10 MLII got me scared

[mshm99]

My son-in-law has an 10MLII ,which he bought at least ten years ago. It developed a quirk this year that honestly scares me. He had the good fortune to get an MLII with a tight bore. By that I mean with a 300gr BO and a Black Harvester Crush Rib it required considerable effort to ram rod the bullet home. The plus side was that it was a sub 1 incher . This year, while loading and seating the bullet, with about 4 inches from home the bullet and sabot resistance at the ram rod almost feels like it free falls and then resists the last inch or so. I’m scared. I let my son in law take my MLII for the week end. What say the wise men? Richard?

[jims]

It sounds a bit like it could be a bulged barrel. Any chance it could have been double charged or too much of a wrong powder? Just an opinion, I well could be wrong and hope I am. I certainly do not have the experience of a number here, hopefully they will have the answer.

[peteo]

That is a bulged barrel that you are describing. Mine did the same after shooting my ramrod out of it. May be time to swap out to a brux 45.

[jims]

Whether this is correct I do not know but have heard that if you run your finger lightly across the barrel area you describe on some you can feel a slight bulge if there is one. If it is one could get a .45 prefit or there are some .50 takeoffs out there I would imagine as a replacement.

[mshm99]

No outward appearance of bulging. I'm going to micrometer the chamber area and compare it to my old MLII. Looking inside the barrel Looks good also. My son in took 2 nice deer this week end with my 2003 MLII. That weapon has taken a truck load of deer. I'll post the measurements later. That should help diagnose. Thanks for the input.

[peteo]

If you are getting 'free fall for 4 inches' the rifle won't shoot correctly. Too much pressure will probably escape around sabot and destroy it by flame cutting. Try pushing a new 458 sabot and bullet for results. I could not see bulging in my barrel but pushing 2 new sabot and bullet combinations with the same results as you had confirmed the damage of a ruined barrel. You are only looking at a few thousands of swelling on the barrel. I knew what had caused my barrel failure, I did it.

[mshm99]

Accuracy has fallen off. Initially blaming scope.Swapped out with known good scope. Same bad accuracy. I don't think a tighter fit would be possible and still get the bullet seated. Been thinking about soft lead slugging the chamber. Need to try my second choice bullet Rem 300 gr hp . Might obturate better, if everything else checks out .The search continues

[peteo]

Occam's razor may apply here, 'the simplest answer is most often correct. Good luck in your quest for an answer, looking forward to any conclusions you may come to realize.

[smokeeter]

you most likely will not be able to see/notice the bulge from the outside. Remove the breech plug and look through the bore against a lighted background if a bulge is present you will see a halo around the bore near the breech end.

[mshm99]

Did look,but will look again with friends bore scope. Thanks

[smokeeter]

no bore scope, pull the BP and look thru the barrel with a light at the muzzle, you'll see a ring/halo if it's bulged.

[mshm99]

Thanks

[mshm99]

UPDATE I pulled the plug and cleaned the barrel .It's very pretty. No halo. I lead slugged the muzzle 500/509. I pushed a lead slug down to the breach plug and hammered it with an aluminum rod to make it swell to fit the bore. .511. So it's .002 bigger. I'm going to see my buddy with the bore scope, and take a look. I don't think it's dangerous to shoot. And if the accuracy had not fallen off I don't think I'd be concerned. It was a sub 1"er .Maybe need to start looking at the Leupold scopes I've tried on it.

[cuda]

Try some JB Bore Bright or some lapping compound and keep it tight in the bore on a good tight swab. And work the whole bore for a few hours then check it with a bullet and sabot no breach plug. Just shove it right on down from tip to the breach. Keep this up till it fits smooth all of the way down and check it with a new bullet and sabot every time you check it. It is fouling and it will come out.

[mshm99]

I believe you are correct. My son in law has never cleaned his breach plug or bore. It always was accurate until it wasn't. Going to give the bore some more love. I bought my MLII in 2003 and I remember doing a JB lap on my bore back then. Thanks

[dannoboone]

Never cleaned his breach plug, either? It's no
doubt full of carbon. Has the vent liner ever
been replaced?

[mshm99]

I changed it out a couple weeks ago. I've issued gentle reminders.He's very busy guy. I've offered. But ya know some guys don't do much until something ain't right. I always had that nightmare the biggest buck ever was 50 yds away and my weapon went click.

[mshm99]

Dec 5, 2021 14:08:05 GMT -5 smokeeter said:

you most likely will not be able to see/notice the bulge from the outside. Remove the breech plug and look through the bore against a lighted background if a bulge is present you will see a halo around the bore near the breech end.

I scrubbed on this barrel a a lot. I'm seeing something at the spot where the rear sight screw is. I thought what ever is there might be carbon , but now I think I see the halo ,if it is a dark ring. Gonna go to my buddy's for the bore scope inspection. I'm leaning towards the barrel is now a tomato stake.

[smokeeter]

The area of the rear sight is the correct proximity of where a bulge usually occurs, some barrels that are bulged can still shoot Ok, I would try it with mild loads before scrapping it.

[sw]

Great time for a 45 but an even better time for a 40 cal barrel if legal there.

[jims]

My concern about continued use would be if a double load was loaded again the metal might have enough fatigue from the first go around that potentially it could fail badly.

[mshm99]

Thanks guys. I can see something in there. Hope to get a good look with the bore scope and a pic. Looks like a pit maybe. Maybe some erosion of rifling.

[Deleted]

Sounds like you may be a little leary about shooting the gun.I think I would put on a new barrel and feel safer than worry about what will happen when and if you do shoot it.Better be safe than sorry.Don't mean to sound like a downer,just thinking of your safety.

[mshm99]

Jan 7, 2022 22:11:43 GMT -5 @brownisdown said:

Sounds like you may be a little leary about shooting the gun.I think I would put on a new barrel and feel safer than worry about what will happen when and if you do shoot it.Better be safe than sorry.Don't mean to sound like a downer,just thinking of your safety.

You read my mind. This is my son in laws weapon. The Daddy of my two precious grand children. I could not live with myself if something I could have done would have saved him from something that would kept him from finishing his Daddy job. I would buy him a new barrel to let me sleep at night. This journey of using a MLII is not without risk. That is why I reached out to our community as a reminder we must be watchful with this exceptional tool

[Deleted]

You can not put a price on a family members safety. If you put a 45 cal barrel on it you will have so many more options.Love your committment to family.

[sw]

Jan 8, 2022 13:00:43 GMT -5 @brownisdown said:

You can not put a price on a family members safety. If you put a 45 cal barrel on it you will have so many more options.Love your committment to family.

I agree except I still prefer the 40 over a 45, where legal.

[Deleted]

In my knight mountaineer 45 I usea 45 cal sabot but I use a hornaday 200 grain sst bullet.Here in Indiana we can use a 44 cal but with that sabot and that bullet that makes it legal.The bullet is a 40 cal and a 10mm 40 cal bullet works just as good.A 10mm is a 40 cal bullet.

[mshm99]

I have a .40. I am very pleased with it's performance.

[Deleted]

If a 40 was legal here I would have went that route.That is why I shoot 40 cals out of my 45 sml.Love their performance on paper and deer.Good luck on finding your choice of barrel.

[mshm99]

Son in law prefers to just do a straight replacement. And I see his logic.

1. We both have a pretty big supply of N120, 300gr BO's and crush rib sabots.
2. Going to .45 would not offer any range extension. Really ,a little past 200yds and any 300 grainer falls of the table at the velocities the
ML2 barrel can safely get .
3. He just not that into sabotless/gotta have the latest thing.

4. It's a tool that works well as is.

5. The whole learning process that goes with something new.