Tweaking a lever gun

[Bronco]

I read in an article in Guns and Ammo about tweaking a lever gun for accuracy! Summary was to allow the forestock and magazine tube to have a little play as allow the barrel a little movement, due to vibration or heat expansion, to increase accuracy. Backing off screws a 1/4 turn at the front of the fore stock,widen the grove in the barrel where the fore stock screw passws through, work the front stock as to not bind on the receiver or the barrel in the barrel channel! Enlarge the holes in the magazine tube and magazine cap by 0.001" for the barrel band.

Have any of you gents who have shot in matches or have done this have any feedback about this procedure ???

[AJMD429]

.
Marlin did that with their 'XLR' series - I thought my magazine tube was just a 'sloppy' install, but turns out it was intentionally as close to 'free floated' as possible - the dovetail attachment is able to slide and give a bit, so changing barrel temperatures won't bend it by virtue of being tied to the cooler magazine tube.

[yooper2]

Pace and Mic McPherson have both written about this. I highly recommend reading both.


Eric

[Griff]

I've done it to a couple of Winchester 94s. Before I altered anything, I stripped everything off the barrel, supported the rifle at the front of the receiver and shot a group with a load that had proven accurate in other rifles. If the rifle (carbine) shot an acceptable group in that configuration, I started adding back on. Started with the mag tube loosely fitted, sans wood. With a carbine I put the front band on with the cap and cap screw, but no spring or follower inside. I'd shoot a single shot with the same point of aim as the initial group. If it held the same point of impact, I'd add the spring & follower. Shoot another shot, add the wood, I don't try to "clearance" the wood or bands, but leave everything a touch loose. To keep screws from loosening, I'll blue Loctite 'em. If, at any step a shot deteriorates the group, I'll back off and see where there's a bit of pressure on the barrel and relieve that spot. I've had to relieve both bands, and wood...

[LeverGunner]

I've done it to a couple of Winchester 94s. Before I altered anything, I stripped everything off the barrel, supported the rifle at the front of the receiver and shot a group with a load that had proven accurate in other rifles. If the rifle (carbine) shot an acceptable group in that configuration, I started adding back on. Started with the mag tube loosely fitted, sans wood. With a carbine I put the front band on with the cap and cap screw, but no spring or follower inside. I'd shoot a single shot with the same point of aim as the initial group. If it held the same point of impact, I'd add the spring & follower. Shoot another shot, add the wood, I don't try to "clearance" the wood or bands, but leave everything a touch loose. To keep screws from loosening, I'll blue Loctite 'em. If, at any step a shot deteriorates the group, I'll back off and see where there's a bit of pressure on the barrel and relieve that spot. I've had to relieve both bands, and wood...

Thanks for sharing your method. I've not messed with any yet, but I might at some point.

[coyote nose]

Oh my is this topic near and dear to me. Several years ago friend bought a Marlin 375 in 375 Winchester. It shot terribly. I mean REALLY bad with factory ammo or handloads. He tried everything for load development but 6" to 8" groups were the norm (3 shot) at 100yds bench. Even tried different scopes on it hoping the scope was bad. The rare 4" group would give him hope but then more testing of that load would bring back the huge groups. Well, I had a Winchester 54 in 219 Zipper he wanted....2 years ago we traded. I had the same issues with the blasted Marlin. Then I read McPherson (actually a few excerpts as I couldn't find the book anywhere).
I tried to take the mag tube off. It was binding so tightly ....it was actually BENDING the barrel up and holding it there! Obviously it was too long. Imagine what the heat of firing and barrel vibrations were doing to the gun as it was being shot. Besides being too long it also had a square end where it entered the receiver port, while the port itself was tapered. I measured the angle of the taper, set the lathe compound to that angle and cut 0.005" off the mag tube, then tried it on the gun without the fore end on. Kept doing that until I had a nice fit ie: no binding but not sloppy loose either....just a little play. Next I relieved the fore arm until it was loose on the mag tube and slightly loose on the barrel. Then putting the fore-end cap back on I noticed edges of the metal were touching the barrel so I relieved that. If I recall screw tightness affected that too. I wasn't done yet but took her to the range. Immediate success! Using correct 375 Winchester bullets 2" groups were the norm. Using modified 275 GN bullets lathe cut flat to 250 GN several groups shot just above 1" size. I now had to get rid of the annoying slop I felt every time I picked up the gun by the fore arm and felt things shift.
The key to stopping that was silicone RTV cement, I believe McPherson mentions this. I read it somewhere. But the key was to use the type (electrical grade?) that supposedly wont remove bluing. I put wax on the barrel and the lip of the receiver that is visible when assembled, as well as the magazine tube, then a bead of rtv on the ends of the wood and around where the magazine cap goes. I put none on the mag tube. The idea was to simply hold the wood at one position and allow some flexing as the barrel heats. Slid everything together, tightened the screws a bit (not real tight) on the fore end cap, wiped off goo that squirted out around the receiver and mag cap (the reason wax was applied as well as to defeat rust) and let it cure for a few days.
Interestingly, I never took the scope off during this, but it shot about 6" lower at 100 yards then it did before the pressure from the magazine tube was relieved! That corresponds to the barrel being bent about 0.040" at the muzzle!! Of course barrel vibrations affected this too so who know how much it was really forced up.
That was well over a year ago, I have not removed anything since. Shoots good. With load development my loads for the 200 GN sierra average just under 2", the obsolete 220 GN Hornady average just under 1 1/2" and the modified 275 to 250 GN average right around 1". THANK YOU Mr. MCPherson!
375 Win is allowed for Ohio deer. I was able to take a doe with this Marlin wearing a 3X weaver scope last December. Didn't like what the 200 GN Sierra did....penetrated through both lungs, didn't expand, left NO blood trail in the snow but I knew I hit and found her about 150 yards away. Next year I will try the 220 GN Hornady. I have 36 bullets left so I plan on using them sparingly.
I didn't do what Griff did by testing the gun at every step but his method would certainly pinpoint the issue. And since I didn't really torque down on the fore end cap screws I do make sure they don't work loose. I know I put clear nail polish on the threads but the next time I take it apart (if ever?) I will blue loctite them as he did.

[LeverGunner]

Oh my is this topic near and dear to me. Several years ago friend bought a Marlin 375 in 375 Winchester. It shot terribly. I mean REALLY bad with factory ammo or handloads. He tried everything for load development but 6" to 8" groups were the norm (3 shot) at 100yds bench. Even tried different scopes on it hoping the scope was bad. The rare 4" group would give him hope but then more testing of that load would bring back the huge groups. Well, I had a Winchester 54 in 219 Zipper he wanted....2 years ago we traded. I had the same issues with the blasted Marlin. Then I read McPherson (actually a few excerpts as I couldn't find the book anywhere).
I tried to take the mag tube off. It was binding so tightly ....it was actually BENDING the barrel up and holding it there! Obviously it was too long. Imagine what the heat of firing and barrel vibrations were doing to the gun as it was being shot. Besides being too long it also had a square end where it entered the receiver port, while the port itself was tapered. I measured the angle of the taper, set the lathe compound to that angle and cut 0.005" off the mag tube, then tried it on the gun without the fore end on. Kept doing that until I had a nice fit ie: no binding but not sloppy loose either....just a little play. Next I relieved the fore arm until it was loose on the mag tube and slightly loose on the barrel. Then putting the fore-end cap back on I noticed edges of the metal were touching the barrel so I relieved that. If I recall screw tightness affected that too. I wasn't done yet but took her to the range. Immediate success! Using correct 375 Winchester bullets 2" groups were the norm. Using modified 275 GN bullets lathe cut flat to 250 GN several groups shot just above 1" size. I now had to get rid of the annoying slop I felt every time I picked up the gun by the fore arm and felt things shift.
The key to stopping that was silicone RTV cement, I believe McPherson mentions this. I read it somewhere. But the key was to use the type (electrical grade?) that supposedly wont remove bluing. I put wax on the barrel and the lip of the receiver that is visible when assembled, as well as the magazine tube, then a bead of rtv on the ends of the wood and around where the magazine cap goes. I put none on the mag tube. The idea was to simply hold the wood at one position and allow some flexing as the barrel heats. Slid everything together, tightened the screws a bit (not real tight) on the fore end cap, wiped off goo that squirted out around the receiver and mag cap (the reason wax was applied as well as to defeat rust) and let it cure for a few days.
Interestingly, I never took the scope off during this, but it shot about 6" lower at 100 yards then it did before the pressure from the magazine tube was relieved! That corresponds to the barrel being bent about 0.040" at the muzzle!! Of course barrel vibrations affected this too so who know how much it was really forced up.
That was well over a year ago, I have not removed anything since. Shoots good. With load development my loads for the 200 GN sierra average just under 2", the obsolete 220 GN Hornady average just under 1 1/2" and the modified 275 to 250 GN average right around 1". THANK YOU Mr. MCPherson!
375 Win is allowed for Ohio deer. I was able to take a doe with this Marlin wearing a 3X weaver scope last December. Didn't like what the 200 GN Sierra did....penetrated through both lungs, didn't expand, left NO blood trail in the snow but I knew I hit and found her about 150 yards away. Next year I will try the 220 GN Hornady. I have 36 bullets left so I plan on using them sparingly.
I didn't do what Griff did by testing the gun at every step but his method would certainly pinpoint the issue. And since I didn't really torque down on the fore end cap screws I do make sure they don't work loose. I know I put clear nail polish on the threads but the next time I take it apart (if ever?) I will blue loctite them as he did.

Thanks for sharing.

[Bronco]

Thank you all for sharing !
I have read both articles but figured to check here for any actual experience from the brain bank I think I will give it a try in the future and go slow. Right now putting a retro AR15 together suppressed with a FRT!

Bronco

[COSteve]

I learned of this tweak some years ago and tried it on my traditional leverguns. I relieved the wood around the mag tube and the barrel and didn't tighten up the handguard as tight so it has a touch of wiggle room. I didn't see any mag tube bending so I didn't fool with them. In every case I got better groups; some better and some a little better but it helped all of them.