Disparate Velocities

[gman]

Here are my velocities from my 20.1 inch barrelled FN-FAL.
Remington once-fired cases, 150 grain Sierra HPBT, IMR-4064 and
CCI-250 primer. Gas setting 4.5.
43 grains: 2703, 2696, 2719 Ave. 2706
44 grains: 2734, 2673, 2668 Ave. 2691
45 grains: 2736, 2732, 2754 Ave. 2740
46 grains: 2803, 2816, 2846 Ave. 2821

Remington Factory 150 grain Corelokt:
2571, 2542, 2536 Ave. 2549

What gives? I don't get this. Either Remington is severly
underloading or I am severly overloading which I do not believe is
the case. My primers are just showing the rounded cup edges being
sharpened up with the 46 grain load, none have any sign of
splashing and ejection is very positive. The interior of the cases are
carbony with less than 45 grains and clean up with 45-46 grains. I
think 2800 is excellent with this short barrel but am I over. The
Nosler book (from which I pulled these powder weights) uses a 24"
Lilja barrel and I am supposed to LOSE ~26fps with each inch. I
should be getting 100fps less shouldn't I?
I think I will load up some with RL-15 and see what happens.
Any comments welcomed.

[Upside Down @ 100 MPH]

Just take it and be happy. You're load doesn't sound hot to me. I'm disappointed to hear about the factory Remington's velocity, I have a half dozen boxes of it. :mad:

That's one of the neat thing about reloading. Through experimenting I've found loads that were "overachievers". Like in my .270, 58 grains of either H-4831 or H-450 with a 150gr. bullet show to have about the same velocity in my reloading manual. But in my gun the H-450 load had 75 more fps. I haven't chroned any of my FAL loads but I guess I should start. I need to discover my overachiever load.

Greg

[Wadman]

It's all about liability. Remington doesn't know what you're going to fire that ammo out of. Is it a strong modern action? Or is it some arsenal rechambered 80 year old bolt action?

Take a look at various versions of reloading manuals from different sources. Two examples are Speer #11 and #12, and also Vihtavouri 1st edition and 3rd edition. You'll see some drastic reductions in charges for some calibers. Did guns suddenly become weaker? Did certain lots of certain powders suddenly develop higher pressures? Or did the load book developers suddenly decide they'd err on the side of caution and really really downgrade certain loadings?

---------

According to two manuals, your 46gr loading is under the listed maximum.

Speer #12 has a max of 47gr.

Nosler #4 has a max of 48gr.

Your extra velocity could also be a result of using CCI 250 primers. My Speer book lists CCI 200s being used with IMR 4064.

[ August 07, 2001: Message edited by: Wadman ]