20 Pup

[Gabe22BR]

Pup brass not hard to make.. at least 1 pc wasn’t…

 

[Kiwishooter]

I've thought about building a 20 Pup on several occasions, I even shortened a 22/250 f/l die to form the cases (you have to shorten it more than .180 that Todd says in the Terrific Twenties)

Todd got 3800-3900 with the 40gr Vmax, Max was aiming for 3650, Todd is known for pretty warm loads.
Todds load was just over 24gr of IMR 4198 and Max was using almost 21 gr of N133

I've been looking for what the case capacity of the 20 Pup is but can't find it, has anyone got a fireformed case?

 

[JSH]

It would be interesting to see some true, hard, lab grade pressures. Guesstimates, measuring, bolt lift, flat primers, etc mean little really. Efficiency gets thrown around pretty loosely, last time I checked speed and pressure runs hand in hand, no way around it.

 

[L.Sherm]

Guesstimates, measuring, bolt lift, flat primers, etc mean little really

What do 99.9% of us have to go by?
I know that land and grooves in barrels and different reamers make a difference also.

 

[JSH]

What do 99.9% of us have to go by?
I know that land and grooves in barrels and different reamers make a difference also.

Oh I completely get it. We have all used one or all of the “clues” at some time.
The technology of the actions and bolts have eliminated a large portion of old thoughts.
We have access to all kinds of ballistics programs and equipment today that wasn’t even a dream 20-30 years ago.
The glue on pressure/strain gauges are available fairly easy, I am just surprised that I see little if any mention of them, I refer to the blog/youtube crowd that have all the new toys and trinkets.

 

[L.Sherm]

Because of alot of variables i put very little stock in " pet" loads

 

[Gabe22BR]

Guess I fall in the warm loads department-
If I could find a reamer to use.. I’d load accordingly to the day temps/ conditions…

I’m running my little 20-221AI on the fast side- 19.26gr on N120 pushing a 32grNoslerBT @ 4024fps…
One could always draw up a reamer I guess.. to accommodate the volume of powder…

I cut my 22-250 die down to .904” shoulder length..all die lengths are different- that was the only way I knew how to do it..
necking the brass down- bushing only goes so far-
I’d probably ream a Newlon blank resize reamer.. then ream a Wilson for a seater..
Then everything would work….. maybe…??

I measured my case at 24GR - taking 21gr of powder..

 

[Gabe22BR]

Guess it’ll be in future needs department..

 

[bobcat93]

Anyone have a 20 pup ??
6ppc for size comparison
View attachment 1566409

How do you make the brass?

 

[Gabe22BR]

From 6 PPC-
Leave 1/8” neck on brass
Use 22-250 Bushing die cut to .904” shoulder height-

Make 3 passes w/ lots lube-change bushings ever pass to squeeze neck-
Trim to 1.336” OAL length

 

[Ledd Slinger]

Pup brass not hard to make.. at least 1 pc wasn’t…

From 6 PPC-
Leave 1/8” neck on brass
Use 22-250 Bushing die cut to .904” shoulder height-

Make 3 passes w/ lots lube-change bushings ever pass to squeeze neck-
Trim to 1.336” OAL length

By “pain in the butt”, I meant the amount of time it takes to make cases, not so much the actual process. 20 Pup might be easy enough to make, but that takes a LONG time!

I’ve done a lot of wildcats over the years from a simple necking down or up of a parent case, to much more extreme processes where the entire neck and shoulder end up in the body area of the parent case. The older I get, the more I appreciate minimizing my reloading times and allotting that saved time to shooting.

With all the 20 cals I’ve built over the last 19 years, I’ve found that they are all really fast, really accurate, and very devastating on varmints. So they are equally fun to shoot. If it’s a bigger case, I build the rifle heavier and maybe do a brake to mitigate recoil. Would like to start using suppressors at some point to reduce recoil and noise but haven’t tried it yet.