No pressure info listed

[Seitz 555]

Where would I go to find the pressure for the loads listed in the Barnes bullet
load data for a 36gr. Varmint Gernade with 12 gr. Lil-gun powder. Their data
lists starting and max fps but no pressure data. Again their data shows a
Velocity for a 14” barrel, and the Contender I’ll be using is a 10” barrel.

[dale2242]

22 Hornet?
No caliber mentioned.

[Seitz 555]

My bad, 221 Fireball

[marlinman93]

I'd consider trying to locate a copy of the old TC Contender loading manual. They have lots of data specifically designed and tested in various TC barreled guns. Here's a new copy on Ebay:

https://www.ebay.com/itm/Thompson-Ce...9024666?_ul=IN

[Larry Gibson]

No pressure data on the 221 FB but that load is going to be quite mild. In my Contender 22 Hornet barrel the pressure of 12.5 gr Lil'Gun under a 45 gr Hornady Hornet bullet ran 22,800 psi. Ergo a slightly smaller charge under a lighter weight bullet in a large capacity case will give somewhat less psi.

[Seitz 555]

Reason for wanting the pressure is, I want to use Remington 6 1/2 primers. Everything I read
on those primers is the pressure needs to be below 37K.

[17nut]

[Seitz 555]

Thanks 17nut, that’s exactly what I needed.

[Seitz 555]

Is there a formula you can use that approximates the reduction/increase in pressure for each inch less or more in barrel length ?

[17nut]

Is there a formula you can use that approximates the reduction/increase in pressure for each inch less or more in barrel length ?

Not in an usefull manner, it depends on powder used!
Slow powders will be more linear in speed loss, fast powders will will be more progressive a little at first but soon it will rise fast.

Say whats on your ming and i will run the calcs.