Long neck .30-30 cases for cast bullets - tested

A while back I sought people's experiences with long neck .30-30 cases.

This was prompted by the obvious mismatch between .30-30 chamber lengths and case length. I have a 1949 Marlin 336A with chamber length of 2.150", and a Savage 1899 (factory replacement barrel) with 2.120" chamber (including spare headspace). My longest useable .30-30 cases are a little over 2.050".

Opinions differed on whether I might expect group improvement from longer cases.

A friend came up with some .38-55 brass for the trial, both Starline 2.125" and Winchester 2.080". Both lengthened about 2.020" when sized to .30-30, which is to say to 2.145" and 2.100". Neck thickness differed, Starline being around .008" after sizing and the Winchester around .010". Winchester brass was trued with a light outside neck turn to leave max .010" neck thickness, as applied to all my other .30-30 cases.

I tried the Starline cases in the 336A with #U321297HP bullets (175 gns with gas check) sized .3125", lubed with Lyman Orange Magic, and 28 gns and 30 gns 2208/Varget. Five shot 50 m groups were 2.08" and 1.75" respectively. Previous five shot 50 m groups with normal Remington cases, but 0.10” neck thickness, were 1.93” (avg of 2 groups) and 1.78” (avg of 4 groups). In other words, no evident effect from the change of brass, and definitely no reason to undertake a more comprehensive comparison. The thinner necks of the Starline long brass would be a negative of unknown consequence for .30-30.

Velocities were 1957 fps (SD 19) and 2078 (SD 12), which were similar to velocities with the Remington cases.

Sights were peep and white bead on a 2" white aiming mark on black background.

The second test was with the Savage 1899, this time with Leupold 2-7 scope, set on 7X, five shots at 100 meters. This was with the WW .38-55 brass, neck turned the same as for the Winchester brass I normally use in this rifle. The long cases were about .020" short of chamber length.

Load was, again, #U321297HP sized to .3125", lubed with Lyman Super Moly, with 32 gns LeverEvolution. Velocity with this load had thus far averaged 2204 fps (SD 10-21) but, inexplicably, was only 2134 fps (SD 27) with the .38-55 cases. Case weights of .38-55 and .30-30 were nearly identical.

Groups with Winchester .30-30 brass in the Savage were 4.08" (group interrupted by cattle on the range and wind affected), 3.22", 1.92", 1.36" and 3.17". Group with the longer .38-55 brass was 2.50", so no reason to think the longer brass was anything special.

The velocity drop with the longer WW .38-55 brass is interesting. In previous testing, LeverEvolution velocities were more uniform with heavier loads. If there is some good reason for the velocity drop with the longer cases, another grain of powder might get the load back into a happier place.

A few groups like this prove nothing but, if there was a big gain to be made from longer brass, I would have hoped to see at least some hint of it - which I have not.

All groups were fired with at least one fouler on a clean barrel, or a warmer after a previous group.

The 336A loads are for LAS Rams. The Savage load is for (real) pigs.

Very interesting isn't it?

Wilderness

Thanks for posting this information. It’s very interesting that the velocity was lower in the .38-55 brass, since you had weighed the brass and the weights (and therefore volumes) we nearly identical. Makes one wonder what caused the variation in velocity. I have two 788 Remingtons in .30-30; and I will try and determine chamber dimensions and see if my cases are shorter than chamber necks. I have .30-30 loads (cast boolits) but no empty brass right now to measure case lengths.

So what happens if you try neck sizing only now?

I have a 1909 mauser rebarreled with a Norwegian military barrel in 7.62 X 51, the neck is long than in that chamber. I reformed some 270 Win brass to make a long neck 308 brass, thinking it might help. After shooting several loads and boolits that shot well before I decided it was not worth the trouble.

A little of topic, but I also have a 1949 336A, a great rifle. I have to lightly turn the neck, mostly just true it up to get a .311 boolit to chamber freely. I also reamed a slight taper in the lead after having trouble seating a boolit out to full length.

Liked your post
Dave

Quote:

---

Originally Posted by jim147

So what happens if you try neck sizing only now?

---

Jim - I'm half way to neck sizing now, running the FLS die with .025" clearance between die and shell holder.

By rights, cases formed from new .38-55s should have less volume than my several-times-loaded .30-30 brass. This should increase velocity rather than decrease it.

Of course we might just be looking at the outlier on the normal distribution.

I do intend to run some more velocities comparing the brass.

When I compared NS to FLS brass in .308 I came up with a velocity difference of about 50 fps (FLS faster), no doubt down to volume change.

Dave - I neck turn my .30-30 brass, but just a touch to get the high spots and to catch the odd thick necked case. Max neck thickness is then .010", and both rifles will accept .3125" cast bullets in these cases.

WMitty - to measure chamber length take a FLS (or new) case, trim about half the neck off it. Then turn down some brass rod to be a tight sliding fit in the neck. Leave a flat faced flange on the end of the rod, equal in diameter to your chamber neck (or neck OD of fired case). With the rod extended beyond expected chamber length, insert the case/tool in the rifle and close the action. The end of the chamber will push the rod back into the case. Remove from rifle and measure length of case plus rod with vernier.