Case Length Reloading Question ??

[Fred McIntire]

I have a Thompson / Center Encore Pistol in 7mm-08 caliber. I am reloading 140 grain Nosler Ballistic Tips over 40 grains of Varget with a large rifle primer.

The maximum case length is supposed to be 2.035". Some of the cases are measuring up to 2.050" in length.

Is this going to create a hazardous pressure if they are not trimmed? Will there be a problem extracting the fired cases? I do not have a case trimmer as of yet; however, I can see that I really need to invest in one.

Also, how do I determine, or what is, the optimum overall cartridge length for this caliber. What do factory loads measure overall length?

Thanks for the info,

Fred

[skb2706]

Two answers w/one question..........
Do the unfired cases (the ones that are long) fit in the gun without doing anything to them ? My suggestion would be to lube them, size them check them in the gun.....if they fit load them up. As long as the brass will fit in the chamber with out jamming the case into the throat area you will not have pressure problems related to overall case length.
Once you determine that the cases will fit (assuming they will) then load them up with primer, bullet and powder of choice but just start the bullet in the neck. With a break action gun like an Encore you can incrementally seat the bullet until the action will close. At this point you can determine how far off lands you want the bullet to be and adjust your die once the gun will close. That or purchase a Stoney point.

[Iowegan]

Most rifle manufacturers cut the throat way deeper than SAAMI specs so the rifle will chamber ammo from any company. The real max length is chamber dependent and varies considerably from one gun to the next.

To optimize accuracy, the brass should be .005" short of bottoming out at the case mouth. You need the .005" space so the brass can "grow" when fired. Most reloaders trim their cases unnecessarily and sacrifice accuracy.  The shorter the brass has been trimmed, the more opportunity the bullet has to drift off center.

I did a lot of research on this topic to understand where the finer points of accuracy came from. As a result, I invented and now market a set of chamber gauges that can be seen at: http://www.cactustactical.com/reloading.html They take the guess work out of trim length (and bullet seating).

Shorter brass doesn't mean it won't work, it just won't be quite as accurate as optimum length brass. If you're happy with your groups, then brass trimming is not an issue. If you really want to get the best accuracy performance, then use optimum length brass.

[Graybeard]

NO!!! NO!!!!!  NO!!!!!!

DO NOT assume it is safe to fire a rifle with brass that is 0.015" too long. Unless you've made a chamber cast to KNOW not hope or assume it is OK then DO NOT DO IT.

It will chamber. Sure it will. BUT if even 0.001" or 0.002" of that case neck is being jammed past where the cut is made you can run pressures up by who knows how much. Easily 10,000 to 20,000 psi. Enough to blow the gun apart perhaps.

If you do not have the tools to trim cases you have no business reloading. Stop right now and wait until you buy the correct equipment.

[bgjohn]

Trimm with a file if you don't have a trimmer. Everyone has a file.
JM

[Reed1911]

Graybeard is absoloutly correct!
 DO NOT load full loads into long cases. If you size the case and the gun will chamber on the brass, that is by no means any indication of the chamber dimensions. If your brass is longer than the Maximum length set by SAMMI, trim to the recommended trim length.

A file will work in a pinch, but it is very easy to file the mouth off square or to file too much. Lee has some very inepensive tools to trim your cases, ITEM # 798-410 from MidwayUSA with a cost of only $3.59.
Or better yet any of the assorted trimmers out there. They all work about the same, some are eaiser than others some cost more etc, etc.

[Catfish]

The only way to really know what your max. case lenth is is to have a chamber case made and measure it. If it`s factory your probibly safe, but if you happen to have one of the 1 in 1000 you could get in trouble in a hurry. If you don`t mind going to the trouble of getting a chamber cast and want all the accuracy you can get go for it. But if you have a factory gun and don`t think it would be worth the trouble and expence, trim the brass.

[Badnews Bob]

The Lee trimmers work very well and with a cordless screwdriver you can power them works well for me and very economical taboot.

[Fred McIntire]

Thanks to everyone for the input! The operation has been put on hold until the case trimmer comes in.

Fred

[leverfan]

Fred-

If you haven't begun to already, you might want to start collecting books on reloading from all the major component suppliers (Lyman, Nosler, Hornady, Speer, Sierra, etc.).  Before I ever dumped powder into a case, I read the instructions in two or three different loading manuals.  I buy new manuals whenever they get updated, so I have an entire set of book shelves full of nothing but reloading manuals that date back decades.  Even now, I read the opening pages of each new book I buy, just to remind myself of things I've forgotten, and to see if any new information is out there.

There will also be a section that details cartridge dimensions, and trim-to lengths.  The theoretical advantages of longer cases, as far as accuracy goes, will almost certainly be too small in your gun to justify the risks involved.  Besides the safety factor, an over-length case can be far worse for accuracy than a trimmed case.  The most important factor is uniformity, with all cases being the same safe length, and all of the necks having neat, evenly trimmed and de-burred mouths.