size only afterward on reduced loads. Otherwise you may not get a good seal.
Blue Dot runs cool and will get higher velocity than Unique...a "gopher load" as opposed to a "tree squirrel" (Unique) load...so research the blue dot and play a little. Just cause you have a hotrod doesn't mean you always have to run it with the pedal on the floor and nitrous in the intake!

 

[snert]

James Calhoon Fine Shootin' Bullets Main Page

See the "revisited" article. It covers Blue dot. If you have a chronograph, you could safely start with 3 grains and move up till you hit the speed you want. Because the case is smaller, and the caliber smaller, I would go slowly, because you will peak quickly.

 

[NorCalMikie]

Tried the 20 VT "short". Brass ended up being junk. Had issues with case head being distorted to the point of FTF till the brass was fired and the case blew out.
Happened to stumble on the 22 TCM. Beautiful factory made brass.
Got some, necked it down to 20 and got my 20 MGM Wildcat.
Around 10 grains of AA 2230, 25 to 30 grain BT bullets.
Have to single load but I can live with that.
Custom made dies from Whidden Gun Works. Custom made reamer cut to my specs.
Another shooter showed interest, so I sold him the reamer. Not sure how far he got with his project but it looks like he got further than me.

 

[saber63]

Snert, lots of good info! Thank you! Stayed up a little late reading lots, chased some leads etc... I ended up finding some ~17gr loads for 55gr that pushed 3000-3200fps. Just what im looking for!!!

Mikie, got any links to your build and results? 20mgm sounds interesting as well! How fast where those 25 and 30's going?

Thanks!
-Levi

 

[NorCalMikie]

Mikie, got any links to your build and results? 20mgm sounds interesting as well! How fast where those 25 and 30's going?

Never checked FPS. More interested in accuracy. Got brass made up/formed from custom dies.
Got starting loads and got as far as popping a few rounds out back.
Was concentrating on getting the short 20 MGM to feed.
Think I'am there but range time will tell for sure. Going shooting by myself just doesn't get it.
The man that got my reamer mentioned something a few weeks back about the 20 MGM and how it works for him so maybe you can find that info. At least somebody is shooting.

 

[drewh]

I have the reamer now. I am still working with components to figure out what works, but the general gist is right around 3000 fps with around 10-10.5 gr of powder. Mine is on a CZ 527. I have a modded magazine for it, but mostly shoot with a Calhoon single shot adapter. It's a great deal of fun, but got put aside for the moment so I can work on match loads for a different rifle. I have a couple of other cartridges in the 20 that move the powder capacity up to around 14-14.5 gr loads that are running just short of 3200 fps. If you look at my profile pic, far left is TCM, the 2 in the middle are 14.5 gr loads and the far right is 20VT.

 

[rickiesrevenge]

What are the middle two cases @drewh ?

 

[saber63]

I have the reamer now. I am still working with components to figure out what works, but the general gist is right around 3000 fps with around 10-10.5 gr of powder. Mine is on a CZ 527. I have a modded magazine for it, but mostly shoot with a Calhoon single shot adapter. It's a great deal of fun, but got put aside for the moment so I can work on match loads for a different rifle. I have a couple of other cartridges in the 20 that move the powder capacity up to around 14-14.5 gr loads that are running just short of 3200 fps. If you look at my profile pic, far left is TCM, the 2 in the middle are 14.5 gr loads and the far right is 20VT.

What are those middle two? Ill admit the more i look, the more i like these little 20's for what i do.

Would you be willing to sell or loan out said reamers? Not any time soon. Maybe this year?

 

[drewh]

What are the middle two cases @drewh ?

The 2 middle cases are the 20/30 carbine, and 20 Viper - 20 VT with the shoulder pushed back .100, but with a longer neck by .050.

 

[drewh]

What are those middle two? Ill admit the more i look, the more i like these little 20's for what i do.

Would you be willing to sell or loan out said reamers? Not any time soon. Maybe this year?

I have the 20 on the TCM case and the 20 Viper reamer still, and would be willing to loan. My gunsmith liked my 20/30 carbine reamer so much he talked me out of it, but I can direct you to him if interested.

 

[NZ_Fclass]

I would have fun with a pistol calibre and save the agro. 9mm/357/38? All capable of 200 yd shooting in a rifle, even with lead bullets.

 

[L1986]

I have the 20 on the TCM case and the 20 Viper reamer still, and would be willing to loan. My gunsmith liked my 20/30 carbine reamer so much he talked me out of it, but I can direct you to him if interested.

What was case forming like on the 20/30 carbine? What is the die situation like?

 

[drewh]

What was case forming like on the 20/30 carbine? What is the die situation like?

The case forming is not bad, if you buy the 5.7 spitfire forming dies for the first 2 steps. Alternately 19 badger brass from Calhoon can be used with an expander mandrel and a fl die. I ordered a resize reamer, and had a Newlon bushing die and a ptg die blank cut and sent off to heat treat. I used a Wilson die blank for the seater, cut with my chamber reamer. As far as I understand, Whidden no longer makes custom dies, which leaves Neil Jones as the only one I know about. Others may be aware of other options.

 

[rayh]

The case forming is not bad, if you buy the 5.7 spitfire forming dies for the first 2 steps. Alternately 19 badger brass from Calhoon can be used with an expander mandrel and a fl die. I ordered a resize reamer, and had a Newlon bushing die and a ptg die blank cut and sent off to heat treat. I used a Wilson die blank for the seater, cut with my chamber reamer. As far as I understand, Whidden no longer makes custom dies, chick leaves Neil Jones as the only one I know about. Others may be aware of other options.

Drew who heat treated your Newlon? Does it leave burnished marks on case after heat treating? Thanks.

 

[drewh]

Drew who heat treated your Newlon? Does it leave burnished marks on case after heat treating? Thanks.

Hi Ray, hope you are well, it's been a bit. I had Fireball heat treat in MA do them - did find out that I sould have gotten all the die blanks from the same place and it ended up being 2 batches because the difference in steel. I did have a little of what you are talking about. I polished the die some more with a bore mop with Iosso on it, in a drill.

 

[rayh]

Hi Ray, hope you are well, it's been a bit. I had Fireball heat treat in MA do them - did find out that I sould have gotten all the die blanks from the same place and it ended up being 2 batches because the difference in steel. I did have a little of what you are talking about. I polished the die some more with a bore mop with Iosso on it, in a drill.

I only have the one Newlon, I'll check them out for price. I had Hornady make me another for the 17Jav Imp but I'd like to get the Newlon working as it should if I ever get rid of one of the guns.. Thanks Drew