Hi All, I recently purchased a Winchester M70 super express in 357H&H, now the rifle was unmarked and looked as new, no signs of wear and very little use. I mounted a Leupold V111 1.5x5 on Leupold QD mounts and bedded the action right out to and including the barrel lug, now do you think I can get it too shoot? no way, the best I can get is 6" at 100yds with factory and handloads, I've been shooting large bores for many years and this one has got me stumped, One thing I have noticed is chatter marks on the rifling near the muzzle it may even go down further into the bore. has anyone seen this problem before and this may be causing the poor performance, any ideas apart from rebarreling, also is that barrel lug really needed...thanks guys.....Les

Hello Les,

Did you try it with the open sights? Did you shoot it before bedding? Is the front ring a half inch or so behind the gold ring, and double check to ensure everything is tight?

A bad crown is never good for accuracy, it's the last thing to influence the bullet. I'm not sure how much the "chatter" marks in the bore would infuence accuracy (I've seen some rough bores that still shot great), but if it affects the crown, that could definitely be your problem. You might try to polish the crown if it's not too bad, or re-crown, or move the sights back and shorten/re-crown the barrel to remove the offending machining marks, or re-barrel. Barrel lug is probably not necessary on a properly stocked 375. If it were purchased NIB, I would send it back to USRAC/Winchester, but I bet that bedding might affect their warranty.

Good luck and let us know how it works out,

Bill

Les,

How do the groups look? are they stringing in one direction or another, or does it look like a large shotgun? can you recover any of the bullets, to inspect them? How does it group at 40-50 yards? Should be about 1/2 the groups size obviously, so check to make sure they aren't first tight then open up at longer distances. Have you -really,really- cleaned the bore to make sure any fouling is removed?

I think the grouping question will tell the most.

Thanks for the reply Bill and Mark, Ok the bore is clean no worries there, scope is secure, for the groups..

2

4 1 3

5

The above group is about average,spread over 6" to 8"...and about the same at 50 ydrs but smaller.
Can't realy use the open sights with my eyes but will try and get someone to test it for me. and I should have tried it before bedding but it's the first thing I do with any rifle I buy, may have learnt a lesson on that one,,thanks for the help guys.....Les

Oh blast the group did'nt come out right, it's a roundish shape ...thanks...Les

Have you tried replacing the scope? Also, just for grins you might try slugging the bore. Perhaps if you are still guessing make a chamber cast with sulphur or cerrosafe to see if everything is concentric.

oops double post!

[ 12-14-2002, 09:09: Message edited by: MarkWhite ]

I would see about recrowning it first before rebarreling

I would send it back to Winchester. This is not the first Winchester that shot like crap out of the box.

500grains is right.

Send it back, like TODAY.

Grab a box of factory ammo, shoot 10 at 100, and send that target along.

They'll fix it, and should do so pronto.

jeffe

I don't think sending it back to Winchester is an option.

The gun was bought used (want to bet it didn't shoot for him either), and it's been bedded.

The "chatter marks" are very likely the cause of it shooting bad and I'd bet green dollars that was a cleaning rod mistake of some kind. I see a new barrel in your future.

The barrel was roto-forged and chatter marks shouldn't be a probem.

Thanks for the replies guys, Have had a smith look at it and the barrel is knackered there seems to be damage to the rifling about 2"-3" down from the muzzle and it's proberly stuffing up the projie on the way out so it's means a new barrel oh well we live and learn and it's a good excuse to customise it........thanks again....Les

still worth a call to 'chester/

A couple years ago, one of the gun writers put out an article called "with a grain of salt" that I took with a 40# block of salt, and one of those items was my long standing disbelieve that a cleaning rod can hurt a barrel, provided it's not steel or pullthrough cable.

Not to start a pissing match, but i can'tsee how a cleaning rod of alum (softer than copper, steel, stainless) or rubber coated ruin a barrel? Do all the autoloaders(and pumps) out there suffer from ruined barrel? I've seen 740/760 rems outshoot really good bolt rifles. And all lever actions.... In all honesty, the only guns that can be cleaned from the breach are a very few autos,doubles, singleshots and bolts guns

Saeed was going to do us a study on this, wasn't he?

jeffe

jeffeosso--

A softer than the barrel rod is called a LAP. Grab ANY aluminum, brass, or wooden rod and look at it under polorized light at 100X. You'll see the grit embedded in the rod that cuts steel. You can't wipe it off and if you polish it *that* grit becomes the lap.

Use nothing but hard, one-piece rods with a polished radius at the tip or a Bore Snake.....which has become my personal favorite.



This Kimber M-82 22 Hornet barrel was cleaned several times but shot less than a hundred rounds.

I see MUCH more bore damage done by cleaning than I do shooting.

Rated by reasons to rebarrel:

1) The customer wants something else.
2) The barrel was abused or neglected and pitted.
3) Cleaning damage.
4) Wear from being shot.
5) Bent, bulged, or welded on.

Mr. Belk, thanks for the insight.

I have always been a bit lazy about cleaning barrels, and now I see that I was on the right track.

JB,
Sir, you are an INCREDIBLE gunsmith. and thank you.. I should change my name to grasshopper.

I mean this will all respect.. and, <grin> I have a REASON to be lacks on cleaning my guns now.

Okay, here's another issue..
On barrel break in... Your thoughts as to how this should be done? clean every shot for 5, every 5? Or, in all honesty, mine.. sight in the scope/sights... clean and shot something else awhile, shoot till I am bored, (10 rounds with big bores.. I suddenly remember other things I need to do) and then clean... so about every 10?

jeffe