22BR

[jde650]

I have a new 22BR barrel, the fired case neck measures 0.251 I don't resize the neck just punch out primer, recharge and seat bullet, neck measures 0.252 after seating.
Will this tight of neck cause high pressure upon firing or am I lucky that I don't have to resize.

Thanks,

Jim

 

[Eddie Harren]

Yes.

 

[jds holler]

It doesn't seem like there is much room for heat/expansion. It would be interesting to know what your actual chamber neck dimension is. jd

 

[snert]

Yes.

Yes to pressure, yes to lucky, yes to one or the other?

I'm thnking the math is pretty tight here and that is a tight neck chamber! I would be concerned about pressure.

 

[jde650]

I thought so, should I turn neck to 0.249.

Thanks for help,

Jim

 

[th82457]

I run .003- .004" clearance in my 22 BR and get excellent accuracy with no pressure worries. I think you should try for at least .002" clearance between a loaded round and you reamed neck size.

 

[snert]

A fitted neck will work just fine if it is planned for. In your situation it sounds more like something that just happened and I'd be more than a little leery of that. I'd pour some cerrosafe in there and find out what the neck diameter really is. (Quote, Berg)

Agreed. Cerrosafe is excellent and easy to use.

When you know the chamber measurement, then you need to measure your case neck thickness. USE A BALL MIC, not a caliper. Measure several places on several cases, take that average number and multiply x2 to get total thickness. Add in your bullet diameter. This should give you the average loaded case diameter at the neck. Then make sure that you have at 2 thou, prefer 3 thou clearance. if you don't, turn the necks down.

 

[snert]

BTW necks in the 22 calibers generally run up to .253 (standard for 222 for example) and may be as low as 250. I have a duece that was 250 and i had it opened (mistake on my part) to 253. Turned out all the brass I use would have worked in the 250 neck. Use the cerrosafe and do you brass measuring to know for sure. Anything else is subject o brass springback so don't count on that .251 measurement being a true indicator.

 

[Eddie Harren]

The last 2 blowups that were brought to my shop were from guys trying to use fitted necks. That theory lost favor a good while ago.

 

[snert]

The last 2 blowups that were brought to my shop were from guys trying to use fitted necks. That theory lost favor a good while ago.

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