Help-Frustration with 30/30 cast loads in M94

[Poodleshooter]

This is really starting to annoy me,so I thought I'd come here for some suggestions. I've got a Winchester 94 that I'm trying to work up a load for,using the Lee 170gr RNFP-GC bullets. I benchrest it for all test groups. I get good accuracy at 100yds with it for about 5-10 rounds (just under 2"),then POI just changes randomly,and the group raises nearly 4-5" at 100yds. The groups still stay in the 2-2.5" range at 100yds,it's just that the POI completely alters when the barrel heats up.

Rifle M94 winchester with leupold 2pc mount and rings,and a cheap remington package scope.
The loads:

Bullet: 170gr Lee RNFP-GC- Hornady gas checks,sized to .310, tumble lubed with alox-mild taper crimp (1/3 turn in on the die)
Powder: WC844 (H335 basically)- from 28-32grs. Best accuracy is around 30-31grs. Velocity at that charge is about 2050fps.
Primer-Winchester LR
Cases-varies,but kept together by lot.
Seating: I seat to right at the driving band on the Lee bullet (above the two lube grooves). This ends up ramming the bullet right into the short throat and engraving heavily,but I haven't seen any pressure problems.

The odd part-these loads seem to shoot very clean. There's no obvious leading,just powder fouling and occasional flecks in the bore. It doesn't look much different than my jacketed loads.
This POI shift has happened in several sessions with the Lee cast load,with two different scopes mounted. The mounts and rings are tight. The scope was used previously on a package .308 which shot unbelieveably good groups,so I know it's a decent (if cheap) scope.
Charges above 31grs tend to open up a bit more and possibly exacerbate the POI shift problem. I get a few shots in a great group from a cold barrel,then I go back to shoot again and POI has changed dramatically.

Any ideas? Is it the load? The rifle?

[docone31]

Sounds like the heat is making the barrel move around.
My Enfield did that when I went to paper patching. I had to bed the barrel to get any predictable accuracy after three shots.

[garandsrus]

Does the same thing happen with jacketed bullets? I would guess that it's the rifle, not the boolit.

John

[big boar]

The forend just sits in a socket at the front of the action, the tubular magazine is a slip fit in the action and then both are secured to the front of the barrel by a barrel band. It's a wonder they function at all and that accuracy is mediocre. I think that when the barrel heats up it puts stress on the band, magazine and forestock and that is what is causing the wandering POI. There is a good book about "accurizing the factory rifle" by McPherson(?) and he details some good info on how to improve lever guns. Great book and most all of the stuff is easy to do. The price of the book is well worth it.

[Rico1950]

Try loosening the barrel band screw a little, helped mine.

[Alchemist]

Ya might try letting the barrel get completely cool between each shot for about a dozen shots.....that'll tell ya if it's a heating issue.

[Baron von Trollwhack]

I had a little of this on my pack rifle, 1/2 magazine.

I shortened the inboard end of the magazine by .o1, put a thin live rubber shim between the outboard end of the mag tube and the barrel where the tube anchors, made sure the forestock could float forwards and back the thickness of 2 playing cards when the forend cap screws were tightened, and made sure the outboard magazine screw into the barrel hanger was tight. The forend is unitized and free to move a tiny bit if the barrel moves a little, the mag tube follows the barrel. Worked for me, but forget 10 shots and a fouler. Five is good. BvT

[jhrosier]

poodleshooter,

I have found that my leverguns shoot much better if I put the front rest right in front of the trigger guard. They seem awful sensitive to pressure on the foreend.

Jack

[STP22]

As others have suggested, let it cool down. The barrel, forend, barrel band, and magazine will expand due to the warming barrel, but at different rates. While these different components heat up, they do so at a different rate. The result is a changing point of impact as the boolit passes thru the bore. If you don`t allow the rifle to cool and keep on shooting, the chamber will heat sufficiently enough to melt the lube on the boolits too, resulting in "wild" shots. BTDT...

[HORNET]

Lever actions have a lot of quirks that affect accuracy as they heat up. You might want to look in the leverguns forum on here and ask some of those guys. If all else fails, I seem to recall seeing some accurizing tips on Leverguns.com . Some of those guys are almost as fanatical as some that you find here.

[lwknight]

Anytime I accuracy check a load/rifle I shoot very slowly and even leave the chamber open for a minute or so allowing everything warms up evenly. After a few rounds if the barrel is noticeably warmer than the ambient I slow down even more.
Then I get bored and start shooting clay targets as fast as I can.

[Poodleshooter]

Thanks for the opinions, guys. I didn't have much time today,as I was shooting 50rounds during the few hours I managed to get off of work this afternoon. I relied a bit too much on an open action and 30deg temps to keep the heat down today.
I did have a good sandbagged rest,and it was right in front of the lever,so it's likely that didn't cause the wandering POI.

I suspect it is the barrel. I think I'll run up some jacketed loads and test those under similar circumstances. I can certainly live with a rifle that will put 2-5 shots into the same group. These Lee 170s shoot better groups than the factory loads I ran through it way back when,so that's a plus.

I'm not really a lever gun guy anyway. I'm a dedicated bolt and auto rifle guy. I have short stubby arms and a thick chest,which makes for frequent short shucking when working the M94 lever from the shoulder (especially in thick hunting jackets). This rifle is a cherished gift,however,so I'm doing my best to wring some accuracy out of it.

[Buckshot]

................I believe the term for that is, 'Levergunitis' As others have mentioned you have the barrel, magazine and forend all bound together via a band. Only one of those 4 things is rigidly attached to the action and that's the barrel. You can remove the magazine and forend and shoot it to see how it does, and if it'll shoot at all it'll shoot it's best like that. Winchester did not design the rifle to be accurate with the mag tube, handguard, and barrel band. They just designed the rifle the way it is and happily many ARE accurate, and some are accurate beyond all original expectations.

The fastest fix for a case of Levergunitis was an old shooter buddy with a Marlin in 357 mag. He placed a piece of aluminum pop can shim between the barrel and the band and it then shot like a totally different gun. How he arrived at it's simply needing the shim I have no idea.

..............Buckshot

[lwknight]

Depending on the cold to keep the heat down might be the problem. Where the barrel is exposed it will cool fast and stay warm next to the wood. Shoot slowly so that everything can stay evenly warm or cold.

[beagle]

All good advise above. Google on "Lever Action Accuracy" and see what turns up. Paco Kelley has written an article on tunning levers as have several others.

Sounds like the heat is causing some binding somewhere. I've found that the levers like a tad of movement in the mag tube or they'll bind and start slinging bullets. This has been mentioned before. I like just a little "click" when I shake the mag tube back and forth.

Another thing to look at is the magazine spring. Both Winchester and Marlin use too much and I chop mine some and this loosens things up a bit.

Check out the accurizing articles on line and I'm sure you'll solve it. The small amount of work will be worth the effort and you'll have astable "lead slinger"./beagle

[NHlever]

One other quick thing to check is the screw that holds the magazine cap on right under the front sight. Sometimes these screws are too long, and put a lot of pressure on the barrel. They need to be long enough to go into the detent, but shouldn't put any pressure on the barrel.