Model 629 V-Comp Compensator Bolt

[dmillhouse53]

I have 629 V-Comp that is 3-years old with 1300+ rounds through it. On two occasions, the bolt that holds the compensator has failed and sheared off. Sent it back the first time to S&W and they replaced the bolt. Trying to decide whether to send it back to S&W a second time or let a local gunsmith see what he can do. Shooting Winchester 240 grain. Each time I shoot I do tighten the bolt as it does slightly loosen after 24 rounds.

Has anyone had this issue? What has been your remedy?

 

[Protocall_Design]

I would get a grade 8 socket head cap screw. That is not likely to shear off.

 

[emptymag]

If the bolt/screw is STAINLESS, I would try a similar fastener in a GRADE 5 Black Oxide (and opt for slightly shorter, rather than longer, if that is possible).

I think some pics may help us with more options/ideas.

 

[dmillhouse53]

I believe the bolt is stainless. I'll post pics tomorrow.

Thanks

 

[dmillhouse53]

Bolt does appear to be stainless
Attaching pics for a better understanding of the conditions.

Thanks for the replies.

 

[Benchrest1]

I think it would help if you used some anti seize on that bolt.

 

[joebuck]

Interesting post. You can see were the threads are peening from recoil where it didn't shear. Yes, try a different bolt and lite duty thread locker to maybe stop it from backing out. Silly you have to tighten it every 4 cylinders of shooting.

 

[stu1ritter]

As an olde retired mechanic I would clean out that bolt hole and run the appropriate tap down there to clean up the threads.

Stu

 

[Protocall_Design]

Get a grade 8 bolt, clean internal and external threads, put blue 242 Loctite, cinch it down firmly. Should be the end of problems.

 

[dmillhouse53]

Bolt is #10x32 x 3/4" long.
I'll update as I progress along with the fix.

 

[colt_saa]

Curious as a 627 V Comp will most likely be the next gun I buy.

I have V-comps in 357 Magnum and 41 Magnum and 45 ACP. The 22LR V-comps do not matter for this thread. Tens of thousands of rounds down range with them so far

Non have given me issue. Obviously they have less recoil than the 629

I had the 3" 629 V-comp but never fired it, a buddy HAD to HAVE it and I let ig go

I would go with the grade 8 bolt and some removable Loctite, #242

 

[dmillhouse53]

I contacted S&W to find out if there was a torque requirement for the compensator bolt. Their reply was "We suggest to tighten it as hard as you are comfortable with". So, no torque requirement.

With respect to the bolt, after research this is what I have found:
1) Original stainless steel (304 or 18/8) bolt has a tensile strength (TS) of 80,000 psi
2) Grade 5 bolt - TS = 120,000 psi
3) Grade 8 bolt - TS = 150,000 psi
4) Alloy Steel - TS = 180,000 psi

I found the alloy cap screws online at Newport Fasteners.
Another item I have discovered is that the cap screw for the compensator needs to be 3/4" long. Cap screw for the plain end tip needs to be 5/8" long. The 3/4" screw will bottom out before it is tight on the plain end.

 

[kilroy2721]

I bought a 629 V-comp years ago. I only fired one cylinder full through the gun, and put it away.

Since you are using the Winchester 240gr load, can you really feel the difference using the comp compared to when you don't? I feel like those ports should be bigger, but I am no expert.

 

[jaymoore]

Whilst a stronger bolt won't hurt, my first thought was that there's likely some bullet contact at the small exit diameter of the compensator. Look for copper (or lead) deposits on the I.D. If it's concentric, maybe it's a factor of recoil, which would lead to rub marks on the bottom. Just a SWAG. (If the bullet was much off center of the exit port, it would remove the compensator straight away.)

ETA: Given the distortion of the failed bolt, it may be a good thing that it is NOT stronger. Next failure points likely the barrel threads and compensator clamping area....