Slotting pin lugs

Pressure from recoil or something else?

expansion

So why only slot in one direction?

It seems too me that expansion would cause more issues vertically than it would horizontally..

If the barrel channel is sealed correctly, would this not elevate moist humidity & moisture or is it strictly a temperature change that would cause the issue?

Of course I’ve never bought into the “floating barrel “ theory either..

I'm going to recite a statement I've made before. Some rifles shoot well and some do not. The ones that don't shoot well require lots of special attention to fix the problem. Sometimes the problem never gets completely fixed. The ones that are naturally good shooters can take most any change or reasonable abuse and still shoot good.

I dunno. Jim recommends slotting the pin holes. He knows a metric $hit ton more that I do, so when I assembled my SMR, I slotted the pin holes...in both directions

painter said:

I dunno. Jim recommends slotting the pin holes. He knows a metric $hit ton more that I do, so when I assembled my SMR, I slotted the pin holes...in both directions

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Yep, and it's hard to argue with what Jim recommends and I'm not the one to do it either. As I said to SMO, there are aspects of slotting that I just don't quite grasp. I see the pros and I still see cons. I'll figure it out one of these days, or not.

TDM said:

Yep, and it's hard to argue with what Jim recommends and I'm not the one to do it either. As I said to SMO, there are aspects of slotting that I just don't quite grasp. I see the pros and I still see cons. I'll figure it out one of these days, or not.

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In one of Jim's assembly videos he explains why it should be done. If memory serves it has to do with thermal expansion. I don't recall if it's to preserve accuracy, or the stock.

There’s a lot in life that I don’t understand but that doesn’t mean it not true. Often it depends on the source.

So true of many things @Phil Coffins.

Ok, I went back and watched part 6 of Jim's SMR build series. I learned some things that I either forgot or was distracted from hearing the last time I watched it a couple of years ago. The most prominent thing Jim talked about was how stocks with lots of curl, which mine has, are more susceptible to expansion and contraction than a straight grain stock. That makes sense. He also stated that few original rifles had slotted tenons/under lugs. But after watching and listening, I plan to remove the barrel of my SMR and slot the underlugs. He also said that the underlug closest to the breech in the thicker portion of the stock needed a slightly longer slot. I'll see how it goes.

SMO....you might be wrong about this. Especially about a free floated barrel.
I slot all my rifles in both directions. Never questioned it.
Then a couple of years ago I had taken apart my 20 year old Lancaster .54 and happened to notice something strange looking about that first slot. Looking closer and checking the clearance in the slot I saw that the stock had indeed moved towards the lock. The steel pin had cracked the steel T and bent it up and towards the muzzle. Being it was deer season and I didn't have time to fix it proper I did it the quick way. I straightened the lug and bent it back down then filed the slot a good bit longer. Lastly I mixed some epoxy and filled in the gaps in the lugs and finished it the next day.
That was proof enough for me. I will always slot my lugs.

Forend on my rifles is 1/16 inch longer in the summer than in the winter. Humidity. Barrel length does not change.

Darkhorse,

Thanks for the reply.
Was the lug that cracked / bent up near the muzzle end or the ram rod entry pipe?

Could the slotting have created the issue?
I’ve never heard of a pin causing a under lug/ tenon too break…
But I can see how elongating the hole would weaken the lug possibly…

But as I said earlier, I been wrong before.

I see no harm in slotting since the idea to to hold the barrel down on the stock. Even if the slotting helps in a stock shrinking with age, etc.= a little slotting seems worthwhile. I think a barrel might go over 100 degrees on a hot day- not sure.
On some rifles I solder a rib to the barrel, as the rib cools it definitely shrinks.

My gun safe really dries out my guns, on my latest build the pins slid out easily after the build was completed, the lugs were slotted. At first the gun shot an acceptable group, after a few months in my gun safe the gun wouldn't group worth a hoot. I check all the pins and found the one closest to the muzzle was so tight I could barely drive it out, I opened up the slot to where could push the pin out with my finger, the gun started shooting cloverleafs again.

I am under the impression that the pins or wedges support the stock and not the barrel, or said another way, that they ensure that the stock stays secure to the barrel and not the barrel to the stock. The barrel is the structural member. Using my assumption slotting the lugs is good, let the wood do what the wood is going to do without affecting the barrel. Am I looking at this wrong?

HSmithTX said:

I am under the impression that the pins or wedges support the stock and not the barrel, or said another way, that they ensure that the stock stays secure to the barrel and not the barrel to the stock. The barrel is the structural member. Using my assumption slotting the lugs is good, let the wood do what the wood is going to do without affecting the barrel. Am I looking at this wrong?

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Your assumption is fact

SMO, The lug was bent up towards the muzzle. I don't believe the slotting caused the lug to crack. One thing I don't understand is why it took nearly 20 years to crack that lug.
I don't have any thing to compare them to but you have seen photo's of some of my targets, some of my good ones how do they compare to those shot with unslotted lugs?

Thanks Ron, I’m not sure how they would compare, but can’t for the life of me see how the lug would bend or break and not cause damage too the pin entry holes in the fore stock..

Honestly, the only advantage I see in slotting the lugs would be too make inserting the pins easier..

My .54 is only 12 years old or so, and I’ve had the barrel off twice.. And don’t plan on ever removing it again, unless something happens that requires it.
I’m satisfied that it’s protected well enough not too ever have any concerns with rusting under the barrel after re waxing it good a few weeks back..

I wouldn’t have pulled it this time but I needed too fix the nose cap..

Wouldn’t drilling the hole in the lug slightly larger than the pin serve the same purpose as slotting?

I have also heard that a jeweler’s saw comes in handy for slotting lugs..