Hard Bolt Close Rem 700 17 Fireball

[Cdv717]

I have a 700 sps 17 fireball. Would like some suggestions as to where to go from here. I have a very tight bolt close with the shoulder bumped .002. I have put sharpie on the entire case and can see no rubbing anywhere except for the case head stamp. It seems to be rubbing there way to much like the case is to long. So i trimmed the neck way back to make sure it wasnt the neck bottoming out in the chamber. I stripped my bolt and used my wilson case gauge and micrometer top to see where i needed to be to get the bolt to close properly. I have to bump the shoulder back .0085 before the bolt will close like it should. I have now tried 2 different brands of fl dies and both have the identical problem. Would like some suggestions on where to start. A friend of mine suggested a small base die but that doesnt seem to be the issue cuz there was no wear on the sharpie mark at all and it is sizing the base to within .002 of a factory unfired piece of brass. After i sharpied a few cases and seen no rubbing i decided to sharpie the stamped case head and that is where i feel the rubbing is occuring. Thanks in advance for any help

 

[jepp2]

When you fire new brass, that the bolt closes easily on, what is the bolt lift like after firing?

From your picture and the amount of brass scrubbed on to the bolt face from the case head, you have "something" restricting the brass from chambering properly. And with 0.0085" shoulder setback and the bolt closing properly, it would seem to be case head to datum.

 

[243winxb]

How was the necks expanded? Standard type dies, with expander? Or a mandrel type expander in a separate step?

As said, seems the head to datum is to long. Most factory dies, on a single stage press, will only set the shoulder back about .005" when making contact with the shell holder. Unless the chamber is on the larger side.

 

[Cdv717]

The bolt lift after firing new brass does not open hard until after its been fired 2 times then im back to the hard bolt close and open when bumping the shoulder .002

 

[Cdv717]

Im using a standard rcbs full length sizer that i polished the expander ball on it. The second full length die is a hornady that guves me the same results. Im using a forster coax press so i have no shell holder and i can definitely bump the shoulder back .0085. Im using the wilson case gauge and micrometer top to do the measuring, same equipment i use to load for several other rifles with no issues , thats why im lost as to whats going on

 

[243winxb]

New brass may take 3 or more firings to fully expand to the chamber size. This gives a false fired brass measurement when using a comparitor.

 

[Cdv717]

I use imperial dry neck lube on the necks before they enter the die, there is no feeling of great resistance when i bring the expander ball back thru the neck so i dont feel im pulling the shoulder back up or anything

 

[Cdv717]

The brass im using has been fired 5 times and we just annealed it, but this problem has been consistent ever since the 3rd firing of it and some even after 2 firings

 

[243winxb]

I size till the brass fits the chamber, not a gauge. Sorry, not much help.

 

[Cdv717]

I feel like to get it to chamber correctly that im working the brass to much and may have exessive headspace as well

 

[Cdv717]

Dont know how it needs bumped .0085 to close nice, then fire it and its really long again, this 17fb brass is not easy to come by and i want it to last as long as it can

 

[Hotshot]

Maybe a chamber cast could help you solve the mystery.

 

[jepp2]

Would like some suggestions as to where to go from here.

I'm a big believer in Newton's Third Law: https://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law

For as much brass transfer as you are getting on the bolt face, you should be able to identify what is causing it. Maybe try the old trick of blackening the case with soot from a candle to find out where the case is contacting. It should be more sensitive than the Sharpie marking was. Since you shortened the neck, it has to be either case taper or case head to datum length.

 

[Cdv717]

My wilson case gauge is measuring case head to datum length corect??? I will try the candle method tonight but seen no signs of the case taper being rubbed with the sharpie only the headstamp and it gets rubbed off almost completely as seen in the photo

 

[BoydAllen]

Usually measuring the diameter of a fire formed case in two places, before and after sizing will tell you what you want to know. Tell us how much sizing you are getting at the shoulder and .200 up from the head. You can also measure up a little higher too. If your case is not hitting at the end of the neck or on the face of the shoulder, then the body diameters are the only place where it can be. Another place that is unlikely would be if the bolt face was severely out of square with the chamber. This would show up by cases and the bolt face having rub marks on one side. This is less common as a cause of a tight bolt lift. I rely more on diameter measurements than I do putting marker on a case.

 

[Cdv717]

I will go thru all the diameter measurements tonight and keep you posted. I have measued my unfired brass at .200 up from the head. It is .004 smaller than my fired brass. After i bump the shoulder .002 then that measurement is only .002 larger than my unfired brass. I will try the candle method but it doesnt make a mark with sharpie on the case at all. Also i will measure .200 above the head on the rounds that i bumped the shoulder .0085 to get them to chamber nice. We will see what i get

 

[Cdv717]

I do see from my photo that it definitely rubs the case head more on one side than it does on the other hope that isnt out of square to much

 

[Pablo]

Looks like you need a custom sizing die. There are large differences in SAMMI chambers even among the same manufacturers. With most sizing dies a guy can get the brass reduced at the shoulder and base enough to get the rifle to cycle well because most chambers are sloppy. Sounds like you have a tight chamber, perhaps Whidden can make a die for you.

 

[boltfluter]

I have run into this several times over the years. I would lay money you need a small base die. One way to find out. Sacrifice a case by systematically cuttingit up. As in cut off the neck and see how it chambers. Cut off the shoulder and test. Etc.... You will find the problem this way. Once the shoulder is gone you can size the body more and more. This will leave no doubt as to where the problem lies. Has never failed me yet! Good luck!

Paul

 

[cw308]

What powder , load , bullet and are you jamming . What barrel , stock or match grade .