Grant, this is an historic moment. A bullet you haven't loaded in 5.7? Next someone will tell me there's no Santa. :laugh:Grantness wrote:You'll generally be able to get more kinetic energy w/ 40gr ballistic tips. I have heard good things about the 35gr LF Noslers....but havnt had the opportunity to try them myself.
Reloading info for the 5.7x28mm
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i noticed that you are getting cratered primers too. I'm having the same issue, are you not worried that thats a sign of overpressure?ddouglas wrote: ↑25 Jul 2010, 16:39Chronograph Tests of Nosler 35gn BT
There has been some discussion of using the Nosler 35gn BT bullet for the FsN5.7 pistol. Since the Nosler plant is close by, I dropped in and bought 100 of those bullets and loaded some 1X Sharch cases with True Blue to test them. The details of the tests are described below.
Chronograph: CED M2
Temperature: ~85 deg. F
Trim Length: 1.130”;
Primer: Win SR
Loads: 6.1gn, 6.3gn, 6.5gn, 6.7gn, 6.8gn, 6.9gn (I didn’t fire the 6.8 and 6.9gn loads for reasons described below.) All loads were weighed using an electronic scale and accuracte to 0.02gn.
The photo below shows the SS197SR (blue & white box) cartridge alongside the 35gn Nosler BT loaded cartridge.
The photos below show the cases. From left-to-right are first, an unfired re-sized 1X case, then the fired cases from the SS-197SR, 6.1gn, 6.3gn, 6.5gn and 6.7gn. The primers for these same cases are shown next.
For reference, I fired 10 SS197SR through the M2. The average speed was 1690 fps with an extreme spread of 50 fps.
For the 35gn Nosler BT, I fired 5 bullets in each of the loads described above. The M2 results are as follows:
6.1gn True Blue
Avg = 1909 fps
ES = 59 fps
6.3gn True Blue
(The last three didn’t register—perhaps because the fast-moving bullet was passing too high up in the sky screen “V”.)
6.5gn True Blue
Avg = 2020 fps
ES = 97 fps
(I changed the target location to shoot lower in the “V”, but one shot still did not register.)
6.7gn True Blue
Avg = 1892 fps
ES = 400 fps
I stopped shooting because at this point, while the cases and primers didn’t show any significant overpressure (the 6.7gn primer was flattened, though), I was concerned about the large variation in bullet speed. Are there any opinions about why this might be happening? Should I shoot the 6.8gn and 6.9gn, or leave well enough alone?
I note that, on the target, the bullets for all shots (including the SS197SR) fell into a consistent group that were all about the same size. I won’t mention the size because that would probably say more about my less-than-good shooting skills than anything meaningful about the accuracy of any particular load. The point is, the loads were all of comparable accuracy.
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