Recommended powder charge for new .20VT

[Goofycat]

I will take delivery of a new Cooper .20VT in ten days and need advice on the starting and ending powder charge values. I plan to use H4198 for now. I have Todd Kindler's manual for all the .20s, but have read that his recommendations are on the "hot" side. I am not interested in a powder charge where I will have to worry about over-charging. I just want a good, efficient load that approaches maximum without going over the top, and still retain accuracy. I will start with 32 grain Vmaxes and Sierras.

Also, does anyone have a current recommendation for a good primer? I have a whole bunch of small-rifle CCI benchrest primers, but they have been used for my .222 and .223 rifles. I have no idea if they would be optimal for the .20VT. Or, is there really any big difference in primers for the .20VT, other than the possibility of poor fit in the base of the case?

Barry

 

[garyw]

GOOFYCAT.i got both TODDS BOOKS 17/20 cal read the notes in them re;loading and as with any loading manual start with caution.work up a load that siuts your rifle with a bit of tweaking on powder charges and seating depth on bullets youl find a combo that works.i did it was worth paying a bit extra to get both manuals sent over here to the U.K.also iv subscribed to TODDS small calibre news,good write ups and load info.
good luck garyw

 

[Goofycat]

Thanks, Gunamonth. The map answers the question of max load,18.7 grains of H4198), but I have no idea where to start. I would imagine around 18 grains, then work up from there? I could go much lower, but I don't want to waste time going too low.

 

[Goofycat]

Thanks again, Gunamonth. I will take your advice and start with 17 grains. I want to end up with a fairly maximum load so as to fire form the cases as much as possible. I am using brand new .221 Fireball brass necked down to .20VT. I have never necked down anything before. Is my thinking right that I should try for as much expansion as possible for fire forming these new cases? Seems to me that if I fail to add enough powder, the cases will not expand as much as they should. Am I right, or does it make little difference in how much powder is required to fire form?

 

[georgetwalkerjr]

I'm also working with new 20VT...and am using Todd's data, along with some from The Twenty Caliber page of 6mmbr. It covers 32Vmx and Berger 35gr. I'm looking for data for 40gr?

Re sizing....highly recommend that you be generous with sizing lube.....I'm using Imperial Sizing wax, and wiping a smidgen over the top of the case to the neck is lubed inside and out. I had to deal with a stuck case last week. :-,

Best,

George

 

[Goofycat]

Why is Imperial Sizing wax better,or is it?) than Redding or RCBS case lube? Easier to use? Works Better? What?

 

[bhoges]

18.2 of 4198 gets me one hole groups. I have a 24in barrel getting very colse to 3600fps. Not much room in the Rem case for much more powdor. No pressure signs so I guess if you can get the powder in you might get a few more fps.

 

[Goofycat]

3600 fps should work just fine. If I were after a faster velocity, I would have bought a .204 or 20 Tactical and paid the price with increased barrel heat. Thanks for the input. I will see what happens with that load in my 26" barrel.

 

[georgetwalkerjr]

Imperial is a wax, and is wiped on using the hands....very easy to make sure it's lubed, without making a mess. I think it's a superior product, but I know that others have diff preferences. Good luck. George

 

[SplatCat]

Guys, I need some advice. I am ready to neck down some .221 Fireball cases into .20 VarTarg cases. The cases have been sorted, the primer pockets uniformed and the flash holes deburred. My questions: which part of the case,other than the shoulder area should NOT be lubed? I.e., since the neck is going to be squeezed to .20, shouldn't the outside of the neck be lubed also to prevent the neck from sticking to the die? Ordinarilly, I lube only the body of the case, plus a very light lube,usually mica) on the inside of the neck.

Also, should the expander button portion of the die be removed during insertion of the case into the .20 die, or should be left in? Or...does it make any difference?

Any other advice, tricks, precautions, etc.?

Thanks,

Barry

 

[ChuckMiller]

I've found that just necking down a 221 case is not enough on the 20VT to chamber a round with my rifle. I take a 221FB FL die and remove the expander stem and do a hard cam over to bump the shoulder back. By not pulling the expander buttom back through it, it in effect takes it down a little, making it easier to size with the 20VT bushing die and moves the shoulder back a little. I then size the neck down pulling the 20 cal sizing buttom back through it. I use Imperial on the outside of the neck and inside to keep from stressing the brass too much. As long as you use it sparingly it's not an issue. If you get a dent it's no big deal, remember your fireforming. Dents will give you a clue as to if your using too much lube though but as long as they chamber their ok. I usually keep the wax close to the press and just spin the case with a little wax on my thumb. My rifle is a Rampro built by Kevin Weaver and is headspaced tight and even with the first step of pushing the shoulder back it's still snug closing the bolt on a fireforming round.

 

[DogBuster]

18/H4198 in my VT using moly 40 V max nets 3636 fps....24" Pac Nor 12 twist tube...its my recycled 204 barrel after 2500+ rds...still going strong & busting dogs @ 450 yds...

 

[SplatCat]

I just returned from the range. Broke in the barrel with a total of 18 rounds on the .20VT, starting with 16.6 grains of H4198 pushing a 32gr VMax. Three rounds each, from 16.6 to 18.2 grains. I found that if too little powder is used, the shoulder seems to fail to end up with the sharpness in the shoulder area that was displayed with a test round by Cooper. Sharpness appeared at 17.8 grains of powder and maxed out at 18.2. I did not load any hotter than 18.2. Bullets were all seated .008" off the lands.

Chuckbuster likes his bullets seated lightly on the lands, so I will probably end up with my bullets seated the same way, but backing off to 17.8, 18.0 and 18.2 grains of H4198, dividing the different charges into three equal groups of cartridges just to check out any accuracy differences. Won't make any difference to the ground squirrels. They will be dead either way, but I ran out of time at the range today and have to leave for the big hunt day after tomorrow. That gives me another day to finish the above loads. Nice little rifle. I will push back the shoulders a bit more next time; the bolt closes just a bit too tightly for me on the empty cases I have to load, and I have no time to run them through the die again. Only a minor inconvenience. Will take care of it after the cases have been fireformed, anyway. :thumb: