Case length pickel

[spudgun]

Ok, now I don't quite know what to do now.

Savage Model 12, 6.5 CM

Trying to trim the cases down to 1.92". Some cases have grown to 1.93-1.94" and are hard to chamber.

My problem is that I have resized this brass using a RCBS SB die and also have primed them. They checked out great in my headspace/case gauge (drop in and fall out).

When I tried to chamber some of the empty resized brass I am getting a very hard bolt close, checked the length and yup, 1.93 or 1.94".

Now my issue is I can run the case trimming pilot down brass that was sized using a NON SB die but the ones that I used the SB die on will not allow the trimming pilot to enter the neck (inside dia too small).

Don't know if I can get a smaller pilot for my forester trimming tool.

Any suggestions?

 

[tflorman]

Isn't the recommended trim length 1.910 for 6.5 Creedmoor? 1.920 is max length and when your issue is hard bolt close, it's probably telling you that your chamber isn't perfect you might want to account for that by trimming a bit more instead of keeping things on the hairy edge.

As for the trimming... you can always use something like the worlds finest trimmer that indexes off the shoulder instead needing a pilot. Of course that adds additional expense to the equation... or you can use a different expander. Measure the difference between your regular die and your SB die and the pilot you're trying to use...I'm sure you'll see that is some variation between them and will have to account for it somehow to get your cases down to the proper length.

 

[mikecr]

Sounds like your SB die, and your sizing plan, is terrible..

 

[Murray Brook]

I believe I would first find out the length of my chamber so as to trim to a proper length. Sinclair sells some inexpensive plugs to determine this.

SINCLAIR INTERNATIONAL

SINCLAIR INTERNATIONAL https://www.brownells.com/brands/sinclair-international/

www.sinclairintl.com

 

[AccelR8]

I have a Lyman case trimmer. I have trimmed cases with no pilot at all. Not ideal, but the results were good.

 

[Bill Rodolph]

Call Forster, they should be able to help you.

 

[dellet]

Having cases that are .010-.020" longer than spec is a problem, having them right at spec, cam be interesting.

A chamber will generally have about .010" room for error, because a shoulder set back anything more than maximum length can push the neck into the step at the end of the neck area of chamber. So for a max length case to fit correctly, base to shoulder also has to be max length.

The problem you are having, or why it did not show up sooner, is because you are checking a sized case.

The neck diameter is smaller so instead of jamming at 1.931" or so, the smaller neck is not hitting the taper until 1.940".

The problem is that when you load a round that is say 1.928", the diameter will grow and you might be headspacing off the lip of the loaded round instead of the shoulder. That pinch can be a big pressure spike.

You need to make sure that your cases, with your shoulder setting, are not hitting the end of the chamber if you are going to run max overall length. A max length case with a maximum amount of headspace, shortest from base to shoulder, will often pinch the bullet in the chamber.

 

[spudgun]

Having cases that are .010-.020" longer than spec is a problem, having them right at spec, cam be interesting.

A chamber will generally have about .010" room for error, because a shoulder set back anything more than maximum length can push the neck into the step at the end of the neck area of chamber. So for a max length case to fit correctly, base to shoulder also has to be max length.

The problem you are having, or why it did not show up sooner, is because you are checking a sized case.

The neck diameter is smaller so instead of jamming at 1.931" or so, the smaller neck is not hitting the taper until 1.940".

The problem is that when you load a round that is say 1.928", the diameter will grow and you might be headspacing off the lip of the loaded round instead of the shoulder. That pinch can be a big pressure spike.

You need to make sure that your cases, with your shoulder setting, are not hitting the end of the chamber if you are going to run max overall length. A max length case with a maximum amount of headspace, shortest from base to shoulder, will often pinch the bullet in the chamber.

At this time I have not really looked into it. It showed up last night when I was on the 600 range. Out of 30 rounds I had 2 that were hard to close and I didn't force them I just brought them home and checked them out. Now I did resize and prime about 50 rounds over the weekend and I did try chambering just the empty cases. the ones that chambered real easy (like they should) were right on the 1.90-1.91". The ones that were hard to close were anything over 1.91" and of course the longer the worse it got.

This gun was purchased about 4 weeks ago because I want to shoot F class this year. It has a very tight chamber. The resized brass that I used a FL die on would not chamber. Took me about 1 day to figure out that the FL die was not sizing the last 3/8 inch of the web portion of the case. Those measured about .001 - .002" larger than specs. They chamber just fine in my light gun 6.5 CM, so I ordered a SB die and everything was great until after reloading the brass about 3 to 4 times then the sizing issues appeared.

My thought is my brass is growing in length due to the SB die. Back in the days of reloading .223 range brass I also needed to trim the brass down. Once I did the brass did not seem to grow back to the over length.

Got a friend that is chambering my barrels and I'l just have his make me a new pilot.

 

[PhilC]

As others indicated SAAMI MAX case length is 1.920", recommended trim length is 1.910" so any case you load that exceeds 1.910" can, and very likely will, cause problems.

I don't rely on manufacturer's adherence to SAAMI specs, instead, I use the Sinclair chamber plugs mentioned above to obtain the actual chamber length on every rifle I own. I then reduce that length by .010" (go .015" if you want an extra safety margin) and use that value as my trim length.

FWIW, chamber lengths on all my Savage rifles, including my 12FV in 6.5CM, are longer than SAAMI spec.

I use a Forster trimmer, have 6.5CM Forster dies, run mine pretty hot, and have no problems whatsoever.

 

[Dave M.]

Ok, now I don't quite know what to do now.

Savage Model 12, 6.5 CM

Trying to trim the cases down to 1.92". Some cases have grown to 1.93-1.94" and are hard to chamber.

My problem is that I have resized this brass using a RCBS SB die and also have primed them. They checked out great in my headspace/case gauge (drop in and fall out).

When I tried to chamber some of the empty resized brass I am getting a very hard bolt close, checked the length and yup, 1.93 or 1.94".

Now my issue is I can run the case trimming pilot down brass that was sized using a NON SB die but the ones that I used the SB die on will not allow the trimming pilot to enter the neck (inside dia too small).

Don't know if I can get a smaller pilot for my forester trimming tool.

Any suggestions?

Just get a WFT (worlds finest trimmer)

 

[spudgun]

Solved my problem with the pilot. I made one with the help of a drill press and a file.

Thanks for all the suggestions.

O yeah, did some looking into the case length. It seems that the Small Base die does increase the length of the case just about .001" after resizing.

Don't know how long it will keep doing it until it does not force the brass up. I will be checking the cases each time I reload them. Right now they are all trimmed at 1.910"