My bulldog thread
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My bulldog thread
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Topic: My bulldog thread (Read 4472 times))
mackeral5
GTA Senior Contributor
Posts: 3343
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Real Name: Mike D
Re: My bulldog thread
«
Reply #60 on:
February 13, 2021, 01:19:01 PM »
I made a very crude depinger. it is 2 pvc caps glued together, with a different arrangement of holes in each cap. It does take up valuable air storage space, I tried to mitigate this by perforating the spacer with a bunch of holes.
It is ugly, but it was less than $5 in cost and the ping is 100% gone. Tune is basically the same----3 shots in the ~1000fps range, then dropping off to 950fps on the 5th shot.
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Lake Harding AL
mackeral5
GTA Senior Contributor
Posts: 3343
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Real Name: Mike D
Re: My bulldog thread
«
Reply #61 on:
February 13, 2021, 03:00:19 PM »
the rain slacked off enough for a quick fill and 1 mag into a target at 80 yards. The first 3 shots of NSA 142gr are over 1000fps with the last shot being right at 950fps, measured 6feet from the muzzle. The NSA 142gr appears to be a perfect match for TJ's 1:26 mandrel.
The gun will shoot better than this, with a better shooter and more effort put into shooting. But this is pretty much real world shooting--I'm on my 2nd Yeti Tumbler of coffee for the day. Target was placed, gun was filled, and shots were taken in a very short timeframe, less than 5 minutes total. Position is standing with bipod on my truck bed cover.
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Lake Harding AL
Airgunhunter73
Sharp Shooter
Posts: 540
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Real Name: Terry
Re: My bulldog thread
«
Reply #62 on:
February 13, 2021, 05:35:29 PM »
Good looking group for shooting like that Buddy and I like the target holder you came up with also.
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Kansas City, Mo
Terry
mackeral5
GTA Senior Contributor
Posts: 3343
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Real Name: Mike D
Re: My bulldog thread
«
Reply #63 on:
February 14, 2021, 05:29:07 PM »
Quote from: Airgunhunter73 on February 13, 2021, 05:35:29 PM
Good looking group for shooting like that Buddy and I like the target holder you came up with also.
thanks Terry. I'm finding the gun to be very consistent, at this stage I would feel comfortable harvesting an animal with it. Maybe next season...
Those wire rose trellis work very well as a portable target stand also.
Like these:
https://www.lowes.com/pd/Garden-Accents-Traditional-Fan-Trellis-64-in-H/1000488461?cm_mmc=shp-_-c-_-prd-_-lwn-_-google-_-lia-_-243-_-verticalgardening-_-1000488461-_-0&placeholder=null&ds_rl=1286981&gclid=CjwKCAiAsaOBBhA4EiwAo0_AnEFnL_7fzJ1hBEUVZOMYbuf6OE1LMDuZEw4prGhWb0GrXAlEi8H_OBoCSIYQAvD_BwE&gclsrc=aw.ds
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Lake Harding AL
mackeral5
GTA Senior Contributor
Posts: 3343
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Real Name: Mike D
Re: My bulldog thread
«
Reply #64 on:
March 27, 2021, 11:15:45 AM »
A bit of an update. This particular gun is also documented over in my .257 Bulldog thread. I will leave the .257-specific notes in the other thread and keep this thread primarily focused on the gun as a whole and .357 performance.
A few modifications have been made to allow for pivoting between .357 and .257 without splitting the stocks. The key to this simple caliber change process is a WAR-style interchangeable bolt probe system.
This picture is prior to adjusting pin length to size.
This pic shows the .357 pin probe installed as well as one of the modifications that enables fast caliber changes. The 2 holes in the breech cover allow access to the barrel screws, without having to remove the 7 hex screws that hold the clamshell breech covers in place.
While testing max power in .257 I stumbled across 2 power limiters that I was unaware of in .357 testing. When I made my first peek poppet I made the stem just approximately .075" too short. This allowed the hammer to bounce off the valve nut, which results in lower velocity and extremely inefficient HPA consumption. I corrected that by making a poppet with longer stem. I've often read in Troy Hammer's posts that he will sometimes use hammer weights to help in higher power tunes. My builds typically involve reducing hammer weight, but I figured what coudl I lose in trying. I made a brass spring guide/hammer weight that weighs approximately 17grams. Worst case I move it to the other end of the spring and use it as a spring guide....
here is an assortment of Bulldog hammer/spring stuff.
The SSG and skeletonized hammer (43grams) are used in a regulated .357 tune for 88gr slugs (15 shots @160fpe, OEM tube with regulator installed.) The dark gray hammer is OEM with exception to the addition of a peek striker. The dark gray hammer and the longest brass spring guide/hammer weight yields ~125grams of striker weight.
Keep in mind I identified and resolved the short stem protrusion and added the hammer weight while testing for max power in .257 w/35" barrel. It maxed out at 240fpe in .257 at 3600 psi.
After converting back to .357 (currently 29" barrel) the gun generates more energy than ever. For this barrel I am limited to an OEM length tube due to interference with the large Neil Clague Reflex moderator. With a high pressure aftermarket tube filled to 3600psi and HST dialed up to max, it will send 174gr BBT's molded from an NOE mold 998-1003fps---Over 380fpe. Dialing HST back will find a 945-960-940fps 3 shot tune.
Then there was the question of accuracy---is the TJ's 1:26 barrel compatible with the 174gr BBT slug? That is a very long slug, about as long as will fit in the BD magazine. I shot a few quick groups at 75 yards to see.
This was good enough for me. The slugs were sized to .357 but unweighed, unsorted. They are not the prettiest castings either, so with better bullets and more care taken groups should tighten up a bit.
In upcoming weeks I plan to order 36" of TJ's 1:26 .357 so I can make up a barrel that will work with my 500cc high pressure tubes. The unregulated is one of Matt/Pitbull's tubes that uses an Airbow end cap. The regulated 500cc was created by combining an OEM length high pressure tube and one of Matt's 160cc plenum extensions. The regulator sits against the tube coupler, if you look closely you can see the vent hole. Currently I can only use these with the .257 barrel due to moderator interference.
Here is a pic of the Bulldog in 29" barrel 357 format along with the 500cc tubes, and 35" .257 barrel/probe setup. In .357 with the 29" barrel and moderator it is 42" long. In .257 with the 35" barrel and a Shogun it is right at 49" long.
«
Last Edit: March 27, 2021, 11:20:24 AM by mackeral5
»
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Lake Harding AL
redlined_b16a
Expert
Posts: 1234
yes
Re: My bulldog thread
«
Reply #65 on:
March 31, 2021, 12:03:45 PM »
Impressive for sure.
Keep it up
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Louisiana
mackeral5
GTA Senior Contributor
Posts: 3343
yes
Real Name: Mike D
Re: My bulldog thread
«
Reply #66 on:
April 11, 2021, 07:37:00 PM »
It's been a while since I set up the low power regulated tube/tune setup. It uses an OEM tube with approximately 90cc of plenum and a Huma regulator set at approximately 1800psi. At this reg setting it sends GT bullets 88gr hollowpoints right at 885fps.
A pic of the plenum spacer. It has roughly twice as many holes in it now, every bit of plenum helps.
In this configuration the hammer system consists of a skeletonized OEM hammer weighing in at a whopping 42grams, equipped with a peek striker. An SSG has the hammer is approximately 1/8" free flight. In the below pic the SSG and the skeletonized hammer should be easy to pick out. The hammer is ugly, but demonstrates that only certain parts/aspects are critical.
A couple more pics of the butchered hammer.
I've posted a 1.06" NUAH target on multiple threads over the course of the past year or so. Over that time this gun has shot thousands of .357 rounds at various power levels up to 380fpe. Not to mention several hundred in .257. I've often said the gun can shoot better than I can and even used the adjective "surgical" from time to time. Almost 1 year (and MANY iterations) later, can the gun still shoot at this level?
Another gratuitous posting of that NUAH target.
To find out, I reassembled using the longer shroud/scope mount and scope which was last put on paper with the .257 barrel. I've found this barrel/shroud/scope mounting system to be very stable. Even when swapping between .257 and .357 it is usually close enough on paper to hold over/under a few mildots depending on which caliber I am swapping from/to.
The shooting position. Target is 102 yards away.
Today the winds were swirling 5-10 with the occasional calm period. This target has 4, 5 shot groups. The 2 groups around the center bull were initial groups shot using holdover of 3 mildots, with a slight adjustment between groups. Then I made a third scope adjustment and there was a nice pause in the wind for the top right 5 shot group. Probably the best group this gun has ever shot- .80" CTC. I tried to back it up but the wind wasn't cooperating and this is evident in the top left group. Sometimes things line up perfectly, sometimes they don't....
Again, ammo is GT Bullets 88gr HP's they market as a .380 ACP bullet. I buy them unlubed/unsized/as-cast and size them to .357. 885fps MV, shot out of a TJ 1:26 liner.
«
Last Edit: April 11, 2021, 07:50:13 PM by mackeral5
»
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Lake Harding AL
Greg_E
Expert
Posts: 1380
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Real Name: Greg
Re: My bulldog thread
«
Reply #67 on:
April 11, 2021, 09:20:04 PM »
I'm going to need to study this thread from the beginning.
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USA, NY, Syracuse
https://odysee.com/@JAAG:c
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My bulldog thread