7-30Waters Reloading Problem

[rimfire]

Some help here! I posted this on the reloading forum, but put here also since it is for 7-30Waters Contenders we are loading and I know some of you guys probably have the same barrel.

VVCG Contender barrels [2 of them] in 7-30Waters. Loading between 35 and 36 gr 748 behind 120NBT or 130SSPB. Using both formed 30-30 brass and federal factory brass after shooting the factory load.

1st time we reloaded with this same die set [RCBS], shell holder, bullets, cases and same barrels...no problem. Cases loaded fine...accuracy outstanding...no problems.

Ever since...problem. Loads will not chamber without shaving some brass off of the lower part of the neck [closest to the shoulder until half way up].

Cases chamber fine after resizing. Don't chamber with a bullet seated.

Bullets are not hitting the rifling. I actually chucked a few in a drill press and sanded off a few thou from the outside of the neck and they would then load and fire. Brass so thin I had to throw it away after firing.

Number of reloads per case makes no difference. I can shoot a factory load, reload it immediately with it full length resized and is will not load.

Overall case length not an issue because 30-30 cases are much shorter than 7-30 and they have the same loading problems when we try them.

What is up here guys? These are the same cases, bullets, dies and guns as before?

I know the Virgin Valley chambers are probably on the tight side of SAAMI specs. Could it be that we are not bumping the shoulder back like we should? Same shell holder, same press, same set of dies???

Would appreciate any ideas as this is frustrating.

[Double D]

Can't realy tell whats going on without physically seeing the loads, but here are my two educated guesses.

Guess number one. Thick necks.

After firing but before sizing see if you can slide a bullet down the neck without resistance. If you can't and this is the first firing of the brass you need to inside neck ream.  After inside reaming then size your case and see it the problem still exist. If that solves the problem then each time you fire the brass try a bullet in the neck if it doesn't slide freely in the neck, first check your overall length, and trim as needed then outside neck turn followed by resizing. Only inside ream on the first firing.

Guess number two Excessive crimp.  

When you are seating the bullets you are collapsing the shoulder and it is bulging slightly as the result of the neck being pushed down by the crimp ring of the die.  The bulge can be at the junction of the shoulder and neck or the shoulder and body, or a little of each.

Try this,  back your seating die out two or three turns,  Then screw your seating stem only down to seat a bullet to the proper depth.  Try that round in the chamber.  

Another cause can be brass that has had the neck turned or reamed at the wrong stage.  Necks that are reamed after sizing will be to thin and seating the bullet can cause the neck to buckle.  Reaming and turning should take place after fire forming and before sizing.  Brass formed from 30-30 may need to be fire formed with Cream of wheat first instead of a bullet and then reamed.

As far as crimping goes you realy don't need it in a Contender.

That's my guesses and they are as good anyone else who haven't looked at  your loads.

[skb2706]

You may want to call VVCG and ask them what the neck area of the chamber measures when they cut a 7-30 chamber. Take a ball  mike and measure the neck thickness in a couple places x2 plus the diameter of the bullet- .284 and make sure you have at least .002" 'release'. My guess is uneven neck wall thickness from one side to the other...............
If you don't bump the shoulder back enough you will have trouble closing the gun and getting the locking lugs to set.

[KYODE]

the very best thing you can do......is email this post, or the same question to jeff stratton at virgin valley. i've dealt with jeff, and he is a great guy. he might be able to help you out.

like you say the chamber is cut really tight(which is good).....but maybe the dies are not sizing sufficiently to fit back in that tight chamber after one firing. :?

the neck would be a possibility. take a sized case....... carefully cut the neck completely off the case. see if it chambers ok then. if so, maybe you can look there.

take a black marker, color the case......see exactly where it's rubbing.

do these things....the contact jeff stratton at vvcg.

[BruceP]

I would have to start with the two things mentioned by Double D. Either the necks are thick or if you are crimping then you are crimping too much. I dont think it is a die problem because you say the case will chamberafter sizing with out a bullet. If you are crimping try seating a bullet with no crimp at all and see if it will chamber. Also measure the OD of the neck just in front of the shoulder after sizing but before seating the bullet and then again after seating the bullet but with no crimp. I use no crimp at all for my bottlenecked cases but if the round will chamber with no crimp and you feel you have to crimp then the measurements taken will allow you to crimp a little at a time and measure after each change in crimp so you will be able to tell at what point your case starts to bulge.
BruceP

[Gavinator]

Howdy, I think you've experienced "brass flowing forward" causing thickening of the neck, in this case. 35.5gr of 748 is a max load with a 120gr and the 130gr in a standard chamber, in a tight chamber the pressure and velocity will be higher. Remington 30-30 brass seems to work best in most wildcatting I've done, I'll bet because it has a greater case volume (which lowers pressure) which should help. Clean out the chamber and make a cast with BROWNELL'S Cerrosafe, compare the neck diameters. .002" is a difference so small that the brass will spring back enough to hold a bullet without re-sizing, it's an absolute minimum, most have a clearance of .005" to .009". Unless you specified a match chamber those are the clearances you should have. If it does turn out you have a close tolerance neck, look how accurate they are, my Forster is still set to OD neck turn 30-30 brass, I'll make you a deal.

[KYODE]

i wouldn't think that brass would thicken the neck in 1-2 firings, but i'm just thinkin :? . it's possible that with hot loads in a tight chamber, the brass has lengthened enough from base to shoulder(stretched) to need the shoulder bumped back with the full length sizer. there are a few possibilities, i reckon, but i'd call n talk with jeff stratton. he'll know more about their barrel without having to take too many measurements.

[rimfire]

Just got home and read the replies.  

We are not crimping.  Case fits in the chamber without a bullet but with the neck intact, after resizing, fine.  Add the bullet and it will not fit.

I was hoping that another idea might work that I found on another post unrelated to this problem.

I was wondering if the shell holder was too thick such that it would not allow the sizer die to get all the way down on the case, maybe it was not completely sized.  It will chamber then without a bullet, but when the bullet is seated added to the shoulder maybe being a little too far forward this just oversized the neck.  If I bumped the shoulder back just slightly it, since the neck tapers towards down towards the tip of the case, this would move the largest diameter farther back in the like tapered chamber neck and maybe allow it to chamber.

Bought both barrels new from Virgin Valley about 6 months apart.  Both with no special chamber requested; i.e. it was supposed to be VVCG's standard chamber.

Still struggle with the fact that the first time we reloaded once fired factory brass [bought box of factory loads, fired, then loaded] they chambered fine.  We now load once fired factory brass [same deal] and they don't chamber.  Still driving me nuts and we think we are setting it up the same way on the press.

[Double D]

Changing the  thickness of the shell holder  is used to control head space and the distance for the datum line.  If that was the problem you would see it when you resized. You problem comes when you add the bullet...The consensus from the responses from two posts that you made is tight necks.

Tight neck chambers really have no place in a Contender due to the limited leverage it has to seat a round in the chamber when closed.  

After you try some of the suggestions that we have posted and they don't work, then let us know.   Humor us an back the sizing die out a turn or two and see what happens.

Also make sure your index your rounds going in the chamber.

[**oneshot**]

I was having a problem with my 308win.  I full sized the cases and verified trim and still would get a few that would not chamber after 1 cycle of shooting and reloading.  I also had a few that seperated after two reloads.   I was using an RCBS die and RCBS press.  I am not nocking the dies or the press, we have used them for many many years without problem.  I went out and bought a Lee collet (neck sizing ) die set and press.    :-D Not one case problem or chambering problem and I'm on my 5th reload cycle.   I initially thought it was a pressure problem and it still may have been since I'm only neck sizing there is a little more space in the case.

[KYODE]

oneshot, possibly, if you had case separation after 2 loadings, you were sizing the case too much......pushing the shoulder back to far, and creating a case with too short of headspace. then when fired, the case stretched beyond it's capability, and separated.
in these single shots, when headspace is right, i've stopped seeing flat primers. if sized a tad too much, the primer will back out upon firing....the case will then stretch as pressure builds, and slam the breech face, flattening the primer.

[cbagman]

:eek: Howdy.. I'm surprised about your troubles. Both my 7-30 barrels have been great. The Custom Shop Carbine barrel has a little bigger chamber than the Bullberry 14 inch barrel. I had to change to RCBS dies instead of Redding ones to get the base sized down enough to chamber in both barrels, as the Bullberry barrel has a tighter base deminsion. Start with the sizing die barely touching the shell holder and seat with minimal crimp..I did notice chambering troubles with the 130 Grain Single Shot bullet because it is fatter than others and hit the rifling when set to the same OAL as the other bullets with less Ogive..So far this worked for me in mine..I don't have any barrels with super tight necks...cbagman

[inzalu]

I am the person doing the reloading and having problems with some of the cases.  I have reloaded for 25 years and not had this problem before.  The case necks are scored just above the shoulder on the cases that are tight.  When measured they a only about a thousands off those that do not stick. I have to play with it a little and will try some of the suggestions mentioned.  I may also purchase a neck sizing die and try another brand of die.  I am using RCBS and have for years.  I did check the bullet in a fired case and it slides in freely.  I also inspect the brass thoroughly and trim accordingly.  I may purchase a outside neck trimer.  Has anyone had luck with them.  I have not had to use them in the past.

  I think the chambers are machined very close and thats fine by me. By the way, the loads are producing sub 1 inch groups consistently with my last going under 1/2 inch.  This barrel shoots more accurate than any barrel I have owned. It has also taken two whitetails.

[Steve P]

You have experienced the "dreaded donut".   :eek:
Sizing of the 30-30 brass to 7mm left you with a thick spot in the neck right at the shoulder.

Pull out your neck turner and turn the neck down.  Put the brass on a .284 pilot and run cutter and you will find the donut at the apex of the shoulder/neck.  

The donut is more prominent if you use heavier bullets as the bullet seats down further in the neck.  If you load a 120 or 140 boattail and seat them so the base of the bullet is even with the base of the neck, lots of time you wont even realize this little section of thicker neck is there as the boattail area does not push it out like a flat base or heavier/longer bullet will.

One of the few donuts you will live to hate.

Good shooting,

Steve  

[inzalu]

I am not using 30-30 reformed brass, but I think you are right about the neck and will try the neck trimmer.  i have buy one first.  Anyone have they want to get rid of before I go buy?  Let me know. We will see how this works.  thanks.