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Best Prices, Fast Shipping & Expert Advice!
Best Prices, Fast Shipping & Expert Advice!
Thor™ Hammer Bullet Sizing Pack - .500 to .503 Diameter

Thor™ Hammer Bullet Sizing Pack - .500 to .503 Diameter

by Thor

4 Pack - Model THOR-SAMPLE
.50 Caliber, .500 to .503 Diameter

Original price $6.00 - Original price $6.00
Original price
$6.00 - $6.00
Current price $6.00


The Thor™ Bullet produced by OPG Gun Ventures is a patented, full bore diameter, bullet conical that is bore size specific. Being 100% copper, the Thor™ Bullet is not soft like lead, and will not size to the bore like lead bullets when loading. As a result, these bullets require sizing to ensure a perfect fit to your bore. The Thor™ Muzzleloader Bullet sizing pack comes in .50 caliber with 4 diameters of .500", .501", .502" and .503". 

Before purchasing your first pack of Thor™ Bullets, you first need to order this test sizing pack which will allow you to correctly size your bore. It is important that you start with the smallest diameter Thor™ Bullet, and work your way up in diameter size until you find the proper fitting Thor™ Bullet for your muzzleloader.

To determine which bullet is best for your muzzleloader, start with an empty rifle, remove the breechplug and slide in the .500 bullet. If it slips easily down the bore, you then try the .501 and so on.  When you find the diameter that requires about 20/30 ft./lbs. of force to push down the barrel (that is comparable to the resistance you get loading a standard sabot bullet), then that’s the correct size for your rifle. While manufacturers have similar bore diameters, they will vary .001”-.002" from gun to gun, so it is extremely important to correctly size your bore to determine which diameter works best for you. 

The Thor™ Bullets are a premium Barnes bullet with proven technology. The bullet’s hollow base expands when the powder goes off, both gripping the rifling and sealing the bore. If it is a quality conical you are looking for that won’t fragment into a million pieces, the conical Thor™ Bullet is the way to go.

***The sizing pack may contain both hollow point and ballistic tipped bullets


Package Quantity
Bullet Diameters
.500" TO .503"


Customer Reviews

Based on 37 reviews
jack w. (Marshalltown, IA)
Bullets, thor

I haven't use them yet. But nice looking items., fast shipping, and well package.

Cody C. (Newberg, OR)
Easy to use

This was extremely easy to use to figure out which bullet I will need for my muzzleloader.

Billy M. (Saint Joseph, MO)
Thor bullets

These bullets are unreal!!! Super tight groups!!! Highly recommend these!! You won’t be disappointed!!!

Michael M. (Arlington Heights, IL)

Sizing pack was simple, and easy to use.

John M. (Belchertown, MA)
.500 was good for me

The .500 went down easy with pressure from the rod, Not sure how to measure 10-30lbs with a reloading rod. My cva MR-X had rifling marks on the lower skirt/cup of the .500 size. .501 was hard to get down but not as hard as some have described. .501 had rifling grooves on the majority of the jacket so I went with the .500, because the instructions card said the round will expand from the heat of the powder ignition.