# Running FMJ through a firearm before using JHP's **URL:** \ **Category:** Guns & Gear\ **Created:** [July 3, 2022, 2:43am UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327 "2022-07-03T02:43:52Z")\ **Posts on this page:** 13\ **Page:** 3
**Author:** ![Ron43xMOS](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/ron43xmos/32/137450_2.png) [@Ron43xMOS](https://community.usconcealedcarry.com/u/Ron43xMOS)\ **Post date:** [July 4, 2022, 7:08pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/41 "2022-07-04T19:08:12Z")
I like that. The fewer the variables, the better. ---
**Author:** ![Nathan57](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/nathan57/32/37700_2.png) [@Nathan57](https://community.usconcealedcarry.com/u/Nathan57)\ **Post date:** [July 4, 2022, 7:35pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/42 "2022-07-04T19:35:16Z")
That is a good point, but often only applies to people with red dots. Very few carry guns have elevation adjustable iron sights, which is what will change with bullet weight/velocity, so it’s more like check your defense ammo to make sure it has a good poi vs poa and if elevation is off too much, use a different ammo ---
**Author:** ![45IPAC](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/45ipac/32/2855_2.png) [@45IPAC](https://community.usconcealedcarry.com/u/45IPAC)\ **Post date:** [July 4, 2022, 7:39pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/43 "2022-07-04T19:39:46Z")
Good point on the sights. It still points out to check the ammo, and firearm as 1 tool. One does no good without the other. ---
**Author:** ![Alexander8](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Alexander8](https://community.usconcealedcarry.com/u/Alexander8)\ **Post date:** [July 4, 2022, 7:47pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/44 "2022-07-04T19:47:58Z")
Yes, and this is another reason not to mix multiple types of ammo in one’s magazine. ---
**Author:** ![Ron43xMOS](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/ron43xmos/32/137450_2.png) [@Ron43xMOS](https://community.usconcealedcarry.com/u/Ron43xMOS)\ **Post date:** [July 4, 2022, 7:50pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/45 "2022-07-04T19:50:00Z")
Maybe unless you are testing a new firearm? ---
**Author:** ![Alexander8](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Alexander8](https://community.usconcealedcarry.com/u/Alexander8)\ **Post date:** [July 4, 2022, 7:53pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/46 "2022-07-04T19:53:26Z")
I meant, some folks interchange FMJ and JHP rounds in their magazine. You can find at least one recent topic about it. ---
**Author:** ![Ron43xMOS](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/ron43xmos/32/137450_2.png) [@Ron43xMOS](https://community.usconcealedcarry.com/u/Ron43xMOS)\ **Post date:** [July 4, 2022, 7:55pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/47 "2022-07-04T19:55:52Z")
People are carrying FMJ’s interchangeably for self defense? Or just for going to the range? ---
**Author:** ![Alexander8](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Alexander8](https://community.usconcealedcarry.com/u/Alexander8)\ **Post date:** [July 4, 2022, 8:00pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/48 "2022-07-04T20:00:32Z")
For self defense. IMO, unless you are defending your B17 from Luftwaffe fighters, don’t load like this. Other people had other opinions. ---
**Author:** ![Ron43xMOS](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/ron43xmos/32/137450_2.png) [@Ron43xMOS](https://community.usconcealedcarry.com/u/Ron43xMOS)\ **Post date:** [July 4, 2022, 8:06pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/49 "2022-07-04T20:06:20Z")
Wow. Do you remember their justification? ---
**Author:** ![Alexander8](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Alexander8](https://community.usconcealedcarry.com/u/Alexander8)\ **Post date:** [July 4, 2022, 8:10pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/50 "2022-07-04T20:10:23Z")
Failure to expand from one round, mitigated by increased penetration from the next. Like I said, inconsistency in recoil alone should dissuade you. I encourage you to look up the thread. ---
**Author:** ![Ron43xMOS](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/ron43xmos/32/137450_2.png) [@Ron43xMOS](https://community.usconcealedcarry.com/u/Ron43xMOS)\ **Post date:** [July 4, 2022, 8:14pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/51 "2022-07-04T20:14:36Z")
Doesn’t sound like a good plan to me, but I’m just a newbie… ---
**Author:** ![Nathan57](https://sea1.discourse-cdn.com/flex015/user_avatar/community.usconcealedcarry.com/nathan57/32/37700_2.png) [@Nathan57](https://community.usconcealedcarry.com/u/Nathan57)\ **Post date:** [July 4, 2022, 8:57pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/52 "2022-07-04T20:57:01Z")
Failure to expand IS increased penetration. That’s how that works ---
**Author:** ![Alexander8](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Alexander8](https://community.usconcealedcarry.com/u/Alexander8)\ **Post date:** [July 4, 2022, 9:01pm UTC](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327/53 "2022-07-04T21:01:07Z")
You are right. Maybe I need to review that old thread, for the logic behind mixing ammo types. [Previous page](https://community.usconcealedcarry.com/t/running-fmj-through-a-firearm-before-using-jhps/83327.md?page=2)