Pressure Problems

[browndusti]

OK here it is
the gun : Browning A-Bolt 243 WSSM

The Load: 35.5 grains 4064
WLR primer
95 gr Nosler Ballistic tip
2.300 OAL

The problem is pressure, heavy bolt lift, lil louder, lil more kick and flattened primers. According to all my accesable data and freinds this should be the starting load for this combination but is this not exxcesive chamber pressure? is it perhaps to much of an underload? before anybody asks yes i trimmed the casings first. any input would be greatly appreiceated thanks

 

[Ganderite]

Every rifle is different. The book gives you an idea of what worked in someone else's rifle. Consecutive rifles down the assembly line will have different pressures for the same ammo.

Every thing you mention is indicative of high pressure. That is God's way of saying "STOP!!" I have seen blown rifles that fired two or three shots first, all showing high pressure.

Some comments on why your rifle may be getting high pressure.

You are using a powder towards the fast end of the spectrum for the long bullet. This means things will get out of hand quickly. You are supposed to start low and work up. If you do that you would stop before getting to where you are now. I have seen examples of the Start load being much too hot for a given rifle.

Powder speeds vary from lot to lot. You might have a "fast" lot. IMR 4064 uses moisure content as part of the receipe that determines powder speed. If your powder has been left in a thrower, it willd dry out and speed up.

I suggest you get a slower powder, like 4350 or RL19 and start testing with the start load. Be prepared to move up or down, depending on the results.