303 loading, low velocity.

Ron Rutherford

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I'm using IMR 4064 with a 180 grain Sierra Spitzer bullet .311. Loading from 37 grain to 41 grains. Problem is very slow velicities, starting @ 1650 and going up to 1995 with 41 grains. 40 grains should read about 2400 fps. Factory ammo seems to be all right. What's wrong
 
Assuming you weights are correct, and you are using a rifle primer.
Are you new to reloading?
I suspect the powder may be contaminated. Is there a lot of bore fouling?
It's also possible that you have a rifle with a very large bore size. Bores in 303 caliber military rifles have been recorded as large as .318.
Your rifle may be passing gas :)
 
I've had the same situation with the same powder load behind a 174gr FMJ bullet. And that was thru 4 different endfields so i would'nt worry to much. personnaly i kinda like the low recoil but that's just me.
 
I'm new to loading so any info will help. I've also loaded 150 grain 312 bullets with the same results. Although the speed went up, it still wasn't in accordance with the books.
 
"...should read about 2400 fps..." My old Lyman book gives 2386 with 42.0 grains of IMR4064. You won't be getting 2400fps with 40 grains. Steve on .303british.com suggests the Sierra 180 grain bullet requires much faster velocities than a .303 will give to function properly.
If you're not getting close to published velocities, your powder may be bad or you've under loaded, like John Y Cannuck says. How old is it? Check your scale too. Are you weighing each charge or using a powder thrower?
A .303 barrel that measures .318" is shot out. .315" is max for an acceptable bore diameter.
 
Purchased the powder 2 month ago. I've also checked the powder load and they are accurate. I'm measuring each load. Scale checks out also. Why does the factory rounds read much higher????? Also used 2 different guns...
 
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Slow?

I'm new to loading so any info will help. I've also loaded 150 grain 312 bullets with the same results. Although the speed went up, it still wasn't in accordance with the books.

Ron, welcome to the club. You have quickly discovered one of the truisms of loading. The actual speed of the bullet very seldom reaches what the book says it will go! For all those years of loading before the cronographs came into use, there was a happy bunch of reloaders. Every load in the books show a 30-06 180 grain bullet as going 2700 fps. In reality, most of those loads are 2550 to 2600, or sometimes even less.This is just an example.
 
If the powder is ok, low velocity is God's way of saying "Go higher." Every rifle is different, and Enfields vary even more due to tolerances and usage. Keep adding powder. 2200 fps is a reasonable load for that bullet and powder.
 
Ron, welcome to the club. You have quickly discovered one of the truisms of loading. The actual speed of the bullet very seldom reaches what the book says it will go! For all those years of loading before the cronographs came into use, there was a happy bunch of reloaders. Every load in the books show a 30-06 180 grain bullet as going 2700 fps. In reality, most of those loads are 2550 to 2600, or sometimes even less.This is just an example.

X2

A crony is a real eye-opener. A shortened barrel will also cause lower velocities. Reloader 15 will help velocity a bit.
 
When I got my P-14,I bought some 180 Winchester PP,advertised 2400,I think,went 2200.That was good brass. My current load by the book should be going 150f/s faster. I think it's the undersized 303 bullet we get to use.
 
I have a P14, and drive the 180 Sierra to 2550 with W760, but the load I'm using I would not recommend for any Lee-Enfield. My Bore mikes right at .313"
Regards, Eagleye.
 
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