I have a 22 BR that I have been working on for several years that I just can't seem to settle down and behave like it should. It is a Shilen 1/11 twist barrel on a single shot FN action.

I have tried a great number of bullet powder combinations. Bullets include Hornaday V-Max (50 & 55 grain), Sierra soft points (45, 50, and 55 grain) and Speer TNT 50 grain. Powders used include AA2230-C, Win 748, & BL C-2.

Worst groups are in the 1-3/4" range and best in the 3/4" range @ 100 yards. First of all, this rifle should be able to beat those groups any day and second, the best groups display pressure signs.

Because I have a supply on hand, I was wondering if H380 may produce a load of lower pressure with acceptable accuracy. I have noticed that a number of the old 22 caliber wildcats of similar case capacity list H380 as one of the powders to try.

According to the Greenhill Equation for Rate of Twist, the Hornady V-Max 55 gr bullet needs 1:12.3 twist to stabilize properly. The lighter weight bullets would need even slower. Your 1:11 twist is just fast enough to not really stabilize.

Might try some heavier bullets (60 gr - 65 gr) to see if they will print a little closer to what you find acceptable.

According to the Greenhill Equation for Rate of Twist, the Hornady V-Max 55 gr bullet needs 1:12.3 twist to stabilize properly. The lighter weight bullets would need even slower. Your 1:11 twist is just fast enough to not really stabilize.

Might try some heavier bullets (60 gr - 65 gr) to see if they will print a little closer to what you find acceptable.

Isnt the Greenhill Equation a calculation of the minimum twist rate? If so, wouldn't I be in a slight "over-stabilization" situation?

It would not really bother me to step a few hundred fps back from the velocity potential of this round in order to achieve it's accuracy potential.

I get my best groups using IMR 4895, it shoots in the .2

The Greenhill Equation is the calculation to stabilize a bullet of a certain diameter, weight and length. The information given as an example of the Hornady 55 grain V-Max was the twist rate to properly stabilize a bullet of those parameters.

Would still recommend a try with a heavier bullet and your favorite powder/primer combination to see if this may resolve the problem.

The Greenhill Equation is the calculation to stabilize a bullet of a certain diameter, weight and length. The information given as an example of the Hornady 55 grain V-Max was the twist rate to properly stabilize a bullet of those parameters.

Would still recommend a try with a heavier bullet and your favorite powder/primer combination to see if this may resolve the problem.

Since my immediate goal was to try to solve this problem with components on-hand, I went back to the loading bench and backed off the charge even further using the recommended powders with the 55gr V-Max. Still seeing pressure signs.

Pulled out a jug of H380... VIOLA!!! Pressure signs went away and nice small groups. Several groups under 1/2" over a range of 2 or 3 grains of powder. I chose one near the bottom that was tightest. Because of weather conditions I am forced to work up loads at temps 20 to 30 degrees below what I will be shooting in.

H380 is a great choice for this type of round.

It was my "go to" powder when loading for a .243 Win.

Glad you found the winning combination.

H380 is a great choice for this type of round.

It was my "go to" powder when loading for a .243 Win.

Glad you found the winning combination.


Ditto's on the H380. I use it in 6mm Rem, 6.5x55, 308... just had never considered it for a case that small. I'll know better next time.