I went to the range last month with my CZ 9.3x62, handloads and my Oehler chronograph. Here are the results...

250 gr Nosler BT
55 grs 4320 2,369 fps avg.
55 grs N202 2,363 fps avg.
55 grs Rel 15 2,335 fps avg.

Went to the range today with heavier loads. Results follow...
250 gr Nosler BT
57 grs 4320 2,370 fps avg.
57 grs N202 2,376 fpd avg.
57 grs Rel 15 2,383 fps avg.

Little or no velocity increase?? Any ideas why? I had the same phenomena with Speer 270's and those three powders.

[ 09-09-2003, 01:34: Message edited by: JKuczmarski ]

How long is the barrel? How many rounds through the barrel? Was there a significant temperature change between the days you fired each group of ammo?

Are the loads you've posted showing pressure signs? If not...

Try H414, IMR 4895, IMR 4064, or some heavier charges of RE15. Of course, work up slowly.

Have you seen the 9.3x62 data on this site?

[ 09-09-2003, 02:37: Message edited by: 9.3x62 ]

9.3x62,

It's a new gun w/a 23.5" barrel. Maybe 30 rounds total through it. No more than 5-10 degrees F difference between the two range sessions. No pressure signs. New Lapua brass.

No 4064 or IMR 4895, but do have 3031, Rel 12, H4895, H380, H414 and W760 in addition to the Rel 15.

My target velocities are 2,500 fps w/the 250's and 2,300 fps w/the 270's...sound reasonable?

Haven't seen the 9.3x62 data on this forum, but will search it out soon. Thanks!

R/Joe

9.3x62,

I have a theory. When initially cleaning the barrel, I noticed that it took more effort than usual to get the copper fouling removed. I wonder if the inside of the new barrel was rough (less smooth than a used barrel) and that this "roughness" caused slightly higher pressures and hence higher velocities in those first chronographed loads. Then as the barrel inside smoothed up, it took heavier charges to equal those initial velocities. Maybe??

R/Joe

Here is the local reloading info for the 9.3x62:

http://www.accuratereloading.com/9362.html

Load up a few more batches (increase each by one grain) with the 4320 and the Re15. You will probably find max around 60 and 61 grains, respectively. Maybe a touch more. If the cases are too full for your taste, switch to H414 (my personal favorite powder for the 9.3x62).

Just last week I fired some 5-shot groups using the 250 Nosler out of my custom model 70 (22.5" pac-nor barrel). OAL was 3.330", 60 gr H414, GM210M primer, with no pressure signs. Accuracy was good, the average being just a touch under MOA. I am currently "between chronographs", so I can't tell you what this load was getting for velocity. I'm going to try 61 gr and 62 gr later this week just to see where max is. I use Norma brass, though I know Lapua brass is also very good.

Past max loads (some gathered from the data in the above URL) allowed 250s at about 2600, 270s at about 2500, and 286s at about 2425.

FYI, Conley Precision Ammo at

http://www.cpcartridge.com/9.3X62mm-P.htm

advertises 2500 fps with 286s, as does the latest Barnes manual.

My 9.3x62 got near to 2,400fps with 58gr of VVN14O (similar to 4895)and the 270gr bullets seated for a very short COL. So I think 2300fps should be easy with sensible powders.

I've never tried 250s but the Nosler book data is for a 26" barrel which plus the Nosler 'factor' means that you may have to be a little careful trying to get what they advertise.