348 Win LBT 250 FNGC / lands hitting front band

[fremont]

Shot 250 LBT FNGCs (sized .349") for the first time in my Win Model 71. I've got to clamp down somewhat to get the lever to close that last inch or so of travel. You can see rifling from the lands on the bullet's front band. Accuracy was well within acceptable range, but I'm not thrilled about the timing of a reload in a hunting situation.

Is this a LBT design issue or common for the 348 M71?

[smokeywolf]

You mention boolit dia. but not COL. Original Winchester, Browning or Miroku? I have not yet run into chambering difficulties in a Winchester.

I did a quick search and wasn't able to pull up a blueprint of the LBT 250 grn. boolit.

smokeywolf

[stocker]

fremont: 71's have no throat to speak of. They will usually accept a boolit with a very short leading band-- 1/10th" or shorter. BTB bullets cause the same problem and possibly they are using a LBT mould. My NEI moulds do not- 2 Mountain moulds did cause early land contact, RCBS and Lyman moulds generally work fine. If the boolit is unhardened you can usually close the action with a bit of effort. Accuracy can be quite good doing this. Or, you can shorten the cases to match the boolit or have the rifle throated a bit to accept them at normal case length. A problem may arise with case shortening with some seating dies as they may not do a roll crimp once the cases are shortened. Been down this road quite a bit.

[smokeywolf]

stocker,

By shortening the case aren't you risking seating a gas check below the shoulder?

[fremont]

You mention boolit dia. but not COL. Original Winchester, Browning or Miroku?

Win M71 loaded to max OAL. Crimped at top of cannelure.

[elk hunter]

For hunting loads can you size down the front driving band a bit so the bullet will chamber more freely? I would love to try cast bullets in my 71, but too many other projects will probably keep me from doing so.

[stocker]

smokeywolf; Probably (in fact they do a bit with some boolits). My checks crimped on solidly so I was not worried about them simply falling off. Additionally my best (accuracy-wise) heavy loads were with Re19 and the 4831's which had small amounts of PSB (about 3-5 grains variable) to provide compression. The PSB appears to give some protection to any exposed alloy, at least I could see measurable accuracy improvement and attribute that to the filler. I did try some loads without the filler and accuracy was a bit poorer but that could have been my error as I think as quickly as I noticed it I reverted to the loads with filler. I got my overall best results with a boolit from the heavy NEI mould and I think the boolits were close to 270 grains. I still have the moulds, but tired of the rifle which was my 4th M71 owned over the past 55 years. Great hunting rifles for big game but none had the accuracy that keeps me interested at the range. I keep looking for a suitable platform to build on (perhaps a Ruger #1) to do further testing so have retained half a dozen moulds for that event. Haven't jumped on an action yet as barrels in that caliber are not readily available here.

[451whitworth]

I shoot LBT 250gr. LCFN's and Accurate 35-220B's out of my three Browning M71's and one original 71. As stated there is no throat in any of them. Any bullet sticking out of the case neck cannot be of bearing length diameter. I also use Precision Reloading shotshell buffer over 42.0grs of RL-15 for 2175-2200fps. The Brownings are hands down the most accurate lever guns i have ever shot.

[Green Lizzard]

i size down a lyman 200 gr .357 to .350, then size the nose to .340 they shoot great in mine. the gas check goes on after sizing to .357 base first