Bolt opening resistance

[bsekf]

I am working up loads for 22-250 AI. Bolt closes with no or very slight resistance on the down stroke, fire the gun, no resistance on the up stroke, but the bolt does not pull pack easily. My first impression is that it is pressure and I am at max load, however the load is a mid standard 22-250 load and there are no other pressure signs, flowing or pierced primers. Could it be anything but pressure? I am going to FL resize this time, I have been using a collet die.

Bill

 

[GSRswapandslow]

same thing is happening with my 223ai....not fireforming loads, not way above max or anything. I have shot up to 72,000psi with no issues after bumping the shoulder, but can shoot a 50,000psi weak load and have it not extract, if I don't bump the shoulder.

 

[jonbearman]

What I found with my 22-250ai was the neck needed turning a few thou and extraction was easy after that.Make a chamber cast or call the gunsmith and ask what reamer specs he used.Is it a no turn or tight neck.

 

[Ackman]

If your chamber is very minimal, check the fired case for any kind of scrape marks. Brass dimensions vary from headstamp to headstamp. My own chambers are snug and and spec'd to the brass. Lapua brass for example won't fit either the 22-250AI or 243AI. And in one of those, PMC will chamber but extracts hard.

 

[LCazador]

If the brass is "sticking to the chamber" it's probably about chamber size vs. brass size, and the brass has stretched beyond the size of the chamber. You mentioned full length sizing next time, check the amount of shoulder set back with a headspace guage. You should seat your bullets into the lands for proper fireforming. This seating into the lands holds the case against the bolt face for reduced stretching IMHO. You should also note the maximum case length of your chamber. Of course knowing your chamber neck diameter is also important as mentioned before.

 

[artbosco]

F/L size ALL the time and Half Measure problems [associated with just neck sizing] go away.

 

[Erik Cortina]

F/L size ALL the time and Half Measure problems [associated with just neck sizing] go away.

With all the posts about problems with neck sizing you would think people would have caught on by now that F/L sizing eliminates most issues associated with chambering and extracting rounds.

 

[tenring]

The lower part of your cases have stretched creating a tight withdrawal. You need to set your F/L sizer so that it is tighter against the shell holder. Turn the die down a little more (about 1/8th turn) so that it "cams over", and problem will end.

 

[Erik Cortina]

The lower part of your cases have stretched creating a tight withdrawal. You need to set your F/L sizer so that it is tighter against the shell holder. Turn the die down a little more (about 1/8th turn) so that it "cams over", and problem will end.

Not necessarily. He needs to set up F/L dies so that it bumps shoulder the minimum amount to provide proper chambering regardless of the die relation to the shell holder.

 

[Ackman]

I am working up loads for 22-250 AI. Bolt closes with no or very slight resistance on the down stroke, fire the gun, no resistance on the up stroke, but the bolt does not pull pack easily. My first impression is that it is pressure and I am at max load, however the load is a mid standard 22-250 load and there are no other pressure signs, flowing or pierced primers. Could it be anything but pressure? I am going to FL resize this time, I have been using a collet die.

Bill

I didn't catch if these are fireform loads, but what you say indicates that. If so, don't FL size new brass, it's irrelevant since the AI chamber is much larger and the case is gonna blow way out anyhow......... just run brass through the necksizer to make things round. And don't go near the neck/ shoulder junction. You want to feel definite pressure on the bolt when closing. Also your fireform load should be more than max for the std cartridge. The tight extraction.....look for marks on the case.

 

[mikecr]

Sounds like an action timing or extractor issue to me. If his bolt fully turns open, the case should be free to extract, whether it's popping loose or not.

 

[roninfl.]

Carbon build-up, give your chamber and throat a good cleaning. Is it possible you're load is too light?

 

[Alex Wheeler]

Sounds like an action timing or extractor issue to me. If his bolt fully turns open, the case should be free to extract, whether it's popping loose or not.

I agree, if the bolt is fully rotated the case should be extracted. Either theres not enough primary extraction (bolt handle timing) or there could be a chamber problem. With the AI chambers there can be very little case taper and if there is a groove in the chamber or too much polishing was done by the shoulder you will get this effect. If the handle opens 80% of the way and the last bit is difficult than its probably a case of the case not being sized properly or chamber issue.

 

[bigedp51]

bsekf

1. What make rifle do you have?

2. How many times have these cases been fired and only neck sized?

As stated above primary extraction is to occur during bolt lift, this should break the case free of the chamber. A neck sized case is repeatedly pounded to the dimensions of the chamber and and there is less and less brass spring back after firing. This causes the case to cling to the chamber walls until the case cools and becomes slightly smaller. Meaning if you wait 5 minutes and the case extracts with less effort its time to get a full length resizing die.

Then again someone with far more experance above also gave you some good advice.............full length resize.

 

[Lapua40X]

Sounds like an action timing or extractor issue to me. If his bolt fully turns open, the case should be free to extract, whether it's popping loose or not.

ditto .........

 

[bsekf]

Not fireforming loads, I am doing ladder tests.

I tried a fired case in the chamber and it stuck, just a little, so I ran all the cases through a 444 marlin die, trying to size the bottom or web area of case, no more sticking. I then ran my sorted cases through a FL die to bump the shoulder. I am ready to do some more testing. Don't think it could be light loads, there is no soot on the necks. Gunsmith told me the chamber was for a no turn neck. Sorted cases are on the 3-4 loading since annealing and FL sizing. They are ready to be annealed again.

If I have no problem at the next range visit, I will pretty well know it has something to do with sizing. If I get more sticking, I will measure the web before and after firing to see if I am getting springback.

If everything worked and all the bullets went in one hole.......it wouldn't be any fun

Bill

 

[artbosco]

F/L size ALL the time and Half Measure problems [associated with just neck sizing] go away.

With all the posts about problems with neck sizing you would think people would have caught on by now that F/L sizing eliminates most issues associated with chambering and extracting rounds.

I think most folks who have acquired dies other than a F/L die and a Seater can't come to grips with the reality that they purchased inappropriate tools and must justify the acquisition by continuing to use them ... regardless of the consequences.

Some keep asking: How can ONE die [a F/L die] be better than TWO [neck and body]?

The answer is that for the User, One sizing die is all that's needed. However, the Merchant would rather sell the reloader Two.

Never ask a Barber if you need a haircut.

 

[mikecr]

And I think f/l sizers lack understanding to do otherwise.. You are stuck while more of us than you think are not.
How bout that?

 

[jonbearman]

I don't know if you read my post but shoot one and see if a new bullet drops in the case neck with zero tension. Mine is a no turn but I still had to do a clean up on the necks.My bolt would rotate but not extract.So I found out the no turn neck wasn't so no turn to begin with.It isn't a timing issue.

 

[bsekf]

Thanks to all! I had 15 collet sized and primed cases and I didn't want to deprime and FL size them, just ran them into the 444 Marlin die to size the web area of the case. Went to the range with loads of 32.5 to 35.5 414/760 under a 69 grain Sierra. NO PROBLEMS Nice node 33.5 to 34.5, I am going to load some from 35.5 to 37 and see if I get sticky extraction and/or find another node. Then, I am going to FL resize and anneal after the next firing and then go back to the collet to see if the sticky extraction resurfaces.

Bill