head space, bolt problem, and a "shoulder bump"?

[cloverleaf]

If you've been browsing the hunting forum you know that I have been looking forward to an antelope hunt in wyoming. (More on that later). In preparation I wanted to do some reloading, (actually Dad does it fior me- he has been for years) but we ran into a problem I dont have an answer for. I shoot a 250-3000 Savage. I sat down to load up a few prior to leaving for my trip. The cases I wanted to use were on there 3-4 reload. I full length re-siized, and loaded up some 100 Gr. BT's. I had a difficult time getting the bolt to close so I trimmed the rest of the casses to factory specs, sized the case and loaded another. It still chambered to hard. Fortunately I had 20 rds of factory brass which I loaded up and they chambered just fine.

While I was out hunting, one of my guides who is a an ex-benchrest shooter mentioned somthing he refered to as a "shoulder bump". Basically what he described is the following:
After knocking out the primer, I put the case back in the shell holder with .003 shim stock between the base of the case and the shell holder, effectively pushing the shoulder back. Viola! my cases chambered just fine.

Whats going on here? I have had the rifle headspaced with a 22-250 go/no go guage by a gunsmith. He descrided this as appropriate since the 250 savage as the parent case of the 22-250. This "shoulder bump" seems hard on brass and encourages a lot of expansion and contraction. Incidentally, the once fired brass has the same problem. There is some transfer of brass to a small portion of the bolt face so I am thinking of having the bolt face trued. (This is an old FN 300 Mauser action) A .001 or two off the area that has brass transfer may eliminate that problem until cases are once fired in the "trued bolt" but then it seems to me I'm back to the same problem.

Additionally, I did not have this problem to the same extent before I had the rifle reblued. They didnt clean the bore of chamber after the job so I have had to work on that extensively. I have used a chmber brush on the thing but I really cant see how the shoulder area is. I suppose this could account for some change in chamber dimensions if I couldnt get all the crud out, but I think I have done that. Any way, as I said the problem was there before, it just seems worse now. Maybe I'm imagining things.

I know Ive asked a lot of questions here and posed several intertwined possibilities but I am at wits end. I have had the rifle to two different smiths and at least one of them had the guts to say he didnt know enough about Mausers to work on them. I really dont want to part with the rifle since it just "poked" a potential record book Antelope, but if I cant reload a 250 Savage aint worth much. What do you think? CL

 

[Powerstroke]

I just went through the same scenario with my .300RUM
Which dies are you using? I have a almost four year old son that loves tools and turning things etc. After about the fourth to fifth reload on these, they wouldn't chamber. ( bolt would not push far enough foreward to close ) I pulled the die down....cleaned etc, but mostly noted the lock ring to be loose. After re-setting the die, all has been well.

The new brass that you mentioned using.......?? You didn't size it before loading and chambering did you??

 

[cloverleaf]

RCBS dies in an old Herters reloader. I asked Dad about the possibility of the die moving and he said it could not, since when sizing the ram goes all the way up it is against the bottom of the die. I did size the new brass when I seated the bullets. (ran the full stroke) The dies seemed tight to me but I hear what your saying.... I dont know.

 

[Guest]

There's nothing wrong with your dies, nor is there anything wrong with your brass. The problem lies in your gunsmith's well-intentioned, but slightly misinformed blunder in setting your headspace. Looking over cartridge diagrams, I find the shoulder of your 250Sav to be markedly different from your gunsmith's 22-250 go/no go guages. Take a look at the following two diagrams, from Accurate Powder's diagrams:

http://www.accuratepowder.com/data/PerC ... data(Rifle)/257cal(6.55mm)/250%203000%20Savage%20pages%20213%20and%20214.pdf

http://www.accuratepowder.com/data/PerC ... data(Rifle)/22Cal(5.56mm)/22%20250%20Rem%20pages%20197%20to%20199.pdf

Notice that the 250Sav has a shoulder length of 1.512" to the first bend, and a shoulder angle of 26 degrees 30 minutes, with a measurement to the base of the neck of 1.638" (from the casehead), giving a neck length of .275" and an overall case length of 1.912".

In comparison, the 22-250 has a shoulder length of 1.514" to the first bend, and a shoulder angle of 28 degrees, with a measurement to the base of the neck of 1.664" (from the casehead), giving a neck length of .249" with the same overall case length of 1.912".

Now, if you had the rifle checked with the wrong headspace guage, that means it is way long for 250Sav. If that gunsmith had it disassembled at any time during the re-bluing and such, then you run into a liability issue. What you need to do is explain this to your gunsmith, and have him re-set your headspace, using the correct guages, which he will no doubt have to order (because he was too cheap to order them in the first place, so he used what he had), at no charge IF the mistake was his in the first place. If it was his mistake, he shouldn't give you any crap, but if he does, explain to him the dangers of shooting the rifle this way, and how that opens him up to negligence lawsuits galore, with an easy path to victory for your lawyer.

Again, if it was his mistake, he should also buy you some new brass, because all the brass shot in this rifle in it's current configuration is in danger of casehead separation due to the abnormal stretching of the case during firing. You must throw this brass away and get new. I would make him pay for it (again, if he disassembled the gun for any reason and then re-set the headspace with the wrong guages). I hope you aren't related to this guy.

 

[rick smith]

Shoulder bump is refering to moving the shoulder back a known amount to create enough headspace to allow the bolt to be closed. Multible firings with just neck sizing will allow the body and shoulder to grow so that the case will no longer fit in the chamber. Stoney point makes a tool for measuring to the datum line on the shoulder. Your die can be set to bump the shoulder back 0.001-0.002" and allow easy chambering. Will not damage the case.Rick.

 

[yeayow]

some length's according to Forster
Caliber 22-250 Remington
Length GO 1.574”

Length NO GO 1.579”

Length FIELD 1.583”

250 Savage
Length GO 1.579”

Length NO GO 1.583”

Length FIELD 1.587”
as you can see they are not the same headspace gauges and i would be angry at my smith. Although i do see how a mistake could be made unless you knew the history of how the 22-250 became a saami cartridge

 

[cloverleaf]

Thanks for the replies!! I dont know that I got any good news....but thats O.K. The rifle was not disassembled for bluing but the headspace may have been a little short right from the start. Now the bolt face has been "trued" just enough to remove the brass build-up along the top. I may be too late to save it....

In any event, I got two great memories from that rifle....a perfect cloverleaf (3 three shots touching at 100 yds) and the beautiful antelope posted on the hunting forum. Thanks again, CL

 

[Guest]

I re-read your first post, and mine. While I still believe there are headspace issues with this rifle, it doesn't make sense that the cartridges wouldn't chamber after full length sizing, according to the diagrams I have looked at. I read the gauge length information posted by yeayow, and it seems counter to what the specs are in numerous load manuals. But I verified his informatoin on the Forster website, he is correct. Now, that said, there should technically be no reason that a case that is full length resized to 250Savage SAAMI specs should not chamber in a chamber fitted to the SAAMI specs for the 22-250, other than that little tidbit of information from Forster (compliments of yeayow). So more information is needed. I have poured over your posts, and it appears that this gun, a Mauser, was always a little trouble, but now it is impossible to chamber a round, right? What you then have to have is a tight chamber, which doesn't make good sense because you say factory brass works fine in the gun. So now, we are down to two fixes. First, I would have the headspace checked with the proper gauges, just to say you know for sure. Second, I would consider the possibility that your dies are worn out. Or perhaps it is a combination of the two. I have never personally worn out a set of dies, but I am sure you can do it. And probably faster using a gun that is out of spec, as well. I suspect you have multiple problems.

The good news is that it doesn't mean the gun is, pardon the pun, shot. Just consider having it rebarreled, or having the barrel rechambered, or even just removed and shortened a smidge, and re-installed with proper headspace. It would be cheap and easy to do the last option, but find a 'smith with the proper gauges first. Rechambering would be easy as well, involve the same exact process, except that the chamber would be reamed while the barrel was off the action, and then everything properly joined back together. Any way you cut it, it is still a good rifle, just in need of a little refurb. Likely get it all done with either of the solutions that keep your own barrel for less than the cost of the cheapest new rifle you could buy. You could get it rebarreled for around $300 or less, depending on the going rate in your area. I suspect to have it removed and reinstalled would run about $125-175, but my figures may be off a bit for your area.

 

[steve4102]

It is possible that your dies are not set quite deep enough. Here is a copy of "How to Partial Full Length Resize". Read number 6 and the "Note" following. It is possible to push the shoulder "Forward" with a full length die.

2. Screw the Full Length(FL) Die into the press so it is about a "nickle's thickness" above the Shell Holder
.
3. Lube a "Fired" case (walls and inside the neck) and squash it.

4. Remove the Lube and try closing the bolt on it in the chamber.

5. If the bolt closes with no resistance, screw the FL Die into the press about 1/8-1/4 turn and repeat steps 3 & 4.

6. As you feel the resistance begin, slow down how much you screw the FL Die into the press so you are at about 1/16 of a turn, or "Fine Tuning". At some point you will not be able to close the bolt and you are extremely close to having the FL Die in the proper position.
NOTE: The reason for this is because the FL Die has begun Resizing the Case-walls down to the Pressure Ring. As it does so, the Case-body lengthens slightly which in turn moves the Case-shoulder slightly forward. Then as the "Fine Tuning" continues the Case-shoulder makes contact with the FL Die and is moved slightly reward(or slightly shortens the Case-head to Case-shoulder dimension).

7. Stop when there is a slight bit of resistance when closing the bolt on the empty case. You now have a "slight crush fit" for the case in that specific chamber, or Zero Headspace

 

[rick smith]

If factory brass fits, your dies are not adjusted correctly. Measuring to the datum line on the shoulder of a fired case and a sized case should tell you what needs to be done.Rick.

 

[yeayow]

if you are full length sizing to saami minimum spec's to the datum line for a 250-3000 it is the maximum for the datum line on a 22-250. Assumming your smith didn't chamber the gun to the no-go length of the 22-250 gauge which i don't think he would your shoulder on the 250-3000 is going to be too long for your chamber.

 

[X ring 7mag]

here's a somewhat simpler cure...if it applies. not long ago, i had the same problem from a m70 in 30-06. i had several explanations...none of which panned out, but in the end, it appears to have been my fault. while sizing this brass, i used the same lube technique as i use the rest of the time, only in this set of dies (lee) it seems to have required a little more attention. i normally just lightly lube each outer case, then with a Q tip, i hit the inside of the neck...reapplying lube to the Q tip every 4 or five cases. long story short, i think the expander ball was actually gripping the neck and stretching the shoulder. sounds far fetched, but from there on out, i scrubbed with a neck brush extensively, and relubed on each case and this problem never happened again. just a thought, you may take a look.

 

[cloverleaf]

x-ring (this wouldnt be the same x-ring that used to hang out on the Marlin forum would it?) If so, as you can see I'm still chasing this issue around with my 250 Sav. Thanks for the idea. Hadnt thought of that either. CL

 

[rick smith]

If you will polish the expander to a mirror finish, you will be surprised how easy it will work. Better yet, get a bushing die and do away with the expander ball.Rick.

 

[steve4102]

Just screw the Die in until the darn thing chambers!

 

[SOTN]

Steve4102 said it.

"Just screw the die in until the darn thing chambers".

Just because you initially adjust your sizing die to where the shell holder contacts the bottom of the die at full stroke, doesn't mean that the case is pushed all the way into the die, and fully sized.

Sometimes, depending on flex in your loading press, it just does't happen, and you've got to "overadjust", or screw the die in a little further. If that doesn't work, your die is not a good match for your chamber, or vise, versa. There are remedies for that situation, but no point in going into them at this point.
Smitty of the North

 

[Seedsntrees]

I had a FORSTER die that I returned to have .300 trimmed and a shell holder refaced in order to close a bolt on a new TIKKA. The chamber was a very short chamber. Works fine now.

Just my 2 cents.

 

[yeayow]

the problem with screwing the die in is it will only go so far as it is a fixed size once it hits the shell holder. the only way to set the shoulder back further is to file the top of the shell holder off to set the case deeper into the die

 

[Ol` Joe]

the problem with screwing the die in is it will only go so far as it is a fixed size once it hits the shell holder. the only way to set the shoulder back further is to file the top of the shell holder off to set the case deeper into the die

Adding 1/8 or so more turn to your die after screwing it down to contact with the shellholder with ram at top-dead-center will make up for the spring in the press and allow the case to go farther into the die. Try screwing the die down until touching and check the die/shellholder contact when sizeing a case. You`ll see a slight gap between them. Add 1/8 turn more depth to the die and the gap will disapear. RCBS, in there instructions, request you use this method when ajusting their FL dies to resize. I have found often seating the sizer to just touch the shellholder with a case from a fairly tight chambered rifle won`t allow the die to contact the shoulder of the case. Further sizeing is sometimes required to set the shoulder back enough to get smooth chambering with out bolt resistance.
http://www.rcbs.com/downloads/instructi ... ctions.pdf

 

[cloverleaf]

Got a call from Dad a little while ago- About 1/6 a turn of the Die and the cases re-sized just fine. Dies were set w/o a case in them. Perhaps having a case in, put just enough tension on the reloader to take up some slack and thereby not re-sizing the case far enough. A change of extractors also helped hold the case a little tighter to the bolt. Thanks to all who replied. I forwaded your thoughts to Dad and he took it from there. 38 Grains of 4350 under 100 grain BT's should set evrything right! Thanks again!! CL