Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 34

Thread: Piston v. DI temp measurements

  1. #21
    Join Date
    Nov 2007
    Location
    New Mexico
    Posts
    3,204
    Feedback Score
    1 (100%)
    I've got one of the Adams Arms 7.5" PDW uppers on order. It'll be interesting to see what the differences are with the short barrel.

    EDIT: I never could get the Adams upper to run reliably on F/A. I tried several combos of buffers and springs with no success.
    Last edited by Tokarev; 06-05-11 at 09:39.

  2. #22
    Join Date
    Jan 2010
    Location
    Poland
    Posts
    1,688
    Feedback Score
    0
    Quote Originally Posted by lanceriley View Post
    yes all free floatrails touch only atthe point of attachment. nevertheless. there is still heat transfer .
    Of course. There is no need to any sort of contact - infra red radiation transfers heat as well. Actually my HK handguard after some 300 rounds of rapid fire becomes quite warm - not hot, but warm enough in area close to gas block that Ergo "rubber ladder" rail cover (that I use on top rail for thumb-over grip) becomes considerably softer.
    Montrala

    I'm sponsored competition shooter representing Heckler&Koch, Kahles, Hornady and Typhoon Defence brands in Poland, so I can be biased

    http://montrala.blogspot.com

  3. #23
    Join Date
    Jul 2010
    Posts
    187
    Feedback Score
    32 (100%)
    Thanks for doing this OP

  4. #24
    Join Date
    Nov 2007
    Location
    New Mexico
    Posts
    3,204
    Feedback Score
    1 (100%)
    In the latest issue of "Small Arms Review" Jeff Zimba writes an article regarding heat in the piston system. He uses a POF 416, Beta mags and a laser thermometer to take heat measurements of the chamber, bolt face, gas block and muzzle brake after 100rd mag dumps.

    The first dump shows heat at the gas block of about 400 degrees. The chamber and bolt face are less than 100 degrees. After the 10th mag, the gas block is at over 600 degrees while the bolt and chamber are just over 100 degrees.

    Looking at the accompanying chart published with the article, the highest temps were taken after the 8th mag. The gas block is at 700 degrees with the bolt face and chamber showing about 150 degrees. But it looks almost like the temps stabilize after the 3rd or 4th mag with temps of about 550-600 degrees for the gas block and 100-150 degrees for the bolt face and chamber.

  5. #25
    Join Date
    Sep 2007
    Posts
    2,954
    Feedback Score
    22 (100%)
    Quote Originally Posted by Mjolnir View Post
    Uh, you cannot state with any degree of confidence that the 20 degrees don't make a difference on the bolt. The endurance strength and cyclic loading is sensitive to temperature. How sensitive? See someone at one of the companies who can run an FMEA Model with the proper boundary conditions.

    I suspect the extractor spring would be more sensitive than you think being such a tiny spring.

    Will it make a difference in a class or four? No, the design is not that marginal. I'll take anything moving in the proper engineering direction: Better is ALWAYS better; even if it's only marginally so.
    So leaving my AR in the trunk on a hot day might have a negative effect on my bolt? Because I can assure you, a trunk in the summer time can get hotter than 120 degrees.

  6. #26
    Join Date
    Sep 2009
    Location
    Barre, VT
    Posts
    7,148
    Feedback Score
    94 (100%)
    Do all Ruger SR 556 rifles come with a FA carrier?
    "Real men have always needed to know what time it is so they are at the airfield on time, pumping rounds into savages at the right time, etc. Being able to see such in the dark while light weights were comfy in bed without using a light required luminous material." -Originally Posted by ramairthree

  7. #27
    Join Date
    Nov 2007
    Location
    New Mexico
    Posts
    3,204
    Feedback Score
    1 (100%)
    Quote Originally Posted by usmcvet View Post
    Do all Ruger SR 556 rifles come with a FA carrier?
    they do not. There is a gentleman over on TOS who has modified an Adams Arms carrier to work properly by filing a little material off the carrier's piston impact surface.

  8. #28
    Join Date
    Sep 2009
    Location
    Barre, VT
    Posts
    7,148
    Feedback Score
    94 (100%)
    Quote Originally Posted by Tokarev View Post
    they do not. There is a gentleman over on TOS who has modified an Adams Arms carrier to work properly by filing a little material off the carrier's piston impact surface.
    Thanks. I remember being disappointed when my buddy bought his Ruger. I wanted to try it on a FA lower and quickly saw we could not.
    "Real men have always needed to know what time it is so they are at the airfield on time, pumping rounds into savages at the right time, etc. Being able to see such in the dark while light weights were comfy in bed without using a light required luminous material." -Originally Posted by ramairthree

  9. #29
    Join Date
    Nov 2007
    Location
    New Mexico
    Posts
    3,204
    Feedback Score
    1 (100%)

  10. #30
    Join Date
    Aug 2008
    Posts
    1,663
    Feedback Score
    6 (100%)
    This is intellectually interesting but thats it as overheating isnt a real issue outside of the internet.
    Dave Merrill
    Terrible Technical Writer. Awful Photographer. Lazy Instructor. Kind of a dick.
    Loves Tacos.

Page 3 of 4 FirstFirst 1234 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •