Author Topic: Bolt probe for bulldog? (Read 709 times)

ShakySarge · « **on:** June 26, 2018, 04:20:17 PM »

I have been tinkering around with the bulldog.357 and currently have opened up the ports to 9/32” and have been able to achieve a maximum speed of 860 FPS and a slowest of 842 FPS with 153gr cast bullets. This is a substantial improvement from stock but there isn’t a lot more that I can do with the platform without sending it off to a professional. That being said, has anyone tried probing the bolt yet? Using cast bullets it should increase the speed slightly. I was thinking about ordering another bolt just to try and see what is or isn’t gained.

Any suggestions on length and width of such probe?

Alan · « **Reply #1 on:** June 27, 2018, 05:11:46 AM »

As you know, all of the WAR models have retractable probes. They take some getting used to, but after 10,000+ rounds, I don't even think about it. All said and done, 860 FPS out of a .357 Bulldog is pretty darn good based on what I've read on the forums.

ShakySarge · « **Reply #2 on:** June 27, 2018, 06:38:09 AM »

I agree. Just tossing it around and decided that I might as well order a second bolt and give it a see.

tkerrigan · « **Reply #3 on:** June 27, 2018, 08:37:19 AM »

You can pick up 20-30fps by removing the poppet spring. Just have to point the gun up if filling from 0psi. I have an improved air valve in mine from JSAR that took my fpe up to 330+ fpe with more possible. They will be selling them shortly for $165. Installation is easy, just remove air tube, and current poppet and spring, and the new air valve just threads between the air tube and the receiver. Regards, Tom

tkerrigan · « **Reply #4 on:** June 27, 2018, 08:38:50 AM »

Oh, and I forgot, it uses a much lighter hammer spring. Real easy to cock. Regards, Tom

ShakySarge · « **Reply #5 on:** June 27, 2018, 09:24:44 AM »

Thanks for the information. I have already removed the spring and it did increase the velocity a bit. Im not looking to purchase anything right now. Just tossing around ideas without tossing around money. Not that it won’t be an option in the future but for now I am quite happy with little increases that are achievable without a machine shop.

ShakySarge · « **Reply #6 on:** July 06, 2018, 05:04:25 PM »

Installed the probe today. 1/8”. Going to let the epoxy set overnight and will do some chronograph testing tomorrow.

ShakySarge · « **Reply #7 on:** July 07, 2018, 08:42:31 AM »

The probe seems to have made a slight increase in speed but nothing dramatic. 5 shots from 3k with 150gr .358 went from 868-876-880-872-859. These speeds don’t seem impressive but with a 150gr bullet sized to .358 it’s fair to say that a smaller diameter bullet would greatly increase the numbers. When I first received the gun new the max was around 750 for the 150gr.

sixshootertexan · « **Reply #8 on:** July 07, 2018, 09:27:44 AM »

255 FPE is nothing to sneeze at. Going from 185 to 255 FPE is a nice improvement.

ShakySarge · « **Reply #9 on:** July 07, 2018, 10:12:50 AM »

I agree. It just goes to show that with a little patience and ingenuity a so-so platform can be made into a great platform.

Alan · « **Reply #10 on:** July 07, 2018, 11:36:40 AM »

Now, Matt, all you need to do is kill a few hogs for the freezer!

By the way, all arrived in good condition, and Peter is elated as I am. Thank you Sarge!

ShakySarge · « **Reply #11 on:** July 07, 2018, 11:42:54 AM »

Hogs would be nice! Glad he got everything. He will certainly enjoy them! I found the JSB 18.13s were the best shooting out of them.

Alan · « **Reply #12 on:** July 07, 2018, 12:39:06 PM »

Funny thing, Matt. That is exactly (excuse the pun) what I told him! Also, he ordered an Air Venturi tank and compressor from PA, along with enough pellets to start a war!

ShakySarge · « **Reply #13 on:** July 07, 2018, 05:24:38 PM »

Outstanding!

ShakySarge · « **Reply #14 on:** July 11, 2018, 05:13:41 PM »

I went through the bulldog today and discovered the reason as to why a probe that clears the magazine is only a minor, and in some cases, zero improvement. It is apparent that if the probe is able to clear the magazine then the pellet, or bullet isn’t pushed far enough into the chamber and actually blocks a portion of the port on the barrel. After realizing this by using a small mirror and a light I went about ways to make it work. I found that by pulling back on the cocking arm while inserting the magazine it not only cleared the magazine but also seated the bullet far enough forward to clear the port.

After another string I found that the speed increased to 899-886-870-862-849 for a max speed increase of 19fps. It just goes to show that with a little patience and a bit of attention to detail, what one can accomplish!