Bulldog modification log .328 porting and more

[Jzizzle]

Once these arrive, I will do some fine tuning and will report back with my chrony strings.

[Jzizzle]

Anvil 150gr in 358 sizing may be too big for my barrel as its takes much more force to chamber and the lower velocities I am getting.

Still tuning for best mix in power and consistency.

Best string so far
846
848
873


NSA 142gr
973
951
863

If that 3rd shot was closer Id be a happy camper.

Need to order more ammo and continue testing.

[Jzizzle]

I'm going to bump this thread.

I've been having issues with the jsar ss valve so I have swapped back to OEM valve.

Ports ported to .3
Custom hammer spring
Hammer polished
Emporer LDC

2900 psi fill

NSA 142

859
861
846

About 225psi/shot

This is my best 3 shot hunting string I could acheive so far.

Shooting off a bipod is about 1.25 inches at 70 yards.

Back when I was shooting around 960 fps, accuracy was reduced.  I don't think it's the projectile but probably the bulldog itself.  I think there is alot of flex happening when you near the 300fpe mark.

[ShakySarge]

I'm going to bump this thread.

I've been having issues with the jsar ss valve so I have swapped back to OEM valve.

Ports ported to .3
Custom hammer spring
Hammer polished
Emporer LDC

2900 psi fill

NSA 142

859
861
846

About 225psi/shot

This is my best 3 shot hunting string I could acheive so far.

Shooting off a bipod is about 1.25 inches at 70 yards.

Back when I was shooting around 960 fps, accuracy was reduced.  I don't think it's the projectile but probably the bulldog itself.  I think there is alot of flex happening when you near the 300fpe mark.

Have you installed barrel supports in the shroud? Mine gained a lot of accuracy with them.

[Jzizzle]

I have them but not installed.

I'm not sure if there were printing errors when pitbull made them but they are way to small diameter to fit.

I have not gotten abound to dremmeling them out to fit yet.

[PCPhack]

Several of them that I had received were so loose, that they would slide down from their own weight and so not really usable without securing them in place along the barrel. They do not have good print consistency.

I have also had issues with their moderator prints, but to their credit, they sent me replacements.

[Jzizzle]

I'm trying to get another 40 fps more with these 142 NSA.  Anything higher then 2900psi shows signs of valve lock.  Adding shims to hammer spring yeilds no increase in fps.
Is this the max?

The 110 NSA shoot around 990fps with current tune for the 142 NSA.

[ShakySarge]

I agree with the print consistency. I had to sand out two to fit as well. To secure them in place I used some steel wool at the points I wanted them and then used quick curing epoxy to keep them in place. Just be sure that they are all exactly lined up before using the epoxy or it won’t fit in the shroud.

[ShakySarge]

I'm trying to get another 40 fps more with these 142 NSA.  Anything higher then 2900psi shows signs of valve lock.  Adding shims to hammer spring yeilds no increase in fps.
Is this the max?

The 110 NSA shoot around 990fps with current tune for the 142 NSA.

That sounds about right until someone figures out how to get even more.

[Jzizzle]

I tested the HiKal BigBore 150gr Anvils a while back in 358 but they were much too tight.  Just got them in 356 sizing and performed extremely well.

Anvil 150gr
2900psi fill
840
847
842

About 1/2 inch at 70 yards.  Most accurate slug I have tested yet.  These also leave a much bigger exit in 3/4 plywood vs the 142 NSA.

These cost more then NSA at $.44/slug not incl. shipping.

[ShakySarge]

I tested the HiKal BigBore 150gr Anvils a while back in 358 but they were much too tight.  Just got them in 356 sizing and performed extremely well.

Anvil 150gr
2900psi fill
840
847
842

About 1/2 inch at 70 yards.  Most accurate slug I have tested yet.  These also leave a much bigger exit in 3/4 plywood vs the 142 NSA.

These cost more then NSA at $.44/slug not incl. shipping.

The Anvils are excellent out of the bulldog. A bit more expensive but certainly worth the money for a hunting round.

[PCPhack]

I am slowly getting the interest to come back and hack about on my Bulldog a bit more.

As there has been no further third party accessory developments to address the design issue of the barrel and overall rifle stiffness, I am brainstorming ways to address this. It could certainly use it, especially in the higher FPE tunes, like the 350 FPE tune I was hunting with this past spring.

Earlier I had one idea, which was to epoxy in the barrel supports, making the barrel and shroud one. Travis suggested to hold off as they might come up with some offering, but they never did (although I am sure they would have done something custom if I wanted to pay). This would give a huge increase to barrel rigidity, and also go a long way to reduce flex within the entire package. The barrel (with shroud permanently attached), would still be removable. This is possible by grinding down the plastic at the end of the breech clamshell that normally goes under the edge of the shroud, so that it can be removed to gain access to the barrel screws.

Another idea, rather than the above, would be to sleeve the barrel with carbon fiber of two sizes concentrically, with the outer one being longer and of the same ID as the larger breech end of the barrel, and then countersink into the breech. Two are needed due to the tapered barrel.

Then, I can think of progressively more extreme, and expensive, measures to stiffen it all, such as changing the stock, barrel, and etc.

I am currently leaning heavily on the first idea, because it is the cheapest, and I don't really want to invest too much more on the platform than I already have. I also like the current form factor, and like it for the utility it has, even if I am rough with it out in the field.

[ShakySarge]

I used epoxy for my barrel mounts and bought three sets and installed them. It isn’t going anywhere. However, I would definitely rather use 4- 3.5-4.5” printed mounts so that more actual surface area was covered and made solid contact with the shroud.

[PCPhack]

I used epoxy for my barrel mounts and bought three sets and installed them. It isn’t going anywhere. However, I would definitely rather use 4- 3.5-4.5” printed mounts so that more actual surface area was covered and made solid contact with the shroud.

Great! You tried the earlier idea already. Are the barrel supports also epoxied to the inside of the shroud? Can you characterize the impact this had to your groups versus the barrel supports alone?

[ShakySarge]

I did not have to epoxy them to the shroud due to the tight space. I did add epoxy to the three sides where needed and sanded them down to fit.

My groups shrank considerably with an average reduction of .45” at 50 yards. There were some slugs that already shot that tight and they literally started stacking as one ragged hole. I will be ordering another bolt and linkage assembly after the first of the month to try a couple other “modifications”.

The key to epoxy when mounting the braces is to do them one at a time with the rear shroud mount on and use the shroud to align each one. It’s slow and methodical but worth it in my opinion.

By the way. I found the two boxes of slugs in my wife’s car still on the usps boxes.

They will ship after the first as well. Let’s just say, when I found them I was a bit unhappy!!!

[gendoc]

when matt and paul pitbulled my carbine bulldog, they reinforced my barrel, shroud and added several supports. then installed there version of an LDC adapter that is
much stronger mounted than the other folks have to offer.

along with other mods & cocker spaniel, its a much different machine now.

i dont have the high pressure tube but my pitbull is extremely accurate out to 50yrds with 3 shots starting @ 250FPE.

soon as the new HP tubes come in, i'm going in head first !!!
i'm wanting 325+FPE.....

[ShakySarge]

when matt and paul pitbulled my carbine bulldog, they reinforced my barrel, shroud and added several supports. then installed there version of an LDC adapter that is
much stronger mounted than the other folks have to offer.

along with other mods & cocker spaniel, its a much different machine now.

i dont have the high pressure tube but my pitbull is extremely accurate out to 50yrds with 3 shots starting @ 250FPE.

soon as the new HP tubes come in, i'm going in head first !!!
i'm wanting 325+FPE.....

The supports I used were from pitbull. Good stuff if secured properly. No comment on the cocking arm.

[gendoc]

No comment on the cocking arm.

i remember you telling me about that......

[ShakySarge]

No comment on the cocking arm.

i remember you telling me about that......

Lmbo. It happens

[PCPhack]

when matt and paul pitbulled my carbine bulldog, they reinforced my barrel, shroud and added several supports. then installed there version of an LDC adapter that is
much stronger mounted than the other folks have to offer.

along with other mods & cocker spaniel, its a much different machine now.

i dont have the high pressure tube but my pitbull is extremely accurate out to 50yrds with 3 shots starting @ 250FPE.

Hi John. I have had both their barrel supports and LDC that supports the barrel since early in my thread here. My Bulldog does shoot accurate, and on par with most others I  have seen posts on. This is a 1 inch group at 75 yards (5 or 6 shots). I want to have that same sized group at 100 yards (MOA), and at 350 FPE. For that, something more will be required, like my epoxy idea.

Matt, what kind of improvement did you see with the epoxy, vs without? Did you mean that adding epoxy gained you .45" more accuracy versus jo epoxy but still us9ng the supports, or do you mean no supports vs supports that were epoxies.