RL19 Temp Sensitive?

DENWA

First day back behind the 300WM in awhile.

Temp this morning was 32F here in Maryland.

Using 3 loads straight from Nosler Manual using Reloader 19 and 168gr HPBT.

71.0 gr supposed to be 2982 actual was 2606-2616 on 4 shots

73.0 gr supposed to be 3087 actual was 2715-2740 on 3 shots

75.0 gr supposed to be 3192 actual was 2790-2884 on 3 shots

All charges were hand weighed using same brass an Winchester Mag Primers.

Worst of all the 73 and 75 grain grouped all shots touching.

Using my 30-06 savage with my M1 Garand loads ( 168gr HPBT with 48.5 and 50 grains of IMR4064 each M-1 likes a little different velocity) posted ~2740 and ~2820 fps avg respectively. Which is slightly higher than I get (from my M1's) at 85 degrees.

Sorry for long winded.

Anyone else have this issue with RL19? Crazy.

Tailgunner1954

ALL powders are temp sensitive, some are just less so. Powders produce lower pressures/velocities as the temprature falls, but the amount your posting seems more like a chamber/rifle issue than a powder issue.
Still using the same cases/bullets AND Nosler data, how does it do with a different powder?

Edit, I load a lot of RL-19 in my tight chambered 30-06 bolt gun, and velocities are within 5-10fps of Noslers, and have remained fairly consistant throughout the year(s).

DENWA

Shooting Factory Ruger MK2 with 24" barrel.

Brass is 3X fired and Neck sized only. (After 1st firing they were trimmed to min OAL.)

As always they are primer pocket cleaned and uniformed and sorted by weight.( +/- 0.05 gram for development loads)


On all of these they are loaded to MAX COL of 3.340 for 300WM. I've never had to mess with COL as this rifle has always shot well at this length.

They chamber very easily and require little force to close the bolt.

In the past I've always used H4350 in this rifle. Actual velocities are usually 50-90fps lower than Nosler published data at 35 degrees according to my log book.

Any ideas?

BTW I just checked my scale and it is dead on. It thought maybe that could explain if all my charge weights were low but. weighed 5 random bullets and all read 167.995 to 168.0034 grains.

MIKE WISKEY

different barrels can have a 200 fps (+-) vel. spread with the same load. just because the 'book' said you should get 'X'fps doesn't mean you will with your rifle.

JustC

you must keep in mind, nosler's data is usually collected from match grade barrels, which will no doubt have tighter chambers and bores, producing higher MV. I have found that to be the case when comparing your chrono readings to theirs with a factory barrel vs their match barrel.

m113103

Check your manual on what lenght barrel they user and what temperature. They also use a minimum (tight) chamber so that the highest pressures will be seen. Up in the really cold country they keep their shells next to their body until they are needed.

DENWA

Nosler Manual lists a 24" BARREL FOR THE 300WM.

I'm just wondering if while shooting prone the dust/debris was getting kicked up and causing my Chrono to read lower velocity?

oneoldsap

We load my son's .300WM with good old IMR-4350 72Gr. and the Nosler 165 partition , Never shot them over a chronograph but they are plenty hot and kill big deer cleanly at 350 yards. I do beleive that ball powders are more sensative to temps than extruded powders. That is just a casual observation over 40+ years of reloading.