Bulldog modification log .328 porting and more

[PCPhack]

Just going on memory, yes, in that ballpark. Maybe closer to 300. Start was around 4200 and ending at 3600 or a little less. I never measured that one with the digital gauge, just glanced at the little 5000 psi analog one on the Bulldog.

[Jzizzle]

Ok thanks.

I won't get to tuning until next Wed so I will follow up with results then.

Thanks to all who have put forth their ideas and experiences.

[Lani52]

I just got my Bulldog back from JSAR, porting the valve from .277 to .30 and installing their 5000 psi gauge.

The gauge has a white dual, numbered to 5k and psi stamped where 6000 would be, but I don’t know if the needle goes that far and have no intention of fining out, I will call it a 5k Gauge for now.

I do love how spell check here exchanges Guatemalan for gauge if you misspell it. ‘Poor spellers of the world  untie”, that’s my humor for the day.

My rifle with the oem tube filled to 3600 psi used 2 hundred psi for 5 shots when ported to .277 and with the JSAR spring and using no projectile, I have not tried that test with the 4500 psi tube and .30 porting yet.

Fuzzy,

FYI, I ordered three Benjamin springs yesterday, F from Crosman, the order number for them, taken from their site was the number you furnished for the detuned spring.

Roachcreek

[Lani52]

David,

You have tried both the Pitbull mega and the Emperor without the Add-onis, which is quieter?

I had my doubts about that Donnyfl end cap alighting properly, makes and they even address it on their website. 

Being as I have a couple of uppers, I have often thought of a 3rd upper, one with the shroud cut back, the barrel threaded 1/2-20 for the Emperor and the threaded barrel end extending past the end cap which would have the muzzle relieved enough to allow the barrel to pass through.  In most of my day dreams about the third upper, the barrel is shortened to 25 inches to gain full velocity with air bolts.  Not that I came up with the idea, I see carbines made  up on the Bulldog with a threaded barrel stub sticking out.

It seems that would cure a lot of alignment problems.

In my description of how I set up my two uppers, Your posts reminded me  that I forgot about relieving the tabs on the front of the plastic upper receiver covers that fit inside the shroud, man how I hated getting those aligned to seat the shroud all the way back.  I relieved mine before I got my 2nd upper going.

On my upper with the Pitbull mega,  the moderator is JB WELDED in place, but just before the ring on the Megamoderator, I drilled 3 small holes into the barrel to allow air to bleed into shroud better before entering the moderator.

I have not compared the two uppers on the crony to see how much velocity is lost, knowing full well some must be lost, but it seems quieter.

Are any of us with the JSAR T I tube using a depinger?  If so which one? Mine that was in the Oem tube, a Pitbull depinger, is now too large to fit in the Ti tube.  I have thought of sanding it down and installing a stand-off tube between it and the valve to keep it from migrating to the valve.

Roachcreek

[Jzizzle]

I don't see any issue with sanding it down a lil bit all while keeping it a tight fit.  Hammer it in with a dowl.

I didn't know that tube was a different diameter.

I also use the pitbull depinger.  It really works wonders.  All that annoying ping in your ear is gone! 

I too am curious on hearing how the pitbull v Donny emporer compare in noise output.  I primarily went with Donny because I like the look of a cylindrical LDC vs the other design.  Plus I preferred metal over a plastic filament.

[Jzizzle]

On a side note, the OEM spring you ordered is the part number I have listed in my manual.
Are you sure this is the low power spring?

[Lani52]

John,

Yes that Pitbull depinger works wonders, I had one of his first bunch he put out and the sound difference, with the mega was impressive.

I think that part # is the full power spring not the detune spring.  I could not find a detune spring on their schematics, did you?

Last night I filled my ti tube to 4200, then shot 5 times with no projectile.  The air usage was only 300 psi total for all 5 shots total. I know from experience that at 3500-3600 psi with the JSAR spring turned all the way in, I would have used 200 psi per shot, either with or without projectile. 

Matt always said he would replace those moderators is they wore out, I find them fragile to remove, but I am ham fisted due to poor eye sight, that is why  I glue them in and remove the shroud, barrel et.al., when I disassemble the rifle.

Roachcreek

[Jzizzle]

I have never seen anything about a detuned bulldog spring  from Crossman.

I see that Crossman offers one for the marauder though.

Do you have a chronograph? Looking forward to your shot strings at x psi and spring combination.

[Lani52]

It is going to be a couple months until my son gets his house built.  He bought 2 lots total of 18 to 20 acres that are on the outskirts of Town and but up against BLM land.  I  may get out to run them over the box at the local shooting spot, it is very rural here, just need to take a cab as the wife and I do not drive.

Roachcreek

[FuzzyGrub]

Sorry, missed the posts on asking about the detune spring.

Did you try ordering it with a "20" in front of it?   See my order below.  Both springs are on the order.

It has the same length and OD, but the wire size is 0.010" less in diameter.   I think I got the number from someone at crosman CS.  It is not the airbow springs.

[Lani52]

No I ordered it over the phone.

I have the new valve, version 2, but no oem spring.  JSAR is sending out a new spring for it, hope to get out and get some numbers this weekend.

Roachcreek

[FuzzyGrub]

As far as I know, the phone is the only option.  Back when I ordered these, May 2017, it was hit or miss if they sent out order details via email.  This order was one of the lucky ones, otherwise I had only documented it in: https://www.gatewaytoairguns.org/GTA/index.php?topic=126825.msg1242622#msg1242622

Outside of this spring part number, I have not seen crosman use a preceding number like that.  Easy to assume it was the item number id from the schematic, which is actually #22, for the hammer spring. 

[Jzizzle]

Small update.
New shot strings with custom spring and 3200psi fill

Max velocities:
NSA 142- 910fps
NSA 110- 990 fps
Nosler 145- 915 fps

I found tightest shot string with -1.5 turns
NSA 110
970
945
922
900

Each shot uses about 180psi.  5 shots brings 3200 to 2300

[Jzizzle]

OP,

Have you tried those 150gr Anvil HP from HiKal bigbore yet?

I just ordered some in 358 sizing.

[Kinetic45^]

OP,

Have you tried those 150gr Anvil HP from HiKal bigbore yet?

I just ordered some in 358 sizing.

Never heard of them before you mentioned them.
Apparently Hi-Kal is using a few of the fine NOE molds from looking over the product page.

I have most of the molds for the bullets they are selling and the one they are calling the Anvil was not the top in accuracy in my testing at longer ranges like 100 yards, adequate but not the best. I had a hard time getting them off the pins as the HP is so deep, and trouble with fill out voids at the base of the HP cavity.  [A bubble forms at the point of the pin as lead fills the mold... it's a common problem but has solutions]
 http://noebulletmolds.com/NV/index.php?cPath=35_299

The Bandit is the Bob's BoatTail, NOE  357-136-FN-BZ4 in HP and shoots well in my FLEX and Pitbull (used to be a Bulldog) http://noebulletmolds.com/NV/index.php?cPath=35_527

The Renegade is the BBT I asked Bob to modify the nose diameter and it is very accurate in my and a couple other guys .357s, NOE 359-174-FN-CE2 in HP
http://noebulletmolds.com/NV/index.php?cPath=35_578

Haha, maybe they will test the new .357 airgun bullet and stock it.... http://noebulletmolds.com/NV/index.php?cPath=35_590

Like I said, have some other molds for bullets they are stocking and although generally I do not shoot lighter slugs (most stock guns can only shoot the lighter slugs well due to lower power)  still bought the molds snd some did good in testing, sure would have been cheaper to buy a hundred from a company to test rather than what I had to do, buy the mold, haha.

Anyway, hope they do well, if I was not a DIY caster I'd try their output.  We need more good companies serving our hobby! And allowing us to test a variety of bullets to weed out what works and what does not in the different rifles.

[ShakySarge]

OP,

Have you tried those 150gr Anvil HP from HiKal bigbore yet?

I just ordered some in 358 sizing.

Richard krebbs at Hikalbigbore makes great bullets for the bulldog. I use the Anvils in mine and they are excellent. His quality control is amazing compared to other places that I have ordered from. His Stingers also perform great with the bulldog. I have a few boxes that I keep on hand as well.

You will love the Anvils. In his gallery, the Anvils that were shot from the bulldog by Matt in TN was a group I shot for him during testing and I shake A LOT. Most folks stack them on the targets.

[Jzizzle]

OP,

Have you tried those 150gr Anvil HP from HiKal bigbore yet?

I just ordered some in 358 sizing.

Richard krebbs at Hikalbigbore makes great bullets for the bulldog. I use the Anvils in mine and they are excellent. His quality control is amazing compared to other places that I have ordered from. His Stingers also perform great with the bulldog. I have a few boxes that I keep on hand as well.

You will love the Anvils. In his gallery, the Anvils that were shot from the bulldog by Matt in TN was a group I shot for him during testing and I shake A LOT. Most folks stack them on the targets.

Did you have a chrony available during the accuracy testing?  Curious how fast these can go before negatively effecting accuracy.

[Jzizzle]

I agree!  We need more quality vendors producing various slug designs and weights.

I was looking for something heavier then the 142 NSA that would fit in the magazine and I came across these.

Glad to hear positive feedback.

Maybe someone can touch on this..through my chrony testings, shot strings are tighter with heavier slugs such as 142 NSA vs lighter slugs as in the 110 NSA I currently use.
Are these typical results?

[ShakySarge]

OP,

Have you tried those 150gr Anvil HP from HiKal bigbore yet?

I just ordered some in 358 sizing.

Richard krebbs at Hikalbigbore makes great bullets for the bulldog. I use the Anvils in mine and they are excellent. His quality control is amazing compared to other places that I have ordered from. His Stingers also perform great with the bulldog. I have a few boxes that I keep on hand as well.

You will love the Anvils. In his gallery, the Anvils that were shot from the bulldog by Matt in TN was a group I shot for him during testing and I shake A LOT. Most folks stack them on the targets.

Did you have a chrony available during the accuracy testing?  Curious how fast these can go before negatively effecting accuracy.

I have a high with the Anvils of 944 FPS in a modified bulldog. They were just as accurate at 750 as 944.

[ShakySarge]

The strings are more consistent with heavier slugs from my experience as well. The smaller.357, .356 and .355 were not nearly as accurate and did not yield the same consistency within the strings.

That being said, I still use the factory valve(modded) and factory air tube so this could change if I went aftermarket.