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Underwood ammo safe to use in a lwd 6 inch barrel?

Discussion in 'The 10 Ring' started by Ken52789, Dec 11, 2011.

  1. Ken52789


    May 15, 2011
    I'm asking for a lwd 6 inch barrel for Xmas from the gf. Just want to make sure underwood's ammo is safe for the extended length.
  2. arushus

    arushus Biggest Member

    Jul 22, 2011
    NE Oklahoma
    completely safe, no worries mate!

  3. 21Carrier

    21Carrier Until I Gota 29

    Feb 4, 2011
    Hoover, AL
    I would be cautious. I almost learned the hard way that ammo made for one barrel does not mean it's safe in another. I had developed a safe max load for my stock G29 barrel (135gr Nosler JHP, CCI 300s, 13.0gr 800-X, COAL 1.260", 1550fps from G29). I shot hundreds through my bone stock G29 with zero issues. I tried the same load in my 6" barreled G20LS. I figured the supposed "full support" of my LWD barrel would assure my safety. I even thought I would be able to bump up the load. I was very happy to see that I hit 1800fps flat. When I inspected my brass, I saw this:


    I'll remind you of two facts here. One, that load tested plenty safe in my G29. Two, that load is VERY similar to Underwood's 135gr Nosler JHP at 1600fps (from a G20). My load should be doing about 1650fps in a G20, and that's about what the Underwood load ACTUALLY does. It's up to you, but I would make sure your barrel has full support, and proceed with caution. Fire ONE round, and check the brass. If it's ok, fire another and check it. I would check at LEAST ten before proceeding. Any sign of a smile means you're pushing it.

    Remember that longer barrels effectively increase pressure. They increase the amount of time during which the brass is subjected to full pressure. The late Mike Willard (owner of Swamp Fox Gunworks) was VERY clear about this. He routinely warned that his ammo was NOT safe in 6" barrels. He warned that he must back down the load for use in 6" tubes, and we saw the smiles and such from more than one user that didn't know. Proceed with caution.
  4. Ken52789


    May 15, 2011
    Thanks 21. I read that post by mike and that's why i posed this question. I guess i'll do as you suggested and shoot one at a time and check them out.
  5. Javelin

    Javelin Got Glock? Silver Member

    Feb 9, 2008
    N. Dallas
    So for folks using Underwoods 135gr & 165gr would be ok to go with standard glock barrels? Just asking?
  6. G29SF


    Oct 24, 2011
    Highland, IL
    Here are some "facts" (think they are true, but have not proven them myself):

    SwampFox (late Mike Willard) produced hot 10mm loads that required an aftermarket barrel and stiffer recoil spring.

    SwampFox said those loads would be OK in G29 and G20 barrel lengths (stock lengths, not stock barrels) only.

    SwampFox said if you used a 6" barrel, he would download for that barrel. End result would be same velocity.

    Underwood produces ammo that is pretty close to SwampFox loadings. I think within 25 fps. Not sure on this though. (I have shot both Underwood and SwampFox's nuclear stuff. I can say Underwood is HOT and love it!)

    I would proceed with caution myself... unless Kevin chimes in and says it is good-to-go.
  7. arushus

    arushus Biggest Member

    Jul 22, 2011
    NE Oklahoma
    His stuff that required aftermarket setups was labeled as such, underwoods loadings are not that hot. They are nearly the same as swampfox's standard max velocity ammo, notthe stuff that required a fully supported chamber.
  8. post-apocalyptic

    post-apocalyptic magnifi ba$tard

    Jul 27, 2011
    I've fired both types of 180gr Underwood, as well as their 165gr and 135gr rnds through both my 4.6" and 6" Glock barrels with no problems. Some of the casings have a slight smile and that's it. They're still reloadable.

    Of course, another benefit of Glock barrels is higher velocity due to their polygonal rifling.