Go above max load or different powder?

[kdsd731]

I was chronographing some loads for my Scar 17. I just ran some loads using 150gr FMJBT with BLC 2 ranging from 45gr to 48gr in .5gr increments. Minimum velocity was 2,428fps and a max of 2,578fps. None of these loads locked the bolt back on an empty mag. I was not checking for accuracy with these loads but rather for operation and pressure signs at this time. I see no primer cratering or flattening of primers all the way through Hodgdon's max load. Is it safe to go above the listed max load data looking for correct operation and signs of pressure or is that asking for trouble and I should just ditch this powder and go for something else?

[MongooseV8]

Generally never a good idea to go above max. In some scenarios it's OK to push it past max. An example would be when seating a bullet really far out to reach the lands in a bolt gun.

But in your case I say stick to the books.

[Meety Peety]

If you are not getting the desired performance at max load, I would be more inclined to look for another powder more suited to the goal you are trying to achieve. That said, there are a lot of folks who load above max and are perfectly comfortable with it. I'm not typically one of those people. Out of curiosity what are you seating to?

[ziconceo]

Op, not to be insulting, but are you sure your rifle is in good working order? Perhaps your bolt catch isn't catching? I'd check that first. Does it lock back when you manually cycle?

Sent from my 0PJA2 using Tapatalk

[silas3d]

Follow the manual.

[baih777]

Sierra book has 48.4 max load for 150gr. I would go higher by .2 Increments. Read your primers. A stuck case in that rifle would be a pain.

[kdsd731]

If you are not getting the desired performance at max load, I would be more inclined to look for another powder more suited to the goal you are trying to achieve. That said, there are a lot of folks who load above max and are perfectly comfortable with it. I'm not typically one of those people. Out of curiosity what are you seating to?

I'm seating to 2.797" (Cannelure).

Op, not to be insulting, but are you sure your rifle is in good working order? Perhaps your bolt catch isn't catching? I'd check that first. Does it lock back when you manually cycle?

It is in good working order. It has 120 rounds through it. It also locks back with my IMR4895 loads and factory rounds.

[kcheung2]

I would double check your powder drop. 45-48 grains of BLC(2) should get you 2700-2900 fps, but the chronometer & bolt not locking back both indicate a low charge, so the next variable is if you really did load a sufficient charge.

[JMP]

It has a short barrel so you won't get that much velocity. That said, I'd expect a little more with 150s. I don't know why BLC2 is so popular with 308s. Try using Varget or 4064 if you can't find Varget.

[kdsd731]

It's a 16.25" 1:12 barrel. Yeah, I was pushing just under 2,700fps using IMR4895. Definitely going to be switching powders. Too bad, I was going to use this powder since I have 8lbs of it laying around.

[slamfire1]

Considering your barrel is 16.25", your BLC-2 velocities are entirely in line with safe and normal pressures. Your IMR 4895 velocities of 2700 fps, you ought to be getting those in 22" through 24" barrels, not 16.25"

A quick web search indicates the SCAR 17 has an adjustable gas block. I think that is where your problems are. Find out why your rifle is not locking back with normal pressure loads.

[kdsd731]

Considering your barrel is 16.25", your BLC-2 velocities are entirely in line with safe and normal pressures. Your IMR 4895 velocities of 2700 fps, you ought to be getting those in 22" through 24" barrels, not 16.25"

A quick web search indicates the SCAR 17 has an adjustable gas block. I think that is where your problems are. Find out why your rifle is not locking back with normal pressure loads.

The IMR load that was 2,675ish (accidentally erased my string of shots) was 45.1gr and showed slight primer cratering. 43.6gr is where the bolt started locking back on an empty mag.
The gas block is a 2 position gas block. One position for suppressed shooting and one for without a suppressor.

[kdsd731]

Bringing this thread back to life.

So I just weighed my bullets I had purchased from Hi-tech ammo which were listed as 150gr FMJBT pulled bullets. They weigh in at 147.8gr. Now is that big deal that they don't weigh what they are listed at? Also, wouldn't that mean I could go higher than my previous max of 48gr because the lighter bullet potentially solving my locking bolt problem. What's weird is I found people on a Scar 17 forum saying they run blc 2 on the low end.

[LynnJr]

Two things pop out.
One is its very cold this time of year so you can usually use more powder and two did you hand weigh your powder charges?
The bullets weight being off 2 grains doesn't matter.
I use 46.5 grains of BLC2 with a 168 grain bullet at 2.800 inches.
If a gun has alot of freebore in its chamber your pressure and velocity will both drop.

[kdsd731]

Two things pop out.
One is its very cold this time of year so you can usually use more powder and two did you hand weigh your powder charges?
The bullets weight being off 2 grains doesn't matter.
I use 46.5 grains of BLC2 with a 168 grain bullet at 2.800 inches.
If a gun has alot of freebore in its chamber your pressure and velocity will both drop.

I use a Lyman gen 5 scale. I think I might try another grain in .2 increments and look for pressure signs. Like mentioned earlier the max listed charge weight showed no pressure signs. I also have some 168 SMK. Would a completely different load possibly change my bolt locking? What velocity and barrel length with that 168 bullet you're shooting?