I want to work up some loads of my 7x57 using H414 and 139gr. Hornady's. Problem is H414 is not listed in any loads in my Hornady manual. What's a good method to use working up a load in such circumstance? Thanks for the input.

Jeff

The answer to that depends on whether or not you accept SAAMI specs as having validity.

If you do, spend a little under $200, and instrument the rifle with a strain gage. That way, you can make chamber pressure measurements.

Normal "pressure signs" do not appear until you are well past SAAMI limits.

Case head expansion and pressure ring expansion have very poor repeatability. There are ways to extract enough information from them to be useful, but they are impractical.

There are only three safe, practical alternatives that I can identify: 1. Shoot commercial ammo, 2. Stick to book loads, and 3. Instrument your rifle with a strain gage.

The way I do it, is to find that powder in another maker's manual for 139 grain bullets and use that data's starting loads and see how they perform with the Hornady bullets. Gradually work up in charge until you feel comfortable.

If you can't find that powder with any 139 grain bullet, check the data for 150's and 120 and ratio their starting loads to get a starting load for the 139's.

IF,..that powder is slower than the listed powders,..you simply interpolate a charge range judging by the charge weights of the slowest powder listed. BUT,...if it is a faster powder than those listed,..I would be VERY CAREFULL.

If it has a burn rate that falls between 2 of the listed powders,..you simply take the difference of the charge weights of those two powders,..split that difference, and as usual, start low and work up looking for pressure. The listed velocities can be used as an indicator of pressure as well as case/primer signs. Once you reach the velocity levels of the 2 listed powders,..you are generally in the ball park.

First go to the Hodgdon site for their load data - 7X57 Data



Then I would select loading data from a similar weight bullet like a Nosler Partition. Then begin with the starting charge weights and work up the load looking for the usual signs of high pressure. A chronograph is indispensable for working up loads. It can keep you out of a lot of trouble while maximizing velocity and accuracy.



According to the Nosler 5th edition manual the starting weight for 140gr Partition is 45.0gr of H-414 this nets a velocity of 2610fps. The max charge weight is 49.0gr of H-414 and this nets a velocity of 2790fps.

Skibum:

I would try checking other manuals. Hodgdon has a website with loading data for your 7x57 using H-414.

knobmtn

Skibum,

Ran a Quick load simulation for H414 for a 7x57 using CIP Pressures pmax pressure of 56564 psi.

For H414 and the Hornaday 139 grain #2820, a good start load would be:

46.0 grains H414 2658 FPS (in a 24" barrel) 43722 psi

Max load:

50.0 grains H414 2887 FPS, 55882 psi

This is only an simulation for modern 7x57's. Use SAMMI spec's for old 7x57's.

Hope it helps,

Bob

I thought it was accepted reloading practice that when adapting a published load to a component other than specified, one should reduce the starting load by 5-8% and work up carefully toward the maximum watching for signs of excessive pressure or velocity.

Hodgdon lists a 7x57 maximum load of 47 grains of H414 under the 140 grain Nosler Ballistic Tip. A starting load for this would be 10% less or about 42 grains. A starting load for the change to the 139 grain Hornady would then be 39 or 40 grains of H414 based on this concept. The maximum load would remain not to exceed 47 grains or a velocity of 2715 fps in a 24" barrel. Is that reasonable?

760 is the same exact powder, and my Hornady manual has a max of 52.4grs. @2900fps, hope this helps, Jay

Ski;

You have had a few responses from guys I know from experience on here, that do know what they are talking about.

My first recommendation is to get out and get a Hodgdon 26th Edition Reload manual and a Lyman 47th edition manual. I think they are two of the best manuals I have seen in recent times, listing a lot of powders.

I shoot 7 x 57 myself, and love it.

Hodgdon's 26th Manual, pages 276 - 278.
7 x 57 with H 414:

100 grain bullet:
53 grains ( 3188 fps) to 55 grains ( 3256 fps) CUP: 46,900

115 to 120 grain bullet:
51 grains (2937 fps) to 53 grains ( 3025 fps) CUP: 47,400

125 to 130 grain bullets:
50 grains ( 2809) to 52 grains ( 2949 fps) CUP: 48,400

139/140 grain bullets:
46 grains ( 2698 fps) to 48 grains ( 2805 fps) CUP; 48,800

145 to 150 grain bullets:
45 grains ( 2559 fps) to 47 grains ( 2724 fps) CUP: 47,000

154 to 162 grain bullets:
43 grains ( 2482 fps) to 45 grains ( 2594 fps) CUP 48,500

168 grains;
42 grains ( 2363 fps) to 44 grains ( 2496 fps) CUP 47,400

175 grains:
42 grains: (2306 fps) to 44 grains ( 2400 fps) CUP 48,400

That should be a wrap!

Cheers and Good shooting
seafire

Skibum: Lots of good info provided here. Another good source would be the very comprehensive information provided by a fellow forum member's web site, Steve's Reloading Pages:

http://stevespages.com/page8c.htm

As always, start safe, start low.

Great info guys. I have worked up a load with H414 and 140 gr. Noslers. I do have a chronograph so I have baseline velocities to work with. My plan had been to start low and slowly work up looking to get the Hornady's in the same velocity range I was getting with the Noslers.

Jeff

Ah, Hot Core, you're still teaching the old notions that have been proved wrong. Time to give it up, and move on.

Ken Waters made very modest claims for the PRE system. He was quite clear that he considered it inferior to both the CUP and strain gage systems for measuring pressure.

My own micrometer tests clearly show that neither the PRE nor the CHE system can repeat the same dimensional reading, given the same cartridge pressure. This test relies solely on micrometer measurements, using matched pairs of cartridges. Neither micrometer based method even came close to qualifying as a satisfactory measurement system. Hot Core knows that, and chooses to ignore it.

Hot Core is going to have to write a letter to NIST and explain to them his eclectic notions of calibration. They haven't caught on yet. I'm sure it would help them a lot if he would bring them up to speed. They still think that you can calibrate a voltmeter by comparing to a frequency based standard, and doing a formula conversion from frequency to voltage, just as we convert physical dimensions by formula to microstrains and pressure.

Some of the best pressure factor work ever done was by Brownell, at U of Mich. I wonder if he knew that his system wasn't calibrated, and that all those number he got mean nothing? What would he know? He only had a PhD in physics.

Come on, Hot Core. You know very well that a good strain gage system can be had for under $200, not the $300 you claim.

Give it up and move on. A strain gage system is calibrated. The PressureTrace costs under $200. It does not disfigure your firearm. It is about as precise as the piezo equipment used in commercial labs.

A $21.95 micrometer does not do an adequate job of estimating peak pressure. Carefully done experimentation shows that the system contains so much random noise that you'd have to average 140 rounds to get a standard of comparison equivalent in precision to the old CUP system, which has less than wonderful precision itself.

Ain't been but one slight mention of the rifle. A 7x57 could be anything from a rolling block up with anything from a 17" to a 29" barrel. Given a 98 Mauser or stronger, I would not worry about SAAMI specs and I damned sure would not worry about a strain gauge.

Ken Waters lists 49.0 grains of H-414 as near max under a 140 grain spitzer as giving 2796 from a 22" barrel. Cut back to 44 grains and work up watching the primer, the case head and the chronograph. Get up to 2800 fps, severely flattened primers, or 49 grains, you stop.

And yeah, I did just that myself but I allowed an extra 100 fps 'cause I am shooting a 29" barrel.

This usta be a pretty good country before it got so sissified.

H414 is the powder for the 7x57 if you have a 06 length magazine and a long throated rifle, as some mausers have..I have been shooting the 7x57 for years in such a rifle, a Brno 21 and a Brno 22, several of each...and with these rifles you can go considerably beyond the book max...

I have all the workup on the caliber with that powder going back 20 plus years, but I would not publish it...If you have an 06 box and can seat a 175 gr. Hornady half way to the cannalure, then send me an email and I will forward you my findings..if not your better off with 4350...

Rifle is a light sporter built by Jeck Belk and Chic on a 1909 Argentine Mauser with a 22" #1 LW barrel. I just got it and worked up my first loads with some 140 ballistic tips and H414. I started at 45.0 gr and worked up to 49.0 gr. which is the book max in my Nosler manual. Velocity at 49.0 gr. averaged 2850 fps. My initial groups have run .75-1.0" on a boringly consistant basis and I haven't played at all with other components, seating depth, etc. Basically I'm thrilled with the rifle so far.

Jeff