Gunsmithing 300wm chambering issue.

[2834]

First post, long time reader, and I hate to start off with a fricking problem. I have several long range guns, all built by a newbie smith. The 308 and the 338 lm initially shot well, never real accurate, but very tight groups.

My 300wm is kicking my ass. The rifle has good parts and shoots ok, MOA constantly. The action is a Savage the barrel is a #9 Krieger, 31 inches long. The barrel is threaded like a Remington 700. VIAS brake, Manners stock a Schmidt and Bender PMII sits on top. Not a bad rifle to shoot.

I have always had feed issues even with new factory brass. The brass is an assortment, RP, PMC, Etc,etc. I shoot matchking 190s OAL is factory or Sierra's load data at 3.340. My standard powder load is 70.4 g of R-22.

My cases measure out to the suggested lengths, yet in am having a hell of a time chambering a live round, or even a casing. Ive measured pre and post sizing. I've neck sized, I've over all sized the case's, and STILL have chamber problems.

I'm using a Wilson case gauge set up off of the belt, the Wilson case gauge has the collet set right, and no joy, when the casing is placed into the chamber.

What am I doing wrong. Is it possible my gunsmith cut the chamber to tight.

Right now this is the only rifle I've got at home, my 338lm is at GAP for a re-barrel, and my .308 is up in Portland Oregon at Northwest Rifle action, being squared up, a new Pacific Tool and Die bolt matched and installed, and the barrel re threaded for its can.

Short of pulling the barrel and measuring the chamber, anybody got any idea's. I'm skunked on this one, and frustrated.

Thanks in advance.

2834

 

[slayer_21420]

"The 308 and the 338 lm initially shot well, never real accurate, but very tight groups."

Please explain this as it seems quite contradictory?

 

[jonaddis84]

"The 308 and the 338 lm initially shot well, never real accurate, but very tight groups."

Please explain this as it seems quite contradictory?

I was going to ask the same thing.

Try getting a Go gauge first before you get all crazy pulling the barrel off, if it chambers then you may not be sizing the brass far enough. Fill out your profile, maybe there is someone near you that you can drop by and see if it will close on a go gauge.

 

[fryj00]

Are you saying that you have trouble closing the bolt on a case? If so, I would guess that your barrel is not headspaced correctly. I would get yourself a go gauge for your caliber and try to chamber it. I bet your bolt won't close on it...which is bad.

 

[Killswitch Engage]

Can you shoot "real accurate"? Not sure how a rifle can group well and not be "accurate"

 

[2834]

Thank you for your responses. All three rifles have Krieger #9 barrels, and shoot tight, meaning I can shoot MOA all day long. By not being accurate I mean, at 100y with the .308and the .338LM, I shoot MOA, but the bullet impact moves 1/2 inch to 1 inch, day to day.

Cold bore and active follow up shots are always the above measurement from point of aim VS point of impact. It's a tight group, it's just not exactly where I want it. By 1/2 inch or sometimes an inch.

Never more then an inch. My loads are solid, and until recently my training and work round had always been 168g matchkings. I'm retired so I've started to go to the 175s.

I'll have to order a go- no go gauge. this stuff is driving me nuts.

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[buffybuster]

Have you tried chambering brand new factory loaded rounds? If those don't chamber, then the headspace is definitely too tight.

 

[Straight Shooter]

I'm in Coos County. I have all those gauges. If you want to drop by you can use them.

 

[2834]

My neighbor brought some factory 300wm over. They chambered fine. He also brought some once fired re-loads, that would not chamber.

I'm using standard RCBS dies. I've got a Redding seater order, but then that just seats bullets. I'm using a reasonable amount of RCBS wax/lube.

Thanks. I'm going to hit up some of the old guys in the area, tomorrow with the brass, the rifle and the sizing die. Hoping they can square me away.

2834

 

[stinkyDrunk]

Take an unloaded cartridge that chambers hard, paint it black with a sharpie. Let dry, then chamber it. The ink will be removed at the resistant points.

 

[2834]

Straight shooter, I've got a couple friends working north bend and coos county. One of the lads out of coos county will be here this next weekend. I may just send the rifle back with him. His children live here and are over there for spring break.

I did the marker on the case gig. I got indicators on the bell area. The casing almost looks like I'm crushing the neck area, it looks expanded.

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[Straight Shooter]

No problem. Just give a call to make sure we're here. We should be able to shed some light on the issue in just a couple minutes.
Shawn

 

[ugsly]

You may need redding body die to run the 300 WM thru to size them down a bit more if your chamber is tight. Just a thought, but Straight Shooter will get ya squared away

Casey

 

[BillyGoatMachine]

My neighbor brought some factory 300wm over. They chambered fine. He also brought some once fired re-loads, that would not chamber.

I'm using standard RCBS dies. I've got a Redding seater order, but then that just seats bullets. I'm using a reasonable amount of RCBS wax/lube.

Thanks. I'm going to hit up some of the old guys in the area, tomorrow with the brass, the rifle and the sizing die. Hoping they can square me away.

2834

This info makes me believe there's something not right in you brass re-sizing process. Especially if it chambers factory rounds without issue. As far as chambering somebody else's once fired brass, it makes complete sense that they will not chamber in your rifle as they were fire formed in another chamber. Do you know what type of reamer was used? Start with the gauges and then your brass prep next.

 

[2834]

SK, I'm sorry but I don't know. I'll have an answer, end of day. Although I've owned this rifle for 6 years, it's been an after thought. I've got maybe 400/500 rounds thru it and it's an OK gun. Sits I. The safe as a back up more then anything. After sending my two main rifles out for a re barrel, and truing work, I thought I'd break this 300out and learn its way.

I had purchased 10 bags of brass, and loaded them to the mentioned specs. After ladder testing the R-22 load was the most consistent, so I loaded 400/500 rounds. They work fine.

When I built the rifle I was just certain it would be a scalpel, it's not, it's an MOA shooter but just. I never made the finite adjustments needed to fit my LOP and the rifle is just awkward.

I've launched most of the 500 rounds over the past 60 days, and had the stock shortened, and a few other personal use changes made to the rifle. So that part is coming along nicely. The re-loading issue popped up recently when I sat down to re load all the shot brass.

All the cases were tumbled, sized, trimmed if needed, and I started to load. My spidey senses told me to check the brass via the rifles action pre and post. Which is when I caught the problem. I actually chambered, or tried to chamber all the 300wm cases I have here. I had purchased several hundred 300 WM once fired cases at a friends gun shop. They were a no go aswell.

Thank you all for your assistance. I've been loading for years, and from time to time suffer from head up ass syndrome.

This appears to be one of those moments.

2834

 

[Killswitch Engage]

your die is not bringing the body back below the chamber size would be my guess. i have a buddy that wen through the exact same issue with his win mag and once fired brass. ended up with a collet die that forced the body back to spec and then it would chamber.

 

[njohn890]

You may be having issues with how your brass is being sized during your reloading process. Use the search function on the website and read up on any posts re " 300 WM sizing". There are some different approaches for reloading, particularly sizing of belted magnum cases that may shed some light on this for you. You will also avoid case head separations if sized properly and get more life out of your brass. The short version is you end up sizing belted brass as if it was a conventional non-belted cartridge and headspace off the case shoulder and not the belt.

I have a few items that I found very helpful for accurate measurement and sizing of fired 300 WM brass and getting my dies set up: an RCBS case mic and a special belted magnum collet die from Larry Willis. The RCBS 300 WM case mic measures off the shoulder just like a conventional case and not the belt.

The belt measurement has no influence on how the rest of the cases size might be interfering with your chamber and sizing off the belt alone can leave the rest of your case either sized to little ( won't chamber) or too much ( case head separations)

In order to sneak up on the precise case sizing you should have some type of case mic. This avoids the "screw the sizing die in until it hits the shell holder" approach and allows for precise sizing of your fired brass.


Hope this helps,

 

[MikeeBooshay]

I have always had feed issues even with new factory brass.

2834

From your first quote - that has led us down a slightly wrong path, njohn890 is right on the money about resizing practices for belted mags. Without the Willis die, most people can't get very many if any reloadings out of belted mag cases without issues. Standard dies don't squeeze the part just ahead of the base enough.

Pay attention to what he is saying about case length gauging also, or head separation will occur. Get a short piece of barrel stub, make a partial chamber, and use that to only push the shoulder about .001". The bolt will close easy on reloads, with enough squeeze in the head end, and not pushed back as much as regular dies do.

 

[2834]

So,e of the old timers here in town have go/no go gauges for the 300wm. I'll run those tomorrow, as I got to the shop late. I did have an email chat with Mr. Willis on Saturday regarding his collet die. I'll be purchasing one on Monday.

This morning we will gauge the chamber, and determine if the barrel is coming off. The chamber reamer originally used, is at the shop. The chamber may get opened up, or not.

In looking at all these cases, the shoulder seems off size, but to mic the length, it's tolerances seem to be correct.

Thanks for your help, seems we are making progress. I'm reluctant to ship the rifle off, as my other two rifles are off being worked on, and I'd like to keep one long gun in house.

Thanks again.

2834

 

[BillyGoatMachine]

Hope it works out, let us know what they find

 

[Phye2003]

I have had rcbs dies expander ball pull the shoulders out where it would be hard or impossible to chamber on two occasions. One on a 22-250 and the other a 243 imp.

The fix was redding dies for me but later on i annealed the case necks and tried the rcbs dies again and the worked just fine.

When i had that problem the cases would only measure .003-.005 longer than before i resized. May be something to check i have only ran in to this with rcbs dies so far.


Sent from my iPhone using Tapatalk

 

[2834]

Good evening, well I finally managed to achieve the of full retard. Started the day at a gun shop using go/no go gauge. The go and the no go gauge indicated the chamber and head space were GTG. I came home and again physically chambered ever 300wm casing I had in the house.
I had called RCBS this morning, they are great to work with. In fact my digital scale and trickle charger took a shit about 11/2 months ago.

I purchased another digital scale, and then thru extensive working with RCBS, their tech determined the issue was the tricker, not the digital scale. He authorized a warrantee change out, and my stuff got lost for a week there in Oroville, at RCBS.
They called and explained the loss, and asked if I could work with them. Of course I can. I'm retired.

The next Monday a complete trickler and digital scale arrived. I was stoked, and very grateful for their gifting me with a complete set up.

So back to today. At about 13:00 I get a call from RCBS's tech. And I'm up and running in three minutes. Literally three minutes. The problem is this.

When using the RCBS rock chucker, and associated presses, you run the lever down, bringing the ram top dead center. Screw your sizing die into the rock chucker, until the bottom of the resizing die touches the top of the shell holder, which is seated on the top of the ram.

Next lift the handle pushing the ram down and turn the seating die in 1/4 inches at a time. Bring up the ram, making physical contact between the bottom of the sizing die and case holder. What you need to happen is for the rams lever to go over center at the very bottom of the downward stroke.


this guys telling me this, and I'm thinking, dude your full of shit.

I did exactly what the tech instructed me to do, I quickly deprimed and sized about a dozen of the 300wm cases which did not cycle in the rifles action early. And sure as shit, every casing chambered.

So I find myself having achieved the level of Going Full Retard this past three days. Please except my apologies for wasting your time. But I am grateful for you all reaching out to the FNG.

If in the future I can be off assistance to any of you feel free to contact me.

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[longshooter]

Okay. Your problem is solved.

But, now how do we deal with those that think belted cases are bad, and those that think the Willis thing can solve a non existent problem?

 

[2834]

I'm a big fan of the bigger rifles. The 300 WM is ok, my 338 lm is my fav, if I could only have one rifle, that caliber would be it, it does everything I like to do with a rifle very very well. Thank you for your support, I will be sending this 300lm to you, after my 308 and 338 are back from re-work.

2834

 

[fryj00]

Glad you got your issue worked out...and cheaply too. Happy shooting.

 

[sakobob]

Okay. Your problem is solved.

But, now how do we deal with those that think belted cases are bad, and those that think the Willis thing can solve a non existent problem?

we don't deal with them and we keep doing what we do and go
on are shooting way

 

[Straight Shooter]

Camming the press over achieves full length sizing to as short as the die allows but if that dimension is more than about .001" shorter than the chamber you run the risk of a head separation down the road. Now the goal is to work the brass as little as possible. Now start backing the die out a little at a time until the fired brass is snug again and then go down a very little at a time until the bolt will close easily on your sized brass. There is no real problems to belted brass. A few of my favorite calibers wear belts. The only issue is down the road a few firings with max loads the brass will expand right above the belt where the regular sizing dies will not resize it causing sticky extraction. You can either toss the brass, use the Willis collet to extend the life of the brass or another option is to keep backing the load down until you get the case life desired and just twist the elevation knob another click or two. I now get around 20 firings from my belted brass; same as my non-belted brass.

A trick way to get the die set perfect time after time is to buy the Redding competition shell holder sets that come in .002" different heights.
Competition Shellholder Sets | Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment