Trim Length

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Quickdraw
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Trim Length

Post by Quickdraw »

I have just aquired some new brass for my 45-110. It is for the 45-120 but I can trim it for the 45-110. Can you tell me the length to trim it? I am going to be shooting paper patch bullets.
Kirk
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Post by Kirk »

2.875"
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Hornman120
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Post by Hornman120 »

While we are on this topic.

For my Shiloh 45-70 (vintage 2006). What is proper trim-to length for it? I know that most loading manuals designate 2.095 but Kirk may have found a different length that works with Shiloh rifles. I assume the 2.095 length is based on tolerances that apply to ALL 45-70 rifles. I know that Shilohs are made with much better precision. :)

Thanks,

Kevin
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Kirk
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Post by Kirk »

I use to short trim a little and have since found to trim it to the exact length which is 2.1". I like to have the case mouth touching where the 45 degree angle starts into the lead area. You have heard Kelly Roos mention neck tension several times, if you keep this at .002" or below and have your brass trimmed perfect you will find yourself not having to trim much at all or ever. If you leave it short and the bullet is a little tight it will stretch out to that angle every shot especially if you accidently over anneal, it will sometimes pull the brass right up into the lead of the rifling, been there done that. This is only my opinion on trimming.

Kirk,
Headhunter

Post by Headhunter »

SHOOO WEEE! I sure am glad you said that Kirk. I trim mine to 2.100 also. I wasn't about to be the first ones to post 2.100 inches.

Thanks! Now I don't feel bad.

Headhunter
Quickdraw
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Post by Quickdraw »

Thanks guys. I appreciate the help. I am going deer hunting out west for the next week but as soon as I get back my attention is getting some loads together to try out my new Quigley 45-110. Can't hardly wait.
Dakota Dick
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Post by Dakota Dick »

FWIW...

As Kirk noted, I also trim my cases to chamber length.

I got some Norma 45 Basic for my 45-110, Full Length resized one, Expanded for bullet seating and trimmed it back a couple thousands over chamber spec and then trimmed it back one thousandth at a time until I got it it fit the chamber exactly when action was closed. Then I used this dimension to trim the rest of the cases after Full Length resizing.

Accuracy improved and leading disappeared!

So I did it for my 38-55 using some "Ballard" 2.125" length brass and did it for my 45-70 using some 45-90 Brass. In all cases, leading all but disappeared and accuracy improved measurably with same loads I had been using.
Now I plan to do the same with my 45-90 using some 45-100 brass when I can find a deal on them.
Once I have determined the exact chamber length, IN ALL CASES, I Full Length resize and then trim to exact chamber dimensions. Then I expand and flare for bullet seating (this results in the case length shortening by .002 to .003. Then I use a taper die to remove the case mouth flair...just enough to allow the cartridge to seat clean and smooth.
After finding the right powder/compression/ bullet combo, trimming to exact chamber length has done more for me in accuracy improvement and leading elimination than any other thing I tried including primers and different alloy mixes.
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Post by ole pizen slinger »

Kirk,
I have a Shiloh 45-70, a Remington RB 40-65, and a Browning Hi-wall 45-90. I have tried to measure the length of the chamber in the following way. I take a case that is too long. For instance, for the 45-70 and 45-90 I use a 45-100 or 45-110 case. I expapnd the mouth so it will catch on the shoulder at the end of the chamber. I put the case in the chamber until I feel the case hit the shoulder. I then take an exacto knife and scribe a line on the case at the end of the barrel--where the head of the case ends. I measure the length between the end of the case and the line scribed on the case. I come up with the following measurements:

Shiloh 45-70: 2.125
Remington RB 40-65: 2.155
Browning Hi-wall 45-90: 2.435

These measurements do not come up to the lengths suggested for these cartridges. Am I overlooking and making a mistake in the measuring process? Or are chamber reamers designed to cut the chamber about 0.025 in long? I know SAAMI specs for a 45-70 recommends a max length of 2.105. I would appreciate your input on this.
ole pizen slinger
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Post by Kirk »

I have seen guys drill a hole big enough in the primer pocket to stick one of my all time favorite tools, the notorious hawkeye bore scope in so as they could see where the case mouth ends in relation to the end of the chamber. Incidentally a bore scope doesn’t see angles very well from a vertical position, they were mainly designed to make sure the copper fouling was gone, or when lapping like Dan Theodore has stated, helps you see that you are taking all of the tooling marks out. Now they keep trimming the brass until they don't see the crevice anymore which is actually the difference of .481” to .458” diameter split in half, this leaves a vertical look at a 45 degree angle step of .0115” deep, now when you stretch that longitudinally it becomes around .012”. When you are pushing, especially an annealed case in buy feel and possibly have deburred the case mouth at another 45 degree angle and using a scribe line to take your measurement from, keep in mind the variance of rim thickness, you can eat up another .010” to .015” pretty fast. Now it is pretty easy to end up with longer cases, not saying this is your case, just stating the facts.

Basically the most accurate way that I have saw to determine chamber length is with cerrosafe. Now you can see every angle, shoulders for bottle necks and etc. Not to get off subject, but especially bottle necks, you can not believe with a cerrosafe cast of sizing dies, where that shoulder is in relation to the chamber, and from the same company a hand full of dies will all be extremely different. This is another reason bottle necks have gotten such a bad rap, it’s always the gun’s fault.

Hope this helps, just my findings,

Thanks, Kirk
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TJW
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Post by TJW »

Kirk, I recently purchased 500 45-70 Rem brass for my Shiloh. This brass averages 2.090 in length. Is this to short? If so, what to do? TJW
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Post by Kirk »

Size them and then measure. Set your trimmer to trim as close to 2.1 as you can so they are all the same length for expansion and bell, then shoot them, they will all most likely come in to length the next go around. Just make sure you size before measureing or trimming, it's a common mistake I've seen people make.
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Post by montana charlie »

TJW wrote:Is this to short? If so, what to do? TJW
If you plan to shoot resized brass, measure and trim after resizing. If you want to shoot fireformed brass, your cases may already be shorter than you would prefer.

This is a link to Page 3 in a long discussion about the same subject.
http://shilohrifle.com/forums/viewtopic ... c&start=30

CM
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TJW
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Post by TJW »

Thanks Kirk, MT Charlie. I'll give that a try.
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Post by Ray Newman »

IMO, talk 'bout case length is for naught unless you know the chamber length.

Do you'll know the chamber length of your rifles??

This info & what the throat/leade looks like & the bore dia. is probably very handy for PP shooting.

Over the years, I've seen more than a few long chambers. Based on my experience w/ a .45-2.4" & watching/talking to other Shooters, short brass will/can lead to leading, increased fouling (esp. w/ BP), accuracy loss, etc. See Kurt’s initial post on page 1 of the above-cited thread cited by Mt. Charlie. & memory serves me, Sharpsman also made comments similar to Kurt's a few months back.

Not meant to disparage any maker, manufacturer, gunsmith, etc., but ea. barrel is different to some degree or another.

As Kirk said above, & I been saying:

"Basically the most accurate way...to determine chamber length is with cerrosafe."

If you don’t want to do your own chamber cast, a gun shop/smith should be able to do it.

Kirk also said something else worth very well noting:

"Just make sure you size [the brass] before measureing or trimming, it's a common mistake I've seen people make." Been there; done that. But only once....
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