Author Topic: Question about .30-30 loads (Read 497 times)

Guy · « **on:** October 04, 2005, 04:15:27 AM »

In looking through a couple of load manuals I've noticed their data for the .30-30 is a few hundred fps less than factory loads. The 150 grain bullets seem to max out at maybe 2100 fps, while the 170 bullets max out at about 1900 fps. Why is this? Am I just looking at the wrong manuals? Are the factories exagerrating their velocities just a bit? What gives?

Idaho_Hick · « **Reply #1 on:** October 04, 2005, 09:19:36 AM »

My Speer manual used a test barrel of 20 inches, while I believe the factory loads use a 24" barrel for their data. So, for this particular manual, the difference could be attributed to different barrel lengths.

Camper · « **Reply #2 on:** October 04, 2005, 10:24:13 AM »

This may be a stupid question, Would the longer barrel increase velocity or would the shorter barrel increase velocity?

Thanks
Camper

bobg · « **Reply #3 on:** October 04, 2005, 11:40:34 PM »

The longer barrel will increase velocity.
bobg

Winter Hawk · « **Reply #4 on:** October 05, 2005, 03:16:29 PM »

Back in the '60s and '70s, factory test barrels were 26". This because they were mounted in pressure guns to check the pressures generated at the same time. I haven't read up on it lately but I believe that a lot of the balistics shown were developed back then. And a 26" barrel will give significantly higher velocities than a 20". You can see this also when comparing pistol amo shot from a handgun with that shot in a carbine or rifle.

-WH-

Paladin · « **Reply #5 on:** October 05, 2005, 03:50:25 PM »

ABOUT 50 ft to the inch or so is claimed

Guy · « **Reply #6 on:** October 06, 2005, 03:04:03 AM »

Thanks for the replies. I guess I just figured since the 20 inch barrel is the most common for this caliber that is what the factory would use to test and develop ballistics.

Steve P · « **Reply #7 on:** October 06, 2005, 09:06:14 PM »

The velocities in the reloading manuals are low because the loads could be put in a 30wcf that is 100 years old and in poor shape. The reloading folks don't need a lawsuit due to blowing up an old gun with new data. It is good starting information.

Most of the load manuals have 45LC loads that are for the old colt revolver, most of the manuals will also give out hotter loads for the newer Rugers, Freedom Arms, etc.

So, you have to look for data in the right places. Factory loads should work in most guns, but as stated before, the velocities are probably from a test fixture with 24" barrel vs 18-20" normal gun barrel. Newer guns and older guns in excellent shape can exceed reloading manual maximum velocities and pressures. You just have to safely work up your loads. I have some nice loads for a Savage 340 bolt action that exceed manuals by quite a bit.

Good luck, and stay safe.

Steve