Does this sound reasonable?

04 September 2003, 11:16

300winnie

Last year I worked up a load for my .300 Win Mag. Extremely impressed with accuracy and velocity, and no apparent pressure signs that I can see. However, I have been on this and other sites quite a bit lately and have been starting to second guess my sanity. That said, I am looking for honest opinions.

Here is what I have worked up.

Gun: Browning Stainless Stalker - 26" tube

Load:

Brass: Once fired, neck sized W-W
Primer: Federal 215M
Bullet: 180 grain Swift Scirocco
Powder: 74.5 grains IMR 4831
Comparator length: 3.800"

Shot 5 groups of 3 shots each with the average being .886"

Chronographed a few after load work-up and found muzzle velocities ~ 3200 fps.

After being on this site, the part that makes me second guess is the velocity.

The interesting thing about the workup is that I have worked up a load for 180 gr. Nosler partitions that chronographed ~ 3150fps that were loaded with 74 grains of IMR 4831. Also very accurate with no apparent signs of pressure.

I am going to go out this weekend and run a bigger sample over the chrono and record the ambient temperature at the time to see what my average velocities are, but I don't expect to see much difference.

Is it absolutely ludicrous to be achieving 3200 fps out of a 26" tube? My Nosler manual (no. 4) has a writeup by Dave Petzel where he states that 3100fps is about all you can expect from a 24" barrel. Is 3200fps with a 26" barrel reasonable [Confused]

I know this is long, but thanks for your input.

04 September 2003, 11:50

Trapdoor

I have no exerience with the 300 Winnie, but what you are getting doesn't sound out of line to me.

2 inches extra barrel length theoretically should give you about 50 fps...and you may just have a "fast" barrel.

04 September 2003, 11:53

N E 450 No2

Sounds like everything is operating within normal parameters to me. [Big Grin]

04 September 2003, 12:05

r d smith

I am getting 3250 out of a 24" with 165gr bullets. I don't think yours is too high.Rick.

04 September 2003, 15:43

<Savage 99>

Of course 3200 fps instrumental is possible but none of the data that I have here shows that high an actual muzzle velocity. The highest that IMR shows for 75.5 grs of IMR 4831 with any bullet is 3105 fps.

My guess is that the chronograph clock is off and or the screens are too close together.

[ 09-04-2003, 06:45: Message edited by: Savage 99 ]

04 September 2003, 16:03

stubblejumper

I would trust the chronograph over any manual or ballistics program.The numbers sound reasonable.

05 September 2003, 03:30

rukidnme

Those numbers are fine.
I get a little over 3200fps with 180 partitions out of my 26" barrel HS Precision rifle.
I get 3100 out of my 200 grainers.
Neither load has any visual pressure signs and accuracy is good with both.

Both loads with H4831sc powder, don't have my load book with me so can't give powder grains in my loads.

05 September 2003, 04:53

Stonecreek

quote:
Originally posted by 300winnie:

Comparator length: 3.800"

Do you mean length over all? That's longer than your magazine.

Every rifle is an individual. You could be getting this velocity within normal pressure parameters, but of course this velocity is certainly on the high side. Time will tell. Load and shoot a single case 3, 4, 5, etc. times consecutively with this same load and note when the primer pocket begins to loose its grip on the primer. This is the surest way to determine if your loads are exceeding a desirable pressure level.

05 September 2003, 10:31

300winnie

The comparator length is the reading on my calipers. It is not a true measurement on the cartridge as I use a stoney point comparator, which makes the reading longer than the cartridge.

06 September 2003, 05:06

Canadian reloarder

Hi. That load seems good to me. I load 180grs Hornadys to 3098fts/sec with 73grs of IMR 4831 in my 24" barrel BSA. This is a max load for my rifle, but if it had a 26" tube 3200 fts/sec would seem posible.

06 September 2003, 09:27

rukidnme

300winnie
Here are my loads for my 300 win mag HS Precision 26" barrel rifle for your comparison.

180gr nosler partition
75gr h4831sc powder
fed match magnum primer
3.45 oal
3170 fps avg over chronograph

just to show the difference:
180gr barnes XLC
80gr H4831sc powder
fed match primer
3.40 oal
3190 fps (5 grains more powder to get essentially the same velocity)

165gr partition
79gr h4861sc powder
fed match magnum primer
3.52 oal
80gr h4831sc powder
3390 fps

These are max loads but show no pressure signs in my rifle.