Belted Mag set back

[str8shooter]

I had a 300 WM built in February. It has less than 100 rounds on it. I've been getting clicks at the top of extraction since the first shot and havn't been able to finish load development because of it. I've tried 3 types of brass (rws, win, norma) and get the same issue each time. My cases have a noticeable bulge about .002 bigger than the rest of the case for about .050 just ahead of the belt. After the first shot with new brass, the cases will not go back in the chamber the bolt close, they go in as far as the bulge then stick. It was borescoped and I was told there was a relief cut made for the belt that was radiused which caused the area just ahead of the belt to be unsupported causing the case bulge. It sounds like the barrel needs to be set back, my question is how much length will I lose on the barrel and can it be done without destroying the cerakote?

 

[Dave Tooley]

I had a 300 WM built in February. It has less than 100 rounds on it. I've been getting clicks at the top of extraction since the first shot and havn't been able to finish load development because of it. I've tried 3 types of brass (rws, win, norma) and get the same issue each time. My cases have a noticeable bulge about .002 bigger than the rest of the case for about .050 just ahead of the belt. After the first shot with new brass, the cases will not go back in the chamber the bolt close, they go in as far as the bulge then stick. It was borescoped and I was told there was a relief cut made for the belt that was radiused which caused the area just ahead of the belt to be unsupported causing the case bulge. It sounds like the barrel needs to be set back, my question is how much length will I lose on the barrel and can it be done without destroying the cerakote?

A couple of things may be causing you trouble. 1. Most likely the chamber is too tight ahead of the belt which doesn't allow the brass to expand and then spring back away from the chamber. The more you shoot it the tighter it gets. The easy fix is to polish out a few thousandths out of the chamber. 2. Your FL sizing or for that matter all FL dies don't size the case immediately ahead of the belt. A common problem with belted mags. The corner in the chamber in front of the belt where it transitions to the body is square with no radius.

Dave

 

[str8shooter]

I have a Larry Willis Collet die and it will resize the brass near the base far enough for it to chamber. However, I shouldn't have to do this on the first firing with new brass and every subsequent firing after that. Dave, are you saying that in the chamber, where it meets the belt it should be square and not have a radius on it? I talked to the smith this morning and he says he puts that radius on all belted mag cases so they go in the chamber easier. My neighbor had the same guy build him two 7mm stw's and both have the same issue as my gun. I appreciat the help guys I just want to try and figure the problem out so I can get it fixed.

 

[Dave Tooley]

I have a Larry Willis Collet die and it will resize the brass near the base far enough for it to chamber. However, I shouldn't have to do this on the first firing with new brass and every subsequent firing after that. Dave, are you saying that in the chamber, where it meets the belt it should be square and not have a radius on it? I talked to the smith this morning and he says he puts that radius on all belted mag cases so they go in the chamber easier. My neighbor had the same guy build him two 7mm stw's and both have the same issue as my gun. I appreciat the help guys I just want to try and figure the problem out so I can get it fixed.

It's cut square and yes then the edge gets broken when we polish the chamber. It sounds like the chamber is too tight. Been there done that in the early days.
It violates RULE#1 Don't do anything to make the phone ring.

Dave

 

[Dans40X]

The chambering is a train wreck to say the least,verified by a bore scope.

OP,have the barrel set back & re-chambered.

 

[243winxb]

After the first shot with new brass, the cases will not go back in the chamber

I would guess a high pressure problem. What is the load/bullet being used? What happens if you reduce the powder charge?

 

[str8shooter]

I would guess a high pressure problem. What is the load/bullet being used? What happens if you reduce the powder charge?

Norma brass, 208 amax. Anything above 75.5 grains of h-1000 bulges the belt. Quickload says I'm running 50,473 psi at 76 grains at my coal, bore diameter, and case capacity. I've tried RWS, Win, and now Norma with the same results.

 

[243winxb]

Hodgdon website lists a col of 3.420" for the Hornady A Max 208gr in the 300 Win.Mag. Strange that SAAMI lists the maximum at 3.340" ?? Your custom chamber, if tight, may raise pressure. A bullet sitting in the rifling may raise pressure. 75.5gr may be your guns maximum??

 

[str8shooter]

Well the barrel was pulled and the chamber inspected. The threads had at least .030 "flop". When the action broke free I took my hand and wiggled the action and saw how loose the threads were, I knew it would be down here from there. The barrel was then indicated into a lathe. There was .028 runnout at the belt and .018 runnout at the shoulder. The wobbling reamer left length wise gouges in the chamber ( these were the ones observed by dans40x and visible on the fired brass). The reamer wasn't cleaned properly when chambering and chips being pushed up had broken all the lands in front of the throat. This is the reason it took 13 shots and over 60 patches before the barrel quite copper fouling, break in alone took 3 hours. I thought krieger barrels were crap because of this. All of the threads had to be cut off and rechambered, so I lost allot more barrel than I hoped. Tonight I decided to see if I could save the once fired Norma brass. I ran it through a redding body die and then through a Willis belted mag collet die. I had to throw the brass away because it literally pushed a wad of brass off each case because the belt was blown so far out of spec. The person that re-chambered my barrel was nice enough to save enough barrel so that I could keep the first gunsmiths logo, lol. I guess that will serve as a reminder of who never to take a rifle/anything to in the future. Here's a pic of the new chamber and original smiths marking.

 

[Mike Bryant]

Probably shouldn't get involved in this thread, but when you say there was .030" flop in the threads explain that to me. .030" of flop guesstimated where? When I thread a barrel, I want the action to have a little wiggle room on the thread fit. I don't want it to screw on so tightly that the action can't move up and down. As Harold Broughton told me years ago, the difference between a tight thread and a loose thread is the amount of clearance between the flank of the rear of the barrel thread and the front of the flank of the receiver thread when the barrel is tightened to the shoulder. With a tight thread there will be clearance at this point. With a loose thread, there will be more clearance. It doesn't make any difference within reason as to how much clearance there is, it's clearance either way. However, if the thread is so tight that the action can't move on the barrel thread, then it may prevent the barrel from seating fully at the tenon shoulder and the receiver face.

Also, when the barrel was indicated in to check the runout on the chamber, where was the indicator run? Was the barrel indicated in front of the chamber inside the bore and the muzzle end indicated at the bore and then checked for amount of runout at the shoulder and in front of the belt or was the barrel indicated on the outside of the barrel and then checked on the runout at those two places? I have a hard time seeing how anyone could get a reamer to cut a chamber with .018" runout from the bore no matter how they ran it in. However, if the original gunsmith used the Gritter's method to indicate the barrel in and then chamber the barrel that if you later set the barrel in to a lathe with both ends of the bore centered in the lathe, that you could get the runout figures that you are stating. To check runout on a chamber, you'd just about have to know which method he used to set up the barrel in the lathe when it was chambered. You'd need to know whether it was set up centered on the bore at both ends or set up to get two points centered at the breech end by moving the muzzle end around in the lathe to get those two points centered.

 

[str8shooter]

Mike,"flop" was the term I used not the smith. His term was "the only threads I've seen looser than these was a chamber I had to re-do last year that was also done by the same guy". I believe he sets his chambers up with a range rod to get close then a uses long reach indicator up into the bore, he aslo indicates both ends as you asked. This is me talking again, the chamber had galling marks in it every where with longitudinal gouge marks throughout the body of the chamber. When I called Don Wednesday, I asked him about the reamer he used on mine, he said "I don't have that reamer anymore, I'd probably done 100 barrels with that thing, on he last one I did it wasn't gutting like I thought it should, so I got a new one". Could it be possible that the reamer was so dull it caused enough chatter to cause the chamber to be that far out? That was my guess what happened. You could tell how far out the chamber was by looking at a piece if the fired brass. Just ahead of the belt, where it was bulged out, you could turn it slowly and see the bulge go in close to the belt on one side then back out as you came back around. Here's a pic of the galling and one of the lands.

 

[Mike Bryant]

A bulge on one side of the case in front of the web is caused from being fired in an oversize chamber. The brass swells out to the weak side of the cartridge case and blows the body out to fit in the chamber. The goal any time you chamber a barrel is to have the reamer cut the chamber the same size as the reamer. I'd guess that a dull reamer could cut an oversize chamber. A dull drill bit will certainly drill an oversize hole.

 

[str8shooter]

Now looking back through this thread I noticed I made no mention of my conversation with Don Wednesday. I called and politely said that I'd been having problems with the gun since I got it and it wouldn't eject cases. I told him about sending the handle to Dan and that he informed me there might be a problem with the chamber from looking in it with a borescope. He completely blew up and basically cussed me out and called Dan a dumbass( after admitting not to know anything about Dan). He then said I had bad brass, I told him I've tried 3 types, he then said I had to be loading to excessive pressures and I didn't know anything about reloading. He then went on to tell me who he was and what all he'd accomplished and that he didn't make mistakes. His last words were I was going to pay if he had to touch it because there was no way he'd made a mistake. Well, since I paid him 600$ for the first crooked/oversized camber, I didn't want to take a day off work and two tanks of gas to drive over there and have him cuss me in person, because that wouldn't have gone over well. So that's when I took it to the other smith, without telling him any of issues I'd had with the gun, so he could borescope. Customer service is a big part of any business, cussing someone out that has a problem that you caused is not professional even if you are in the hall of fame.

 

[243winxb]

My cases have a noticeable bulge about .002 bigger than the rest of the case for about .050 just ahead of the belt.

 

[wadebrown]

I love the 'smiths comment "I never make mistakes", that says a lot right there.

 

[jwa]

What state is this smith in? He sounds awful familiar.
Jerry

 

[Charles E]

What state is this smith in? He sounds awful familiar.
Jerry

This is sort of getting to be a "Wilbur" issue. Wilbur doesn't allow trashing vendors, including gunsmiths, on BR Central, even if they seem to deserve it. Usually the thread only gives one side of a story, and someone's livelihood can be involved, that sort of thing.

In any case, however you feel about it, it's Wilbur's "House Rule."

BTW, there is already enough information in the thread to allow many people to guess the name...

 

[alinwa]

Guess? Figure it out? Not any more! There are also so many things wrong with the "assessment" that the thread should disappear just because it's rife with bad information coupled with bad judgments. There may have been a problem with the chamber, we'll never know, but a lot of the the assertions posted here are flawed.

Someone please give me a logical mechanism for an "oversized" 300WM chamber to hang onto those tapered cases? (Ohhh, he said EJECT cases....)

And someone please 'splain to me how to re-index a 300WM back and prove runout....with a "long reach indicator???"

And 30thou of "thread flop" and "13 shots and 60 patches before it quit fouling" and "galling on the land"

And how a tight chamber raises pressure??? (OOOPS, it's an "oversized chamber" ain't it?)

And how chips "break the lands off"

And "Quikload sez"....

Lotta sad stuff going on here but it ain't all one-sided.

IMO

al

 

[str8shooter]

Al, I don't get on here to bash anybody. I got on here for answers. I was trying to figure out why this gun stuck cases that were under pressure since day one. I got no answers when I called the smith 2 days after it was chambered. Was told primary extraction issues, so I sent the gun to Dan Armstrong, he looks in the chamber and said it looked horrible. Take it to a local guy we both look in it and it did look horrible. He Re chambers it out of kindness. I go to the range today and shoot 30 times and not one single ejection issue. The new chamber has a .040 shorter throat ( should reach pressure sooner) and I ran up to 78.5 grains of h-1000 with no issues, 75.5 stuck previously. Same bullets, barrel, brass, powder, and primers only difference was the chamber. All I know is I was charged 950$ in smithing fees to begin with and haven't had a gun that would shoot until now.

 

[Charles E]

...All I know is I was charged 950$ in smithing fees to begin with and haven't had a gun that would shoot until now.

I -- & I suspect all of us -- feel for you. We've all been there, if not with rifles, then something else.

About All I can say is, for future projects, and using Benchrest Central, ask the folk here for recommendations. You won't get a clear answer (there are a number of good 'smiths out there), but I can't remember anyone recommending a 'smith that wouldn't deliver a professional product at a professional price. Likely it has happened & my memory is being a little selective, but even if so, the incidence was low -- or I would have remembered!