shotgun chamber holes

[olafhardt]

I drilled and tapped two 8x40 holes into the chamber of a 12ga NEF to mount a peep sight. The holes completely penetrate the chamber. Did I ruin the barrel?

[hansumtoad]

I've got 20+ years of experience behind a gunshop counter with four degreed gunsmiths on staff.

Cheaper to just buy a new barrel. Gunsmith will have to mig or tig weld the holes, draw file the outside amd at the least cold blue the patch, rechamber the inside, and then likely move the mount slightly to not penetrate the patched area.

With shotgun chamber pressures not exceeding much over 12000 psi, you SHOULD be okay.....with all of that said, the repairs are more than a new barrel.

[legi0n]

Next time solder the sights.
I did just that recently (using plumbing silver solder) and had no problems even with the biggest slugs.

[nanuk]

Oy...

I don't think I'd trust it now.
metal stretches a bit upon firing..... Now imagine one of those screws stripping out and leaving that stretched hole... How fast do you think they'd be moving?

is it worth the risk? only you can decide

[243winxb]

I posted your question here for a 2nd opinion. http://www.shotgunworld.com/bbs/viewtopic.php?f=12&t=261424

[Ozarklongshot]

Yep
Next time try a mic and bottom Drills & Taps

Also High temp solder works well too

[Hang Fire]

Just something to consider. Take that 12,000 psi (pound per square inch) x .164 (diameter of a 8x40 machine screw) and you get exerted pressure of 1,968 psi on the screw diameter.

[HangFireW8]

I agree with my namesake- even if the screws were save, you'll have problems with sticky ejection. (And I don't think they'll be safe).

[HangFireW8]

Just something to consider. Take that 12,000 psi (pound per square inch) x .164 (diameter of a 8x40 machine screw) and you get exerted pressure of 1,968 psi on the screw diameter.

I think Pounds and not PSI is the final unit you want. PSI will still be 12,000.

[Uncle R.]

I think Pounds and not PSI is the final unit you want. PSI will still be 12,000.

The area of the screw is roughly .021 square inches.
(Pie Are Square you know...)
times the 12000 psi comes out to closer to 250 lbs. on the #8 screw. Sounds a lot more reasonable, no?
I still wouldn't shoot the dang thing if it was MY face just a few inches away.
Be safe - replace the barrel - chalk it up to experience.
<
Uncle R.

[mroliver77]

I would be interested in buying the ruined barrel if you replace it. I know it hurts. I have had more costly *****s.
Jay

[243winxb]

The 22lr is 24,000psi. Shotguns are 11,000psi. Had 7 holes drilled into the rifling right in front of the chamber on a 5 1/2" bull barrel Ruger MK1 pistol. This was to vent gas and make an almost recoiless ISU rapid fire pistol back in the 1970. The holes tapped 6-48, #31 drill used to make the holes. The allen screws were put back into the threaded holes to use the pistol in the normal manor. No screw ever blew out. :confused::confused:

[frkelly74]

Well you could reline it to 44 mag or 357 , It is already to mount a scope on. Make a Rook rifle. Turn a lemon to lemonaid.

[olafhardt]

Does somebody have some sort of shotgun that came from the factory with a scope rail on the chamber? Would you stick your finger in and feel for holes? The shell body serves to seal the holes. However the holes leave a mark on the shell. If screws are too long the holes are concave, too short convex. I have fired several rounds through it. I bought in part to check this out. A new bbl costs 55-75 bucks plus mountlng and shipping cost. I have blown (pun lntended) much more on other experiments. If we could show this to be safe it would be an interesting way to make sniping shotguns (I proudly claim credit for that term).

[nanuk]

I have a thought to enhance safety here.... just a thought

mount a scope one piece rail on it.
tin the mount, then pound down some solder Thiiiiiiinnnnnn
Permanent locktight on the screws (make them just long enough to fill the barrel holes) and heat to make the solder flow

the soldered one piece rail would give an extra measure of strength to the screws, being they would be locked into the rail AND the chamber.

something else, it would give you a platform to stub it, and install a slip fit rifle barrel into it for a low pressure round, perhaps a 30-30, or 38spl.... something in the mid power range. I'm looking into this option myself right now... (I've got 2 30cal barrels, thinking a 30/357, or a shortened 30-30, for cheap brass project)

[HangFireW8]

The 22lr is 24,000psi. Shotguns are 11,000psi. Had 7 holes drilled into the rifling right in front of the chamber on a 5 1/2" bull barrel Ruger MK1 pistol. This was to vent gas and make an almost recoiless ISU rapid fire pistol back in the 1970. The holes tapped 6-48, #31 drill used to make the holes. The allen screws were put back into the threaded holes to use the pistol in the normal manor. No screw ever blew out. :confused::confused:

In front of the chamber and in the chamber are two very different things. So is the gas volume of a shotshell, and likewise possible ejection issues. Holes in the barrel don't affect extraction (except maybe to make it easier).

[olafhardt]

It's me agian. I got our two s&w 22's, a 34,and a 317.The 34 has the head totally surrounded the 317 has quite a bit exposed. I dont think the rim metal is very thick and these wheelguns operate at about twice the pressure of a 12 gauge. The 317 has never bobbled and is a great lil gun. All revolvers do have holes in the chamber, at each end.

[Hang Fire]

The area of the screw is roughly .021 square inches.
(Pie Are Square you know...)
times the 12000 psi comes out to closer to 250 lbs. on the #8 screw. Sounds a lot more reasonable, no?
I still wouldn't shoot the dang thing if it was MY face just a few inches away.
Be safe - replace the barrel - chalk it up to experience.
<
Uncle R.

Your are absolutely correcto. My bad.

[MtGun44]

I doubt you have any problem other than the roughness possibly grabbing the
shells. If you put in screws that are just a hair too long, with red locktite so they
stay, and then carefully work off the excess with a fine cut rounded file you will
be just fine.

Shotgun pressures are low, the screws are strong and as long as they are smooth
I will bet you will never notice a thing.

Oh, yeah - BSME and MSME, 35 yrs structural analysis experience. As long as you
have good threads (not boogered up or cut loose) and a good quality screw, like
a socket head or torx head, I'd be fine with it. If the threads are badly cut and
the screws don't fit well, then all bets are off. If well cut, and the screws fit normally,
not a problem.

Bill

[Junior1942]

Lots of "if this" and "if that" and "maybe you could/should/would" but one question remains: would you let your granddaughter take that barrel duck hunting? I say your barrel would make a fine tomato stake.

[Cap'n Morgan]

Load the gun with a 3" magnum cartridge. Pour an extra 1/2 ounce shot down the muzzle. Tie the gun to a fence post and pull the trigger with a loong string. My bet is no harm will be befall the gun - and you can now use it without any worries.

[nanuk]

Oh, yeah - BSME and MSME, 35 yrs structural analysis experience. As long as you
have good threads (not boogered up or cut loose) and a good quality screw, like
a socket head or torx head, I'd be fine with it. If the threads are badly cut and
the screws don't fit well, then all bets are off. If well cut, and the screws fit normally,
not a problem.

Bill


Now that adds a bit to the comfort level. Thanks for that Bill

[243winxb]

Good advice here >
I doubt you have any problem other than the roughness possibly grabbing the
shells. If you put in screws that are just a hair too long, with red locktite so they
stay, and then carefully work off the excess with a fine cut rounded file you will
be just fine.

Shotgun pressures are low, the screws are strong and as long as they are smooth
I will bet you will never notice a thing.

Oh, yeah - BSME and MSME, 35 yrs structural analysis experience. As long as you
have good threads (not boogered up or cut loose) and a good quality screw, like
a socket head or torx head, I'd be fine with it. If the threads are badly cut and
the screws don't fit well, then all bets are off. If well cut, and the screws fit normally,
not a problem.

Bill