20 Practical Build

[Coyotefurharvester]

Nice shot! Are you saving your pelts this year?
Paul

Any pelts without rubs, mange or red/brown hair are going to auction. I had pelts still held over from last winter. So I figured add to the pile.

 

[boltfluter]

Any pelts without rubs, mange or red/brown hair are going to auction. I had pelts still held over from last winter. So I figured add to the pile.

Good for you.

 

[LTRDavid]

Starting to get ready for load development and wanted to share some early results with pressure testing. I’m fortunate to have a bullet trap in the shop to determine where the max loads are without having to waste time at the range. I started with H4198 and 32 gr V-Max. My question is how much would you reduce the charge to start your load development? Keep in mind summer PD town temps can get up to 105°!

Here are some results with Re10x


I’ve got results with AA2200, Re7x and N133, so let me know if anyone would like to see those. Thanks for letting me share and I look forward to pertinent responses.

LTR out

 

[Coyotefurharvester]

I would consult Hodgdon 20 tactical load data, and a chronograph. I have Lee making a custom factory crimp die, to use on my AR 20p loads.

 

[Fast14riot]

When I had a 20P I used 20T starting data mostly. But, I generally back down 10% from pMAX.

 

[DiRTY DOG]

Nice build! A few questions for all:
1. Would you do a 11 twist again vs 10 twist? Any reason for 10 vs 11 twist?
2. Does the #4 barrel hold up to 5-shot groups? I've been considering a 20"-22" #4 or #5 for a walking varminter.

 

[L.Sherm]

I have no regrets on my 3G11 twists to 40 gainers. I'm in the camp no reason to spin a bullet anymore than necessary. For a 55 a 9twist.

 

[DiRTY DOG]

I have no regrets on my 3G11 twists to 40 gainers. I'm in the camp no reason to spin a bullet anymore than necessary. For a 55 a 9twist.

But is the "ideal" twist rate closer to 10 or 11 or 12?

 

[L.Sherm]

But is the "ideal" twist rate closer to 10 or 11 or 12?

What is " ideal"

 

[L.Sherm]

12 isnt

 

[L.Sherm]

Theres been tons of threads on this, search it you will find all kinds of opinions on "ideal"

 

[searcher]

But is the "ideal" twist rate closer to 10 or 11 or 12?

Depends on the bullet, intended distance of shooting and the particular barrel. I use 12" twist Hart barrels and they have no problem stabilizing 40 V-Max or 39 Blitz King and they shoot the 32's and under like crazy. Others report having had problems with their particular barrel in stabilizing the 40's with a 12". I personally believe the 10" is overkill for any bullet 40 grains and under. If you want to be safe, go with a 11". I'd personally opt for the 12" twist, figuring that if I was unlucky enough to get a tube that didn't stabilize the 40 V-Max, it will still likely stabilize the 39 Blitz king - and the 32's and under would be no problem. The best virtue of the .20 Practical is the laser trajectory. I want to do all that I can to maximize that.

 

[LTRDavid]

Nice build! A few questions for all:
1. Would you do a 11 twist again vs 10 twist? Any reason for 10 vs 11 twist?
2. Does the #4 barrel hold up to 5-shot groups? I've been considering a 20"-22" #4 or #5 for a walking varminter.

DD, thanks for the kind words.

1. I have a Rem 788 I built with an 11 twist Douglas chambered in 20 VarTarg using the 32 gr V-Max and it performs very well in the low .100’s You can read about it here. Anyway, this time I went with the 3 groove Lija as I read in Fred Ziglin’s biography of P.O. Ackley the 3 groove barrels foul less. But, to answer the 10 vs 11 twist I choose the 11 based on what I read in Kindler’s book and the practical experience of friends shooting 20 calibers. So, I never considered a 10 twist. My .02.

2. re: groups, I don’t know yet, I haven’t take it to the range yet, but I‘ll share that info when l do here soon.

 

[LTRDavid]

As I make this post I’m in SD helping out with the prairie dog problem… This is the maiden safari with the 20 Practical. The first shot/kill was 315 yds. The max yd kill was a double at 525! My biggest impression is I see the dog fragment before I hear the impact. Too cool.

 

[RegionRat]

Well Done!
What recipe did you end up with and did you get to chrono it in the local conditions?

 

[LTRDavid]

The recipe I settled upon is 32 gr V-Max, 28.1 H335, Rem 6.5 primer, 1.830 O2H, 4220 fps @ 70F & 500’. Hang on, I’ll setup the chrono… Here you go! The temp here is 75° F 1850’ Alt. I noticed the chrono pic is unclear. It reads 4266 avg fps over 24 rds.

 

[L.Sherm]

The recipe I settled upon is 32 gr V-Max, 28.1 H335, Rem 6.5 primer, 1.830 O2H, 4220 fps @ 70F & 500’. Hang on, I’ll setup the chrono…

Dang 6.5 primers, I tried them quite few years ago in the first primer scare in a 222 and it pierced about 50% of them.
Switched to 7.5 and nary a problem since then

 

[LTRDavid]

Dang 6.5 primers…

Thx, I’ll keep that in mind. FWIW, I got up to 4301 fps before I started seeing any pressure signs, but the 4220 fps produced the best groups.

 

[L.Sherm]

Thx, I’ll keep that in mind. FWIW, I got up to 4301 fps before I started seeing any pressure signs, but the 4220 fps produced the best groups.

That is smoking right along

 

[Fern]

That is smoking right along

Understatement. That’s a laser beam lol
Only thing faster I have seen is a 40g Nosler in 22-250 at 45xx