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Checkmaker™ -Gas Check Forming Tool and Die Sets





Source for GAS CHECK Metals

Ejector Arms

Checkmaker™ Prices

Order Information

Do Checkmaker™ gas checks STAY ON once fired?

Customer Testimonials and Compliments


The 1# choice...

Checkmaker™ -gas check making dies are guaranteed to perform flawlessly as currently proven by numerous cast shooters:


Checkmaker™ Gas Check Forming Die Sets:

-Meet or exceed accuracy shooting results of factory gas checks.

-Very user friendly- fast and easy to use, and to set up.

-Produce a bare minimum of material waste.

-Produce concentric gas checks that fit and STAY on, using the accuracy of your reloading press.

-Heavy duty machined quality with no moving parts or springs to break or gum up.

-Flexible- accommodate a wide range of material thickness- and work with a wide range of Boolit diameters all within one caliber set.

-Lifetime purchase and user re-sharpen able-


I fully guarantee EVERY die set to be spot on and work flawlessly to your satisfaction, with a "No BS" warranty.



-Heavy duty designed quality machined-


"The proof is in the accuracy results"


For cast shooters- accuracy is the quest we all seek with our beloved silver stream.

Why invest in a gaget that claims to make a pile of checks in record speed, when Checkmaker™ dies produce excellence at only a slightly slower pace.

I want a die that produces results that shoot, not just sit there and look pretty.


.... B. R. James


All calibers will be offered in a "PB" plain base version (shown) as well so you can push your favorite plain base mold boolits to places like never before. PB calibers in production NOW!


"I tried the 35 plain base checks in my brothers 9mm thats been giving us fits. I tried a load that put quite a bit of lead in the barrel according to my notes. I put the checks on the boolits this time and guess what???

No more leading and very accurate in his pistol and carbine. These PB checks make 9mm loads very easy now. No more problems. Right there made this tool worth the money. Awesome results!"

- Ken Dodge



Checkmaker™ PB version dies are breaking new ground-


The beauty of the my PB version dies is you can take advantage of inexpensive thin metals. Shooters are now able to use and buy plain base molds in place of check shank molds and have the best of both worlds in one mold without the higher cost of thicker metals, or expensive factory gas checks.


We are getting remarkable performance out of firearms, even auto loaders with group sizes shrinking, and no more leading. The PB dies have truly broke new ground, and have proven their performance with Checkmaker™ dies for 6 years now.


I now have customers who are winning local IPSC competitions with PB gas checks.



Calibers Now in production-


22 cal, 22T cal (tall about .095 in Tall w/.014 AL and depending on metal used, .081 inside), 22PB cal, 22PB-AR cal (tall about .095 in Tall w/.006 AL and depending on metal used, .081 inside, great for the AR platform), 243 cal, 6mm cal, 7mm cal, 7mmPB cal, 270 cal, 270PB cal, 30 cal, 30PB cal, 303 British cal, 7.62x39 cal, 7.62x39PB cal, 338 cal, 8mm cal, 8mmPB cal, 32 cal, 32PB cal, 32-20PB Winchester (includes 32 S&W Long, 32 Colt New Police), 348 cal, 348PB cal, 35 cal (includes 9mm), 35PB cal (Plain Base, includes 9mm) 38-55PB Winchester Cal, 375 cal, 375PB cal, 10mm cal, 10mmPB cal, 40 cal, 40PB cal, 41 cal, 41PB cal, 416 Rifle cal, 44 cal, 44PB cal, 45 cal (fits both pistol and rifle), 9.3 cal, 45PBP Pistol cal, 45PBR Rifle cal, 45PB-AR cal (tall), 50 Cal Pistol (.501), 50 Cal Rifle (.512), 50PB Pistol, 50PB Rifle.


-more calibers including:


25cal, 25PB cal, 6.5 cal, 6.5PB cal, 405 cal

405PB cal ,480 cal ,480PB cal.




Hello Pat,

I have bought some of your gas check makers awhile back. Both for .44 magnum but one for plain base.

I just wanted to say, using these are probably the nicest addition to my casting/reloading as to date. I may just be an over happy customer, but I honestly believe that my shooting has improved using gas checks made with your tools then ones I used to use by Lyman... And trust me, I am a HUGE fan of Lyman!

Anyway. I just wanted to let you know how awesome your tools are. I refuse to part with them.

In the near future I have been getting more and more interested in both .38-55 caliber and also the .45-70 caliber. When time comes, is it possible I can contact you for making gas check makers in either caliber, both regular and plain base as I like to have both handy as with me and my fathers .44magnum set up?

I have been spreading the word around about your gas check maker and the above superb quality to my friends.

Thanks again for everything, you and your company are true craftsmen at the finest!


Michael E Boffemmyer



You made my morning! I get a lot of praise from time to time and it's what keeps me going in this business- manufacturing, which is not easy by any means but the compliments and customers like you keep me motivated.

I already have 38-55 and 45-70 in production.

Happy shooting,




-To Order-

-Email your name, address and order wishes/questions and I will email back an order confirmation with payment instructions-


MAKE SURE West Coast Engineering is NOT in your email trash bin. Many times folks never realize I have emailed them back and my email gets blocked.


We accept Check, Money Orders, and PayPal payments.

Pat -

West Coast Engineering








"If I were starting over in pistol molds I would get only plain base molds. The plain base gas check makes the plain base boolit dual purpose. Only have to cast one boolit for either application."

-Robert Freestone


Here's an official PDF download link for Checkmaker™ die instructions:



-We are now fully automated CNC and are running various calibers-



How to make Gas Checks (a tutorial pdf )


PatMarlins .30 Cal CheckMaker (video)


35 cal gas checkmaker (video)



The accuracy reports keep rolling in!...

(please note some of these links are real old)


Checkmaker™ dies and a Polygonal Rifle Barrel


The Beretta Storm Carbine and Checkmaker™ Gas Checks


Testing Aluminum for Gas Checks


Patmarlins... Production Updates and the Great 44 cal Checkmaker™ Dies


Checkmaker™ Gas Checks and a 30 caliber Spitzer


Introducing the 50 Caliber Checkmaker™ Dies


Using the Checkmaker™ 45PB Pistol Caliber Dies


Explanation of the Theory and Engineering behind Checkmaker™ Gas Check Forming Dies-


Mother of all Checkmaker™ Dies Links


Comparison between PatMarlins Checkmaker™ 32/8mm checks & Hornady commercial-


Just in- New test report on the 35PB cal Checkmaker™


Pat's 35 caliber Checkmaker™


It's Alive! -The 45 Cal Checkmaker™


Checkmaker™ G/C Range Test .014 Thickness AL


Lee Challenger Breech Lock Press for Pat's tool


Checkmaker™ sized with LEE push through dies for Ben's 35 cal dream rifle:

Introducing the 22T Caliber Checkmaker™

I'm now offering 22T caliber dies. T for "Tall" and currently they're being put through their paces by shooters out in the field. It's my first version of (5) to come in 22. If they do not fit your mold shank, you will have full credit towards another version of 22 caliber in exchange that will fit.


22T cal Checkmaker™ dies (about .095 in .014 depending on metal used) will gobble up some- if not all of the first lube groove on some molds, but with bucking prior wisdom of the past concerning gas checks, my dies have uncovered new ground and new accuracy by matching, and out-shooting factory checks even, in many instances.


Below are pictures of Lyman 22415 and 225462 and the 22T gas check out of soft Amerimax .014 aluminum. Since this is such a tall check, and with the thickness of soft .014, the top edge is jagged, but this will not effect accuracy. The tall check should be beneficial to the AR platform as well.


I think this tall check will shoot like gangbusters without much lube near the check. Less lube, and less lube grooves often times has proven to improve accuracy with cast shooting. The dies are very easy to setup and use with your reloading press.


The proof will be in the performance at the range. These are very different from factory and FreeChex.


The efforts of the last 5 years of hard work, investment, and sacrifice developing Patmarlins is coming together well and that translates into more product available and faster shipping times.


If you would like to proceed with an order for any of my dies, email your final order wishes, mailing address (and model of press) and I'll send an order confirmation with instructions, and you can proceed from there if you wish.


Many thanks for your kindness and your business.


Happy shooting,


Pat ...

35 caliber dies: also work for 9mm .356 diameters.


45 caliber dies:

45 caliber dies for shank molds work for both 45 cal pistol and 45 cal rifle with one (1) set. You simply (if needed) adjust metal thickness. You need a solid bench and press.


45PB caliber dies (plain base) use a separate set of dies each- one (1) for pistol and one (1) for rifle. You need to specify which one.


50 caliber dies:

The standard (shank mold) 50 caliber Checkmaker™ dies will only work with a modification to your mold. Standard 50 cal cast bullet shanks are designed to use .022 metal which is expensive.


I designed Checkmaker™ dies in standard 50 caliber to work with inexpensive thinner metal. You need to order a 50 cal mold with a .486 shank, or have your mold shank opened up to .486. This way you can use inexpensive metals from .010 to .016 and the best performing .014 Amerimax Aluminum. Again- the 50 cal standard Checkmaker is not designed to make a gas checks with (expensive) .022 thick metal.


However, all Checkmaker™ 50PB caliber (plain base) version dies are designed to work with no mold modifications. You can make PB gas checks with up to .014 metals to fit any 50 caliber pistol, or 50 caliber rifle plain base dies.


50 caliber dies available:


50 Cal Standard - now works for shank molds in both .501 pistol and .512 rifle in one die set. (You modify your mold shank to .486). You adjust metal thickness for best performance.

50PB Pistol cal (.501) plain base for metals up to .016.

50PB Rifle cal (.512) plain base for metals metals up to .016.






Thank you for your Kindness, business, and support of a Home Grown -American Manufacturer.


-Email your name, address and order wishes/questions and I will email back an order confirmation with payment instructions-


We accept Check, Money Orders, and PayPal payments.

Pat -

West Coast Engineering

Pat says the following :

"These Checkmaker™ dies are fast and easy to set up, fast and easy to use, and produce accurate, concentric, gas checks with the help and accuracy of your reloading press and leave an extremely small amount of material waste."

He is ' dead on ' with his comments. This is a quality product and will work just as he describes. The ones I made this afternoon ( made from .010 CU ) were tried on 3 different .30 cal cast bullet designs. They fit tight on all 3.

Great Product Pat ! ! ! ....Well Done !

-Ben Hays

Hays Gunstock Refinishing and Repair



Just a small sample of our customer feedback...


.30 cal tool used at last...


Pat I just had to let you know that the shoulder problems are almost gone (Jerry tore his rotator cuff) and I produced a pile of great looking checks today. The tool does exactly what you said and I'm in hog heaven.


Thanks for all your efforts.


Jerry B.


mold maker


Simplicity and elegance

It went together like butter on hot toast and is a really nice simple



I may have to order more and I am sure once buddies see it they will

want one to clean up their tabletop.


Thanks for a great product.


Gary Banas


Everything including the saeco , fits like a glove!!!


You have fixed a problim I have had with mounting these presses for the last 25-30 or so years.

I am like a kid with a new toy! Take care and god bless.....Buck


First of all, Pat. Quality and very easy to use!!

Ernie Plumber

This seems to be one d*mn slick little tool. I had a very short learning curve, as you would with any tool. I'm sure I'll continue to refine as I experiment. I have a small pile of soda can gaschecks forming.

Patrick L.

Had a box waiting for me when I arrived home this evening. First bit of advice I can offer - retreat to your man cave before you open the box. Failure to heed this warning will cause you to be reintroduced to the Hoover. This will make sense when you open the box.


The tool is a very clever design and just takes a few minutes to become acquainted with the various parts and how they fit together. I had two materials I had put aside to try, mainly because they were free. I have some .008 soft copper and some .012 aluminum roof flashing. Both materials formed good checks. The copper was easier to work with because it cut and formed easier. Checks formed from both materials seated perfectly on the shanks of 30 cal boolits I have laying around. I did not try any through the sizer yet, but will soon.


The tool works as advertised, and looks to be an interesting gadget to experiment with. Nice job, Pat!


Hi Pat, I finally got a chance to get down to the shop and try the new punch you sent.


Not tight, not loose, perfect! Thanks for all the help. Oh, and thanks for the extra CFF in the box. With all this flux, I need to find another motherload of wheelweights. Now I need to get what I loaded down to the range and see how they fly !


Thanks again Ernie (aka Plumber)

I have been pleased with the results using these checks. Todays results - same gun and load as before. 1" ~ 7/8" ~ 1" Not quite one hole, but better than I was doing with factory checks.

Robert F.


 Received the mount and plate today!  What can I say but that they are beautiful.

Trevor Green

Thank you pat, I received everything today, and have put it together.

I wish I'd of had one of these a long time ago.

It's very well made and strong.

Thanks again, Keith Marshall

Satisfaction or your money back...! You are investing in quality here. All of my products come with a "No BS" warrantee. My aim is to make you happy with your purchase.

Kindest regards,



Made in the USA!