Meplat uniforming is a relatively new and advanced procedure that many long-range shooters are performing on their bullets or ammo. Meplat uniforming refers to trimming the nose of the bullet to remove any irregularities created during the pointing of the bullet and at the same time uniforming the meplat of the bullet. The meplat is more commonly referred to as the “hollow point” opening. The premise behind uniforming meplats is that bullets with uniformed and cleaned up meplats will produce a smaller group at longer distances. Meplat uniforming, when accompanied with pre-sorting your bullets by ogive length, will produce a group of bullets with uniform ballistic coefficients.

A few of us at Sinclair uniform the meplats on bullets used in our long-range loads and believe that our loads shoot better because of it. We generally shoot these bullets at distances of 600 yards and beyond. We don’t see a lot of advantage to meplating bullets used at distances less than 500 yards unless you are using a load where the velocity drops off quickly. Many of the shooters that uniform meplats see measurable improvements in their group sizes.

Meplat uniforming is performed on the bullet with a two-flute or four-flute cutter. The Sinclair Meplat Trimmer utilizes a two-flute cutter, which we selected due to the clean cut it provides. The trimming can be done prior to the bullet being loaded or after the bullet is loaded. A very small amount of material is removed; you just skim cut the top of the bullet with the cutter. All you are doing is removing any high points of the jacket that resulted as it was folded/pointed to create the hollow point. (See picture at right) Normally, you don’t want to remove much more than .005” of material unless you are working with larger bullets (190-grain or larger). You may want to follow up with wet/dry sandpaper to remove any burrs depending on the cutter used. The Sinclair Meplat Trimmer utilizes a Delrin housing specific to the caliber of bullet you are trimming. The housing contacts the ogive as you insert it into the housing and holds the bullet square to the cutter face insuring consistent and uniform cuts. The hand crank makes it rather easy to uniform the bullets and you can quickly go through a box of 100 bullets or loaded rounds. The tool is very easy to setup and you can switch calibers in a matter of seconds by just changing the housing. We designed the tool so you don’t have to buy a complete tool for each caliber; just buy the appropriate bullet housing.

If you are handloading your own ammo, we recommend that you pre-sort your bullets using a bullet comparator prior to meplat trimming. We use a Sinclair Bullet Comparator (the style that mounts to a caliper blade) and an electronic caliper to sort our bullets. This setup measures the bullets from base to ogive. As we measure the bullets, we use small paper cups (bathroom size) to segregate them. A separate cup should be designated for each unique length in thousandths; just write the measurement on each cup with a marker. We try to use bullets with an extreme spread of .005” if possible. Any bullets measuring outside this spread can be used for practice or at shorter ranges. Sorting the bullets in this manner prior to uniforming the bullets results in more uniform ballistic coefficients.

For more information on bullet meplating, check out the products on our website or call and talk to one of our knowledgeable technicians.

Tags: Meplat Trimming/Uniforming

This entry was posted on Friday, December 12th, 2008 at 4:17 pm and is filed under How-To Articles. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.