Stumped and need HELP!

[eschafer]

proud primer.... or.... cases need careful deburr AND chamfer.... (bullet, when seating, could be pushing brass to the outside of the case where it drags on the neck of the chamber.....

 

[Warrenoliver]

Could your seating die be adjusted too low causing it to crush/deform the shoulder a bit?

 

[436]

I'm in need of a little advice as to how figure out an issue I'm having with a Weatherby 7 mag. I'm starting load development (for a friend) using the 120gr Hammer Hunters and here's my dilemma. First of all the brass is once fired factory ammo through this particular rifle. My process is to remove primers, clean, anneal, and size full length with .002 shoulder bump and trim. I check every case in the chamber with the firing pin removed to make sure there are no anomalies. Now here's the dilemma, when I seat the bullet (20 thou under mag length) the bolt is stiff to close. On nearly all Weatherby's, I start there and with the excessive free bore, it's not even close to the lands. The OD neck measures the same as a factory round loaded with the TSX and it chambers fine. I've completely colored a case with a sharpie and there are no marks whatsoever. Again I've taken every measurement possible and have no idea what's causing the issue. Also, I've cleaned the barrel and the throat to perfection that's verified by with the bore scope. Any advice or answers is more than welcome as I've thrown in the towel.

What brand name of sizing die are you using?

 

[Varmint Hunter]

Run the case into the seater die without a bullet and see how that chambers. It may give you another clue to solve the puzzle. It's a rather strange problem.

 

[yoteslayer]

I'm with warrenoliver try turning your seater die out a half a turn and adjust the seating stem in to your desired length and see if the problem goes away

 

[Ackley Man]

Is there a possibility that the resized brass is actually head spacing on the belt of the cartridge and not on the shoulder? Is the bolt unusually stiff on the lock-up? All of my reloads are slightly stiff on the camming action of the bolt.

I should have asked if the chamber of the rifle has been scrubbed clean and checked for anything that shouldn't be in there like a rough area or stuff built up.

LOL a belted case does head space off of the belt not the shoulder.
A belted magnum might have .005" headspace on a new case which is the dimension between the front of the belt and the recess in the chamber it will bear against. But that same case may have .020" between the new case shoulder and the chamber shoulder. Then after firing you would have to push the shoulder back .006" or more to have it headspace on the belt again.

But if your chamber has a headspace of .001" which, again, is the distance from the front of the belt to the recess in the chamber against which the belt will stop forward movement, then after firing you would only have to push the shoulder back .002" to have the belt again act as the headspacing agent.

Now all of this will vary with different makes of brass and how the chamber was reamed.

 

[antelopedundee]

Everything you all have stated, I've checked over and over and over. The rifle is an early 60's Mark V. When I received it, the first thing I did was clean the barrel down to bare metal and removed the carbon ring. Verified to perfection with the bore scope. Measured the shoulders with a comparator gauge. Then proceeded to anneal and all other steps before sizing. Using his new RCBS standard full length die, I bumped the shoulder .002. With the firing pin removed, the case fit perfect with zero resistance. I continued to do so for the entire batch (22 pieces) checking each one in the chamber. Once complete, I primed 10 cases to do a ladder test starting at 74gr of H4831SC. I seat a bullet into the first case and with the firing pin still removed, I chambered the round and that's where the problem began. The bolt was moderately stiff to close. Necks are perfect and every measurement on the case is correct. I've done this process for over 30 years and I'm overly anal. So last night, I took a dummy round that was bumped.002 and bumped it to .004. Seated a bullet and it was still stiff but not as bad. Pulling the bullet and bumped to .006 and there was still friction but very little. Pulled the bullet and bumped to .008 and finally there was nothing. I completely agree that .008 is a lot but after checking and verifying everything else what else is the to do? For example a factory loaded 180 TSX the comparator shoulder measurement is 2.111 and with a .008 bump on these rounds the measurement is 2.120 and started (once fired) 2.128.

What is the reason for removing the firing pin from the bolt if you're chambering a case that has no primer in it?

 

[Dot_3]

What is the reason for removing the firing pin from the bolt if you're chambering a case that has no primer in it?

It allows a resistance-free bolt close/open once you have a case properly sized. You'd also remove the ejector.

 

[Jpron]

Could your seating die be adjusted too low causing it to crush/deform the shoulder a bit?

Pretty sure we have a winner here, something going on with the seating die

 

[eschafer]

Pretty sure we have a winner here, something going on with the seating die

I now agree.... But OP mentioned reloading for 30 years, same technique, (new brass can require adjustments to one's process). An improperly installed die hadn't even crossed my mind at first.... A straight edge along the side of the case, pointed into daylight, often reveals the crushed shoulder.....

 

[antelopedundee]

Pretty sure we have a winner here, something going on with the seating die

If you want to make use of the crimping feature built into the seat die you need to turn it down so that it touches or nearly touches the shellholder. I don't think that there should be any contact with the shoulder. It's possible the neck is being pushed down with some expansion at the shoulder. He said that he measured things and found nothing that differed from factory ammo, but he may not have measured that dimension. Sometime back I tried crimping some some 6.5-06AI loads and I just collapsed the shoulder. He might be doing the same here. He could pull the bullet from a couple rounds and see if takes effort to chamber those cases.

 

[cape cove]

I had the same thing happen to me with my 270 Weatherby mag. The problem was expansion just north of the belt. Would adjust down the sizing die and it would chamber good only this bumped the shoulder back to far and case seperation would occur. Would you by chance have a sizing die for another larger belted mag ie 300 Weatherby 300 Win etc.

 

[Seabeeken]

Is it possible the tightness is just forward of the belt because the die isnt sizing enough? Sharpie that area and check again

 

[Dean2]

The difference in chambering ease ONLY happens after a bullet has been seated once. It continues to happen to that case even after the bullet is removed from the case. You have clearly identified the issue, bumping the shoulder back may be making it easy to cahmber but the shoulder bump is not the problem. The comment about donuts or bulged crimp are spot on. One of those is the likely cause of what you are seeing. Try neck sizing a round with no shoulder bump, chamber it, then seat bullet and see if problem repeats.