barrel hole trend

[yekcoh]

I'm starting to see guys with a barrel hole cut into the comp and the muzzle thread.

 

I know SVI has been cutting holes half way into the comp but now I see guns with an entire hole drilled into the comp before the first 

comp port starts.

 

I guess the benefit could be that the holes drilled are far away from the chamber making it easier to achieve power factor.

but then that's not how pressure works and things start to behave strangely with slow powders we use.

 

what are the thoughts on the first barrel hole drilled into the comp and the muzzle thread?

My initial take was that this could hurt the integrity of the comp or the barrel as it drilled into both but SVI has been doing it for a long time so it must be reliable.

 

[sfinney]

Not a new idea.

[cautery]

Nope.  Not new.  Can be done safely by any competent and ethical craftsman with the right tools or contractors.
If you have doubts about either their competence or ethical adherence, then they shouldn't be building your firearms.

THAT thins the herd considerably.

[Maximis228]

That set up is fine. I've had similar set up myself. The main issue you will run into is the locktite for the comp can break free more easily due to less thread contact (Due to the hole). 1 set screw is fine, but 2 is better for that type of set up to avoid your comp clocking on you. 

 

As for pressure... you run into issues with holes closer to the chamber itself. So the one hole in the comp isn't going to change much. The furthest hole to the rear of the barrel is what is causing the largest drop in pressure. 

[zzt]

That's got to be a 38SC gun.  You would never make major in 9 with that many large holes.

[Nathanb]

3 minutes ago, zzt said:

That's got to be a 38SC gun.  You would never make major in 9 with that many large holes.

I’ve got four poppies on a 9major gun and it makes major just fine 

[zzt]

Just now, Nathanb said:

I’ve got four poppies on a 9major gun and it makes major just fine 

 

What size?

[yekcoh]

10 minutes ago, zzt said:

That's got to be a 38SC gun.  You would never make major in 9 with that many large holes.

Thats 9 major

[jubi351]

I have a MPA DS9 with nine holes and it makes 167 power factor with 9.8 AA7 and 124PDV2 bullet. I don't know how they do it but their barrels are fast.

[yekcoh]

you got pics?

2 hours ago, jubi351 said:

I have a MPA DS9 with nine holes and it makes 167 power factor with 9.8 AA7 and 124PDV2 bullet. I don't know how they do it but their barrels are fast.

you got pics? And please don't count comp ports as holes

Edited October 11, 2023 by yekcoh

[jubi351]

 

Edited October 12, 2023 by jubi351

[yekcoh]

1 hour ago, jubi351 said:

 

Looks great. Whats your load recipe? I was told the side holes dont impact the velocity. Im very impressed with the hole spacing of the mpa

Edited October 12, 2023 by yekcoh

[jubi351]

This was 9.8 AA7 124PDV2 @1.170. This ammo at Nationals in my Bul with 2 3/16 holes was 171. I would not shoot a level 2 or higher with this load in the MPA, would bump up .1 or so but it's fine for locals.