Stupid question that has probably been asked before....

[polishshooter]

But I am relatively new to loading for my rifles, in the past I was just after loads that matched factory, not really after accuracy, or else like with my AR-15 limited by the magazine, so I just set my seating die to a factory cartridge and forgot about it, but now with the Swift, I want to get it seated pretty close to the lands, if not up against them, and will experiment to see what it likes.


But my question is...short of making a cast of my chamber, how can I easily measure what the maximum OAL is for a particular rifle chamber?

BTW if it matters, its a Ruger 77 MkIIV


It's probably been asked before, but I guess I didn't pay attention in class or something, sorry

[polishshooter]

And I guess "new" is the wrong description, "inexperienced" would be better

I dabbled with rifles for about 10 years, but total I have probably only loaded about 20 for my son's 6.5 Jap, a couple of hundred .223 for my AR, and about a hundred or so for my Mosin Nagants.

I've loaded probably 100k or more .45 ACP over the past 30 years or so, along with a few thousand shotgun shells, but my rifle loading knowledge, especially ACCURATE rifle loading knowledge, is what is "limited."

[army mp]

I use the Hornady LNL Overall Length Gage it runs about $30.00 at Mid south shooter and you will need a caliber specific Modify case. They are about $5.00 each.

[mikld]

I Gogled "how to determine OAL" and got a bunch of hits but not the specific one I was looking for. In this article though, are instructions on how to find OAL for a specific bullet in your rifle using a cleaning rod. I used tape instead of the cleaning rod stops suggested in the article. Instructions are near bottom... http://www.surplusrifle.com/shooting/oal/index.asp

[todd51]

LDBennett and JLA have posted some good info on this topic. Here is just one.

http://www.thefirearmsforum.com/show...touching+lands

[polishshooter]

Yeah I heard of the cleaning rod method and some others but it scares me in that it kind of reminds me of the NFL measuring for first downs with the chains after somebody spotted the ball "by eye"...using calipers to measure just EXACTLY where I "happened" to put the tape or the stop on the rod or pencil mark on the dowel to three decimal points seems kind of iffy...

What about this, that one of my rifle shooting buddies came up as an alternative....

I take an empty case, drill out the primer hole then tap it, and get a bolt or threaded rod and run it into the case,,,then seat a bullet against the bolt or rod...then hold it tightly in the chamber and turn the bolt or rod against the base of the bullet until I just feel resistance against the bullet? Then back off .001 or so?

I have a drill press, a couple of oddball cases, taps, etc..I'd just have to find a .224 or less threaded rod or bolt about 2 3/4 " long... and I think it would work?

What do you guys think?

[JLA]

heres my method polish.

Take a fired case and pop the primer out (use a universal dacapper) leaving the case unsized.

Now mash the neck agaist the bench to create a flat spot so it will hold the bullet.

Now take a bullet and start it into the case with your fingers (just barely start it in there)

Now color the bullet black with a sharpie marker.

Now close the bolt on the round.

Closing the bolt will mash the bullet deeper in the case scraping the marker off the bullet.

Once you get the bolt closed open it and extract the case, the bullet may stick in the barrel so a cleaning rod will come in handy to tap it out.

Then simply put the bullet back in the case to where the case stoppe dscraping the marker off and measure.

I like to do about 10 of them and take an average. then I seat .015" off the rifling

[polishshooter]

Well, this weekend it looks like rain and snow, AGAIN so nothing probably to do except play with the rifle, INSIDE...

Thanks for all the suggestions, maybe next weekend I'll be shooting for groups.

[JLA]

good luck!

[creektrails]

I second JLA's suggestion. It is actually written up exactly like that in my old Nosler reloading manual. I did it with my 30-06 and seems to work fine.
Warning though, you may pick up quite a bit of length off your factory recomended length. I went from 3.22 to 3.34

[polishshooter]

Yeah, I like JLA's method now too, because I can do it the same way when I change bullet type and weight as well.

Plus I don't have to drill and tap anything

[JLA]

Originally Posted by creektrails

I second JLA's suggestion. It is actually written up exactly like that in my old Nosler reloading manual. I did it with my 30-06 and seems to work fine.
Warning though, you may pick up quite a bit of length off your factory recomended length. I went from 3.22 to 3.34

Same here. I have a very high quality custom match grade criterion barrel on my savage .308 and the OAL to bullet jam is 2.880. The sierra manual lists 2.800 for the 175 sierras and im seating them to 2.865" which will just barely run thru the magazine...

[steve4102]

[JLA]

Very nice steve. That explains it way better than I did. I saved that BTW...

[A-FIXER]

Originally Posted by army mp

I use the Hornady LNL Overall Length Gage it runs about $30.00 at Mid south shooter and you will need a caliber specific Modify case. They are about $5.00 each.

http://www.cabelas.com/tools-accesso...gauges-1.shtml
http://www.cabelas.com/tools-accesso...-cases-3.shtml
Just as army mp said is the easist and quick, 35.00 any you can have the tool and modified case. then just buy the other needed cases of different calibers. Then after you have the modified case and you switch a different type of round you have the simple tool to remeasure it without the hassle.

[polishshooter]

I am going to try the felt marker technique today, since that is what I have at hand.

I MAY order that gauge the next time I order from Midway, but I just may make my own, it would be easy to drill and tap one of my once fired cases and then buy a die to thread an aluminum rod....Hhhhmmmm....

I have to run to town today, so I may just stop off at my hardware store and nose around....

I might be in business TODAY with my own version and save shipping!

[polishshooter]

Well I did it

I have a drill press, and know how to tap, and I have once fired Frontier/Hornady cases that I can use, so I went browsing down to the local Ace Hardware store...and $8.88 later, I had my "Polish Precision Bore Measuring Device"

I used a 8x32 threaded roid, I WOULD have used a 10x24 which would have been a little tighter fit but they didn't have the tap so I went with the 8x32.

I set up my press and drilled the first case and tapped it, but it was just a little off line and i felt pressure when it started through the neck, so I was worired I might not "feel" the bullet going into the chamber, so I drilled another case taking my TIME this time so I knew it was STRAIGHT and it worked like a charm.

Of course I "flattened" the case a little too much and had to use a punch to make it round again

I then decided I needed something to hold the case tight in the chamber and fitted a section of an old aluminum target arrow I had over the rod and used that to apply pressure to the case in the chamber.

But here are my measurements with a 52 gr Sierra Matchking 2.814, 2.804, 2.796, 2.797, 2.794, 2.796

The first one I threw out because it was the first, the biggest and I probably wasn't careful enough fumble fingering the calipers, but the average of the remaining 5 is 2.797, subtract my .015 and I get 2.782....my Hornady manual calls for an overall length for all bullets of 2.680....


And I SAVED $35.00 plus postage! I LIKE that.

The good news is that while this might not work for everybody, since, I already had the drill press and knowledge of tapping threads, it was a piece of cake threading the brass, I didn't even use any cutting oil. I BELIEVE if you had a good vise and took your time you could drill the hole with a hand drill straight enough.

Total cost $2.29 for the 2 foot threaded rod, $5.19 for the tap and drill (a HELLUVA lot more convenient now than when I FIRST had to tap on a gun project, when you bought the tap then tried to find the right drill bit!) and I wasted another few cents on nuts, wing nuts, and washers that I ended up not needing but I can throw in the junk box.

The OTHER good news now I am set up for ANY other cartridge as well, just give me a once fired case nad I can drill and tap it too and be in business....