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.17 Rem. pressure

Hunter375Hunter375 Member Posts: 612 ✭✭✭✭
I recently purchased a model 700 LVSF in .17 rem. and loaded up a couple hundred rounds. Using 20 gr. v-max and 22.5 grs. H-322 I am getting some pressure signs on the primers. They are not pierced, but have a substantial raised area just around the dimple from the firing pin, and are a little flattened. I use CCI 400 small rifle primers. Max load with 20 gr. bullet is 23.1 grs. in Hornady manual.

On a side note, this rifle/cartridge combo is a tack driving duo. I topped it with a Weaver classic 4-16x 42mm fine crosshair w/ 1/8 MOA center dot. Average groups from a sandbagged rest are .86 MOA.

Save the seals-club a liberal instead.

Comments

  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    Nick,

    Just a couple of observations first:

    All powder and bullet manufacturers have different contexts and equipment for testing their products as well as the products of others. They are not going to agree with each other all of the time.

    Generally speaking, ball powders are at the faster end of most burning rate charts. Ball powders are usually more prone to pressure excursions. The Hodgdon ball powders have not been, and probably won't be, re-formulated to be 'Extreme' powders, so they are also more sensitive to temperature fluctuations.

    Looking at the entire group of primers available to the reloader, Remington 7-1/2 and CCI400 have the hardest cups.

    In conjunction with your reloading, did you do any testing before you loaded up "a couple of hundred rounds", or did you just go for it based on what your one book stated?

    My notes indicate a couple of things about your load. H-322, even though recommended by several manuals, is probably the fastest of the recommended powders and it is a Ball powder which means that the load density will be low. That's two things against this particular combination. The amount of H-322 does not come close to filling this case, in fact the case is only about 88% full, which leaves a lot of open space for powder position to come into play. Again, the ball powders are temperature sensitive and subject to pressure excursions of the higher variety. Small variations in powder weight for these .17 caliber loads can result in major pressure differences. Load differences that are meaningless in cartridges with bigger diameter bores, can be disasterous in the .17's.

    Since the CCI primers are noted for having harder cups and yours are showing some cratering, my guess would be that you are having a problem with high pressure, not catastrophic, but high none the less. If you switched to softer primers, you could end up with blown primers instead.

    In my opinion, I think that H-322 is too fast for this combination and you started with a near top end load instead of starting low and working up to the top end. If you insist on using H-322, I would back off and test your way up to a lower pressure load but with good accuracy which I think your rifle is capable of getting.

    The powders that I would test in order of preference and performance are:

    V V N-135

    Varget

    Re-15

    AA-2520

    Your rifle and scope are one of the good ones, it's just that I would work on a different load combination, keeping a close watch on pressure indicators or better yet, use a chronograph.

    Best.
  • MIKE WISKEYMIKE WISKEY Member, Moderator Posts: 9,961 ******
    edited November -1
    i'd also suggest checking your fireing pin (main) spring, a weak one will also cause this. if the rifle was used it may have been shortened to get a better trigger pull.
  • Hunter375Hunter375 Member Posts: 612 ✭✭✭✭
    edited November -1
    Update. I did forget to mention the brass; it is new Remington brass. Generally speaking, I do tend to load toward the max from the get-go, because I buy a gun in a particular chambering with the intention of using it to it's full potential. I chronographed yesterday and got an average of 4154 FPS with with a high of 4186 FPS and a low of 4108 FPS. Standard deviation is difficult to determine, as my buddy drilled the chronograph with his .45 pretty early in the session. Another load I am going to try is IMR 4198.

    Save the seals-club a liberal instead.
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