New barrel trouble

[local41]

Hi, I recently installed a new barrel on my Stevens model 200. It is a 7mm chambered by one of the better gunsmiths. I used to have a McGowan barrel on the rifle and it shot great.
After installing barrel on action in started load development . Accuracy is OK but not great. The main problem I have is after shooting the brass will not resize without really forcing it into the full length sizing die. When I do this it is so tight the brass forms almost another belt on the case.
I have checked my die it works fine, it only does this on brass from this barrel
I tried both new and once fired brass
I have no sign of excessive pressure
Bolt closes on go gauge, doesn't close on no go gauge.
Does anyone have any idea what I could be doing wrong? I have about 800$ into this barrel, and don't want to send it back if I'm doing something wrong.

[RC20]

Barrel experts will have to weigh in, it seems the chamber is so large the brass is expanding far too much and then you are trying to squeeze it back down from way past the dies capability.

303 is bad that way but never heard anyone have it to that extreme.

Shades of the wrong chamber even. Phew,

[sharpshooter]

7mm what? It could be that the brass is undersize. I've seen this on 7 mm WSM.

[local41]

Sorry it's a 7mm rem mag. I'm not sure what you mean by the brass is undersized, could you please explain. I should note I had the same issue with some once fired brass and the guy that chambered the barrel said it wouldn't happen if I used new brass. All brass is nosler

[Zero333]

Gotha...

Your chamber is tight. I have a very tight 300winmag chamber and I know exactly what you are talking about.

Your die is unable to size above the belt. Or your chamber is much tighter than the sizing die can size.

You need a body die or a "Belted Magum Collet Resizing Die" from Innovative technologies.

[yobuck]

I'm interpiting the poster as saying that new unfired brass will chamber, but fired brass will not.
Also that his full length resizing die wont resize it enough so that it will chamber.
I'm just assuming its the same die he used with his old barrel chambered for the same cartridge.
Personaly, id be sure I'm not using the old brass, although the die should allow for doing that.
The new fired brass from the new chamber should rechamber even without resizing in my opinion.
Otherwise those who neck size only couldn't do so.
Id be first assuring myself the die was set properly, and new brass was used in a trial.
Id then be taking the gun to a different smith and have a chamber cast made then compare those dimensions with Sammi specs.

[psharon97]

My load for 308: IMR 4895 43g, Lapua brass, shooting 168 TMK. Shoots great to 1000 yards. This is a 26" Douglas bull contour. Not the same barrel, but a great load.

Also try: 41g of Accurate 4064 with 168g SMK.

45g of IMR 4895 with Hornady AMAX.

These loads have worked great in a variety of 308 rifles I have tried with custom barrles and factory barrels.

[RC20]

Gotha...

Your chamber is tight. I have a very tight 300winmag chamber and I know exactly what you are talking about.

Your die is unable to size above the belt. Or your chamber is much tighter than the sizing die can size.

You need a body die or a "Belted Magum Collet Resizing Die" from Innovative technologies.


I don't get your reasoning.

If its a really tight chamber, the die won't have to squeeze much if anything. It might not re-size to needed dimension, not likely but possible.

If the brass comes out, it should go back in.

I am not fond of Nossler brass but I don't believe its an issue in this case (longevity yes)


The OP seems to be saying it can't squeeze down the brass without a huge distortion.

That sound like a vastly too large chamber where the brass over expands and then the re-size die is trying to stuff the over expanded brass back down.

[darkker]

Yeah, I agree with Yobuck's assesment.

Also, I'm never a fan of "I don't see any signs of pressure". This needs to a a big fat sticky when you log-in. Very carefully Calibrated Copper Crushers, in Very tightly measured Chambers and Barrels, by The best ballisticians, from EVERY member of SAAMI, using tightly controlled Reference lots of powder; have LONG known that Copper Crushers ARE NOT ACCURATE when used above 45,000 psi.
A reloader who uses brass that has no stated tensile strength, or known hardness spec, with primers of the same issue; can NOT stare at the brass or primer, and magically know where your pressures are, period.

From the many different rifles and cartridges we have tested with a Strain guage system, the bulk of factory brass(NOT Federal) has a tensile strength around 75,000 psi. So if a reloader "sees signs" of stretching or growth, that's because you have about met the tensile strength of the brass.... Typically around 75,000 psi.

The way to know reasonably where your pressure is, is the velocity. If your load, all but regardless of specific charge, exceeds book velocity; you exceeded book pressure.

[yobuck]

Read the post about die length. It could also be what you are experiencing.

[RC20]

Re-reading this, we need to know what the loads are?

Powder and how much, primer and whose, bullet weight and how COAL was determined.

I glossed over it as OP had previous barrel and would assume it was decent load but in this case assume is bad.

[local41]

I do not have trouble with the brass not chambering the brass, the problem is when I try to resize brass after shooting it. The loads I have tried have been 162 grain eldx with 69-73 grns of retumbo, loaded .015 from lands. 180 berger vld with 69 grain of retumbo.
I say I don't see any signs of pressure because I loaded in .5 grain increments until I start seeing signs of overpressure ( flattened primer, stretched brass,loose primer pockets, any noticeable extractor marks, sticky bolt lift,ect.) How do you decide where your max load is?

If I shoot any load through this rifle I cannot get brass to go into resizing die. I know I am not an expert but I have loaded my own ammo for 25 years, and have never had an issue like this.

[Hotolds442]

For starters, compare the measurement of your once fired brass to the reamer print. Until that's done, everything else is just speculation without any real data.

[Robinhood]

Local 41, How did you set the head space on your new barrel?

[hafejd30]

For starters, compare the measurement of your once fired brass to the reamer print. Until that's done, everything else is just speculation without any real data.

This is your starting point. Either the reamer is off or the sizing die is wrong/maybe not enough lube to fl size etc. You can run as much pressure as you want, your brass will only extend to the size of your reamer. Blowing up the gun or ruining brass life aside. If your reamer is
The correct size the brass can only expand to that point, period. Other things give out past that point

You could also have your die adjusted wrong and be forcing more brass downward, as in not bumping .002" etc but way more due to incorrect setup. The brass would flow somewhere and just below the bottom edge of your die would be the first spot. I did this once but mine crushed just below the shoulder

[local41]

Headspace was set with ptg go gauge. I snugged barrel on it and the tightened the barrel nut, after this was done in put in no go Guage bolt will not close on no go Guage.
I will try to get the reamer print, but the Smith wants me to send my brass, and die to him. I'm not sure he will give me the print.

[Zero333]

The die is not sizing the brass enough.

Either you're not setting up the die correctly or you're headspace is next to zero which will not work with belted cases.

Are you using a headspace comparator or a bump gauge when sizing ???

[darkker]

I say I don't see any signs of pressure because I loaded in .5 grain increments until I start seeing signs of overpressure ( flattened primer, stretched brass,loose primer pockets, any noticeable extractor marks, sticky bolt lift,ect.) How do you decide where your max load is?
n

We need to know the velocities with those charges. But if you stopped because you "saw signs" your powder is much quicker. As I said when you "see" signs, you are well above SAAMI. I think you should cast the barrel, and double check your dies.

Out of curiosity, what brass "brand" are you using? Federal is dangerously soft.

[yobuck]

Pack up the gun, some fired cases and the die and go visit a good gunsmith.

[local41]

Velocity is 2900-2910 with 180 berger 162 I don't know yet. Both loads are below max listed . Nosler brass I'm going to try some factory ammo today, this problem occurs even at starting load pressure